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The National Academies of Sciences, Engineering, and Medicine (NASEM) — a storied institution signed into law by Abraham Lincoln in 1863 under an act of Congress — finds itself at the center of growing controversy over how it has mixed climate change science and politics in violation of its Congressional mandate and the organization’s commitment to objectivity, independence, and excellence.

It would be easy to simply dismiss the issues here as just another arena where pathological partisan politics has taken root — science institutions have certainly not been immune. While it is certainly true that universities and many institutions of expertise have become increasingly politicized and political targets of the current administration, partisan battles are not all that is going on.

There is a real scandal unfolding at the NASEM.

Today’s post explains a new element to the growing scandal, why it matters, and recommends that Congress amend the federal charter for the NASEM in the near term.

Let’s start with what the NASEM is and what it does. NASEM is a private, nonprofit, tax-exempt 501(c)(3) organization operating under the congressionally chartered National Academy of Sciences (NAS).1

Congress mandates the NAS to mobilize the nation’s scientific and technical expertise in service of the public welfare. Its functions include:

• stimulating and coordinating research; identifying important scientific, environmental, economic, health and national-security problems;

• organizing research to address them;

• connecting domestic and international researchers with the federal government;

• reducing duplication while preserving individual initiative;

• and collecting and disseminating scientific and technical information to government and the public.

The figure above displays how the NASEM describes its values . The organization exists to serve the national interest, improve public policy and public understanding, benefit the public welfare, and furnish scientific and technical advice to government and other organizations. The NASEM serves everyone.

The scandal is that the NASEM has been acting well beyond this mandate as a political advocate — trading on its authority and legitimacy to serve special interests, whether those are of its non-governmental funders, those charged with executing its projects, or its leaders.

In my book The Honest Broker — which gives this site its name — I explain that:

The Issue Advocate focuses on the implications of research for a particular agenda. . . Issue Advocates are found everywhere, and science is no exception. Whether the issue is a presidential election, the Nuclear Test Ban Treaty, or the Kyoto Protocol, many scientists are willing to take sides in a contested political issue, and use their status as scientists, or invoke their specialized expertise, to argue for their cause.

I argue in the book that issue advocacy is fundamental to a healthy democracy, and draw a straight line to the importance of its functions as described by James Madison in Federalist 10. In general advocacy by scientists or organizations is not problematic at all — it is an important contribution to democracy.

However, the NASEM was establishing to serve a role other than as an issue advocate — by design and in practice. Consider how the institution characterizes its role with respect to advocacy:

“We will NOT undertake work that is inconsistent with scientific evidence, for which an evidence base is insufficient, or that appears to be advocacy or have a foregone conclusion. We will avoid projects that would require us to make value judgments or that would be viewed as advocacy for specific policy or social outcomes, and we will avoid sponsors that may be viewed as advocates for such outcomes. Partaking in such work would serve to undermine our credibility.”

The unfolding climate scandal is a scandal because the NASEM has undeniably and egregiously violated these principles.

After that long wind up, let’s jump straight to a smoking gun.

The image below was included in a letter sent on August 28 from Rep. James Comer (R -KY) — chairman of the House Committee on Oversight and Government Reform — to Neil Shubin, the president of the NAS. In the letter, Shubin’s predecessor as NAS president, Marcia McNutt (whose term ended June 30, 2026) is asking a donor to the NAS, Carol Cicerone, for permission to use the donated funds to prepare a NASEM report.

The report was to be submitted to the Environmental Protection Agency (EPA) in support of “federal investment in CO2 reduction” and to counter “a handful of climate deniers” whose work McNutt feared would lead to a rescission of EPA’s Endangerment Finding on greenhouse gases.

The figure below, also from the Comer letter, comes from the NASEM unit that organized the climate report, and makes clear that the report was intended to influence EPA and the Department of Energy — the scientific community and the general public were “secondary audiences.”

In his letter Comer concludes:

“Read together, this evidence suggests NAS’ intent to salt the scientific battlefield against EPA’s proposed action for purposes of both litigation challenging any EPA rescission of the Endangerment Finding and other policy efforts aimed at undoing a rescission.”

There can be little doubt that Comer’s reading of this evidence is correct. The purpose of his letter was to request from NASEM further internal documentation associated with the climate report’s production that NASEM has thus far refused to provide — if that documentation offers an alternative explanation, why not provide it?

Let go beyond Comer’s letter.

The internal unit of NASEM that led the production of the climate report to be submitted to EPA is called Climate Crossroads which has a mission to harness

“the breadth of the National Academies’ expertise, resources, and advice to catalyze actions to meet the climate crisis.”

Climate Crossroads operates with an explicit advocacy orientation. Among its external funders is the Waverly Street Foundation which also funds the Sabin Center for Climate Change Law at Columbia University, which is a focal point of climate litigation.

As chance has it, the NASEM selected two people affiliated with the Sabin Center to author the climate-science chapter in the Federal Judicial Center’s Reference Manual on Scientific Evidence. I earlier showed that the chapter’s authors work in support of climate litigation, with a plaintiffs’ attorney — and another Sabin center affiliate — apparently ghostwriting portions of that chapter.

Small world.

The advisory board of Climate Crossroads includes:

• Peter Frumhoff, formerly chief climate scientist at the Union of Concerned Scientists now at Harvard and who focuses his work on advancing climate litigation;

• Carlton Waterhouse, a board member of the Environmental Law Institute, which operates the Climate Judiciary Project, accused of “attempts to influence the impartiality of judges” involved in climate litigation.

• Cynthia Atherton, who until 2023 (while she joined the advisory board) was the Science Program Director at the Heising-Simons Foundation, which is among the funders of Columbia’s Sabin Center (discussed above) and a funder of the NASEM climate attribution committee (which is another part of this growing scandal).

As I said, small world.

Many other members of the advisory board make clear that the orientation is advocacy, far removed from the NASEM normal activities.

As the NASEM role in climate advocacy and its embedding into the philanthropic climate activism ecosystem have become exposed, public statements by NAS officials have shown the organization struggling to justify its activism.

In April 2025, on X several people pressed NAS president Marcia McNutt on why the Academies had never studied Covid-19’s origins, with the full exchange shown below.

McNutt explained that the NASEM could not perform a study of COVID origins because the government had not called on NASEM to perform such a study: “Y’all have it backwards,” she told them. The organization’s charter has the federal government calling on the Academies to conduct studies, “not the other way around.”

Four months later, NAS launched, financed, completed, and publicized its fast-track climate study to provide to EPA and no federal agency had requested that study. The climate report was initiated from within the NASEM and paid for with non-governmental funds.

McNutt’s letter to Cicerone also contradicts what NASEM says about itself. Testifying to the House Science Committee in 2019, McNutt stated:

“We do not advocate for specific policy positions.”

That is obviously not true.

Shirley Tilghman of Princeton, who chaired the committee that prepared the fast-track climate report, said the committee worked toward “the ultimate aim of informing the EPA, following its call for public comments.” The report describes the work as a response to “EPA’s request for public input.” At the September 2025 release of the report, committee members pointed to Clean Air Act language directing EPA to consider National Academies input, and said the money came from two NAS endowments “to ensure the independence of the project.”

The Cicerone Endowment holds outside money, given by Ralph and Carol Cicerone and apparently required donor approval for its particular use — hence McNutt’s request to Carol Cicerone in the letter I shared near the top of this post. That is the opposite of independence — funding was predicated on the specifics of the promised policy advocacy.

This is clear from Cicerone’s reply to McNutt, shown below, which approved the use of the funds for the fast-track report and shows that she clearly understood what the report would conclude: to advocate to EPA the continuing need for CO2 reduction and opposition to rescission of the Endangerment Finding.

I searched for any another situation where NASEM may have convened a fast track study to provide input to a Federal Register notice related to any type of federal regulation. I could find nothing remotely analogous.

In July 2018 the presidents of NAS, NAE, and NAM filed a comment in EPA’s docket on transparency in regulatory science, warning that the rule would discard valid evidence and pointing the agency to Academies reports already published — but no new study was commissioned. In March 2020 state attorneys general and city attorneys asked NAS to review EPA’s supplemental proposal in that same docket, and I find no public record of a response.

The Academy does have a precedent of weighing in on climate science in highly political contexts — but it did so in response to government requests. On May 11, 2001, John Bridgeland, director of the White House Domestic Policy Council, wrote to NAS President Bruce Alberts asking where climate science held the greatest certainties and uncertainties, and for an answer as soon as possible.

A committee chaired by Ralph Cicerone produced a report, Climate Change Science on June 6, 200, less than a month later telling the White House — which was then reviewing its stance on the Kyoto Protocol — that temperatures had risen and human activity likely drove most of the recent change.

Two days later, NAS convened a closed-door forum at Senator Larry Craig’s request with about ten climate researchers, three senators, and a cabinet member. I happened to be one of those ten researchers — small world! That forum was the event that prompted a leading climate scientist to contact me ahead of time and suggest that I downplay my work on the role of growth and development in explaining rising disaster losses, lest it take away from calls for emissions reductions. I wrote about it at the time — but I digress.

The turn to climate advocacy at NAS has occurred as NAS has come to rely more and more on non-federal funding, mostly philanthropic and from organizations with political aims. The figure below shows that from 2011 to 2023 the share of federal funding of NAS dropped from about 85% to under 60%.2

Government support peaked in 2011 at $277 million and fell to $201 million in 2023, before inflation. In response, the NAS has increasingly sought, and collected, other sources of funding.

That has led to mission creep: Climate Crossroads cultivates sponsors, raises money, and coordinates communications and congressional engagement. The NAS even has a pitch on its website inviting sponsors interested in shaping “policy agendas.”

In 2026 there is not much that distinguishes the storied National Academy of Sciences from the myriad partisan NGOs advocating for everything under the sun — like the Union of Concerned Scientists or The Heartland Institute. The NASEM has become just another 501 (c)(3) organization pushing an agenda.

Ironically, in the end, the NASEM fast-track climate report turned out to be irrelevant to EPA’s case for rescission of the Endangerment Finding in its final rule.

• The DOE report that McNutt characterized as being written by “climate deniers” was released July 23, 2025.

• EPA announced the proposed rescission of the Endangerment Finding July 29.

• McNutt approached Carl Cicerone July 31.

• Climate Crossroads sought internal approval August 7.

• NAS published its fast track report September 17, days before comments closed.

That same day Judge William Young ruled that DOE had violated the Federal Advisory Committee Act (FACA) in how it prepared its report. The lawsuit was brought by the Environmental Defense Fund and the Union of Concerned Scientists — whose arguments were legally sound, in my view. DOE had no choice but to disband the group.

Then EPA dropped science altogether from its rescission. The final rule, issued February 12, 2026, rests on statutory interpretation and judicial precedent — and explicitly disclaims reliance on the DOE report, and calls the NAS submission and other NAS climate-science material “not pertinent.”

As I have argued, justifying the rescission of the Endangerment Finding on scientific claims would have been deeply flawed — if the NASEM fast-track study did contribute in some way to the elimination of scientific claims from the rescission rule, it just may have made the arguments more likely to survive judicial review.

There is a further irony here — NASEM may have also violated FACA with the fast-track committee: Whether FACA was violated depends on whether NASEM created it under an agreement with an agency. NASEM says it paid for the study from endowment funds and the motivation was internal.

But Comer's letter documents that the report was written with EPA and DOE as its primary audiences, and the records NASEM has withheld would reveal what, if any, contact NASEM had with those agencies related to the report. That is another possible reason that NASEM is refusing to release the documents requested by Comer.

In 2006, in my Conversations with Presidential Science Advisors series, I asked Frank Press — President Jimmy Carter’s science adviser and then NAS president from 1981 to 1993 — why the Academy never assessed Ronald Reagan’s Strategic Defense Initiative.

Press explained that a sign-on petition opposing SDI had included signatures from roughly sixty percent of Academy members, and he judged that the petition had compromised the Academy’s ability to provide an independent voice on the subject. He said that any NAS report, even one from a balanced committee, would be dismissed as compromised in the political process, because the institution had seemingly signaled its position already.

No independent assessment of SDI ever materialized. Frank Press gave up a study to protect the Academy’s credibility.

The National Academy of Sciences should function as a very special organization — one of the very few that can truly serve as an honest broker. Much reform is needed, but an important and straightforward first step would be for Congress to amend the Federal Charter for the NAS to prohibit funding from non-governmental organizations and require that all studies be requested by federal agencies or Congressional committees.

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The many videos I’ve seen from the Nepal glacier/rock flood are horrific and tragic. They remind me of those of the 2004 Boxing Day tsunami. The death toll is sure to run into the thousands, likely making the event’s mortality one of the top non-earthquake events this century.

As now happens in the aftermath of every disaster, the metaphorical ambulance chasers of climate advocacy seem to dominate the discussion of why it happened and what to do in response — NPR, the New York Times, the Associated Press and many others have each spent days trying to convince us that climate change caused the disaster (or made it more likely), and that emissions reductions are the solution.

The stampede of climate reductionism once again has us missing what matters most for saving lives in the future.

Today, I argue that we know exactly why the disaster happened and what we need to do to reduce the risks of future such disasters.

A precipitating event — a hurricane, an earthquake, or a glacial/rock collapse — is necessary for a disaster to result, but that event is never sufficient. Human exposure and vulnerability are also necessary elements, and almost always the ones that we can most effectively influence in the very near term.

In the case of the Nepal disaster, the number of people in the region exposed to flood risk has increased dramatically over recent decades. The figure below shows that the population of the affected districts increased by nearly a million people over four decades.

Nepal Electricity Authority reports 14 hydropower projects damaged — nine operating plants plus five under construction. Those plants had workers and those constructing the new plants right in the path of the flood. As of this writing, more than 900 hydropower workers are missing. The damaged operational plants accounted for about 8% of Nepal’s total generating capacity.

Tourism has recently increased as well, doubling in August from 2022 to 2025, as part of the post-pandemic rebound, as shown below. That meant many more people sitting in buses at the border crossing in the image at the top of this post at the moment the flood struck.

The people in the region represent exposure to risk. Given that exposure, we can ask: What actions would have saved lives in the event by reducing their vulnerability to harm?

The answer starts with knowing where risks exist and providing a way to warn people downstream of an impending event before the water arrives. That means cataloging potential hazards and putting into place early warning systems.

Until January 2025 the United States supported this type of vulnerability reduction in Nepal and across the broader region. Specifically, SERVIR-Hindu Kush Himalaya (HKH) was a joint USAID and NASA program with ICIMOD in Kathmandu, serving as a regional hub, covering Afghanistan, Bangladesh, Myanmar, Nepal and Pakistan.

The program applied satellite Earth observation and geospatial analysis to disaster risk reduction, water resources, land cover and air quality. Its concrete outputs include Nepal’s National Land Cover Monitoring System, annual forest-fire monitoring, flood and drought risk services, collaboration with the Nepal Red Cross Society on risk communication, and a collection of more than 170 public datasets covering glaciers, land cover, disasters and vulnerability. The program described the region as acutely exposed to water-induced disasters given its fragile geology, rugged terrain and monsoon regime, and characterized inefficient risk communication as increasing risks of disasters.

The SERVIR-HKH informs users that the initiative formally concluded in January 2025. ICIMOD’s 2025 year-end review lists it among three projects hit by the withdrawal, termination or restructuring of U.S. funding. SERVIR’s history page explains that the twenty-year USAID–NASA partnership ending in 2025. Across Nepal, the Kathmandu Post documented $321 million in terminated U.S. assistance when the Trump administration announced cuts of 83%, before shuttering the agency.

Jeremy Konyndyk, who ran the USAID response to the 2015 Nepal earthquake, wrote this week on X that DOGE keyword searches across programs included “climate” and that identified the USAID–NASA collaboration on flood prediction, early warning, disaster readiness, glacier inventories and the mapping of dangerous glacial lakes in Nepal, along with seven other Nepali disaster-risk-reduction projects.

These “climate” programs were then targeted for termination.

Konyndyk asks:

“Could these programs have helped foresee or mitigate this week's glacial flooding catastrophe? Hard to say with an outlier event like this. But that was their purpose.”

Nature India explains that, “The Hindu-Kush Himalaya holds the largest volume of ice outside the polar regions and feeds ten major Asian river systems.” The characteristics of sudden-onset flood events mean that:

“Downstream settlements could have as little as five to thirty minutes of warning before a flood wave arrives, too short for evacuation without automated detection and alert systems. More than 200 glacial lakes across the Himalaya are classified as ‘very high risk’ for downstream communities, but new evidence shows that smaller lakes can also pose a serious threat.”

From the many videos of the event, it is seems clear that most (if not all) people in the path of the flood had no warning at all, and many lives could have been saved with even minutes of warning.

However, effective warning systems are not widely in use in the region:

“Early warning systems using remote sensors, cameras and satellite monitoring have been piloted in Nepal, Bhutan, Pakistan and parts of China. However, coverage remains sparse, and expeditions to install or maintain sensors above 5,000 metre are logistically difficult, costly, and limited to short summer windows. Nepal’s hazard sits in a transboundary basin. The glaciers and upstream monitoring infrastructure lie partly in Chinese territory. So effective warning depends on data-sharing and coordination across the border.“

The lack of an effective warning system is being discussed in the region. One regional news organization has an excellent report, worth quoting in some detail:

The devastating flood that tore through Nepal’s Bhotekoshi river corridor on August 26 has raised questions about whether the country’s flood early warning system is equipped to deal with sudden and extreme events.

According to the Department of Hydrology and Meteorology, the flood travelled about 36 kilometres from the Nepal-China border to Betrabati in roughly 40 minutes, an unusually rapid movement compared with previous floods.

Binod Parajuli, chief of the department’s Flood Forecasting Section, said a sensor near the Nepal-China border was transmitting flood data every 10 minutes. Data were received normally until 8:40am, but the 8:50am reading was not received.

Another sensor at Betrawati, about 36km downstream, continued transmitting data until 9:20am. Its 9:30am reading was also not received.

The timing suggests that the flood entered Nepal between 8:45am and 8:50am and reached Betrabati at around 9:25am.

“This means the flood was moving extremely fast compared with other floods in the past,” Parajuli said.

Previous floods have taken about 14 hours to travel from the Nepal-China border to Devghat, he said. The August 26 flood reached Devghat in about seven hours, with a recorded discharge of around 200 million cubic metres of water.

The extreme flow also destroyed flood monitoring equipment at Langtang, Rasuwagadhi, Betrabati, Syafrubesi and Malekhu. Only the stations at Devghat, Bhorle and Kalikhola near Muglin remain operational.

“We had installed most of the equipment on bridges, considering them relatively safe and strong structures,” Parajuli said. “But the bridges themselves were swept away, along with the equipment.”

One flood warning expert, Anup Khanal, explained:

“authorities need to examine the entire system — including sensor capacity, data transmission, warning thresholds, sensor elevation, backup systems, the flow of warning information and whether equipment can continue operating during extreme disasters.

A technical investigation should determine how long each sensor transmitted data, when communication failed, when the stations were damaged, what the actual nature of the flood was and whether the available data provided enough time to issue warnings.

“The incident shows that Nepal’s flood early warning system needs to evolve beyond simply measuring water levels,” Khanal said. “It must be capable of surviving extreme floods, transmitting data rapidly, using backup sensors and issuing immediate warnings based on risk levels.”

He also stressed the need for continuous satellite monitoring of glacial lakes considered at risk of bursting.”

The technologies exist that are necessary for implementation of an effective early warning system in the Himalayan region — including both detection and alerts:

• A 2019 survey in Frontiers in Earth Science catalogued the remote-sensing tools available for cascading hazards across High Mountain Asia — defined there as a primary trigger like heavy rainfall, seismic activity or snowmelt.

• In 2022, an integrative screening method in Science of the Total Environment identified potentially dangerous glacial lakes across the Himalaya.

• And in December 2025 the Bulletin of the American Meteorological Society published a design for a Himalayan GLOF (glacial lake outburst floods) monitoring network.

What is lacking is not the knowledge or technology, but the funding and expertise necessary for deployment and implementation of a system that works across the region in the context of conventional flash floods, GLOFs, glacial/rock landslides, or other hazards.

That’s where the U.S. funding cuts matter — whether or not the funding came through any one agency or another, the United States is one of the few nations around the world with the resources to help less wealthy countries implement such systems in support of vulnerability reduction. Such efforts would not just save lives, but strengthen alliances in support of U.S. interests.

Some might say it is not the responsibility of the United States to support disaster risk reduction in places on the other side of the planet.

To them I’d simply respond: First, if the U.S. can contribute to the saving of thousands of lives anywhere — by investing dollars, expertise, technologies, or other resources, ideally in collaboration with other nations — that is money well spent. It is also the right thing to do.

And second, more parochially, some 90 Americans are missing in the Nepal floods. It turns out that the world is a pretty small place and we are all connected.

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There’s an old joke. A traveler stops and asks a local old timer for directions. The local scratches his chin, thinks a while, and says: “Well, I wouldn’t start from here.”

That sums up my reaction to today’s Federal Register notice — from the White House Office of Science and Technology Policy (OSTP) and the interagency U.S. Global Change Research Program (USGCRP) — that opened a two-week comment window on a proposed amendment to the Fifth National Climate Assessment (NCA5). A national climate assessment is required under the 1990 law that established the USGCRP (and in fact was also the focus of my 1994 PhD dissertation).

The amendment makes three corrections to the NCA5:

• RCP8.5, SSP5-8.5, and equivalent pathways no longer serve as “expected, likely, baseline, business-as-usual, central, or policy-relevant planning futures.”

• Findings that rely on those pathways now require labels identifying them as “outcomes associated with implausible high-end scenario assumptions.”

• And future assessments must evaluate scenarios for plausibility.

OSTP/USGCRP justify the amendment with Executive Order 14303, Restoring Gold Standard Science, and specifically its comments on the now-retired climate scenario, RCP8.5:

[A]gencies have used Representative Concentration Pathway (RCP) scenario 8.5 to assess the potential effects of climate change in a “higher” warming scenario. RCP 8.5 is a worst-case scenario based on highly unlikely assumptions like end-of-century coal use exceeding estimates of recoverable coal reserves. Scientists have warned that presenting RCP 8.5 as a likely outcome is misleading.

This is sorta correct — RCP8.5 was never a “worst case scenario” and its assumptions are not accurately characterized as “unlikely” but rather, the scenario is implausible and already falsified.

The Trump administration is directionally correct in recognizing that RCP8.5 is problematic, but at the same time: the administration’s proposed amendment to NCA5 cannot succeed, because NCA5’s problems are systemic and irreparable.

NCA5 is beyond fixing. The report should stand as it is and serve as an ignominious historical marker of what happens to scientific integrity when an assessment process becomes pathologically politicized — bad science, rampant conflicts of interest among contributors, and, in the end, an unreliable guide to understanding publicly-funded climate research.

Today’s post documents the top 10 problems with the NCA5 and proposes what Congress should do to improve the national climate assessment process, which is important enough to get right.

Let’s get to it.

A Countdown of the Top 10 Problems with NCA5

From 10 to 1.

10. NCA5 recommends the use of implausible scenarios

The assessment’s Box A3.1 tells readers that (emphasis added):

“very high climate scenarios, such as RCP8.5 and SSP5-8.5, can be useful tools when considering a range of plausible greenhouse gas concentrations past 2100.”

The assessment ignored the literature on scenario plausibility, notably the work pioneered by Justin Ritchie.

The review editor — the person responsible for ensuring that the chapter accurately characterized the literature — for the NCA5 discussion of Scenarios and Datasets was Donald Wuebbles, of the University of Illinois, who has also been a long-time defender of RCP8.5.

He stated falsely in 2020:

“Last I knew, we are still on the RCP 8.5 pathway as of 2019, so let’s not get carried away too much with how unrealistic RCP 8.5 is.”

Assessments are supposed to accurately reflect the literature, and not serve as a gatekeeper to the idiosyncratic views of its authors.

9. “Common practice” substituted for expert judgment

NCA5 Chapter 12’s authors acknowledged that there was in fact debate over scenario plausibility and brushed it off:

“Although there continues to be debate on the likelihood of a high-end GHG emissions scenario, it is still common practice to quantify the full range of potential damages to infrastructure” (p. 12-34).

A scientific assessment exists to assess science, not to excuse it by claiming that certain research was being commonly used.

The common practice of using RCP8.5 in real-world planning was a huge problem then, and it remains a huge problem today.

8. The assessment endorses RCP8.5 as legitimate regulatory guidance

NCA5 Chapter 19 reports approvingly that

“the California Public Utilities Commission now asks energy utilities to use downscaled climate projections for a very high scenario (RCP8.5) for climate adaptation planning, investment, and operational purposes” (p. 19-16).

There was no acknowledgment of the debate over scenario plausibility or the fact that real-world use of implausible scenarios could lead to unnecessary real-world costs to real-world people.

This is the path from a flawed scientific assessment to your utility bill.

7. The sea level headline contradicts the literature on which it is based

The NCA5 Overview tells readers that projected continental US sea level rise of 3 to 7 feet (~0.9 to ~2.1 meters) by 2100 represents “distinct possibilities that cannot be ruled out” (p. xxviii).

Now turn to Table A3.1, which USGCRP’s authors built from the 2022 Interagency Sea Level Rise Technical Report. At a 3°C warming level, exceeding one meter by 2100 is estimated at a 5% likelihood and exceeding 2 meters is negligible.

The Overview’s 3-to-7-foot range comes from the low-confidence ice-sheet column that the interagency report conditioned explicitly on very high emissions (SSP5-8.5).

The NCA5 cherry picked an extreme, unlikely value, and misleadingly characterized it as a distinct possibility.

6. Reviewers asked for inclusion of the loss-normalization literature. The authors refused, and gave excuses for its exclusion that were false.

As I documented in November 2023, several reviewers asked NCA5 to engage our work on extreme weather and US losses. The NCA5 called the request “inconsistent with the author team’s thorough assessment of the science.”

Further, another reviewer asked the NCA5 to acknowledge our work on normalized hurricane losses.

Bizarrely, the NCA5 argued that we had not updated our work since 2005, which was completely false (see image of our updated analysis below). It is hard to believe that the assessment authors could have been so inept. (More on Grinsted below.).

Review comments exist to catch errors and too improve assessments. Here the process was used to justify gatekeeping and exclusion of research that the NCA5 did not like.

5. A troubling number of NCA5 citations do not support the NCA5 claims

There are plenty of examples. Here are two:

• Chapter 2, p. 2-20 (emphasis added):

“There is no long-term trend in the frequency of landfalling hurricanes in the United States since the late 19th century, but there has been an increase in basin-wide hurricane activity in the North Atlantic since the early 1970s. [152,153]”

Reference 153 goes to Vecchi, Landsea, Zhang, Villarini, and Knutson (2021), Nature Communications, “Changes in Atlantic major hurricane frequency since the late-19th century.” Here is that paper’s abstract on the point cited by NCA5 (emphasis added):

“We find that recorded century-scale increases in Atlantic hurricane and major hurricane frequency, and associated decrease in USA hurricanes strike fraction, are consistent with changes in observing practices and not likely a true climate trend. After homogenization, increases in basin-wide hurricane and major hurricane activity since the 1970s are not part of a century-scale increase, but a recovery from a deep minimum in the 1960s–1980s. We suggest internal (e.g., Atlantic multidecadal) climate variability and aerosol-induced mid-to-late-20th century major hurricane frequency reductions have probably masked century-scale greenhouse-gas warming contributions to North Atlantic tropical cyclone activity.”

NOAA scientists published a paper arguing against reading a meaningful trend into the post-1970s increase in hurricane activity, and NCA5 miscited the paper as evidence for a meaningful trend counter to the century-scale data.

• A second case, from the same chapter. NCA5 reports “that tornado outbreaks have become more frequent,” citing Tippett, Lepore, and Cohen (2016). The paper supports that sentence. But its supplementary material qualifies it by explaining that

“[t]here are no significant trends or apparent discontinuities in the annual number of tornadoes rated F1 or EF1 and greater”

The accompanying Science editorial summary of the paper adds that

“the changes are not necessarily those that one would expect from climate change, which makes it difficult to predict whether this trend will continue.”

NCA5 kept the increase and dropped both qualifiers, giving an impression contrary to the cited literature.

4. The Overview drops every finding of no detected change

The NCA5 neglected to include in its Overview that there were no detected trends in hurricanes, tornadoes, hail, or flooding. Instead, it mentioned only three variables that had seen increases and completely misrepresented what the evidence shows for other phenomena (emphases added), writing:

“Many other extremes, including heavy precipitation, drought, flooding, wildfire, and hurricanes, are becoming more frequent and/or severe, with a cascade of effects in every part of the country.”

With respect to drought, flooding, and hurricanes this sentence is just wrong.

These trends haven’t changed since NCA5 and you can see the up-to-date data on the THB US Extreme Weather Dashboard.

Climate data should not be buried deep inside a 1,800+ page report. Americans should not have to visit THB on Substack (as fantastic as it may be!) to see what the data they paid to have collected actually shows.

But for now, the only place you can reliably get this information is — right here at THB.

3. The Overview’s headline finding is that climate change causes more billion dollar disasters

The NCA5 Overview leads with NOAA’s billion-dollar disasters: one every four months in the 1980s, one every three weeks now. Climate change, obviously.

The report then states that rising costs stem from asset growth “and the increase in frequency or intensity of extreme events caused by climate change” (p. 1-17).

The NCA itemizes 89 events over 2018–2022: 76 of these events are floods, severe storms, and tropical cyclones. None of these phenomena in the U.S. have increasing trends, much less have trends attributed to increasing greenhouse gases. Normalized tornado losses have in fact fallen. Normalized hurricane losses show no trend, while normalized flood losses have dropped significantly. None of this is mentioned by the NCA5.

NOAA has since retired the billion dollar disaster dataset after I documented its many scientific integrity failures in npj Natural Hazards. The dataset was so flawed that NOAA did not even try to defend it — it wound up moving to a climate advocacy organization.

The leading argument of the NCA5 now rests on a discredited dataset.

2. On loss normalization, NCA5 cherry picks and ignores the literature

Here is the report’s only normalized-loss claim, Chapter 2, p. 2-20:

“Slower-moving storms can result in more heavy rainfall, wind damage, storm surge, and coastal flooding; notably, after accounting for changes in the value of property and other assets placed in harm’s way, hurricane damage in the United States has generally increased since 1900. [159]”

Reference 159 alone supports that sentence: Grinsted et al. (2019).

Three things about that curious choice.

• First, and most importantly, their base damage series relies on the fatally flawed ICAT Damage Estimator, a compilation an insurance company assembled from our own earlier work and then altered without documentation and posted online. I laid out the biases in JAMC (2025) and have called for retraction of the studies built on it — including Grinsted et al. 2019. The trend identified by Grinsted et al. is entirely a result of using the Frankenstein dataset.

• Second, the result contradicts the climatological record NCA5 itself reports two sentences earlier — no trend in US landfall frequency since the 19th century. An unbiased normalization should track the climatological record of landfalling hurricanes — with no trend sin landfalling hurricanes, overall or the most intense, there is no reason to expect trends in an unbiased normalization. When the two time series diverge, the method deserves scrutiny, not elevation above all other studies in the literature without such a divergence.

• Third, and most damning, look at the number of studies NCA5 passed over:

When the NCA5 was produced in 2023, there were about 20 published US normalization studies. Fourteen published prior to 2023 found no trend. Two found decreases. Three found increases without claiming attribution.

Only one study available in 2023 claimed a detected and attributed the increase to carbon dioxide emissions — Grinsted et al. 2019 — and as I’ve shown, its trend depends on the misuse of the flawed ICAT tabulation (as do the other two studies that rely on the flawed ICAT dataset, whoops).

Ignored by the NCA5?

US tropical-cyclone normalizations that found no trend: Pielke & Landsea 1998, Collins & Lowe 2001, Pielke et al. 2008, Schmidt et al. 2009, Bouwer & Botzen 2011, Klotzbach et al. 2018, Weinkle et al. 2018, Martinez 2020.

1. NCA5 treats RCP8.5 as the baseline, RCP4.5 as policy success, and the difference as the payoff from mitigation. All three are wrong.

This one sits at number 1.

The NCA5 gives readers key definitions for interpreting the report in Table 3 of the Guide to the Report (p. xxvi). The no mitigation scenario (i.e., a baseline):

“Among the scenarios described here, these reflect the highest range of carbon dioxide (CO₂) emissions and no mitigation.”

The mitigation scenarios (i.e., policy success):

“These scenarios reflect reductions in CO₂ emissions from current levels. Total annual CO₂ emissions in 2100 are 46% (RCP4.5) and 67% (SSP2-4.5) less than the year 2000. Mitigation efforts include low-carbon technology (SSP2-4.5) and expanded renewable energy compared to 2000 (RCP 4.5).”

That means that RCP8.5 shows what happens absent policy, RCP4.5 shows what climate policy does.

Other chapters draw conclusions implied by the framework.

For instance, Chapter 24, p. 24-17:

“By the end of the century, approximately 1,200 deaths related to extreme heat would be avoided under an intermediate scenario (RCP4.5) compared to a very high scenario (RCP8.5).”

Here is how the NCA5 emphasized different scenarios across the report:

As THB readers well know, RCP8.5 was always implausible and misused from the start as a baseline. But what about RCP4.5 as policy success?

RCP4.5 is not a policy achievement. Current policies already put the world near or below its emissions trajectory.

NCA5 says so itself, once, deeply buried in the report on p. 2-29:

“Over the past few years, a number of analyses have narrowed the plausible range of current emissions outcomes based on policies in place today ... putting the world on track for a central warming estimate of around 2.6°C (ranging from 2°–3.7°C) by 2100.”

IPCC AR6 had SSP2-4.5 projecting 2.7C temperature increase by 2100.

That means that NCA5 acknowledged that current policies were similar to SSP2-4.5, and yet still used RCP8.5 as a baseline and RCP4.5 as policy success.

And the NCA5 authors knew that their framing was contested. Chapter 3’s Traceable Account, p. 3-39, states clearly (emphasis added):

“Scenarios of future emissions and land-use change are developed as plausible alternatives, but no relative likelihood is attached to them. Some recent studies, however, have argued that the highest scenario, SSP5-8.5, is no longer plausible without a reversal of current trends in the adoption of renewables and energy efficiency. The scenario development community is always testing the structural uncertainties of integrated assessment models and, therefore, the assumptions that produce the alternative emissions pathways. Timely updates of the baseline from which future projections are made, on the basis of current trends and observations of emissions, are necessary to maintain the plausibility of alternative pathways.”

Note what that paragraph does not contain: a citation to the literature, which by 2023 was quite robust on problems with RCP8.5 — including many of our papers. The NCA5 seems to have been allergic to our work.

These ten problems with the NCA5 are not fixable.

The report is a hot steaming mess.

What Congress should do to fix the NCA

The National Climate Assessment matters. Congress created it for good reasons, and the U.S. citizens who have invested tens of billions of dollars into climate research deserve an assessment of that research with the highest standards of scientific integrity.

Fixing it requires amended legislation, not executive orders.

Here are a five proposed amendments to the Global Change Research Act of 1990 (P.L. 101-606):

1. Most importantly, move the assessment out from under the White House. Vest assessment authority in a body insulated from direct executive control — a standing National Academies committee, or a structure under Congress resembling CBO or GAO, with an empaneling committee, staggered terms, and appointments from a bipartisan group of legislators (like the members of the House Science committee). Nearly every failure on my list traces back to an author team that produced a report that sounded more like a marketing or communications strategy than a dispassionate review of climate research. This fix will make sense no matter who holds the White House.

2. Require a published plausibility assessment for every scenario used. Any scenario supporting a projected impact must arrive with a documented evaluation against observed emissions, energy-system trends, and demographic projections — and any scenario difference presented as a policy benefit must state its reference case explicitly. Notably, at the international level ScenarioMIP still has not done this. A US assessment could show the world how its done.

3. Make review comments and responses public and binding. Publish every substantive comment, every response, and every rejection with its stated and supported reason and a named responsible author.

4. Mandate an independent citation audit before release. Here AI tools may prove useful. Citations are more than window dressing or plausible deniability for claims — they are the basis for the claims. In my areas of expertise the NCA5 failed to accurately represent the literature it was supposedly assessing, in favor of cherry picking and misrepresentations. The review process for NCA5 failed comprehensively.

5. Require conflict-of-interest disclosure. The image below shows just some of the climate advocacy organizations and businesses with interests in climate policy whose employees played major roles in writing the NCA5.

Imagine if these organizations were those opposed to climate policy and from fossil fuel companies. The problem would be the same. There needs to be one COI standard for the NCA and applied consistently.

Bottom line:

If the Trump administration wants to improve the national climate assessment process, forget about corrections and executive orders. Work with Congress to improve the process and create a NCA6 with scientific integrity that can be trusted by the American public.

That’s where I’d start.

Comments on the proposed amendment go to federalregister@ostp.eop.gov, subject line “RFI Response: Proposed Amendment to NCA5,” by 11:59 p.m. ET September 9, 2026.

Comments welcomed!

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The EPA Took It Down, Roger Put It Back (In Defense of Climate Change - Episode 7)

In the seventh episode of In Defense of Climate Change, Bryce Nickels and climate policy scholar Roger Pielke Jr. discuss Roger’s new Extreme Weather and Climate Change Dashboard, a resource designed to make long-term trends in extreme weather accessible to scientists, journalists, policymakers, and the public…

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13 days ago · 12 likes · 1 comment · Science From The Fringe and Bryce Nickels

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I take the title of today’s post from the closing line of a fantastic 2014 article by Dan Sarewitz in Slate. Sarewitz wrote:

“Climate change, added on top of all the other causes of these problems, will often make things worse. But for the most part there will be no way to tell which ones are worse than they would have been anyway, or how much worse they have become. So it’s not that apocalyptic fears about climate change are utterly fantastic—climate change may well exacerbate a range of serious and potentially even disastrous problems—it’s that the monomaniacal, apocalyptic version of climate change gives us a picture of the world that is so incomplete that it’s much worse than simply wrong. Worse because, just like religious and political orthodoxy, it cannot be falsified. On the contrary, everything that goes wrong simply reinforces the conviction that there is just one explanation for all our problems—climate change—and that there is only one thing we can do to keep the world from collapsing—stop burning fossil fuels. And thus, worse because the climate-change-as-apocalypse orthodoxy thereby radically narrows the range of viewpoints we are willing to tolerate and the range of options we are willing to consider for dealing with complex challenges to our well-being like natural disasters and infectious disease and poverty and civil strife.”

The notion of climate change has collapsed our discussions of complex environmental-social-political issues into a cartoonish characterization of “climate change” as an all-purpose causal agent responsible for just about everything that people don’t like — Wildfires? Climate change. Immigration? Climate change. Jellyfish? Climate change.

The climate does change and humans influence the climate. Neither Sarewitz nor I here at THB challenge these basic realities — they are not the problem.

Back to Sarewitz on what is the problem:

“The real problem is . . . the hysterics . . . who insist, often in the name of science, that all the suffering to come will have only one true cause, and that redemption can be achieved only by following one true path. No matter that long and sad human experience teaches us where such absolute orthodoxies lead. Indeed, with climate change being blamed for almost everything these days, the one phenomenon that seems to have escaped the notice of scientists, environmentalists and the media alike is that, perhaps above all, climate change is making us stupid.”

One constant over my career — dating to my postdoc at NCAR in the mid-1990s — has been a focus on extreme weather and its impacts. Over the decades, when it comes to extreme weather, I have observed the dynamics described by Sarewitz move from advocacy into journalism and eventually into climate research itself.

How we talk, and apparently think, about climate change has become stupider.

Let me illustrate with an example.

You may recognize the graph below which from its formatting looks like it comes from the new THB Global Extreme Weather and Climate Change Dashboard. I’ve blacked out the variable name to just focus on the data for a moment.

The time series dates to the 1960s and you don’t have to be a statistician to see that the variable has an increasing trend. That trend meets the criteria for a “detected change” without establishing causality according to the standards of detection of the Intergovernmental Panel on Climate Change (IPCC).

With such a trend in a climate variable, it is common to see explanations like the following from authoritative sources (emphases added):

• European Commission: “Floods are the most common and most costly natural disasters in Europe. They are becoming more frequent due to climate change. . . ”

• Nature: “The frequency of the most persistent heatwaves is increasing rapidly because of climate change.”

• Canadian government: “Climate change is making natural disasters more severe, more frequent, more damaging and more expensive.”

• npj Natural Hazards: “Floods are intensifying globally, primarily due to climate change.”

Such assertions are ubiquitous and banal.

In fact, it has become so common to associate any trend (or event) with “climate change” that we seem to have lost the ability to see just how dumb our discourse has become.

Let me try to escape the banality.

The figure above is not a climate time series and it does not come from the new THB Global Dashboard.

It is actually a baseball time series — showing strikeouts per team per game over the 1966-2025 MLB seasons. There are more strikeouts per game now than in earlier decades.

Let’s call this detected change Baseball Change to refer to a change in a statistic of the game of baseball that occurs over decades and is larger than the variation we’d expect season-to-season.

Let’s revisit those four climate change quotes above and reinterpret them in the context of strikeouts and baseball change:

• “Strikeouts are a common and defining feature of baseball. They are becoming more frequent due to baseball change . . . ”

• “The frequency of strikeout streaks per game is increasing rapidly because of baseball change.”

• “Baseball change is making strikeouts more frequent, with more contactless swings, and more long walks back to the dugout.”

• “Strikeouts are intensifying across the MLB, primarily due to baseball change.”

If you or I heard anyone talk like this we’d think that they might have a screw loose, because these sentences don’t actually mean anything.

Strikeouts per game have changed for lots of reasons — height of the pitching mound, designated hitter rules, changing definition of the strike zone, umpire grading, use of the bullpen, pitching, grip and spin, hitting, expansion of the league, and more — it is much more complicated and interesting than baseball change!

I started conceptualizing this post after I noticed that the recent NASEM report on the Attribution of Extreme Weather and Climate Events and Their Impacts (July 2026) did not define climate change anywhere in the report.

However, throughout, the NASEM report characterizes climate change as a causal agent (emphases added):

• “Climate change increased the intensity of the rainfall” (flooding in Germany 2021, p. 37);

• “Climate change caused snowfall to increase in northern Spain... but decrease in southern Spain” (Storm Filomena, 2021, p. 105);

• “Increased rainfall due to climate change caused a 5–19% increase in flood volume” (Cyclone Idai, Mozambique, p. 107);

• “Climate change led to an increase in the maximum wind speeds by approximately 7 percent” (Hurricane Melissa, p. 108).

Given that the IPCC has not claimed to have achieved detection for flooding, snowfall, or tropical cyclone maximum wind speeds, I found it odd that “climate change” was claimed to have such a large causal effect on these individual events, given also that the IPCC definition of “climate change” does not characterize it as a causal agent.

I felt like I was reading about baseball change being the cause of not just more strikeouts over decades, but why Abimelec Ortiz struck out on a 1-2 slider in the first inning last night, the pitch that made Jacob deGrom the second-fastest pitcher ever to 2,000 strikeouts.

Imagine the headline: Baseball change caused Ortiz to swing and miss last night.

Puzzled and curious, I emailed the chair of the NASEM committee, Jim Hurrell at Colorado State University, whom I know a bit from our overlapping years at NCAR in the 1990s and early 2000s, and I asked him the following questions about the report, which I share here for completeness:

I have a few questions about how the [NASEM] report uses the term “climate change,” and I’d value your view.

I note that the report does not define “climate change” (it does define 23 other terms) — yet throughout the report “climate change” is invoked as a causal agent that influences weather. This is contrary to the IPCC usage, which defines “climate change” as

“A change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use.”

For the IPCC, “climate change” is not a causal agent, but the outcome of causes.

The report does define causal factors much as the IPCC does:

“Influences on the climate system, including both external forcings—which may be either anthropogenic (greenhouse gases, aerosols, ozone precursors, land/water use) or natural (volcanic eruptions, solar cycle modulations)—and slowly varying components of the system (sea-surface temperatures, sea ice, soil moisture, snow cover) that are known to influence climatic conditions on seasonal timescales.”

Yet, neither the report, nor the EEA [Extreme Event Attribution] literature, attempts to disaggregate attribution in the context of this complexity. For instance, WWA-style [World Weather Attribution] methods assign the full difference between factual and counterfactual worlds to “climate change” without partitioning attribution among the causal factors the glossary distinguishes.

The report is also explicit that it

“focused primarily on greenhouse gas emissions and industrial and biomass burning aerosols as the dominant factors in current anthropogenic climate change, while acknowledging that other human-driven influences play a role and can also be considered when studying the full scope of human impact on the climate. These other factors include non–greenhouse gas pollutants and changes in land use such as deforestation, urbanization, agriculture, and water use and diversion, among others.”

The report also notes, “the committee focused on the overall accumulation of greenhouse gases from human activities…”. The narrow focus on GHGs (or just CO2) becomes problematic in situations like European heat wave trends where aerosol changes are hypothesized to be as or more important than GHG forcing.

The report does not discuss individual GHGs (e.g., methane appears just once, SO2, N2O do not appear).

So my questions:

• Does the report implicitly use “climate change” as synonymous with “greenhouse gas emissions and industrial and biomass burning aerosols”?

• Or is “climate change” simply synonymous with fossil fuel-related greenhouse gas emissions, as the Chapter 2 discussion of the Vermont Superfund Act might imply?

• Or, a third option, is “climate change” supposed to reflect all of the causal factors (as defined in the glossary and reproduced above, consistent with IPCC) in one big bucket with no disaggregation?

• Or is there another implied definition other than these possibilities? Multiple meanings across chapters?

Let me know what you think. Many thanks from Boulder,

Jim quickly and graciously responded to my email, shared in full below (emphases added):

Thanks for your thoughtful note.

The committee did not intend “climate change” to be synonymous with any particular forcing, nor specifically with fossil-fuel CO₂ emissions. Throughout the report, the term is used to refer to the anthropogenically altered climate state that is compared with a counterfactual climate state in attribution studies.

Importantly, the anthropogenic perturbation represented in that comparison depends on the design of the attribution study. Some attribution studies evaluate the combined effect of anthropogenic forcings, while others are designed to isolate the influence of particular forcings or processes. The report therefore does not assume a single universal definition beyond the experimental framing of a given attribution analysis.

The report explicitly recognizes that anthropogenic forcings such as aerosols and land-use change can be important —particularly at regional scales — and identifies improved quantification of their individual contributions in event attribution studies as an important research priority (Conclusion 4.9).

I appreciate Jim’s straightforward reply, and the NASEM committee deserves credit for openly acknowledging a significant shortfall in extreme event attribution methods.

But take a moment to see what has happened here: Climate change, as explained by Hurrell, is not a statistical measure of how the climate has changed — as it is under the IPCC. It means a difference between an imaginary modeled world (what Hurrell calls the “counterfactual climate state”) and either some local observations or another modeled world standing in for the world we live in.

The difference between the imaginary world and the supposed real world is “climate change” which is not just a descriptor of the difference, but also an integrated, all-cause explanation for why those differences exist.

The NASEM report shrinks that all-cause explanation significantly when it explains that it primarily equates “climate change” with the consequences of greenhouse gas emissions and industrial aerosols, even while acknowledging that there are other factors that influence climate (p. 22):

The committee focused primarily on greenhouse gas emissions and industrial and biomass burning aerosols as the dominant factors in current anthropogenic climate change, while acknowledging that other human-driven influences play a role. . . These other factors include non–greenhouse gas pollutants and changes in land use such as deforestation, urbanization, agriculture, and water use and diversion, among others.

The NASEM report also observes that the literature it is surveying does not actually do any sort of attribution as defined by the IPCC (p. 126):

Very few event attribution studies consider the role of non-greenhouse-gas forcings such as aerosols, irrigation, and land-surface changes, despite their substantial influence on historical climate trends in several vulnerable regions... Isolating the role of multiple anthropogenic forcings is important for identifying the physical drivers of events, attributing event characteristics to regionally relevant forcings, and accurately assessing the magnitude of influence of greenhouse gases . . .

The NASEM has defined “climate change” in a way that makes detection (a la IPCC) unnecessary and attribution (a la IPCC) assumed away.

If “climate change” is defined study-by-study — as Hurrell explained in his email — then claims that “climate change” increased Germany’s flood or Hurricane Melissa’s winds are impossible to interpret — other than as an ink blot.

Like Sarewitz said, “climate change” is making us stupid.

In closing, I reproduce, in full, a text box from the IPCC Fourth Assessment Report (2007) describing detection and attribution.1

I can’t help but read this — and you should also — and conclude that we were once much smarter about these concepts.

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I am happy to announce that one of the biggest projects I have ever undertaken has just gone live: the THB Global Extreme Weather and Climate Change Dashboard — with 288 indicators from 57 variables across 8 phenomena and for the entire world and every continent. The site also has a dedicated page for normalized losses and a consistency check with the IPCC AR6, and more.

The THB Global Extreme Weather and Climate Change Dashboard applies the IPCC’s detection framework — the same standard its sibling site, the US Extreme Weather Dashboard, uses for the contiguous United States — globally, across 8 phenomena and on one shared statistical standard. No comparably broad, global, IPCC-aligned trend-detection dashboard exists publicly: most public climate-hazard tools cover either a single phenomenon or a single country, not consistent global detection across an entire hazard set.

Tropical cyclones, extratropical cyclones, extreme heat, cold spells & frost, river flooding, drought (hydrological and agricultural/ecological), and wildfire drive nearly all of the human and economic toll of weather and climate: they account for 99.7% of global weather/climate-related economic losses and 97.7% of weather/climate-related deaths.

The new site is full of information, data, analyses, graphs, literature and much more.

Please go explore the site, let me know what you think, and how I can improve it, as it is a work in progress. Click on the button below to check it out.

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This post will serve as a running comment board for discussion of the site.

Today I am pleased to publish an invited guest post by Sigrid Bratlie, molecular biologist and author of The Wuhan Mystery. An earlier version of this post was first published in Norwegian at Minerva. —RP

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It is hardly an exaggeration to say that few American bureaucrats in recent years have been more polarizing than Anthony Fauci — best known as the leader of the US pandemic response.

Now the debate is raging after he was found in contempt of Congress for refusing to answer questions about the origins of the pandemic under oath. Republicans have made him almost solely responsible for everything that went wrong during the pandemic. Democrats call it a conspiratorial vendetta and an attack on science.

The rhetoric is disappointingly superficial on both sides — and so is the coverage in most media so far, which portrays the whole thing as vengeful Republicans against a somewhat inexplicably silent Fauci.

The matter is far more complex.

A new and more dangerous world

There are at least two, each complicated, layers to this story. The first is about decades of misguided bipartisan policy on research into dangerous viruses. The second is about how the US government and academia have communicated the relationship between this strategy and the origin of the virus from 2020 onward. The first may have had disastrous consequences for global health security; the second has contributed to eroding trust in American democracy.

In 2001, the United States was shaken by terror. First the September 11 attacks, then letters containing anthrax spores sent to journalists and politicians . President George W. Bush and Vice President Dick Cheney laid out an ambitious strategy against biological threats and appointed Fauci to lead the effort. He worked in the health administration, but in practice had responsibility for both the civilian and military sectors.

In his recently published diary, we see what that entailed. He produced white papers that would give the US cover to circumvent the Biological Weapons Convention in order to conduct research in the legal gray area. He was planning to go to Iraq with the CIA to search for Saddam Hussein’s bioweapons, weapons that the US administration used as a main justification for the war, but which were never found. Fauci led and funded US research into dangerous viruses both at home and abroad over many decades – which provided ample opportunities for collecting intelligence in countries that were otherwise inaccessible.

There was no shortage of warnings, especially when the research Fauci funded took a turn toward so-called gain-of-function research to make natural viruses more dangerous in the laboratory. Experts heatedly debated whether this created an unacceptable risk of a pandemic. Fauci believed the risk was acceptable and sent money to research on genetically modified SARS-like viruses in Wuhan, among other things. Warnings from State department diplomats about poor security at the laboratory and that the research could be misused by China for military purposes (dual use) were ignored.

The US strategy was a response to a world that Americans perceived as more dangerous after 9/11. The question is whether it also contributed to making the world more dangerous. The subsequent question would be: How would the people who were partly responsible for this strategy react to information that the strategy they had contributed to might have led to a catastrophe?

Risky strategy

When a SARS-like virus broke out in Wuhan in late 2019 – just a year after scientists there, in collaboration with US scientists, had applied for funding to conduct experiments on SARS-like viruses that included the insertion of furin sites – a distinctive feature of SARS-CoV-2 — alarm bells should have rung.

That is to say: They did, but not in public: Several leading virologists privately told Fauci in late January 2020 that they suspected a lab leak. Fauci’s own internal communications indicate that he too was alarmed and launched internal investigations into whether their own research projects in Wuhan could have anything to do with the matter.

Just a few days later, however, Fauci told the world that “we know that such viruses have a natural origin, other claims are to be considered conspiracy theories .” This was before there was a single published study on COVID-19 origins, before he had investigated matters related to the research he funded in Wuhan, and at a time when the scientists he consulted in the backroom were deeply divided and still believed that lab leakage was at least as likely an explanation as natural origin.

Yet, the same scientists shortly afterwards published the controversial article “Proximal Origin of SARS-CoV-2” with the conclusion that a lab leak was not even plausible.

They themselves have claimed that they changed their opinions through a normal scientific process, but later released internal communications show that uncertainty persisted and that they were far less convinced of their conclusions than they stated publicly.

More evidence has recently emerged to support these suspicions. In June 2020, three months after the paper was published, lead author Kristian Andersen of the Scripps Institute in the US wrote privately to his co-authors that he

• “found both scenarios [lab leak and natural origin] to be equally probable”,

• that “we said in the paper that this work is performed ‘all over the world’, but that’s not true – it has been going on exclusively in Wuhan, at BSL-2 [a low safety level]”

• and that “most scientists I talk to believe there is a likely connection to the lab”.

Andersen justified his renewed skepticism in part by new information that had come out at the time, but the problem is that this communication is part of a pattern: Fauci and these scientists communicated aggressively in public about natural origins, while all doubts were kept private. Furthermore, when there is a significant lack of data and information about the matter under scrutiny, it is irresponsible to conclude definitively, as Andersen and his colleagues did already in March 2020.

New information has repeatedly caused them to doubt their own conclusions. In the summer of 2021, it became known that researchers in Wuhan and the US had planned to produce a SARS-like virus with a furin site – the main characteristic of SARS-CoV-2 – in 2018 (The DEFUSE proposal).

Andersen and his colleagues were outraged and wrote to each other that “it really isn’t beyond plausibility that someone went ahead and tried some of this stuff” and that it was neither technically difficult nor scientifically illogical to make such a virus in a lab – the opposite of what they had argued in the Proximal Origin article.

Influenced US intelligence

Where did this gap between public and private communication come from? The answer is likely complex, involving a set of political considerations, academic vested interests, and private ties. But the scientists were not operating in a vacuum.

In my book The Wuhan Mystery, I accuse Fauci of steering the scientific narrative about the origins of the pandemic unreasonably strongly in the direction of natural origin, both through his own public statements and by influencing the scientists who addressed the question. For example, released communications show that he was one of those who initiated the Proximal Origin paper and helped with its content, but significantly downplayed his involvement in public.

Now I expand on the accusation: He also steered US intelligence agencies away from the lab leak theory.

Fauci has previously maintained, under oath, that he had nothing to do with the intelligence community in connection with the origin of the pandemic. New information paints a different picture: In May 2026, a CIA whistleblower testified, under oath, that the agency concluded in the summer of 2021 that a lab leak most likely caused the pandemic, but that an agency leader ordered analysts to change their conclusion after Fauci came to visit.

The whistleblower’s claims are supported by internal emails from the intelligence service released a few weeks later :

An email, written by the head of the CIA analysis team, describes how Fauci, during a June 2021 meeting, objected to the team’s assessments and suggested they instead talk to his preferred experts, particularly Kristian Andersen, who supported natural origin. Another email confirms that the lab leak conclusion was dropped as a consequence of this meeting, just before publication.

A third email states that:

“The Intelligence Community took direction straight from NIH ... the people who funded the Wuhan lab ... A complex web of money and politics influencing analysis.”

I have no objection to the intelligence community seeking input from external scientists (although US intelligence also has its own experts). But in a situation where the scientific arguments could not produce definitive proof, other intelligence information is of course very relevant to understanding the probability of different scenarios. That is precisely why it is problematic if Fauci, in his role and with his conflicts of interest, tried to influence the intelligence community’s conclusions.

Silence as defense

These circumstances would have been difficult for Fauci to explain away in the hearing on July 29 this year. He had a dilemma: Telling the truth about how he under-communicated the possibility of a lab leak and how he steered others in the same direction would have been too explosive, but lying would have been too risky.

President Biden gave him a preemptive pardon in January 2025 for actions dating back to 2014, but it does not cover new offenses, such as lying under oath. This is why, in my opinion, Fauci chose to take the Fifth Amendment and remain silent — under the pretext of a political witch hunt.

But we are not dependent on Fauci’s testimony to find better answers about what triggered the pandemic and what role the US has played if it was caused by a lab leak. The fact that we still — more than six years after the pandemic began — do not have all the facts on the table is because, from the US perspective, full transparency could point to a lab leak that was not only due to bad choices made by an individual, but also deliberate, bipartisan policy over several decades.

Greater transparency would also show that the cover-up that took place during the pandemic has been well known in both the US government and the US intelligence community. The information we have available has largely been forced out through FOIAs and document leaks — not transparency and willingness to clean up the mess by responsible politicians and government. Thousands of documents remain classified, even though the Republican and Democratic parties jointly passed a law in 2021 requiring everything to be made public.

Political responsibility

We deserve better.

We deserve to be informed about one of the biggest and most impactful events of our time, and that all parties avoid making it a political game.

I don’t care whether it’s the Republicans or the Democrats who ultimately get to the bottom of this matter, just as I don’t care which of them takes credit for the Epstein files finally seeing the light of day.

Instead of pointing to one political scapegoat, we should stand together to hold decision-makers accountable across the political spectrum and across countries.

And we should of course expect the same from scientists and academics. That is perhaps the most disappointing thing about the whole debate about the origin of covid: That scientists have become political actors, who communicate selectively and strategically, who are not open about conflicts of interest, who can be subjected to pressure and who exert pressure on others.

The debate about the origin of the virus continues, no conclusive answers can be given, and unfortunately we cannot trust that the same scientists who we now know kept quiet about their doubts repeatedly in both 2020 and 2021, now are open and without other agendas.

Transparency and accountability cannot be chosen when it suits, they are an essential part of a democracy.

You can listen to Sigrid Bratlie talking about her recent book with Bryce Nickels here:

Science From the Fringe

Sigrid Bratlie - Unraveling 'The Wuhan Mystery': The Hunt for the Origin of COVID

In this episode of Science from the Fringe, host Bryce Nickels speaks with Sigrid Bratlie, Norwegian molecular biologist and science communicator, about her comprehensive new book The Wuhan Mystery: The Hunt for the Origins of COVID…

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10 months ago · 16 likes · 3 comments · Science From The Fringe

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I appear on a lot of podcasts, but I rarely share them here at THB. Today, I make an exception for a conversation I had earlier this week with Darren Samuelsohn, who writes at Love, Journalism on Substack, and until recently served as the White House, Congress, and campaigns editor at USA TODAY.

Readers can find a full transcript of our conversation below. You can also head over to Darren’s site if you’d like to see me beaming out of the THB Global Headquarters or listen to our conversation as a podcast.

I’ve known Darren professionally for going on two decades, and I respect him enormously for his many years of reporting at E&E News and Politico. On a personal level, Darren has always treated me fairly. He never adopted the overt or stealth political advocacy so ubiquitous on the climate beat. Instead, he acts as a journalist should — reporting facts, calling things like he sees them, and recognizing that the world is complex and nuanced.

I share our conversation because Darren asks me some questions that no one else has — as I said, he is a pro. In our discussion I talk about The Honest Broker on Substack, how I approach my work at THB, offer some personal reflections on my career, my thoughts on journalism and journalists, and discuss some of the complexity and nuance that I’ve explored across many topics.

Give Darren a follow over at Love, Journalism — you’ll be glad you did.

love, journalism

How Roger Pielke Jr. Became Voldemort in Climate Science

I'm Darren Samuelsohn, and this is The love, journalism Show. We're talking with Substack heavyweight Roger Pielke Jr. about how controversy in academia became a career in storytelling…

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23 days ago · 3 likes · Darren Samuelsohn

HOW ROGER PIELKE JR. BECAME VOLDEMORT

Love Journalism Show by Darren Samuelsohn

Lightly edited for readability.

DARREN: It’s been a while since Roger Pielke Jr. and I caught up. That’s how it’s been with a lot of guests lately. David Roberts, the old E&E crew. Climate has only become more everything since I moved away and into other horizons 15 or so years ago. Roger Pielke of the Honest Broker on Substack, a senior fellow at the American Enterprise Institute, is here to talk us back into this discussion. Welcome to the Love Journalism Show. I’m Darren and this is Roger.

ROGER: Hey Darren, good to be with you.

DARREN: Great to have you, Roger. So last time I saw you, you were, gosh, this was a long time ago and you were in academia. You are now quite popular on Substack, writing about all the topics that you and I met on all those years ago. Tell us, tell my audience who your audience is.

ROGER: My audience, that’s a good question. Substack is amazing, as you know. It has an enormous reach. I have more than 40,000 subscribers in every U. S. state in 174 countries around the world. And about half of them are in the U. S., half overseas. And it’s an eclectic, politically diverse, highly educated, smart group. I’d be interested in hearing your views. I have a small proportion of people who Seem to be interested in being regular commenters. But it gets shared around and discussed. And I tell people, it’s no exaggeration. I’ve written a bunch of books as an academic. And I bet you in one week, more people read my Substack than over the last 30 years, all my books combined ever. So it is a remarkable platform. And it’s very rewarding.

DARREN: Do you read the comments?

ROGER: I read all the comments. I respond to some of them. And I do restrict the comments to my paid subscribers, which really elevates the quality. Everyone writes under their own name. And I’ve been doing it for six years now. And I can count it on the fingers of one hand, the incidents I’ve had where I’ve had to intervene. It’s a great community that has sprung up.

DARREN: One of the rules in a newsroom is never read the comments underneath the story. Did you get that memo or do you avert your eyes sometimes?

ROGER: Ha! I enjoy engaging. And for me, and this goes back a long time, more than 20 years, back when what we now call Substacking was called blogging. I use it as a form of extended peer review. I put ideas out there. People critique them, and they’re not shy. Sometimes I push back, and we have a debate and discussion. For me, engaging with the participants is actually a form of learning and getting better at what I try to do.

DARREN: It’s what the media world has gone into. if you don’t engage, you’re screaming into a mountain valley, I presume, right? Right, right. Tell us about your cadence. So how much are you writing? When are you writing? Are you doing in the morning, afternoon, every day? Are your ideas coming to you constantly?

ROGER: It’s another good question. I’m always writing. Writing is how I think. I just put together a new site using Claude Code where I compiled all my blogs from 2005. And you can map out what I’m thinking, not day to day, but pretty close, every couple of days nonstop for the past 20 years. And honestly, I write much more than I post because I don’t think my readers would like to hear all that much from me. I’ve done this even before Substack. I organize my professional life in public through my writing. And, ideas go from half-baked notions out there that get refined, and eventually some appear in the peer-reviewed literature, some appear in books. So the cadence is I publish a couple times a week, two to three times a week, pretty regularly. And I probably have two or three posts that I write that I don’t publish every week.

DARREN: So how do you find the stories that you’re going to tell? Where do you make the decision on I’m going to write about this when there’s probably 100 other things that you could easily write about in the course of a day?

ROGER: Oftentimes I will write on something on a particular day that I didn’t expect I would write on, just because of breaking news or a paper being published, or something else coming out. Part of the, and I’m sure you have this sense too, part of getting older and being around for a while is that I have a lot of experience on a lot of these topics. And so when something pops up unexpectedly, It fits into a stream or a thread or some longer term discussion I’ve had on topics that I can build upon. So there isn’t too much that comes across that I have to approach entirely anew.

I do a column for The Dispatch. And last week, my column was about data centers. And I do a lot on energy policy, but I’ve never written anything on data centers. So that was useful in the sense that I had to force myself to get up to speed on a lot of the energy and climate debates around data centers. But that’s more a parallel lane, I guess. I learned a lot doing it. And the reason I wrote about it is because I wanted to learn about it. So those things come up every once in a while.

DARREN: What’s your news digestion? Like, are you on Twitter all day? Are you re-flowing your social media posts and clicking and reading papers? Or are you stepping away because that wisdom, I presume, of you probably can anticipate the news to some extent doing this as long as you have, right?

ROGER: I was a public policy professor for almost 25 years, University of Colorado, and I teach it and I breathe it. I’m at American Enterprise Institute, which is a great think tank. So, I live on a steady diet of information and news. And so I read all sorts of sources and I really enjoy the triangulation that comes with seeing different perspectives and different arguments. So I would say I’m probably in the upper tier of news consumers.

DARREN: So if any of my watchers, listeners spend some time with Roger Pielke Jr.’s Substack, The Honest Broker, you’ll see he’s in the weeds. You’re in the weeds. You belong in the weeds and your audience loves the weeds. Tell us why are you in the weeds and why does your audience like that? I’d be just curious to have you explain that to folks.

ROGER: If you would have told me that I would have had 40,000 subscribers who are reading about the innards of climate scenarios and details of scientific papers that are relevant to policy, I would have laughed. But there are a lot of people who want to know the details and the details matter on these issues. And when I used to teach public policy to undergrads and grad students, I’d always tell them that when I was young and you first came to an issue, things started out being black and white. Like, I know it’s obvious. The answer is obvious. It’s obviously this. It’s obviously that. And the more I learned in my areas of expertise, the more the world was painted in shades of gray and red and purple and green. And you realize that there’s a lot of nuance to issues that often get painted as black and white. And so I do spend a lot of time on issues trying to help people see the shades of gray. And, we live in an era where everything is partisan. Everything is left or right. You’re MAGA or you’re a socialist or whatever. I just find that those descriptors and those clubs do a very poor job of describing the real world that we happen to live in. And I think there’s a lot of people who are actually hungry for understanding nuance, even if it doesn’t always map identically onto their preferred politics.

DARREN: You just described the life of a trade journalist in some respects, because we lived in, for many, many years living in the world of nuance. When you try and write to a larger audience or to a mainstream audience, you end up, you have to water things down. You have to water things down. I’m curious, as you’ve grown your audience at 40,000, I’m sure there are some people, this goes way over their heads, what you’re writing about. So do you ever try to water things down? And if so, what does that do to your writings?

ROGER: I don’t know if watering it down is how I would characterize it. It’s knowing how to, and it’s always an imperfect process, but knowing how to explain complex issues to normal people, I think I’ve gotten better at it. I think writing and getting feedback, you have to get better at it or you won’t do it anymore. But trying to preserve the nuance and the realities, And so, I do come at issues from many different directions. I’ve been writing about climate scenarios for almost 20 years. And you could not invent a more arcane, impenetrable set of issues. I don’t think anyone has to be super smart to understand them. It’s just that the effort required to wade through the acronyms, the jargon, the history, and the overlay of politics, it does take a lot of effort.

DARREN: That couldn’t be a better, I guess, segue to what you just did. You just built a whole new public database tracking heatwaves, wildfires, hurricanes, drought. I don’t think you have locusts on there, but the other types of extreme weather that are going on, I guess you do have drought, so we get to locusts from there. And partly you’ve done this because the feds pulled their own climate indicators offline last year. What should Americans actually understand about what’s going on outside their front doors right now in their backyards, maybe the next door state, as we just learned from the fires in Canada that are going to drift all across America? So how do those things connect or don’t they to everything else that’s going on in the mix?

ROGER: I have to say my dad, who’s a retired atmospheric scientist, sent me a paper last week about locusts in the 1870s and the Great Plains were infested by, I don’t know, Gazillion, bazillion locust infestations. So it happens. so I wrote a paper with a guy named Ken Kunkel, who I think is just recently retired from NOAA, and Stan Changnon, who was an old school climatologist, no longer with us, 1999, and we basically surveyed what the data said about trends in extreme weather and its impacts in the US. And it’s, it’s a widely cited paper and it was a huge effort to pull together all that stuff back in that day. And then, as you mentioned, the new THB Extreme Weather and Climate Change Dashboard was motivated in part by the Trump administration, taking offline a lot of climate data that was readily accessible.

It motivated me to say, well, in this era of AI, I’ve become somewhat proficient in coding with Claude. I started my professional career out as a Fortran programmer, so I have a programming background. And so the tools that are available now allow just an integration and presentation of a massive amount of data. And so I’ve been building some data dashboards and one that I wanted to build for a long time is one that presents trends in extreme weather events in the United States. And I’m working on one for the world. We could talk about that. That’s a much bigger and more difficult effort. But the U. S., props to NOAA and the U. S. government and Congress and presidents for generations for supporting the creation of these data sets. That are publicly available.

And I wanted to put the data out there so that normal people, so journalists, policymakers have one stop shopping if they want to know what are flood trends in the US, hurricane trends, drought trends. There are so many claims made, particularly in the media, but also that filter into policy that are based on single studies. And, the headline will say, scientists say hurricanes are getting worse. And, those studies may or may not say that, But having access to what the official data sources actually say can help people put those things into context and better identify, I would think, when science is being sensationalized or misused or abused. And so right now, the dashboard has 32 indicators across seven different weather phenomena. IBack in the day, it would have taken me a couple of years and probably a team of PhD students to put this together.

And I was able to put it together in a couple of months. So it’s, it’s work in progress. It’s going to be improved. But, and then I guess the other thing I did is I wanted to align what the official data says with what the Intergovernmental Panel on Climate Change (IPCC) has concluded. And, good news for the IPCC and good news for my Dashboard, they align just fine, just perfectly. So, the IPCC working group one is perfectly consistent with this official data.

It’s funny, I put this out there and I don’t know if it’s yesterday, day before I was reading on X/Twitter, someone was saying, this is all fake information because you can’t believe this guy. And, you take 30 seconds and you’ll see all this is just official data from government sources scraped off the internet, once a week.

DARREN: Don’t read the comments. Have you gotten a Claude sponsorship deal out of this? Because, you’re preaching to the choir here. I love what Claude has been able to do to my life, but I got to pull off here for a second and just speak to my audience about what artificial intelligence has done for your career, please.

ROGER: Ha! I think, Claude, at this point, Claude should advertise that I’m sponsoring them for how much I’m paying and how much I’m using. artificial intelligence, for me, I use it almost exclusively for my quantitative work. I treat Claude like I would a human research assistant, a highly skilled research assistant. So I built a decarbonization dashboard. I used to have a research assistant that I would have do this for me. And he would take, a couple months to pull together. a spreadsheet that was a rudimentary form of what I was able to pull together in a couple weeks. For doing math, for doing statistics, for replicating analyses AI tools are better than people at this point.

The Honest Broker on Substack does not have a back office staff of, people with abacuses or spreadsheets or anything. It’s me and Claude working to produce these things. And it’s been fantastic. It’s game changing.

DARREN: Do you have a name for your Claude?

ROGER: No, just Claude.

DARREN: Fair enough. I will not bore you. But if you bring me on your show, I’ll tell you all about my cloud system, which is crazy and insane. But let’s go back to extreme weather for a second. You spent your entire career pushing back. On the idea that every extreme event in climate change is climate change in action. And I think that’s maybe where I first found my way to you and to your dad for that matter. Here we are. It’s 15 years later. When you look at the data and now you can look at the data in a probably instant way, you’re tracking yourself. What’s changed? What hasn’t from what you were talking about back in 2005, six, seven period even?

ROGER: I’ll go back further than that. I did a postdoc at the National Center for Atmospheric Research, NCAR, in the 90s. I started in 1994. And my mentor, guy named Mickey Glantz, who ran a social science group at NCAR on climate impacts, came in the office in January 1996 with a copy of Newsweek. And it said, hurricanes, floods, and blizzards blame global warming. And at the time, there was some connection of extreme weather and climate change, but not anything like today. And he gave me this. And I tell my students, it was a magazine. It was made out of paper and it had a cover and it came in the mailbox. He gave me this and he said, this looks interesting. Why don’t you take a look at that? And so I blame Mickey for setting me down that path. My postdoc was on hurricanes and floods.

And so at the time, it was pretty clear that the claims that were being made about trends in extreme weather didn’t match with what the data said, even then. And so I started working on hurricanes and floods and branched out to fires and heat waves and things like that, tornadoes.

Everything changed in 2006. And there was this interesting combination of events. I won an award from the National Academy of Sciences, the Roger Revelle Award. Roger Revelle was a professor at Harvard. He happened to be the professor that turned Al Gore on to climate change. And I won an award for my work on extreme weather, in particular demonstrating with data and evidence that rising costs associated with extreme weather events were due to more people, more property, more wealth in harm’s way, not a change in the statistics of the events themselves.

That was in March 2006. In May 2006, Al Gore’s movie came out, An Inconvenient Truth. And people of a certain generation will remember the movie poster had a hurricane coming out of a smokestack, spinning the wrong way, by the way. That was Hurricane Katrina. It was flipped over. And late in the production of that, apparently, as I gather, Hurricane Katrina occurred in October of 2005. And they reoriented some of the movie to focus more on Hurricane Katrina and its impacts, which was a horrific tragedy and obviously badly handled, but a very extreme storm. And for me, that represented a real change in how my work was received and how I was portrayed by journalists and in the media, because all of a sudden extreme weather was the face of climate change. And this was a concerted effort.

People like Matt Nisbet, who’s a professor at Northeastern, have documented how environmental funders, philanthropists gathered together and they thought we have to bring climate change home to normal people. We can’t just say we’re going to have a three-degree temperature change in 2100, that’s not going to get people to act. Extreme weather is very photogenic. It has horrific impacts. It happens everywhere, every day on planet Earth and in the United States. So it feeds the media cycle. I was already well-established as a researcher. I was a young researcher, doing great. But my work, right away, it was palpable. My work was inconvenient because it didn’t fit that narrative. And I remember thinking: Am I still going to work in this area?

And I had colleagues saying, maybe you should downplay your work or it’s going to cause you trouble down the road. And they were probably right about that. But I faced a choice. Do I want to keep doing this stuff or do I just want to go along? In 2006 or 2007, I could have had a very different career track if I would have just joined the bandwagon and said, every hurricane is getting worse. And we need to reduce emissions so that we can modulate future extreme weather events. I might have gone down a very different path than I did.

DARREN: You know who took that path? I remember this so well because I was driving home from a vacation when Katrina hit. And I remember for some reason, because I like listening to, I don’t remember what exactly it was. I remember coming on to Sean Hannity on the radio and the person arguing with him right after Katrina about hurricanes was Robert F. Kennedy Jr. Yeah. Which is just boggles the mind to think about where he sits today. Right. And what position he was taking compared to where we are today.

ROGER: Well, you might have seen some of this because around that time, 2006, 2007, 2008, first it was Grist. I was one of their favorite punching bags. Then it was the Center for American Progress for a long while. And, as people left their early jobs there and moved on. Some of them, like Dave Roberts, who you had on before, decided I was public enemy number one. And there were journalists at places like the New York Times and elsewhere who decided that the work that I did couldn’t be correct, obviously, because it was contrary to a narrative. But things really changed at that point for me.

DARREN: So around that period, I’m covering climate science, but my focus was the policy. I’m covering the regulations, I’m covering the cap and trade bills that ultimately would crash and burn in 2010. So none of that stuff passed. And yet, I just was for the hell of it looking today, 15, 16 years later to see where emissions went, comparing to what those bills required. And emissions have come down anyway, for reasons most of those lawmakers, presidents, agencies never really had in mind. What’s your read on that? What actually moved the needle? What does it say about climate policy itself versus everything else that happens in energy markets and energy, overall?

ROGER: So I came to climate change ass backwards. I started with adaptation and extreme events, and later moved into energy policy and decarbonization. And one of the, this is down in the weeds again. So down in the weeds on my side, I often talk about decarbonization of the economy. So it’s carbon dioxide emissions per unit of GDP. It’s a simple metric. And that metric has been declining for as long as we have data for 60 years, which is good news. That means that we’re moving in the right direction. We’re not reducing emissions fast enough to meet targets. But one very fascinating aspect about that particular curve, if you look at the United States or the world, for that matter, it’s a linear, it’s a straight line downward.

And so if climate policy and mitigation policy efforts to reduce emissions, deep decarbonization, if that’s working, we should see an acceleration in that curve. We’re moving it downward faster. And so we don’t. We don’t see that at all. There is no evidence. You start in 1992 with the Earth Summit, 1997, Kyoto, Paris Agreement. In the US, clean power plan, cap and trade, name it, IRA, pick your favorite proposal or outcome. And there’s no evidence that any of it has moved the dial. And people get upset when I say that. Part of the reason is that what we used to call other names, maybe environmental policies, maybe economic policies, we’ve relabeled them as climate policies. So maybe there are things we call climate policies that contribute to decarbonization, but they haven’t accelerated decarbonization.

There are other things, particularly the rise of natural gas over the last 20 years that has displaced coal. Policies that have made coal more expensive and more difficult to build have contributed. Expansion of solar in particular and wind to a lesser degree have also contributed to that. But in terms of reducing emissions, there’s no evidence that our climate policies have done anything to accelerate the rate of decarbonization, which I would think should cause us to think, all right, so what is it we’re doing? And why do we think doing more of the same is going to lead to better outcomes? So I’m a proponent of deep decarbonization. I think it makes a lot of sense just to take that risk off the table. I wrote a book about that 15 years ago, 16 years ago now. But what we’ve been doing is obviously not working.

DARREN: I think I want to go to the politics of this for one second, because over this 26 years that I guess I’ve been in this world in Washington, and this really does overlay with the Bush years and the rejection of Kyoto, we’ve seen the politics of climate rise up, as you said, and it’s dropped down to nothing, and then it’s popped back up again, I think, around maybe the Inflation Reduction Act in Biden is when it gets another swing. And now, again, we’re down into a place where there ain’t nothing happening per se on climate. But the figures have changed. I mentioned RFK Jr., for example, 2005, screaming at Sean Hannity, what the hell are you talking about? It used to be, again, in that Obama era, they needed to win over some Democrats and they couldn’t win over those coal state Democrats. They’re long gone.

And the Tea Party is a brand new thing. And then MAGA is a brand new thing. So talk to me about the politics of climate change for a second, where you see them today versus where they were. And is this Is this one of those issues that’s just going to forever be third rail in the same way as you name it on the other political issues?

ROGER: I’ve been around long enough to remember when George H. W. Bush was campaigning for president saying he was going to counter the greenhouse effect with the White House effect. And there was a good faith battle over the degree to which government and government regulation should be the driving force in decarbonization. And it fell along predictable, old school, New Deal Democrat versus regular Republican conservative lines. But there was a debate about that. And that was, I think, a natural outcome of how climate change, global warming originally was originally framed. And people have to understand that the knowledge of climate change emerged from very sophisticated earth system models. And one, I guess it’s a career risk for modelers is that it’s very easy to map your model onto the real world.

And so if you want to reduce emissions, you put a knob or two in your model that reduces emissions such as going from scenario A to scenario C. And that gets translated into a real world understanding of something like a carbon price or some regulatory fiat to change technologies. And that early framing of climate change, mapping a model onto the real world, did get interpreted by people on the left as, well, we need more regulation. We need some top-down approach to manage the economy. And resistance from the right, who said, well, no, we’ve got to let the free market work. We need more innovation. Basic research is great, but none of this regulation stuff. That, I think, was normal climate politics and normal discussion.

I do think that the Bush versus Gore presidential election, going to the Supreme Court, Al Gore becoming, honestly radicalized on climate issue and making that his signature issue and combining that with the anti-Bush administration stuff helped to make climate change a very powerful wedge issue. And everybody knows what a wedge issue is, but I feel very strongly that folks on the right and folks on the left felt very strongly they could use climate change instrumentally to get political advantage, regardless of what it meant for decarbonization or adapting to climate, that it just became a symbol. And with the debates 20 years ago over the hockey stick mapped very nicely onto that. Honestly, the Republicans, Joe Barton, James Inhofe, they like to pick on climate scientists.

And to be fair, climate scientists, many of them haven’t been shy about advertising their progressive credentials and criticizing Republicans. And so everybody put on their partisan costume, and the politics became pretty poisonous for a long time. And it culminated with, if you look at the Inflation Reduction Act passed with, straight Democratic vote. And, the One Big, Beautiful Bill Act that ostensibly, probably not too significantly, but rolled back a lot of that was all Republican. And so climate change at some point morphed into just another place of the political battles of the U. S. And, the normal politics of climate change is a distant, distant memory.

DARREN: I almost I got asked like the alternative question, George W. Bush. For anyone in our world knows, in 2000, he actually campaigned on a pledge to reduce carbon dioxide emissions and only changes it thanks to the Cheney Energy Task Force at the very beginning. Had we gone the other way, like had Bush actually pushed through a bill in 2000, not giving Al Gore then the Inconvenient Truth platform, that then changes, I’m sure, the John McCain presidential run in 2008 and Obama, it changes everything. Right. What do you think happens if George W. Bush keeps his dad’s like environmental mantra going all the way through and try and answer it in three minutes because we’re going to run out of time in this particular segment of the Zoom. I think we should come back for a second. So, yeah.

ROGER: I think it’s a fascinating alternative history. I do think I’ve said this for a long time, that there is a huge opportunity for folks on the right for Republicans with energy policy and climate policy. There’s a term that Obama coined or his campaign coined, all of the above strategy. And it’s very popular again today. But all of the above means all of the above. Not everything everywhere all at once, but wind has a place. Solar has a place. Nuclear has a place. Natural gas has a place. Coal has a very small place, maybe for chemical reactions. But the most recent administrations have all played well. They’ve been picking winners and losers. And that goes for Trump. That goes for Biden.

And so I do think that for whichever political party picks up a mantra that, yes, reducing emissions is part of smart energy policy, I think there’s an audience for that out there electorally. And it moves us away from fighting over science and the vile partisan nature of the issue.

DARREN: You did so well so we got two and a half minutes left. I’m going to milk this question just one more line. And when I learned this policy back in the days, when I walked into E&E News, my old boss, Kevin Braun, would scream all the time, energy is not a partisan issue. Energy is not a partisan issue. It is a regional issue. And nobody understands that. And that got drummed in my head to understand the way that the country breaks down on where you’re getting your energy from and where you live and how you live and why they need air conditioning all the time. But has that changed? Has the regional dynamics changed because of our politics and tea parties and MAGA issues? Or are we still in a regional, energy war?

ROGER: Energy is always going to be regional in a country as big as ours. most people don’t realize that California gets a significant part of its finished gasoline product from overseas, from South Korea, from India, from the Bahamas, because the refineries in the US can’t process it. That’s very different than other parts of the country. Texas is an electricity island, and it’s not connected to other parts of the country. If you’re in North Dakota or Wyoming, Natural gas and coal are a big deal. West Virginia, Joe Manchin came out of West Virginia, which coal is part of the history, part of the culture. So yes, of course, energy is going to be a regional issue.

I do think there’s one big change I’ve noticed. really over the long term is that in 2005, the Bush administration and the U. S. Congress led a discussion over national energy policy, which we haven’t had really since then. From 2005 and that time, through Obama and then through Biden, climate policy usurped energy policy. It became the umbrella and energy policy was underneath. And, I think that was a mistake because energy policy means something to everybody everywhere, even if it means different things regionally. In climate policy, it turns out there was just a new report that came out this past week. The working class across ethnic groups in the U. S.—people of all races without college degrees—, climate change is not a big deal. So climate was the umbrella and energy policy was folded under that. And what it meant was that a lot of focus on issues that people care about in different places was lost to this big globally focused issue, but it also meant that things associated.

With energy policy falling out of the discussion other issues go with it, most notably affordability, inflation in an era where energy, particularly electricity demand is picking up, how to meet that demand is lost because you’re talking about reducing emissions, not growing energy systems. The big change has been in really the last couple of years, that’s flipped again. And now energy is the umbrella and climate to the extent that people are still talking about climate, which I think they should be, is underneath that. And I think it’s perfectly compatible to have an agenda that’s an all of the above energy agenda, focused on affordability, energy expansion for growth, for things like data center and AI and reducing emissions.

So, hopefully we’re poised to be in a better place for this discussion, but the partisan elements of climate seem to have lost some of their power over the left and the right because they’re not really talking about it.

DARREN: When you add the data center element, which you just said you were digging into, what did you come away with? Because that’s not in the equation 15, 20 years ago.

ROGER: Necessity is the mother of invention. And so for the U. S. for 15 years or so, we were fat and happy. We had plenty of electricity. It wasn’t a lot of demand growth. None was really expensive. There were a lot of projections that we would become ever more efficient and energy demand wouldn’t be as high as it was. And that’s changed. And it’s not just data centers, but the push to electrify heating and electrify the automobile fleet is going to have a greater draw on electricity. And so with the expectations of much greater demand comes questions, well, how are we gonna meet that? What technology is going to meet that? And that forces people to start having a discussion that we haven’t had for a long time.

And so one reason why people often point to China as the true all of the above energy nation is because they have to keep bringing online more and more Energy, not just electricity. And so we’re experiencing a taste of that ourselves in the US.

DARREN: Roger, now you and I have known each other for a long time. I spent a little bit of time looking back through some of my notes where I found your name, thanks to Claude, looking back through things. And I had a chance to look through things. You spent over a decade as a lightning rod. You spoke to that a moment ago. The congressional testimony I found from like 2012, 13 on the nuances of uncertainties, writing for FiveThirtyEight for Nate Silver in 2014, what you’ve been just discussing about the IPCC report. What do you think people misunderstand about why you keep ending up in these discussions, in these fights that are playing out in the online space increasingly more and more?

ROGER: It’s interesting. I think there’s a much greater understanding today than maybe back then. In 2013, you mentioned my congressional testimony. I don’t know how these things happen. I testified before Congress—the Senate first, and I think the House second. But my Senate testimony, which I gave first, when we give testimony, you have a five minute opening statement and you’re supposed to summarize what you say. But my five minute opening statement, somebody put it on YouTube and it went viral. And it got 400,000 hits in the two weeks. And that drew a lot of attention. All I did—the same thing I’m doing with my extreme weather dashboard—was summarize what the IPCC says about extreme weather and climate. I just laid it out there. That led to the Obama White House coming after me, John Holdren, President’s Science Advisor.

That led to a congressional investigation of me by Raul Grijalva, rest in peace, claiming that I must be taking money from Exxon in exchange for my congressional testimony. Ridiculous things. And as I mentioned, there was an organized effort by the Center for American Progress and Michael Mann and a few others to get me fired from Nate Silver’s 538, which they succeeded in doing.

And so I think part of it was, looking back in time, and having the perspective, part of the issue, I think, is that I just didn’t quietly go away. this was the early in the era of deplatforming and canceling. And, I don’t even believe that you can be canceled unless, you’ll let people cancel you. And the climate issue was notable because of the degree to which, legitimate, authoritative organizations, not just people, but in the media and in science wanted to clear the stage of people who were perceived to be off message or inconvenient.

And what I’ve always said, and it’s always been true, my work is just right in the fat part of the scientific consensus. The IPCC cites my work, it’s peer reviewed. The stuff that I do is not contrarian, it’s not skeptic, it’s just normal science. But as the climate movement, And this includes a lot of scientists became increasingly extreme in their rhetoric and their claims. The normal scientific consensus started looking a little boring, not exciting enough. And so I guess the other the other flaw I had is that my work got a lot of attention, probably just because I’ve been around for a long time and I write a lot. And I didn’t fall for the bait, didn’t go off the deep end, didn’t join some extremist party or anything like that.

Today, it’s vastly different. My stuff is widely read. It’s widely accepted. We could talk about climate scenarios. I saw that go from 10 years ago, same playbook. I first started writing about that. Oh, you must be a climate denier, climate skeptic, to now everybody in the world accepts all that stuff. They may not like it, but that’s where the science is.

DARREN: Has Substack helped? talk to me about the good and the bad of what Substack allows you now to do that maybe you couldn’t do 10 years ago and you were probably screaming into what, a Twitter universe that was not very rewarding, I presume.

ROGER: I don’t know what the secret sauce of Substack is. So I joined Substack in 2020, mainly because the platform was so elegant, so simple to use. I like to write and think. I don’t like to work on images, do HTML coding. I’d use Blogger and WordPress and things like that. And they were just clunky but you could get things out there. And Substack also, I came to learn, and I’m sure you learned, it has an ecosystem so people can find people. And I just thought it was going to be a blogging platform. And then at some point I decided, so I was having kids during the dot-com boom and, working and starting my job as a professor. So I felt like I missed that era, went by me. And I thought, well, if I’m going to do this new, approach to doing research, to doing writing, I’m going to be an early mover.

And so joining Substack, it was immediately rewarding. And this is another dynamic that I did not expect. At some point, I decided there are expenses associated with doing research and coding and things like that. But I thought, all right, if I’m going to pursue an alternative approach to research and writing than academia. And for reasons that are well-documented, I left academia in 2024. But I thought, all right, I need to pay the mortgage. And so I’m going to try this paid version of Substack. And if I could ever get to half my academic salary, I’m out of here, which I thought was a pipe dream at the time. But the minute I turned on the paid subscription thing, my readership started on a different slope. So I don’t know if people thought, well, if I have to pay for it, it must be good, or I don’t know what it was.

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But what Substack does is it gets a writer’s work out there. I hear literally every day from people around the world in organizations, governments, businesses that I would have no access to without Substack.

So I did meet half my salary. I left academia. I joined the think tank later, but Substack, for me, has been a completely new approach to doing what I always have done, which is do research, write, do good work, get it out there, talk to people about it, and have agreements, disagreements. It’s not an exaggeration to say that for me, Substack was life-changing.

DARREN: Has it changed the way what you’re willing to say that you couldn’t have said as an academic?

ROGER: Not really. I’ve been pretty unfiltered. Academia is a weird place and it’s probably been a weird place for a thousand years, but there are a lot of ways that your peers and your colleagues can put pressures on you. So like in the climate space, I’ve never been invited to participate in the IPCC. I was told by an IPCC official, you’ll never be picked. And, IPCC for a lot of people is central to their career advancement. So that’s, and, at the University of Colorado, for a long time, my office was taken away from me. My classes were taken away from me. It’s just, making your life miserable. When you work for, I have 40,000 subscribers. Obviously, not all of them pay, but they all should — Ha, ha!

But when you work for, thousands of people who each pay you a small amount of money, there is essentially no pressure. Nobody’s going to write to me and say, I’m going to cancel my subscription unless you say this, that, or the other thing. There are people on my Substack who are obviously on the right and some on the left, and they tell me they don’t like my politics on this issue or that issue. And the beauty of it is if you’re coming to get partisan points, you probably should go to somebody else’s Substack, and that’s fine. So the decentralized nature of it is actually, it’s liberating in the sense that there absolutely is no pressure on me to do anything other than what I want to do. So in that sense, it’s a very empowering environment.

DARREN: What’s the biggest challenge of doing this, like outside of that institutional backing that you have had before? The thing that, nobody warned you about as you got into this.

ROGER: I have to say, for me, being associated with AEI, which maybe 90 years ago was created after the New Deal, which is a center-right think tank full of heterodox thinkers, very well positioned. That replaces a key element of what I had in academia. As an academic, for better or worse, you get stature. Oh, you’re a full professor and you got a PhD and all that. You’re at an R1 university. And I do think, if I was just a Substacker right now, I wouldn’t have that institutional authority. I’m lucky that I get a chance to talk to elected members of Congress from both parties and if they don’t know who I am, and if I say, I write The Honest Broker on Substack, they still won’t know who I am. But if you say, oh I’m a senior fellow at AEI, all of a sudden I get credibility.

And they don’t know what I’m going to say, but if you’re at AEI, you must be somebody I can listen to. So I do think I was lucky in that I had this dual role where I write, I do all my work first and foremost on Substack, and then I have access to the policy world through AEI. And I do wonder, if I was just an independent scholar, I really doubt I would have the footprint that I do in the intellectual world. So that was maybe something I didn’t think through 100% when I was thinking about getting half my salary through Substack. But that said, if you’re an old professor and you fade into the sunset, you write for your little audience, that’s not a bad outcome either.

DARREN: Has any piece of your work landed totally differently than you expected?

ROGER: I’m working on a book. It’s almost done on, the gender wars in elite sport. so I’ve been working on, on sports governance issues for, going on 20 years and I led a sports governance center. It’s one of the things I did when I went out in the wilderness and left the climate debate after getting investigated by Congress and it’s super rewarding. and, and I, it’s like my climate work.

If you understand the nuances and the shades of gray of gender eligibility in elite sport, it’s not a black and white issue. And it’s not a MAGA versus progressive issue. It’s much more complicated. And there’s real people and real humans. And so I have a book, it isn’t coming out yet because I don’t have a publisher, but the book’s almost done.

And it’s about women who traditionally, historically have been called intersex or DSD, differences of sex development or variations of sex development, —my preferred term. But they’re born female, identified female, raised as female. They are what I call collateral damage in the war over trans athletes. So it’s not a book about trans athletes. It’s about this group of women. And one of the things that I’ve come to very deeply appreciate is that people on the left really like my work on gender and sport. And people on the left really don’t like my work on climate. And people on the right have the exact opposite view.

And so for me, when I’m writing on these issues, both of them, I do have to orient my mind in very different ways to kind of, make sure I have my bases covered because my work doesn’t get critiqued from one political direction all the time. And so as far as how things land, I do have to take care in crafting nuanced arguments that are politically robust, realizing that the politics depends on what issue I happen to be writing about.

DARREN: I think you’ve checked all of the boxes. You might have like the equivalent of an EGOT for your career. You’ve been investigated by Congress. You’ve testified before Congress. I think I saw that you were cited by a Biden White House on one of your tweets when you gave praise to a nominee. I think you’ve clearly got the EGOT at this point.

ROGER: Ha! I was in WikiLeaks and I was in the ClimateGate emails and I was in the Proximal Origin Slack messages.

DARREN: I’m going to award you the EGOT for climate policy nerddom right now. Who on Substack is doing something you wish you’d thought of first?

ROGER: That’s a good question. I wish there’s a lot of people who are really good at doing podcasts like you, for example. And I did a few podcasts and produced them. And I did one that I’m pretty proud of. It was about how I became Voldemort in climate science. But Good Lord, it was a lot of work and it was just challenging. And it’s, I’m not a media person. I’m not a journalist. I don’t have those skills. And so I’m a good writer and I write a lot, but it’s like a rebounder in the NBA who can’t shoot. So I can do one thing really well. So I do wish I had the ability to have a greater diversity of media outlets. Robert Bryce, a guy who does an energy Substack, he’s a friend of mine. He told me one of his kids helped him get onto TikTok and he’s done one- and two-minute videos and they get a lot of views and a lot of hits.

But I’m not good with the video or the podcasting thing.

DARREN: So your dad’s been in this world forever too. Does climate science in your bloodline change how you write or just how people read you from your perspective?

ROGER: That’s another great question. I’m close to my dad. He’s just about to turn 80. He’s still super smart, super active, doing a lot of stuff. When I grew up, he was a young father. he treated me like his students. I used to take his college atmospheric science exams when I was in elementary school and stuff. And so I do think I’m very familiar with a lot of aspects of climate science, the jargon, the literature. I think the fact that I got my initial postdoc at NCAR was probably helped by my name. There’s no doubt about that. There’s some privilege being Roger Pielke Jr. So I do think working at the interface of science and policy, you have to know something about the science to be able to connect it to policy. Collaborating with him and just having someone to talk about these issues has been really important.

In the 1990s, after I did my postdoc at NCAR, when I was focused on hurricanes and floods, he and I decided to write a book together on hurricanes. And I remember, we literally would sit next to each other and he would explain something about, baroclinic instability and Coriolis force. And, then I’d say, all right, we’re going to write this in English for people so they can read it. And so we’d go back and forth and we still do that thing. So I think, it’s anyone who has a chance to grow up in a household with a world leading scientist on any topic is going to benefit probably in ways if they decide to apply it professionally.

DARREN: What on earth do newcomers think if they get invited to your house for Thanksgiving dinner? Do they beg you guys to not talk about this or are they just sitting back, with their mouths agape?

ROGER: No, I think everybody’s by this time familiar. We lost my mom not too long ago. And so he’s making a lot of new friends. And when he starts talking to people, everybody likes to talk about the weather. he’s a weatherman. People love to talk about the weather. And, he starts out with an atmospheric science graduate level discussion. So, so that’s always a challenge, but, our family discussions don’t center too much on the stuff that we do.

DARREN: Has your relationship with the phrase climate change changed over the course of your life, your career?

ROGER: I think it has. It’s really interesting that for a long time, Climate change was understood in common parlance, just like it was in science, that climate change was a statistical description of some change in a variable that we care about related to weather or climate. A change in the average temperature of the earth is like a change in a hitter’s batting average, right? And over time, climate change, particularly in the media, but this is filtered back into science, climate change has become an all-purpose causal actor. So, was the heat wave “caused by climate change”? And that doesn’t even make any scientific sense from the standpoint of the IPCC, because climate change, it’s a little bit like saying the hitter’s home run, was that caused by his batting average change? No, but the home run might filter into how we interpret his batting average.

And so when I talk about climate change, and I’ve been writing much more about this lately, I go to great lengths to explain that climate change is not a cause. Climate change, greenhouse gases might be a cause, aerosols might be a cause, changing the land surface might. But climate change is not the cause. It’s a completely circular discussion. So I’ve had to really change how I talk about climate change and make sure I don’t slip into that lazy formulation of, Was this caused by climate change? Because it doesn’t make any sense. So the understandings that people have, I think, have become much flatter over time, which makes it even more difficult to break through with a more nuanced discussion. Because if you say climate change doesn’t cause anything, the first response you get is, well, you must be a denier, of course it does.

And you say, well, no, climate change is a statistical concept. It’s not an actor, right? people go to sleep when you start talking like that. So, yes, I do think it has become much more difficult to actually talk about the notion of changes in climate, which are real and have a significant human impact. And there’s something we want to mitigate. But if we can’t talk about it accurately, it’s going to be real hard to implement policies that make any sense.

DARREN: And yet it does feel like, again, maybe this is just because I’ve been in this world myself, like awareness feels higher thanks to the Gores, thanks to, our just going outside and just having a human experience. So how do you square that when people are able to talk or people are aware of the concept, they talk about it again. And in the last 25 years, we can now literally. We could turn off this camera and we would instantly know what’s happening the other side of the planet in a way that we wouldn’t have known 25 years ago. So how do you spur those two things?

ROGER: It’s interesting. If you look at opinion polls, and we did an opinion poll, Rui Teixeira and I at AEI right before the 2024 election. climate change as a concept is incredibly salient. It’s very popular. People, if you say, do you want to do something about climate change, you will get a very high proportion of people across the political spectrum, obviously more on the left than on the right, but still it’s very, no one’s against doing something about climate change. The problem is that I think that becomes very disempowering. So, do you want to do something about climate? okay. Let’s do something about climate change. And so you’ll see a lot of advertisements about, public support for climate change.

But then when you ask people, would you pay $10 more a month on your electricity bill to do it, the majority of people say, hell no, I’m not going to do that. And then when you talk to policymakers or when policymakers talk to the public, like with respect to the fires that have occurred in Europe or in Oregon, it’s very easy for a policymaker that says, we really have to do something about climate change. And that’s an avoidance of responsibility or accountability. we’ve got to do something about climate change, but it’s not going to help with your exposure to fire risk this year, next year, in the next 10 years, even longer. And so joining up climate change with the thing that just happened, I find to be very disempowering and a little bit frustrating.

DARREN: What’s the most undercovered policy story in this world right now?

ROGER: On climate change. I think that the most undercovered story still remains the retirement of the most extreme climate scenarios that have dominated climate research for the last several decades. I talked to a lot of people. I was just presenting it in a workshop on response to rural disasters, and I presented on the extreme scenario retirement. Nobody had heard that these scenarios had changed. In their local communities, they’re still using the outdated retired scenarios for their planning. It is remarkable to me. There was a flurry of coverage. It was mostly in response to Trump’s tweet a bout RCP 8.5. Had you told me, a president, much less Donald Trump, was going to tweet about a climate scenario. I would have laughed a few years ago.

But the media coverage was more Donald Trump said this thing and here’s where he’s wrong rather than going into the details of, what are these scenarios? Why is a little committee in Europe making them and they influence what central banks do? I do think that there’s a continued neglect by the larger media, I don’t know if we call it mainstream media, but the larger media of the actual details of climate science in favor of continued hype and hyperbole and partisanship.

I will be doing an interview with a big Australian outlet on my new climate dashboard. They’re the first media group that has contacted me about this. I would think that this would be the stuff that the media would eat up, but who’s going to show a dashboard where six of the seven indicators don’t show any significant change over many decades?

So I do think that the basic elements of consensus climate science are well undercovered today.

DARREN: I’m going to close out our entire show here. I got a couple of questions for you. I know you just said a couple of minutes ago, you don’t have a media training, you’re not a journalist, but I ask these questions of everyone. And I think in the context, you’re making money on Substack and you’re writing every day. And there is no license to be a journalist. I’m going to call you a journalist. So welcome to the club. And I guess one question I ask everybody is, is there one thing? Whether it be tangible, physical, that you carry with you from, that you need to do your job day to day, whether it is a pen, a pencil, it sounds like maybe it’s Claude, but is there a thing that you carry with you that you do, that you need every day in this space?

ROGER: That’s a great question. I need a steady diet of information and that can come. honestly, I don’t watch much TV or, sometimes I have TV news on in the background, but I don’t get a lot of information from that. I do find that X/Twitter is an absolutely fantastic resource for surveying what people think, pointers to information, things I should read. Honestly, I’ve dabbled, I guess I would say, in the discussion over COVID origins, which is another science meets policy topic that is fascinating and problematic. I would say 95% of what I’ve learned on that topic has come from people on social media pointing to me to things I should read, science articles, public lectures. theses that were recovered from Chinese students in the archives and translated.

So to do what I do at this intersection of science and policy requires the best, the latest information so that I can start triangulating among it to figure out what I think is what.

DARREN: Really quick, Twitter of old versus Twitter of new, which do you prefer, the Jack Dorsey Twitter or the Elon Musk Twitter, if you had to pick?

ROGER: I haven’t noticed a change. I don’t go into the partisan spaces all that much. the earlier one, I’m pretty sure I was throttled or rate limited because of some of my climate stuff. Not all, but many of the climate journalists on the climate beat have me blocked. So, I don’t hear from them. I don’t get much crap from people on Twitter. And so for me, Twitter, I do put stuff out there, but it’s the ratio of Substack to Twitter for how my stuff is taken up in the world. It’s probably 99 to 1. Twitter for me is an information resource and I use it the exact same way now as I did before. So I don’t do any of the Nazi stuff; I don’t do any of the socialist stuff. So my bubble is pretty cleansed to all that stuff.

DARREN: And last but not least, you’re on the Love Journalism show. Tell me if journalism has loved you back.

ROGER: Yes and no. I think I have long thought that what what journalists do and what public facing academics do has a lot of things in common. We seek the truth. The work that we put out is often a first draft at best of that truth. We try to get better over time. We try to refine what we’re doing. We’re all telling stories as they occur and as they evolve. Peer review gets, people call it the gold standard and it’s great, but peer review is a minimal standard. I had stronger review of things that I wrote when I wrote for The Atlantic or The Wall Street Journal, The New York Times than, a lot of academic journals. The fact checkers did a lot more rigorous job. And so, at its best, I have learned an enormous amount from journalists and journalism. And I couldn’t do what I do without a strong, vibrant sector of journalism.

At the same time, obviously, it’s very publicly known. There have been a number of journalists who’ve seen their job is to silence me or criticize me or label me and somehow in their stories. There was just a Political article in the last few months where, they tried to make it sound like I was some raging, crazy MAGA guy. it’s always funny when they, I work for AEI, which is a fantastic think tank. And it always comes in certain outlets with, the “conservative” AEI think tank and, others in the same article who are associated with left leaning groups, they don’t get, they don’t get an ideological label. So I could have done without over my career journalists who are campaigners and seeing their job to shut me down, ha haa. But at the same time, if that’s the worst complaint I have, it’s not that big a deal.

So I love journalism. Journalism is done great by me for the most part.

DARREN: 40,000 subscribers certainly agree that you certainly got a message to share. And I really appreciate you taking the time, Roger Pielke Jr., for our show today. This one really plugs right into the whole recent run we’ve been doing on energy and environmental policy with David Roberts, with the E&E crew, as I said, and then check out my Powerlines series of photos of power plants, excuse me, Powerlines that just pop up whenever you take a picture of Out there in the world. Last but not least, Sunday brought something very different from Love Journalism, my poetry collection. Please, God, let there be a bowling alley in heaven. Please go check it out and please subscribe.

If you’re among the next couple of people to subscribe, next couple dozen people to subscribe, you’ll get hooked up just like my other subscribers with my first ever book, which I self-published, just like Thomas Paine, Jamie Frazier, or Alexander Malcolm from the Outlander series. This has been the Love Journalism Show. See you next time.

Postscript: Andy Revkin, former NYT journalist and current Substacker, coined the phrase “Voldemort of climate science” to characterize me as “he should not be mentioned” — a reference to the broad commitment among journalists on climate beat to pretend like I and my work does not exist. Its a good one! Below you can listen to a podcast I created with original source materials explaining how that all came to be.

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Here is something that few people are aware of — per capita carbon dioxide emissions (pcCO2) from fossil fuels peaked globally in 2013 and have remained below that level ever since. The trend in pcCO2 is best characterized as a plateau, as shown in the figure below. In fact, in 2025 global pcCO2 was only 2.3% above 1979, even as world population increased by ~88% and total energy consumption doubled.

Today I am starting a new series on what we can learn about decarbonization and how it might progress into the future by looking closely at pc carbon dioxide emissions around the world, taking advantage of forthcoming data and tools at the new THB Decarbonization dashboard.

The first thing to understand is why pc carbon dioxide is a useful metric. The figure below summarizes its derivation from the Kaya Identity. Whether pcCO2 rises or falls is the outcome of a competition between increasing per capita GDP and decreases in energy intensity of GDP and carbon intensity of energy.

That means pcCO2 is an integrated metric that reflects the sum total of all factors that combine to result in decarbonization. That makes it a very simple yet very powerful tool for understanding what factors lead to decarbonization and how they might play out into the future.

Of the 78 countries tracked in the Energy Institute Statistical Review of World Energy (2026), covering ~6.5 billion people, about 80% of the world population:

• 57 have already seen pcCO2 peak and decline (representing ~28% of world population and ~52% of global GDP),

• 9 have plateaued (~4% of population, 3.7% of GDP),

• and 12 are still rising (~47% of population, ~37% of GDP).

Today’s post takes an initial look at what sets apart countries that are past peak pcCO2 (peakers) from those that have yet to peak (non-peakers). Those that have peaked and declined are shown in the figure below with the peak of each set to 100.

Upon hitting their peak, the peakers are richer than the non-peakers — on average with more than twice the per capita GDP and on average consuming about 4 times the per capita energy of the non-peakers. Interestingly, population growth rates differ little between the two groups.

So what does distinguish the two groups?

• Coal: The economies of large, populous, still-industrializing economies — China, India, Vietnam, Indonesia, the Philippines, with a combined population of ~3.4 billion, 41% of 2025 world population — depend on coal for 45% to 65% of their energy consumption.

• Wealth: The peakers are much wealthier with per capita GDP at the peak much higher than the non-peakers today. Non-peakers however are growing GDP faster with an average annual rate of 2.5% and peakers at 1.3% per year.

• Energy intensity and carbon intensity: Among the peakers, 51 of 55 (with available data among the 57) have seen average annual declines on both EI (energy intensity) and CI (carbon intensity) since peaking. Among the 21 non-peakers, 10 have seen declines in CI or EI, but not both, 8 have seen declines in both CI and EI, including China and India, suggesting that a peak may be in their near-future, and 3 are moving the wrong way on both CI and EI — Vietnam, Indonesia, and Iran.

The figure below shows a scatterplot of CI and EI growth rates for the 57 countries with decreasing pcCO2. Almost all sit in the quadrant where both CI and EI are decreasing. This figure shows that CI and EI are complementary, however, as we will se later in this series, simple math means that CI must carry the load to achieve deep decarbonization.

The figure below shows a scatterplot of CI and EI growth rates from 2000 to 2025 for the 21 countries that have yet to hit peak pcCO2. Importantly there are some countries — notably China and India — that are in the quadrant where both CI and EI are improving, but not enough to have caught up to the growth rate in per capita GDP and lead to falling pcCO2, but they are moving in the right direction.

This initial look at pcCO2 tells us several interesting things about conditions that are favorable for emissions reductions, which are required to hit targets for deep decarbonization:

• Wealth is a prerequisite;

• So too is a high level of energy consumption;

• Energy intensity and carbon intensity reductions combined must exceed growth in per capita GDP;

• Overall population growth is a secondary factor, if even that.

As this series continues look for these future discussions:

• Projections of pcCO2 can be used to create simple, understandable, transparent, and plausible scenarios of future emissions;

• When we might expect China, India, and other countries to hit their peaks;

• Improvements in CI will matter more than improvements in EI, and specifically the future of coal;

• A lower-than-projected future population would imply greater pcCO2, but lower cumulative CO2 over the century.

• Why I think that the world has likely passed peak pcCO2. However, whether or not the world has already seen that peak depends significantly on what happens across Africa this century.

As I get towards the end of this series I’ll release a new data dashboard, from which all of the images above were taken. You will then be able to explore the data, assumptions, and create projections yourself.

Meantime, you can explore per capita carbon dioxide emissions at THB Decarbonization Around the World.

Don’t go just yet — Please click that “❤️ Like” button.

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It has been a busy few months here at THB, including the recent rollout of several new data dashboards (with more to come!):

• Global Tropical Cyclones (with Ryan Maue)

• US Extreme Weather and Climate Change Dashboard

• Decarbonization Around the World

Please explore them — and let me know suggestions for improvements or if anything does not appear to be working like it should. They are work in progress and will be consistently improved and expanded.

On the new decarbonization page I included a tab with per capita carbon dioxide emissions for regions and countries around the world. Below, you can see that the world’s per capita emissions have remained just about constant over the past 60 years, while per capita emissions of both the U.S. and Europe have dropped significantly.

In the coming weeks, I’ll be digging into the per capita emissions data more deeply with an analysis of what it implies for climate scenarios and projections — there are some important surprises there, so stay tuned.

Going into the weekend I thought I’d share my summer book pile and invite your recommendations for good reads in the comments.

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I’ve just released a new data dashboard — Decarbonization Around the World.

The site allows you to explore rates of decarbonization for countries and regions around the world. Decarbonization is a reduction in the ratio of carbon dioxide emissions to GDP. Every climate mitigation policy seeks to accelerate the rate of decarbonization — when that rate exceeds the rate of economic growth, emissions go down. Approaching net zero this century requires a significant acceleration in decarbonization.

The image below shows decarbonization for the world, U.S., and EU from 1965 to 2025 — and no signs of any acceleration in the era of climate policy.

The site also allows you to get a sense of the scale of the decarbonization challenge that each country faces. The figure at the top of this post shows that for the U.S. to achieve a 50% reduction in carbon dioxide emissions (from fossil fuels) — assuming growing energy demand at 0.3% per year — would require the equivalent of more than 1,500 new 1 GW nuclear power plants (about 1.2 coming online every week, starting now) or more than 1.3 million new 3 MW wind turbines (more than 1,000 per week).

If you assume that all the waste heat from combustion can be forgone (some can, not all of course), then these numbers are reduced to 0.7 nuclear plants or over 500 wind turbines per week — still a huge number.

You can adjust any of these variables to explore different scenarios.

You can download figures and data. I encourage you to share what you find on your favorite social media platform and to tag me when you do. Click on the button below to start exploring.

Decarbonization Around the World

Check it out — it is work in progress, so suggestions, critique, and advice are all welcome!

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The pattern is very familiar: With every extreme event comes claims — from journalists, scientists, and politicians — that we can reduce the impacts of those events by quickly cutting our emissions of carbon dioxide from the burning of fossil fuels.

Here are a few examples just in the last week with respect to the wildfires across southern France:

• “[I]f we want to reduce our fire risk, the first thing we have to do is reduce our emissions;”

• “To counter this escalating threat from wildfires, societies need to re-double efforts to mitigate the effects of extreme weather and reduce carbon emissions towards net zero;”

• “The science on the cause is unequivocal . . . What needs to be done is equally clear: leave coal, oil and gas behind faster, scale up renewables and protect people where the impacts are already hitting hardest.”

The logic is attractive: emissions cause warming, warming causes fires, so cutting emissions stops the fires.

Today’s post, as in a recent THB analysis of France’s heat waves, takes such policy causality claims seriously, and asks: What effect would cutting emissions — all the way to net zero and beyond — have on wildfires in France?

This post makes three arguments that I suspect, as a set, many will want to disagree with — and I hope that we can discuss them in the comments:

• First, the fire weather climate in southern France has changed. Fire weather days (defined below) have become much more common in recent decades;

• Second, actual fire on the landscape in South France measured as area burned has not increased, and arguably has decreased, over that same period;

• Third, compared to today, aggressive mitigation is not expected to have discernible effects on the number of fire weather days this century, and perhaps much longer. Further, the benefits of mitigation are a function of faith in models not evidence from the real world.

This post considers each in turn.

A note on scope. This analysis covers Southwest France — the Landes region, home to the largest fires of recent years — and the Mediterranean coast where most of France’s big fires have historically burned. It makes no claim about the whole planet, or even the whole country.

Point one: fire weather has changed in Southern France

Fire scientists use the Fire Weather Index, or FWI — a number combining temperature, humidity, wind, and rainfall — to assess a day’s favorability for fire. A hot, dry, windy day has a high score; a cool, damp, still day has a low score. The FWI measures weather, not fire.

The figure above shows the FWI for Mediterranean France for 1980 to 2024 from the Copernicus Climate Data Store’s European Climate Data Explorer — the monthly reanalysis Fire Weather Index for the Mediterranean region.1 This product computes the FWI from the ERA5 reanalysis, which reconstructs past weather from measured conditions.

In the data I downloaded from Copernicus, I used five months — May through September — and averaged them within each year to give one fire-season FWI value per year. You can see in the figure that the index has a lot of variability, but it is also unmistakable that there is an upwards trend over this time series.

Issues of attribution go beyond today’s post, but this evidence shows that weather conditions conducive to fire in Mediterranean France have increased over the past 45 years.

Point two: but the area actually burned did not rise

If fire weather conditions, you might expect the area burned to also increase. In France it has not.

The figures above show from two different data sources — MODIS satellite observations (2002–2024) and MODIS + VIIRS (2012-2026) — trends in area burned across France. Note that the Mediterranean region accounts for about 70% of the nation’s total area burned. The orange bar for 2026 is area burned year to date.

From 2002 to 2024 the total area burned decreased and there is no trend from 2012 to present.

How can fire weather worsen while area burned holds steady or falls?

Weather is just one ingredient for fire. Whether or not a landscape burns depends on other factors as well: how much fuel has accumulated, whether an ignition occurs (in France, humans cause about 95% of ignitions), and how effectively crews suppress fires. France invested heavily in fire prevention and firefighting, and much of Europe watched burned area fall even as the climate warmed, largely through land management and fire suppression.

Thus two things are true: a clear upward trend in fire-favorable weather and a flat-to-declining trend in actual fire on the landscape. They don’t contradict each other — they simply show that the climate does not equal the outcome.

If I had a dollar for every time this past week I saw someone posting online trends in fires in France or area burned as an argument for or against detection of changes in climate I’d be able to buy a house in Mediterranean France — with AC!

Point three: emissions reductions are not a fire risk control knob

Let’s set aside all that complexity — fuel, ignition, suppression, the divergence between climate trends and fire trends — and grant the strongest reasonable version of the mitigation argument:

Suppose we care only about fire-weather risk, and let’s assume further that it is tightly associated with cumulative carbon emissions. If we cut emissions to achieve net zero (and beyond), how much less fire-weather risk would southwest France face by the end of the century?

A 2025 study in npj Natural Hazards — Lanet et al. — gives us information we need to engage this thought experiment with numbers. That paper projected how often summer days would cross the “extreme fire-weather day” threshold — the level that days exceeded only 10% of the time during the 1991–2020 baseline period.2

The study looked at RCP2.6 and RCP4.5 (yes, RCP8.5 is in there also, but I have ignored it in this analysis — I am modeling good practice!).

In the figure below I have graphed what Lanet et al. found for the increase in the probability of extreme weather days for RCP2.6 (blue dot, typically interpreted as being consistent with hitting a 2C target) and RCP4.5 (yellow dot) versus each scenario’s cumulative carbon dioxide emissions — and drew a straight line between them. I next added the two new CMIP7 scenarios that bracket a current/pledged policy range — MEDIUM (orange diamond) and MEDIUM-LOW (green diamond) — based on their cumulative carbon dioxide emissions.

That straight line allows me to estimate changing probability of extreme fire days under the methods of Lamet et al. for the new scenarios that bracket where CMIP7 thinks the world might be currently headed.3 I also calculated the midpoint of the two CMIP7 scenarios. All this is summarized in the table below the figure.

In the table, I converted each scenario’s fire-weather probability into something more tangible: the expected number of extreme fire-weather days in a typical July or August at the end of the century, averaged over 30 years.

A present-day baseline has about 3 extreme days per month. Based on these probabilities, expected variability is about +/- 3 days per month.4 Under the higher-emissions baseline cases, under the methods of Lanet et al, an average August could see 6 to 7-and-a-half such days — about double today.

So the conclusion of Lanet et al. is a strong response of extreme fire weather days to accumulating carbon dioxide — which is perfect for an analysis of the effects of mitigation on their projections of fire risk.

Let’s next introduce strong mitigation — that envisioned under RCP2.6, which reaches net-zero in the 2080s and goes net-negative after that. Under that scenario, at the end of the century July and August would average about 3 extreme days per month — essentially the same as today.5

Mitigation, under these assumptions, provides benefits in preventing modeled risks from increasing, but mitigation does not reduce risk from today. That means if the fires in France today are a problem today, then mitigation has no potential for reducing risks from today for generations at least, if ever.

Let me say that again — Under assumptions most favorable to the fire weather impacts of mitigation,6 end-of-century fire weather resembles the fire weather we already live with.

The CMIP7 midpoint projects 10.8 extreme fire days in July and August, averaged over 2070-2100, while RCP2.6 projects 5.9 — about five fewer days. In the modeled results, mitigation does cut risks relative to the baseline.

So the answer to the question “does cutting carbon lower fire danger in the Landes region of France?” has two defensible answers from a single study depending on the metric: no and yes.

• No, not with respect to today’s level of risks,

• Yes, with respect to a difference between two alternative, modeled futures.

This means that the mitigation benefit — the difference from the path not taken — is unobservable. Strong mitigation has an effect between the modeled RCP2.6 world and a modeled imagined higher-emissions world. But the quantification of benefits exist only in model land — not in the real world.

The yes or no answer depends not only on which baseline is assumed but on which variable you measure. Lanet et al. track two fire-danger indices that, under the same low-emissions pathway, move in opposite directions: the daily Fire Weather Index eases (an extreme day’s odds fall from 0.12 to 0.08 in August), while the seasonal hot-dry index climbs (from 0.03 to 0.15). One risk metric falls under mitigation while another rises — from the same paper.

None of this means that mitigation would not influence future risk of fire weather, but it does mean that the benefits of mitigation only exist insofar as we trust a model to accurately represent the world and our ability to accurately project where the world is headed under alternative pathways.

Were we to introduce in our analysis more variables, more scenarios, more models, more assumptions, more baselines — the scope of plausibly defensible perspectives would multiply. We have entered the garden of forking paths.7

Let’s illustrate this with numbers: If we assume a baseline of RCP4.5, then a signal of mitigation by following RCP2.6 emerges 38 years after the scenarios diverge — which would be sometime well into the second half of this century.8 Assume a baseline that approaches RCP2.6, and the time of emergence stretches to infinity. There are many defensible positions on where the world might be headed as a baseline scenario that fall in between RCP2.6 and RCP4.5 to satisfy every proponent or opponent of mitigation.

Science cannot resolve these perspectives.

The real-world impact of mitigation on fire risk in this case is thus a function of what future one believes we are headed for — which can not be resolved empirically. This is not an argument saying that mitigation can have no benefits for reducing fire risk, but rather, an explanation why our perspectives on what that benefit might be rests on beliefs and faith, not data and science.

Where this leaves us

To their credit, the Lamet et al. study acknowledges that adaptation to fire risk is not just necessary, but essential. Unlike those quoted at the top of this post, they do not treat emissions reductions as a fire weather control knob:

Adapting to the escalating risk of wildfires necessitates a comprehensive approach that addresses the three fundamental components of risk: danger (also referred as hazard), exposure, and vulnerability. Mitigating the hazard involves decreasing the likelihood and potential severity of wildfire events. This can be achieved through public education campaigns that promote fire-safe behaviours among residents, tourists, and professionals. Fuel management practices, such as prescribed burning and mechanical thinning, have proven effective in reducing wildfire severity. Exposure can be curtailed by regulating the expansion of human settlements and infrastructure into fire-prone areas, particularly the wildland–urban interface (WUI). The WUI, where human development meets undeveloped wildland, has been identified as a zone of heightened wildfire risk. Efforts to limit development in these areas can reduce the number of structures and lives at risk. However, it is important to recognise that even without further expansion, existing exposure within the WUI remains substantial. Moreover, many peri-urban areas—often overlapping with the WUI—provide essential affordable housing, underscoring the need to balance wildfire risk reduction with broader social and economic considerations. Finally, reducing vulnerability entails enhancing the resilience of communities and systems to withstand and recover from wildfire events.

This post does not argue against accelerated decarbonization. It argues that justifying decarbonization as a fire-risk reduction policy — as so many are about France this month — misleads the public and distracts from policies that can actually make a difference.

For accelerated decarbonization to gain wide public support, its benefits must be both near-term and perceptible.

Even granting the strongest reasonable assumptions, strong mitigation leaves end-of-century fire weather in Southwest France looking much like today’s — thus, the promised risk reduction cannot be delivered, even in highly simplified models.

Further, the benefits of mitigation for fire weather risk — not actual fire on the landscape — are entirely a function and magnitude of assumptions made about counterfactual futures. That doesn’t make benefits unreal, but it does make them intangible and determined by faith in models and beliefs about the future.

There are many better reasons for accelerating decarbonization of our economies than reducing fire risk in France. If those good reasons for accelerating decarbonization have a potential side benefit of contributing to lower fire risks, even if not completely quantifiable, so much the better.

My advice to climate advocates: Lead with the better arguments. Don’t preach weather control. That is bad science and a false promise.

Mitigation matters, justifications for it should matter too.

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Paid subscribers can download an Excel file below with all sources, data, and calculations in this post.

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Back in 1999, I published a paper in the Bulletin of the American Meteorological Society with Ken Kunkel and Stan Changnon titled “Temporal Fluctuations in Weather and Climate Extremes That Cause Economic and Human Health Impacts: A Review”. The paper looked at long-term trends in extreme weather in the United States based on the understanding that to understand whether climate has changed in ways that matter to people, you have to examine long-term, high-quality records of variable associated with the extremes that actually cause harm — and you have to try to distinguish any observed trend from the noise of internal variability.

That paper included a time series of the frequency and intensity of heat waves across the United States which was adopted by the U.S. Environmental Protection Agency (EPA) as an official climate indicator, featured on the EPA’s Climate Change Indicators website.

That resource no longer exists. In December 2025, the EPA removed at least 80 climate-related webpages, including the Climate Change Indicators section that housed data on heat waves, coastal flooding, wildfires, snowfall, and droughts. Whatever you think about the politics, the removal took a widely used, taxpayer-funded reference — built on official data and years of careful analysis — offline.

So I build a new and much better extreme weather and climate change dashboard, which I am releasing today.

The THB US Extreme Weather and Climate Change Dashboard

The THB US Extreme Weather and Climate Change Dashboard follows the Intergovernmental Panel on Climate Change’s (IPCC) framework for detecting a change in climate in the context of internal variability. The dashboard tracks 32 variables across 7 types of extremes: heat waves, tornadoes, flooding, drought, winter storms, wildfire, and hurricanes.

THB Extreme Weather Dashboard

A few principles guide the project:

It relies on official data. The underlying records come from authoritative government and scientific sources. The dashboard presents the observational record based on the best available data.

It respects the limits of the data. The site presents data only for the full range judged of sufficient quality for trend analysis. Users are empowered to explore the data over different time windows. Data and figures can be easily downloaded.

It places the data into the context of the IPCC AR6. The dashboard follows the IPCC framework for detection and attribution and explains how the information presented is or is not consistent with the most recent assessment of the IPCC Working Group 1.

Detecting a change in climate demands long records, attention to data quality, and an understanding of historical variability. The dashboard empowers users to look at the data themselves.

Use this page to:

• learn the facts on trends in extreme weather in the U.S.,

• hold the media accountable,

• find graphs and data to share online,

• elevate your game in debates about climate,

• and to jst explore some wonderful data from outstanding scientists and important organizations about this wonderful, complex world we share.

Long-overdue

From one perspective, this dashboard updates our 1999 paper in which Ken Kunkel, Stan Changnon, and I sought to integrate data and research on trends in the extremes with the greatest societal impacts. The dashboard takes that same approach across seven phenomena and 32 variables, using the records we have now instead of the records we had then.

That paper took a few years to complete — Using AI tools, I built this one in less than a month (again, thanks to Ryan Maue for the education!).

I am surprised that no such dashboard exists. The U.S. National Climate Assessment, with far more resources than I have available, could have created an ongoing, browsable set of extreme-weather indicators that anyone can explore. So could any number of research groups and agencies. Yet as far as I can tell, no one has.

So I built it myself.

An invitation

This project remains a work in progress. I plan to add variables, refine sources, fix mistakes, and improve the presentation in collaboration with the readers of THB. If you spot an error, know of a better data source, or think a phenomenon deserves an indicator it lacks, tell me.

Next up — a global dashboard!

Suggestions welcome!

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The image above shows global tropical cyclone landfalls from 1980 through 2020 — via the IBTrACS global best-track data — and plots the difference between the two ENSO phases. Blue indicates coasts where more storms make landfall during the La Niña phase and red shows coasts where El Niño has more landfalls — the darker the shading the wider the gap between phases — using NOAA Climate Prediction Center ONI v5 ENSO index.

For the Caribbean, Central America, and U.S. Gulf and East coasts, the La Niña phase has about twice as many landfalls as during El Niño — 2.1× across the basin and 1.4× along the U.S. coastline. The Northwest Pacific — including the Philippines, China, Japan, and Korea — and the eastern Pacific toward Mexico and the South Pacific islands have more landfalls during the El Niño phase.

El Niño means fewer Atlantic hurricanes. But worldwide, El Niño years have more tropical cyclone activity. Today’s post explores what the emerging El Niño means for tropical cyclone activity and what it implies for U.S. damage potential.

1. What happens in the Atlantic

William Gray1, of Colorado State University, established the core dynamical understandings in the 1980s: During El Niño, warm water in the central and eastern equatorial Pacific drives an atmospheric response that strengthens vertical wind shear over the tropical Atlantic, and shear makes it difficult for developing storms to grow stronger. During La Niña the pattern flips: shear is reduced and the Atlantic main development region is more active.

Accumulated Cyclone Energy (ACE) is a metric that integrates tropical cyclone frequency and intensity, and the figure below shows that ACE values in the Atlantic are generally higher during the La Niña phase than El Niño — but that does not completely rule out the possibility of a very active El Niño year or an inactive La Niña year.

From 1950–2025, the median North Atlantic season had ~129 units of ACE in La Niña years versus ~79 in El Niño years — a ratio of ~1.6×. Neutral years fall in between, at ~97. For major hurricanes La Niña seasons average ~3.6 annually and El Niño seasons average ~2.0.

The figure above shows ACE for 1950 to 2025, shaded by ENSO phase. Most El Niño Atlantic seasons fall below the long-term ACE median of 99.4, but not all do, and vice versa for La Niña.

2. U.S. damage: updating our 1999 analysis

In 1999, Chris Landsea and I published a paper in the Bulletin of the American Meteorological Society, “La Niña, El Niño, and Atlantic Hurricane Damages in the United States.” We assessed U.S. hurricane losses normalized to 1997 values according to ENSO phase and we found a strong relationship — La Niña years had much more normalized losses.

The figure above updates our analysis through 2025, and shows that our original findings have stood the test of time. In fact, the relationship is even stronger than that which we documented in our initial analysis.

• The median La Niña year has ~$12 billion in damage versus ~$2 billion for the median El Niño year — a factor of six difference.

• La Niña years have losses above $10 billion about 52% of the time versus 29% for El Niño years, a 1.8× gap, about what we reported in 1999.

ENSO shifts the odds without removing the possibility of extreme losses. Also, about 40% of years are neutral, also with large variability in losses. A very large loss year can strike in any ENSO phase when a major hurricane meets an exposed coast.

3. The global picture

Summing all six tropical cyclone basins, the median global season generates more ACE in El Niño years than in La Niña years — about 29% higher. El Niño does not merely relocate the planet’s storm energy; it raises the total — led by the Western Pacific, which is responsible for ~40% of global ACE across years.

An El Niño therefore has both a strong Atlantic signal and a strong Pacific signal, but in different directions.

Our 1999 paper covered only U.S. losses, but it turns out those losses are a big part of the global story. The figure below shows that global insured losses are significantly influenced by whether or not the U.S. mainland experiences a major hurricane that hits a populated region.2

Significantly, at the global level, El Niño has more tropical cyclone activity but global economic losses are generally higher in La Niña years.

Where storms hit matters more than how many or how strong. The Pacific generates most of the world’s cyclone energy, but landfalls there cross coastlines with far lower insured values than the U.S. Gulf and Atlantic coasts. So global losses follow the Atlantic ENSO signal, not the global pattern.

The figure above shows that separating years by whether a major hurricane struck the U.S. coast reveals a huge insured loss difference: U.S. major hurricane landfall years have a median insured loss of ~$119 billion; non-landfall years have about ~$47 billion — about a 2.5× difference.

The five costliest years — 2017 (Harvey, Irma, Maria), 2024 (Helene, Milton), 2022 (Ian), 2011, and 2021 (Ida) — all featured major U.S. landfalls, and four of the five were La Niña years.

4. What to expect for 2026?

NOAA has issued an El Niño Advisory, and forecasters expect the event to strengthen into winter, perhaps into a very significant El Niño event.

The Atlantic hurricane season thus far has been mostly dormant: Through 27 July, the Atlantic has produced 2 named storms, no hurricanes, and about 5.3 units of ACE — about 35% the typical year-to-date.

The rest of the world is well above the long-term average with global ACE at about 365 units year-to-date, about 29% above the 1980–present average — and growing fast. A quiet Atlantic and busy Pacific is exactly what the data record would lead us to expect.

If El Niño deepens through the August–October Atlantic hurricane season peak, as expected, history suggest that odds shift toward a below-average U.S. damage season with about a two-to-one chance of a sub-$10-billion loss year. A strong El Niño could see very low U.S. losses — as in 1982 and 1997, years with significant El Niño events.

In contrast, 2004 — an El Niño year, but with 4 hurricane landfalls in Florida (and 3 of them major) causing more than $100 billion in normalized losses — showed that an exposed coast can experience a catastrophic year in any ENSO phase. ENSO changes the odds, but does not eliminate risk.

For decision-makers who act on probabilistic information — reinsurers and commodity brokers among them — a developing strong El Niño has a signal in the Atlantic basin with economic value. However, for anyone on an exposed coastline, in any basin, don’t let your guard down, a big one could hit in any year.

Data sources and references: North Atlantic and global tropical cyclone activity from NHC/CPHC HURDAT2 and JTWC best tracks, via global-tropical-cyclones.com (through 27 July 2026). Global landfall maps from IBTrACS v04r00 (NOAA NCEI), all basins, 1980–2020. Normalized U.S. hurricane damage from Weinkle et al. (2018), extended through 2025 (2024 dollars), building on Pielke and Landsea (1998) and (1999). Global insured catastrophe losses from Swiss Re sigma and Munich Re NatCatSERVICE annual reviews (nominal USD, 2010–2025). ENSO phase by August–September–October Oceanic Niño Index (ONI v5). ENSO status from the NOAA Climate Prediction Center; 2026 Northwest Pacific context from Munich Re. References: Pielke, R. A., Jr., and C. W. Landsea, 1999: La Niña, El Niño, and Atlantic Hurricane Damages in the United States. Bulletin of the American Meteorological Society, 80, 2027–2033. Camargo, S. J., and A. H. Sobel, 2005: Western North Pacific Tropical Cyclone Intensity and ENSO. Journal of Climate, 18, 2996–3006.

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In early February 2020, four virologists — Kristian Andersen, Eddie Holmes, Robert Garry, and Andrew Rambaut — told each other and Anthony Fauci — then director of the National Institute of Allergy and Infectious Diseases (NIAID) and member of President Trump’s just-created Coronavirus Task force — privately that a lab origin for SARS-CoV-2 looked plausible.

Weeks later the same group published a paper — “The Proximal Origin of SARS-CoV-2,” hereafter Proximal Origin — declaring flatly that “we do not believe that any type of laboratory-based scenario is plausible.”

That paper became the authoritative justification for treating the lab-leak hypothesis as a conspiracy theory and settled science. Fauci and NIH director Francis Collins promoted Proximal Origin from the White House to quash debate over COVID_19 origins, without ever disclosing that they helped set the paper in motion.

Here at THB, I’ve previously discussed the email trail that shows this gap between private doubt and public certainty forming in the first two weeks of February 2020, before anyone drafted the paper.

What happened after publication remained murkier — did the authors’ doubts fade as real evidence came in, or persist while the group kept defending the paper in public?

This week, Senator Rand Paul (R-KY) released two new batches of the group’s Slack messages — first batch (AM drop) and a second batch (PM drop} — spanning April 2020 through September 2021, with incredible details of how doubt never faded for the Proximal Origin gang, despite their public expressions to the contrary.

Whatever the origins of COVID-19, we know with certainty that there was a concerted effort to cover-up the possibility that COVID-19 may have emerged from a research-related incident. Let’s dive in . . .

A quick primer for anyone catching up

SARS-CoV-2’s spike protein contains a furin cleavage site, a short genetic insertion that helps the virus enter human cells. No other close relative found in nature carries one at that exact spot, which made it a focal point of the origins debate from the start.

Scientists on both sides agree the insertion looks unusual: they disagree about whether evolution might produce it, or if instead it required a lab to intervene.

Proximal Origin argued for the former and dismissed the latter.

“[Baric] would be really in the cross-hairs without [Proximal Origin]”

The details discussed below come from this week’s Slack release, and add significant new context and details.

In a May 1, 2020 exchange, Andersen tells Holmes about a conversation he had with Ralph Baric, who then ran one of the world’s most prominent coronavirus labs at the University of North Carolina. Baric’s group specializes in the exact kind of research at the center of the origins debate: taking coronaviruses found in bats and modifying them in the lab to test whether they can infect human cells.

On what Andersen calls a “White House committee call” in “early January” 2020 — one of the government-convened scientific advisory calls set up in the earliest days of the outbreak, before most of the world grasped its scale — Andersen had predicted two things about the new virus: that its receptor-binding domain (the part of the spike protein that grips onto human cells) would bind unusually well to human receptors, and that its furin cleavage site would turn out biologically active.

Baric brushed him off. Andersen recounts it this way: “He essentially said that was all bullshit and I couldn’t possibly know” (Andersen, Slack messages, PM drop, May 1, 2020). Four months later, after research had confirmed both predictions, Andersen commented to Holmes about Baric’s dismissal: “Well.”

That exchange quickly shifted from Andersen’s victory lap to comments far more significant: Holmes tells Andersen that Proximal Origin “did him a MASSIVE favour” — “him” meaning Baric — and adds:

“He would be really in the cross-hairs without it” (Holmes, Slack messages, PM drop, May 1, 2020).

Andersen agrees, and mentions that a co-author on one of Baric’s papers — a 2015 study Baric ran with the Wuhan Institute of Virology that spliced a bat-virus spike protein onto a lab-adapted coronavirus backbone specifically to test its ability to infect human cells (Menachery et al., Nature Medicine, 2015) — had emailed him the day before to thank him for writing Proximal Origin (Andersen, Slack messages, PM drop, May 1, 2020).

In other words, the authors understood in real time that their published conclusion — that no lab could plausibly have made this virus — doubled as protection for a specific colleague whose own published techniques might have otherwise come under greater scrutiny. Further, the authors were being lauded by colleagues who might have been in “the cross-hairs” for writing the paper.

Five days later, on May 6, 2020, the group faced a version of that same scrutiny itself. Holmes learned that The Daily Telegraph, a British newspaper, intended to publish a story claiming he worked “in the pay of China” (Holmes, Slack messages, PM drop, May 6, 2020) — implying a financial motive behind his public dismissal of the lab-leak theory. Holmes told the others he’d received no such money. But he added a line that undercuts the group’s public position more than it defends him:

“the irony is that we were some of the very first people to actually raise the lab escape issue, although I obviously can’t say that” (Holmes, Slack messages, PM drop, May 6, 2020).

Andersen followed with agreement on that point:

“we were the first to take this seriously — and so we did. And our conclusions are solid and, importantly, stick 100% to the science” (Andersen, Slack messages, PM drop, May 6, 2020).

In public they were taking credit for dismissing the notion that COVID-19 may have come from a research-related incident, while in private they were taking credit for being among the first to assert its plausibility.

May–June 2020, just after Proximal Origin, doubt continues

By May 12, 2020, eight weeks after publication, Holmes asks Andersen and Garry for their

“latest thinking about whether any lab manipulation would involve cell culture or live animal passage” (Holmes, Slack messages, PM drop, May 12, 2020).

Andersen answers:

“I’m starting to worry about cell culture again because of some of the things we’re noticing in the cell culture sequencing experiments” (Andersen, Slack messages, PM drop, May 12, 2020).

He lists three concerns:

• the furin site repeatedly appears and disappears depending on tissue-culture conditions;

• a bovine coronavirus picked up an identical-length furin insertion through tissue culture alone;

• and SARS-CoV-2 itself kept acquiring similar short insertions elsewhere in the spike, but only in culture (Andersen, Slack messages, PM drop, May 12, 2020).

A month later, on June 11, the doubt sharpens. Andersen tells the group:

“some smoking(ish) guns starting to appear that I’m not comfortable with,” and points out that the furin insertion sits exactly where earlier lab experiments on a related coronavirus inserted one experimentally (Andersen, Slack messages, AM drop, June 11, 2020).

In the same message he goes further (emphasis in original):

“we really don’t have any hard evidence one way or the other... we also can’t rule out that somebody actually put it in there. That’s obviously not to say that somebody did, but we can’t rule it out” (Andersen, Slack messages, AM drop, June 11, 2020).

Then, about Proximal Origin’s central conclusion:

“Our paper was pretty strong in saying ‘there’s no way’ — I have less confidence in that statement at this stage” (Andersen, Slack messages, AM drop, June 11, 2020).

The lead author of the world’s most influential lab-leak rebuttal privately walked back its headline claim, just three months after publication, while the paper was being used in public to argue that the COVID-19 origin was settled science.

The same thread has Andersen noting that the paper mistakenly described risky low-containment coronavirus culturing as happening “all over the world,” when in actual fact it concentrated almost exclusively at the Wuhan Institute of Virology (Andersen, Slack messages, AM drop, June 11, 2020).

By the end of the conversation the four scientists traded private odds on lab origin:

• Holmes at 80/20 against,

• Andersen at 70/30,

• Holmes later revising to 90/10 (Andersen and Holmes, Slack messages, AM drop, June 11, 2020).

Months after publicly ruling out a lab origin, the authors debated it privately as a real and significant possibility.

Other scientists raised the same red flags

The new messages also show the group fielding legitimate technical pushback from outside their circle — echoing comments they had made amongst themselves — and dismissed those critiques rather than engaging.

On May 22, 2020, a BBC correspondent forwards a detailed critique from an anonymous molecular biologist:

“It is the acquisition en masse of these 4 key new residues and nothing in flanking sequences that raises the distinct impression that someone deliberately inserted these 4 residues in one step... there is absolutely none — all the residues on each side are identical — this is what is so concerning.” (unnamed critic, quoted in Andersen, Slack messages, PM drop, May 22, 2020).

He asks whether investigators should independently examine WIV’s records. Andersen’s private reply: “’Molecular biologist’ — my arse... I think we know who this is,” (Andersen, Slack messages, PM drop, May 22, 2020). He decides it doesn’t deserve an answer.

Three days later a second scientist raises a parallel, more technical point:

“The furin cleavage site insert has the unusual codon usage for the RR dimer of CGG-CGG... most laboratory use optimized codon primers and kits use CGG routinely; including in primers in published papers from the Wuhan Institute of Virology.” (unnamed critic, quoted in Andersen, Slack messages, PM drop, May 25, 2020).

Andersen calls part of it “pure bs” and moves on (Andersen, Slack messages, PM drop, May 25, 2020). Both comments anticipate arguments the group makes to each other in private within weeks.

September 2021: reverse-engineering the DEFUSE proposal

More consequential material comes from September 2021, after DRASTIC and The Intercept published a leaked 2018 grant proposal — DEFUSE — that EcoHealth Alliance submitted with the Wuhan Institute of Virology and Ralph Baric’s UNC lab. The proposal, written before the pandemic, expressed an intent to insert furin cleavage sites into bat coronaviruses.

Holmes’s reaction, on September 21, does not mince words:

“We still have no evidence for SC2 in that lab and they must have sequenced it first. But it is very striking that a bat-derived CoV with an FCS turns up in a city that was on a grant proposing to muck around with FCSs in bat-derived CoVs” (Holmes, Slack messages, AM drop, September 21, 2021).

Holmes calls the central coincidence of the whole lab-leak hypothesis “very striking” in private, eighteen months after publicly ruling one out.

Once DEFUSE became public, Andersen, Holmes, Garry, and Rambaut reconvened to check whether its methods could explain SARS-CoV-2’s furin site.

In the messages, Andersen lays out a formal work plan to explore that possibility: spike-protein alignments, flagging the grant’s described sites, codon-usage analysis to determine whether the insertion looks designed or natural (Andersen, Slack messages, AM drop, September 21, 2021).

He and Rambaut debate cloning strategy and which codons a lab would plausibly pick if engineering the site deliberately (Andersen and Rambaut, Slack messages, AM drop, September 21, 2021).

Nearly a year and a half after publishing a paper ruling a lab origin implausible, its authors privately ran a forensic check on whether people they knew, using a grant they knew about, had built the virus.

The clearest sign of what drove this exercise comes from Rambaut himself, at the start of that morning’s exchange:

“It really isn’t beyond plausibility that someone went ahead and tried some of this stuff. We just need to re-convince ourselves it is coincidence” (Rambaut, Slack messages, AM drop, September 21, 2021).

This doesn’t sound like a scientist following evidence wherever it leads.

What follows undercuts one of the strongest public claims against a lab origin. Proximal Origin and its authors have repeatedly pointed to the furin insertion sitting “out of frame” as evidence against deliberate design — a lab-made insertion, the argument goes, would look cleaner.

In this exchange, Rambaut and Andersen work through how a lab could produce exactly that messy, “natural-looking” signature on purpose. Rambaut poses a key question:

“Key question is — would anyone chose to put the FCS we see in SC2 in and put it out of frame”? (Rambaut, Slack messages, AM drop, September 21, 2021),

He then provides one answer:

“The alternative is that it was inserted in frame and then mutated to make it look out of frame” (Rambaut, Slack messages, AM drop, September 21, 2021).

Andersen adds a second, more technical route:

“if the use restriction enzymes and there would be an easy way to insert an FCS with PCR utilizing REs already present in the sequence, then it could be a way to do it. Not the optimal way, for sure, but sometimes ease trumps perfection” (Andersen, Slack messages, AM drop, September 21, 2021).

None of this shows SARS-CoV-2 came from a lab.

But it does show that the Proximal Origin authors, eighteen months after publication, treated “out of frame” — one of the specific technical points used publicly to rule out engineering — as something a real lab could plausibly produce using ordinary methods.

Right after Andersen proposes an investigation to explore if the virus’ furin site matched what DEFUSE’s methods would have produced, Rambaut writes:

“And stay off email.”

Then:

“Or carefully curate some emails for the FOI records” (Rambaut, Slack messages, AM drop, September 21, 2021)

These suggest intent to keep their discussions out of any official record, using Slack and Zoom instead of email because email carries more exposure to public-records requests.

What Andersen told Congress was completely different

Andersen later testified under oath before the U.S. Congress. At the July 11, 2023 House Select Subcommittee hearing, he told members:

“By the time we published our final version of Proximal Origin, however, I no longer believed that a ‘culturing’ scenario was plausible” (Andersen testimony, House Select Subcommittee on the Coronavirus Pandemic, July 11, 2023).

He described the zoonosis conclusion as something that

“has only been further supported by additional evidence and studies” ever since, and added that “currently, no such evidence exists” that would justify revisiting that conclusion (Andersen testimony, House Select Subcommittee on the Coronavirus Pandemic, July 11, 2023).

We now know that these statements fail to accurately convey the doubt in Proximal Origin that he had expressed to his co-authors after it was published.

Why this matters

We already knew that Proximal Origin’s conclusions didn’t match what its authors privately believed when they wrote it. These two new batches of Slack messages reveal that after the paper was published, the authors still did not believe what they had written.

When outside scientists raised the same concerns through legitimate channels, the group mocked them in private and ignored them in public, even though their critiques anticipated arguments the group made to itself. And when the group finally investigated whether their own colleagues’ grant-funded research could explain the virus’s key feature, one author’s instinct led him to keep that investigation off any record public-records law could reach.

None of this proves SARS-CoV-2 came from a lab. It does show that the public, and eventually Congress, were badly misled by a small group of scientists in coordination with officials of the U.S. government.

The effect was to reduce the chances that there would have been any high-level investigation of COVID-19 origins — as there should have been — compromising our ability to ever know the details of what might have been one of the most significant failures of science institutions in history.

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We have just released a new website that is one-stop shopping for official data on tropical cyclones and climate. The project is a collaboration with Ryan Maue, who is teaching this old dog some new tricks. If you do not follow or subscribe to Ryan’s fantastic weather site, you should (check these out).

The site is Global Tropical Cyclones and can be reached by clicking the button below.

Global Tropical Cyclones

Global Tropical Cyclones is the first of what will be a growing number of data dashboards available here at THB — which you can access from the menu bar at the top under THB Data Dashboards.

Global Tropical Cyclones tracks storm counts by intensity, Accumulated Cyclone Energy (ACE), and more across all six ocean basins and globally, drawing on the operational best-track data from NHC, CPHC, and JTWC via IBTrACS.

The site updates daily with year-to-date totals compared against 1980–present averages, and offers storm rankings, annual rankings, basin-by-basin running totals back to 1966. The site also includes a dedicated climate change section putting current activity in historical context, drawing upon the IPCC AR6 and GFDL.

The site includes a daily briefing on tropical cyclone activity year-to-date and a monthly briefing with the latest on hurricanes and climate change.

It's built for anyone who wants the underlying numbers on tropical cyclone activity rather than headline-driven claims about them. Check it out!

Comments and suggestions welcome!

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Consider how prominent voices in the climate discussion describe the link between fossil fuels and extreme heat:

• World Weather Attribution claims that scientists can now “predict how heat waves will grow more frequent and intense unless emissions are cut drastically.”

• A climate scientist, David Faranda, argued that to prevent severe early-season heat across India and Pakistan: “The only sustainable solution is to stop burning fossil fuels and reduce emissions.”

• UN Secretary-General António Guterres, in his Call to Action on Extreme Heat, agreed: “To tackle the root cause, countries must phase out fossil fuels — fast and fairly.”

Such claims are ubiquitous: fossil-fuel emissions are framed as a control knob for extreme weather, and turning the knob down will reduce the incidence of weather extremes. In fact, much of climate advocacy is grounded in claims that climate change causes undesirable weather and the solution therefore must be to quickly transition off of fossil fuels.

Today’s post takes such claims seriously and explores the science behind them in the context of European heat waves.

Could decarbonization actually increase European heat?

Recall the causal structure from Part 1. Atmospheric circulation generates a heat wave and dry soils, brightened skies, warmer upwind seas, and city surfaces make it hotter. Greenhouse gases raise the energy in the climate system but do not cause the weather. Cutting carbon dioxide therefore acts on one input only, and slowly: soil moisture, jet-stream patterns, and the heat already stored in the Mediterranean and the Atlantic do not respond to an emissions cut the way a room responds to a thermostat.

Part 1 also discussed the hypothesis that cleaner air drove a large part of Europe’s rapid summer warming since 1980: as sulfate pollution fell, more sunlight reached the surface, adding about half a degree of regional warming (Schumacher et al. 2024) and possibly reshaping circulation patterns toward conditions more favorable for heat waves.

If that hypothesis is correct, then reducing the burning of fossil fuels, and thus carbon dioxide emissions, would also contribute in the near term to increased heat waves in Europe: Stopping the burning of coal, oil, and gas also reduces particulate pollution. Those aerosols mask some warming by reflecting sunlight. Globally, aerosol cooling offsets a substantial share of greenhouse warming; removing the aerosols unmasks that warming. In some projections, the near-term warming from reducing aerosols rivals the warming avoided by cutting the carbon dioxide itself (Palazzo Corner et al. 2023).

The point here is not against cutting carbon dioxide emissions. It is against claiming that reducing those emissions is a solution to Europe’s heat waves as cutting emissions might not deliver what is promised.

When would we detect the effects of reducing emissions?

Let’s assume that the world achieves net-zero carbon dioxide emissions: When would we detect the effects on climate?

The scientific literature provides a clear answer: not soon. Tebaldi and Friedlingstein (2013) found that even under an assumption of strong mitigation, a change in the global mean temperature trajectory might not be detectable until later this century (e.g., “up to 60 y[ears] for RCP4.5 vs. RCP2.6”). At the regional scale the time of emergence of the impacts of mitigation on climate would necessarily be longer than at the global scale. For extreme events, longer still.

For European heat waves under strong mitigation policies: When would European heat wave frequency stop climbing, and when might they turn down?

A sensitivity analysis of a modeled climate under net-zero carbon dioxide emissions — and no other changes to forcings, including aerosols — finds that heat extreme frequency over Northern Hemisphere land might be reduced by 40% over a century following reaching net-zero (Cassidy et al. 2023):

Land-based hot temperature extreme frequencies are projected to decrease as much as 40% within the century after net zero CO2 emissions, with largest reductions over land in the Northern Hemisphere. Reduction in land-based local monthly temperature extreme frequency within only a century after CO2 emissions cessation is a promising result, as heat extremes can have severe infrastructural impacts and can lead to loss of life.

We can take these idealized numbers and perform a quantitative thought experiment. The figure below shows the same data that I shared in Part 1 — European heat wave days have increased since 1950 — as the dark blue bars.

I assume that the increasing trend of 2.6 more heat wave days per year continues until 2060, when I assume that the world hits net zero. At that point I assume a reduction in the number of heat wave days of 40% over the following 100 years (to 2160), following Cassidy et al. 2023. For the entire projected time series of 2019 to 2160 I have included random variability of the same magnitude as in the data from 1950 to 2018.

The thought experiment illustrates clearly why reducing emissions — even to net zero by 2060 — is not a “solution” to heat waves. In this idealized example, mitigation does have benefits in the form of reducing heat wave days over the century after reaching net zero. Yet, at the same time there would be no detectable reduction across the lifetimes of anyone alive today. Even in 2160 the number of European heat wave days (~20 per year) would be similar to that of the 2020s (~20 per year). And in reality, net-zero by 2060 is a questionable assumption.

This gets to a core challenge of framing mitigation as weather control — the time scale of promised benefits, even in the best of cases, is far, far longer than the time frame for the costs of action. Aligning costs and benefits closely in time makes good political sense, in most any policy context — but it also means leaving behind promises of better weather through climate policy. I do wonder if climate advocates are too vested in such promises to ever leave them behind.

This thought experiment does not include the possibility that unmasked aerosols might act to increase heat wave days following net zero or that internal variability is larger than suggested by the period covered by the original time series. Other literature suggests that the climate system response to achieving net-zero is more complex than just a reversal of changes leading up to net zero (see, e.g., Smith et al. 2025 and King et al. 2025).

Such possibilities mean that the thought experiment here might be unrealistic in assuming that carbon dioxide emissions reduction is actually a “control knob” for heat wave days. But even under this scenario, reducing carbon dioxide emissions does not fundamentally change the nature of the heat wave problem facing Europe.

So what would accelerated decarbonization actually do?

Getting to net zero still makes sense even though it is not a solution to heat waves or other extreme weather events: Achieving net zero would halt the growth of the greenhouse gas contribution to the Earth’s energy imbalance. On that basis alone, seeking to accelerate decarbonization makes good sense — something I’ve argued for decades.

Of course, emissions reductions necessarily will take place in the broader context of costs and benefits, a topic that goes far beyond the scope of today’s post (but have a look at The Climate Fix for much more!)

The fact that carbon dioxide is not an extreme weather control knob does not weaken the case for reducing emissions. But it does mean that many climate advocates are justifying their calls for net zero based on a false promise — that emissions reductions will improve the weather.

As I argued in Part 1, there are far better justifications for accelerating decarbonization than trying to convince people that climate change causes bad weather. Selling emissions cuts as a solution to bad weather not only misstates the science; it makes a policy promise that can’t be kept.

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Back in April, THB broke the news to the world that the only three official reference scenarios used for the past 15 years in much of climate research, assessment and policy had been retired. The CMIP71 conclusion that RCP8.5, SSP5-8.5, and SSP3-7.0 were “implausible” was huge news.

Today, I share more big news about how official climate scenarios continue to evolve.

CMIP7 has just published the final versions of its new scenarios as they have emerged from integrated assessment models (IAMs), updating the placeholders that accompanied their April announcement. The final versions — once again — dramatically reduces the cumulative carbon dioxide emissions from fossil fuels from the April placeholders.

The table below shows just how large these changes are in gigatons (Gt) of carbon dioxide emitted from the burning of fossil fuels to 2100 — both in terms of the highest cumulative emissions across the scenario set (in the first bullet below) and in terms of the scenarios designated as reference or current policy (second bullet below):

• SSP5-8.5, 7,380—> CMIP7 HIGH 1.0, 4,349—> CMIP7 HIGH FINAL, 3,438

• SSP5-8.5, 7,380—> CMIP7 MEDIUM 1.0, 3,098—> CMIP7 MEDIUM FINAL, 2,528

The bar chart below shows just how large the reduction of projected emissions has been.

You can see in the table above that each integrated assessment model associated with each new scenario has been identified, however, the ability to share the details of each scenario awaits the publication of those IAM runs and associated papers. ScenarioMIP explains that this embargo holds until September 1:

The data can be used only for scientific purposes aimed at the production of peer-reviewed publications. The posting of the scenario data and/or analyses based on the data on social media or other dissemination (in the public or the press) is thus strictly prohibited.

I will of course respect this embargo and this post — and any other discussions of the new scenarios here at THB — will rely only on the publicly available data archive accompanying Van Vuuren et al. 2026.

Based on the publicly available data accompanying the CMIP7 paper describing the new scenarios, I can provide an analysis of the new scenarios based on Pielke et al. 2022.

The figure below shows the annual trajectory of emissions for the retired reference scenario SSP5-8.5, along with several of the new CMIP7 scenarios. CMIP7 HIGH is intended not as a reference, but as an exploratory scenario assuming increased greenhouse gas emissions, “resulting from deep political, technological, and structural deviation from current trends.”

The figure below — based on Pielke et al. 2022 — shows how the new CMIP7 scenarios compare to the AR5/SSP scenario database in terms of cumulative carbon dioxide emissions and implied 2100 global average temperature. Note that these temperature estimates are from the emulator used by Van Vuuren et al. 2026, and have yet to be run in earth system models, so are preliminary.2

For the MEDIUM scenario, CMIP7 explains:

The Medium emission scenario is a benchmark that shows the consequences of the current policy situation (as of 2025) and trends continuing over the century. In the scenario, it is assumed that policy effort is continued at the current level. As for other scenarios, also this scenario should not be considered as a “most likely” scenario.

For the MEDIUM-to-LOW scenario CMIP7 explains:

The Medium to Low emission scenario describes a future in which strengthened mitigation efforts are delayed, falling short of the levels required to meet the objectives of the Paris Agreement. . . . The underlying logic of the scenario is that political constraints limit rapid near-term action; however, these lessen over time as the magnitude of observed climate impacts increases and mitigation costs decline with technological progress.

While MEDIUM is the only scenario framed as “current policy” in the CMIP7 set — at 3C in 2100 — it sits above other “current policy projections,” which you can see in the table below. In addition, the MEDIUM-to-LOW scenario at 2.3C in 2100 is just about at the lower end of the projections that assume that national pledges are met.

Thus, the range from MEDIUM-to-LOW to MEDIUM — with medians of 2.3C to 3.0C in 2100 — can serve usefully as the equivalent of a baseline or reference range. The HIGH scenario, at ~3.4C in 2100, is explicitly designed as an exploratory scenario to illustrate a world in which policies are adopted that increase emissions. CMIP7 explains:

Clearly, this scenario is not a “business-as-usual” scenario nor the no-policy reference scenario for the other scenarios.

This point needs to be emphasized. HIGH is not a baseline or reference scenario and should not be treated as such. I’m sure this warning will be ignored by some.

What is the significance of the new emissions scenarios? Some thoughts:

• The massive scale-back of projected future carbon dioxide emissions means, all else equal, less future changes in climate;

• As a consequence, there will surely be enormous political pressures placed on the climate science community to create projections with greater changes in climate, based on factors other than carbon dioxide emissions;

• If so, then we should expect significant challenges to scientific understandings that have long been stable, such as related to the carbon cycle, climate sensitivity, aerosols, and other greenhouse gases;

• Any such evolution of understandings may well be scientifically justifiable and legitimate, but a political overlay will create challenges;

• Meantime, tens of thousands of studies reliant on the implausible scenarios need to be reconsidered carefully, as the new reference range undershoots the 4.5 scenarios that were often presented — and misrepresented — as climate policy success;

• The range from MEDIUM-to-LOW to MEDIUM spans ~4.1–5.7 W/m², so the current and pledged policies range now sits below what RCP4.5 was presented as achieving with aggressive policy;

• None of this affects the huge magnitude of the challenge of accelerating the decarbonization of the global economy, which is not affected by scenarios;

• Climate research, assessment, advocacy, policy, and politics all need to catch up to the altered view of the climate future.

However things evolve, climate science and policy are now in a new era.

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Paid subscribers can find sources and data for the figures and tables in the Excel file below.

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The image at the top of this post is real — not AI. It shows the Earth as a thermostat with the message: “You Control Climate Change.” The 2006 PR campaign was developed by the European Commission — in the words of European Commission President José Manuel Barroso — to make:

”. . . clear to which extent we all are responsible for climate change and what individuals can and need to do to limit this threat.”

In the twenty years since that campaign, the way that we discuss climate change has changed significantly. Back then “climate change” referred to an outcome, specifically, a change in the statistics of weather variables over time, consistent with the definition of the Intergovernmental Panel on Climate Change (IPCC).

Increasingly, “climate change” has morphed into an all-purpose causal explanation for extreme weather events.

For instance, over the weekend the Financial Times — in an otherwise very good article on increasing heat waves in Europe and the UK — explained that:

“[C]limate change drives more extreme weather”

Saying that climate change drives extreme weather is the equivalent of going to your doctor and having them tell you that your body’s abnormal high temperature is being driven by a fever.

Well, yes . . . but most of us would want to know what is causing the fever and then, based on an accurate understanding of causality, what might be done to address the illness causing the fever.

Nowadays, discussions of climate and climate policy are often simplified into a linear, causal chain that goes directly from fossil fuels to extreme weather.

As an explanation for the causality of undesirable weather, this causal chain might suffice for conversations with your neighbors —

— but if taken too seriously, the framework implies that we can modulate weather by reducing consumption of fossil fuels. When that framing pits adaptation against mitigation, for example, it can lead to poor policies.

This logic has been on display in recent weeks in the context of extreme heat across Europe, such as in reporting by the BBC:

Far from attacking the root causes of global-warming, [French climate] activists said, recourse to la clim [air conditioning] was merely attenuating the effects of global-warming.

And by making those effects more bearable, it distracted from the essential fight against the causes.

Not only that, but air-conditioning is often criticised by environmentalists for aggravating climate change.

This is because it requires electricity to run - and though most of France’s electricity comes from nuclear power, elsewhere it means more fossil-fuels being burned.

It is not just the media.

The simple, linear explanation for weather events and their impacts has found its way into the peer-reviewed literature. The image below illustrates what has been called “end-to-end” attribution that purports to be able to quantify how “climate change” causes both weather events and their impacts.

Does climate change cause heat waves or make them more common or more intense?

That answer then leads to an important question from the standpoint of policy: If “climate change” is not a cause of European heat waves or their intensification, then what is?

Today’s post, Part 1 of 2, takes this question on, and the answer is far more complicated and interesting than the simple story illustrated above.

The climate has changed

The increasing number of heat wave days and their intensification across Europe is well documented. The figure below shows that the number of heat wave days across Europe has risen steadily since 1950, at a rate of about 2.6 days per decade.1

Europe’s heat waves have also become more intense. The magnitude of each year's worst heat wave, from the Oliveira et al. (2022) dataset, has increased since the 1970s, as shown below.

Why have European heat waves become more frequent and intense?

The increase in heat wave frequency and intensity represents a change in climate, but to assert that “climate change” is the cause of the increase is, at best, completely circular. Let’s dig into the scientific literature for a more satisfactory and accurate set of explanations for the observed trends.

Let’s start with the IPCC. Hot extremes at the global level, including heat waves, are the extreme weather phenomena for which the IPCC has the most confidence in detected changes and their attribution to human causes.

However, the IPCC provides more nuance when discussing heat waves at the regional level. The IPCC Sixth Assessment states that trends in extreme heat observed in a particular region are influenced — sometimes modified, sometimes amplified — by factors such as soil moisture, land use, aerosols, and internal modes of climate variability:

The effect of enhanced greenhouse gas concentrations on extreme temperatures is moderated or amplified at the regional scale by regional processes such as soil moisture or snow/ice-albedo feedbacks, by regional forcing from land use and land-cover changes, or aerosol concentrations, and decadal and multi-decadal natural variability.

The IPCC is careful to add that its confidence in these regional and dynamical factors is lower than for overall global trends.

I consider the attribution of causes of increased European heat wave frequency and intensity in terms of three bins2:

• Bin 1: the direct effect of increasing concentrations of greenhouse gases, particularly carbon dioxide, in the atmosphere due to human activity, notably the burning of fossil fuels;

• Bin 2: the indirect effects of increasing concentrations of greenhouse gases;

• Bin 3: factors other than greenhouse gases.

The literature reflects the greatest confidence in the role of Bin 1 and there are areas of uncertainty, conflicting claims, and dueling hypotheses when it comes to Bins 2 and 3.

Let’s take a closer look.

What is a heat wave?

A heat wave is a weather event — a stalled weather pattern, or more technically, a high-pressure “block” or ridge that settles over a particular region. Under it, skies stay clear, air sinks and compresses (which warms it), and the sun heats the ground. This is basic meteorology, and it’s the proximate cause of every major heat wave in Europe or elsewhere. Different regional atmospheric blocking patterns produce different regional heating, which is why no two heat waves are quite alike (Sousa et al. 2018; Liu et al. 2020).

So the first thing to understand is that heat waves are made by circulation — the movement or stalling of air. Greenhouse gases do not create a heat wave. A weather pattern does.

Bin 1: The effects of increasing concentrations of greenhouse gases

Every surface — land, ocean, air — constantly radiates heat outward as infrared. Carbon dioxide, and other GHGs, absorb part of that outgoing infrared and re-emit it in all directions, including back down, which is the essence of the “greenhouse effect.” More downward infrared radiation means that the Earth’s surface and the lower atmosphere warm — and this dynamic has been directly measured over Europe. This heating is what is meant by the phrase “global warming.”

Since 1971 the Earth has accumulated roughly 380 zettajoules of excess heat, and the overwhelming majority — about 89% — has gone into the ocean, about 6% into the land, about 4% has melted ice, and only ~1% has gone into the atmosphere itself (von Schuckmann et al. 2023). So the single biggest reservoir of the energy that greenhouse gases have trapped is the global oceans.

Of the ocean’s share, about a tenth has gone below 2,000 meters, into the deep ocean, where it is sequestered on timescales of centuries and does little to influence weather. That deep heat matters for sea level.

That extra energy in the climate system heats the land, the near-surface air, and — critically — the oceans and the source regions upwind of Europe. So when a stalled high-pressure pattern occurs, it does so in a climate system that has more energy than it did decades ago. That means that normal, meteorological extreme heat events will — all else equal — be hotter than they used to be.

The first order greenhouse effect changes how much energy is in the system. It does not directly alter atmospheric circulation.

Bins 2 and 3: What else is going on?

In much of western and central Europe, summer temperatures have risen about three times faster than the global average since 1980 — faster than expected from the direct effect of the Earth’s changing energy balance. Western European heat extremes have increased at roughly 3.4°C for every 1°C of global warming, the fastest rate of any comparable region on Earth — outside the poles.

A recent decomposition attributes a substantial share of this excess warming — the part above the global rate — to changes in atmospheric circulation rather than to the direct energy-budget effect alone.

Philipona et al. (2009) identified the disparity early on:

Mainland Europe’s temperature rise of about 1°C since the 1980s is considerably larger than expected from anthropogenic greenhouse warming.

Explanations in the literature emphasize three other factors contributing to the increasing frequency and intensity of European heat waves:

Dry soils. When soil has moisture in it, the sun’s energy goes partly into evaporating that water, which cools the surface. When the soil dries out, that cooling stops, and the sun’s energy goes straight into heating the air instead. This is a large effect. Modeling studies that eliminate the soil-moisture feedback conclude that more than 70% of the extra hot-day warming in Central Europe disappears in the model projections without this feedback. Drought and heat feed each other: dry ground makes the air hotter, and hot air dries the ground further (Fischer et al. 2007; Dirmeyer et al. 2021).

Cleaner air. Starting around 1980, Europe’s air pollution was considerably reduced (Yang et al. 2020). The tiny particles in that pollution — from coal smoke and industry — used to reflect sunlight back to space, partly via clouds that were brighter and more reflective. As the pollution fell, more sunlight reached the ground (Philipona et al. 2009), with a direct warming effect on the surface, separate from greenhouse gases. Schumacher et al. 2024 estimate the resulting warming effect at about half a degree Celsius, a meaningful part of the observed warming in Europe.

Warmer seas and land upwind. The air that flows into Europe during a heat wave comes from somewhere — often over the Mediterranean, the Atlantic, or the hotter landscapes of Iberia and North Africa. All of those are warmer than they used to be, in part because the same greenhouse and aerosol changes have been heating them for decades. So the same wind that would have brought hot air decades ago now brings hotter air (Vautard et al. 2020).

Complexities. Here is where things get complicated — Drier soils and warmer seas and land are influenced by greenhouse gas warming. So there are second order processes at work.

At the same time, cleaner air is not directly influenced by greenhouse gases. There are also hypotheses that suggest that circulation changes that lead to increased blocking, and thus more heat waves, are a consequence of the drop in aerosols. So here as well there are second order processes in play.

Several studies now attribute the observed weakening of the summer jet stream — which makes weather patterns stall more often and longer — primarily to the drop in aerosols (Dong et al. 2022; Chemke & Coumou 2024; Kang et al. 2024). A 2026 study goes further, arguing that the accelerated western European warming is, to a large extent, a response to changes in aerosol forcing. If accurate, the cleanup of air pollution is warming Europe in two ways: directly, by letting in more sun, and indirectly, by making the stalling patterns that cause heat waves more common.

Both increasing greenhouse gases and reducted pollution are human effects on climate, but they operate very differently. Lumping them together as “climate change” subtracts from our understanding.

Modes of variability. An even further complication is that not all of a detected trend might indicate a change in climate — it could reflect the consequences of different modes of internal climate variability. European summer heat is affected by patterns in the ocean and atmosphere that redistribute heat without requiring any change in external forcing.3

That said, the IPCC AR6 is explicit that the heat wave trend in Europe cannot be explained without human influences:

“[D]espite strong internal variability, observed trends in European mean and extreme temperatures cannot be explained without accounting for anthropogenic factors. Before the 1980s, warming by greenhouse gases was partly offset by anthropogenic aerosol emissions. Reduced aerosol influence in the recent decades has led to an observable positive trend in shortwave radiation."

The IPCC AR6 further notes that the greenhouse effect on temperature extremes is moderated or amplified regionally by, among other things, “decadal and multi-decadal natural variability.”

How much of the recent trend in European heat extremes is due to internal variability of the climate system rather than a forced change is not fully understood, and the IPCC AR6 is also explicit on this point (emphasis added):

“Anthropogenic forcing (e.g., increases in greenhouse gas concentrations) directly affects thermodynamic variables, including overall increases in high temperatures and atmospheric evaporative demand, and regional changes in atmospheric moisture, which intensify heatwaves, droughts and heavy precipitation events when they occur (high confidence). Dynamic processes are often indirect responses to thermodynamic changes, are strongly affected by internal climate variability, and are also less well understood. As such, there is low confidence in how dynamic changes affect the location and magnitude of extreme events in a warming climate.”

The component of the trends in European heat waves resulting from changes to atmospheric circulation — that is, dynamic processes — whether forced by greenhouse gases, driven by the reduction in aerosols, a consequence of internal variability, or the interactions among all these, is where attribution is uncertain.

Urban heat islands. Heat waves are hotter in cities: Pavement and buildings warm during the day and release that heat slowly at night, less greenery means less cooling from evaporation, and narrow streets trap heat. The result is the urban heat island. During the 2003 heat wave, a modelling study of the West Midlands found that roughly half of the heat-related deaths were attributable to the urban heat island rather than to the regional heat, and across 85 European cities the urban effect raises the risk of death during extreme heat by about 45%. Cities dominate the human toll of European heat waves, because that is where the people are: about three-quarters of Europeans live in urban areas.

Complexity matters

I am unaware of any robust quantification of how much of Europe’s heat wave trend comes from greenhouse gases versus aerosols versus soil moisture versus circulation changes versus modes of variability versus cities — much less the complex inter-relationships among these various factors. What I do know is that the simple story that climate change causes heat waves is unsatisfactory.

The figure below — which better represents the real complexity — illustrates a far more nuanced set of factors that contribute to the documented trends in European heat wave frequency and intensity.

The politics of the climate issue have favored a simple story that collapses all of the complexity in the figure above into the phrase “climate change” which is typically and incorrectly oversimplified into a synonym for carbon dioxide emissions from fossil fuels. Political advocacy runs on simple descriptions of cause and effect. However, effective policy making depends on accurate understanding of causes and effects.

Let me be perfectly clear — Nothing in this post is an argument against cutting emissions. In fact, as I've often argued, cutting carbon dioxide emissions is a matter of long-run risk reduction, and on that basis alone, makes good sense. Reducing emissions is not about modulating the weather — and certainly is not a thermostat. There are far better justifications for accelerating decarbonization than trying to convince people that climate change causes bad weather.

Today’s post sets the stage for Part 2, where I explore what effects efforts to accelerate decarbonization of the global economy might have and on what time scales for future European heat waves.

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The retirement of implausible baseline climate scenarios is now starting to have real-world consequences as decision makers realize they’ve been making decisions that have had unnecessary real-world, negative impacts on their constituents and clients.

In a letter shared 1 July 2026 with local communities across New Zealand (reproduced below), the country’s Minister of Climate Change, Simon Watts, has asked public officials to reconsider using RCP8.5 and other retired scenarios in their planning decisions.

Councils, the letter states, have used these implausible emissions scenarios in a way that,

“results in unnecessary costs being imposed on ratepayers, businesses, and communities.”

The letter also instructs councils that they “should not automatically” continue to treat these scenarios

“as the central or most likely future when making decisions that affect infrastructure investment, land use, property rights, or rates.”

A first hand look at what the impact of RCP8.5 looks like in New Zealand can be seen in Managed Out, documentary on “managed retreat” from the coasts filmed before the minister's letter.

On the Kapiti Coast, residents describe hazard notations stamped onto their property files that are based on a consultant's report built on futures projected under RCP8.5. One local resident complained:

"They're using RCP 8.5 which is the most extreme outcome. House prices are on the way down, insurance prices are sky-rocketing, because they have put notations on all of our LIM reports [Land Information Memorandum, which assesses hazards] which uses the extreme modelling."

A former Wellington city councilor in the film argues that the problem lies in:

"the use of the IPCC 8.5 model that is supposed to be used only for stress-testing and not for policy-making."

These residents are experiencing the unintended consequences of the use of a scenario that scientists built originally for exploratory earth system modeling to inform global climate negotiations turning up in the price of their homes.

Using RCP8.5 to predict coastal hazards in New Zealand — or anywhere else — and thus serve as the basis for home pricing and insurance is simply a misapplication of science (that may have had valid uses in research in other contexts).

How things went cattywampus

A baseline scenario — also called business as usual or a reference scenario — is according to the IPCC, a “scenario used as starting or reference point for a comparison between two or more scenarios.”

Climate policy analyses, including cost-benefit studies, typically start with a baseline scenario as a representation of where-we-are-headed and then compare that to other scenarios in which policy is introduced within the scenario. Such scenarios are typically called policy (or mitigation) scenarios.

Such a comparison, in principle, allows decision makers to evaluate the expected effects of implementing a policy versus not implementing that policy.

Based on the IPCC’s official AR6 baseline scenarios — RCP8.5, SSP5-8.5, SSP3-7.0 — New Zealand councils had drawn hazard lines across property titles, adjusted infrastructure plans, and shifted insurance and lending exposure, with real economic consequences for New Zealanders.

Thanks to the correct decision by the CMIP7 scenario committee, we now know that all of these decisions and consequences have been based on a scenario now officially recognized as implausible.

In a recent interview with Alistair Harding in New Zealand, Detlef van Vuuren — the Dutch scientist who helped to lead the development of the 2011 RCP scenarios (including RCP8.5) as well as the new 2026 CMIP7 scenarios that officially retired RCP8.5 — was asked if it was ever a fair description of RCP8.5 and the like as business-as-usual (BAU) or a no-mitigation future.

His answer:

“No, that was always a wrong way to describe it.”

And yet, as has been carefully documented here at THB, the set of three baseline scenarios has — for fifteen years — been characterized as a BAU or baseline or reference scenarios throughout climate research and policy. That designation trickled down to land use decisions in coastal New Zealand.

Van Vuuren now says that we all got that wrong from the start.

What happened?

Confusion from the beginning

In the original 2011 paper announcing the RCPs to the world, Van Vuuren et al. 2011 (VV11) describes the four RCP scenarios in a way that has been lost to history:

• one very low mitigation scenario (RCP2.6),

• and three that its Table 4 classifies as baselines:

  • RCP4.5 a "very low baseline,"

  • RCP6.0 a "medium baseline,"

  • and RCP8.5 a "very high baseline emission scenario."

You read that right — originally, there were supposed to be three baseline scenarios, spanning a very wide range, not just RCP8.5.

As baselines, RCP4.5, 6.0, and 8.5 were meant to represent the range of baselines found across the literature on scenarios. RCP8.5 was at the upper extreme of this range and RCP4.5 was at the lower extreme — both were equally valid as baselines.

At the same time, RCP4.5 and RCP6.0 were simultaneously also supposed to represent policy/mitigation scenarios, which are not baselines. They were thus intended to fulfill two conflicting roles in representing the literature, as shown in the table below, from VV11.

But when it came time to select the specific scenarios from the IAM literature to characterize the RCPs, the scenarios actually chosen to fill the 4.5 and 6.0 slots were policy scenarios, not baseline scenarios. Thus the RCP4.5 and 6.0 scenarios had their own baselines, but they were well above 4.5 and 6.0 levels of radiative forcing. Only RCP8.5 was from an IAM baseline — a world with no climate policy at all.

You can see this in the figure below from Pielke and Ritchie 2021. Confusion is the only predictable result and that is exactly what happened.

For anyone who took the RCP pathways as they were constructed and presented, rather than as the broader range they were meant to represent as described in VV11 — the set read as a single baseline and three policy scenarios.

The only unambiguous no-policy reference in the framework was RCP8.5.

The scenario community was at the time well aware of the confusion this might cause. For instance, the image below is a slide from a presentation given by Richard Moss, another leader of the RCP development process, warning that RCP8.5 was not a reference scenario for the three other RCPs — another detail lost to history.

Despite the warning, tens of thousands of papers have been published that pair RCP8.5 as a reference scenario with the other RCPs as policy scenarios (typically RCP4.5 and RCP2.6). In particular RCP4.5 was often treated as representative of the consequences of aggressive climate policy,1 when under the RCP framework, it should have been treated just like RCP8.5 — as a baseline.

Without correction from people who knew better — which includes the many people who have participated in scenario development the entire time — the misinterpretation of RCP8.5 as the only baseline scenario in the set took off and came to dominate how the RCPs (and SSPs) have been used for the past 15 years in both science and policy.

As one unnamed Dutch scientist told De Volkskrant in 2020:

“You simply do not realize that the RCPs can start a life of their own.”

Scenarios were flawed — which is why a wide range matters

It is now widely understood that the RCP and SSP scenarios were flawed from the start, based on reliance on a narrow set of assumptions — the details of which I won’t revisit today. However, the story here is much more complicated than just that.

The figure below shows how the official scenario baseline range of CMIP and IPCC changed from VV11 (original RCP) to CMIP5 — to IPCC AR5 (2014) — to CMIP6 and AR6 (2016-2021) — to CMIP7 (2026).

Two things to highlight:

• Over more than a decade, from the development of the RCPs through IPCC AR6, the baseline scenario range became both more extreme and narrower;

• The original VV11 range largely (but not entirely) spans the new CMIP7 range.2 Were the CMIP7 update being done off of VV11, the changes would fairly be considered a slight readjustment, not the massive change that you can see from AR6 to CMIP7.

The reason that the VV11 range largely lines up with CMIP7 is not because the individual scenarios held up.

The ranges largely overlap because VV11 included a very wide range of baselines, reflecting fundamental and irreducible uncertainties and ignorance — two characteristics of our understandings of the real world that scenario planning is, in principle, designed to help us grapple with.

A wide range of assumptions is what would have allowed the 2011 framework stay useful even though RCP8.5 later collapsed.

The lesson here is that the value of a scenario set lies in the breadth of assumptions it spans, not in the correctness of any single pathway. Incorporating a range of assumptions into scenarios is the hedge against the flaws of the details of any individual scenario, because the builders cannot know in advance which of their assumptions will hold up and which will not.

Even though the implausible baselines have been retired — appropriately — it seems that the importance of a diversity of assumptions across scenarios has not been appreciated by the CMIP7 scenario creators.

Correcting course is just starting

Returning to New Zealand and the RCR Van Vuuren interview — he expresses sympathy for those in the country whose fortunes have been compromised because of the unwitting use of RCP8.5 as a baseline scenario for current land use planning and regulation (emphasis added):

If I was owning a house somewhere and there is a risk in 2150, I think it [RCP8.5] is useful information. But I would expect that my mortgage being out 30 years or so, that it would be completely unfair that the value of my property would be so much determined by something that is uncertain and way out.

Van Vuuren suggests that, from his perspective, the RCP scenarios were never really intended to be used in local decision making:

The way that I normally use these scenarios is in climate negotiations. It is quite interesting that even these rather abstract scenarios have such consequences as well in daily decisions . . .

Interesting, indeed.

The mistakes made in New Zealand in using RCP8.5 as a scenario depicting an expected future, a forecast even, is understandable as a cascade of confusion and conflicting intent for the role of scenarios in climate research. However that cascade has had material consequences for real people in real places, reaching far beyond New Zealand.

With the RCPs, the scenario community pulled four scenarios from a literature of many thousands. That literature spanned an enormous range of possible futures, and appropriately so, as the future is a fuzzy place. The small group of four scenarios was asked to do double duty — to represent futures that we might be headed to without any consideration of climate policy, and futures that required considerable climate policy interventions. The intent was to “jump start” earth system modeling, not to serve as the basis for decisions all around the world spanning the local to the global scale.

Along the way, as mistakes were made, no one spoke up or pointed out the unfolding errors of scenario design and application.

We now know — and have known since 2017 thanks to Ritchie and Dowlatabadi — that the single anointed baseline was fatally flawed. Out in the real world (as opposed to model land) RCP8.5 was variously interpreted as a projection of our most likely future or even as a forecast and thus wired into consequential decisions.

Had the climate community recommended that scenario planning be based on a wide range of baselines, from 4.5 to 8.5, some may still have chosen the most extreme of the set but others would have had the chance to consider other baselines. By considering that wide range, the recalibration of that range would have likely been less consequential than the huge change in expectations that many are now experiencing.

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The 2026 Energy Institute Statistical Review of World Energy — successor to the old BP Statistical Review, and an authoritative accounting of global energy data — has just been released with data through 2025. As I have done here at THB for years, in today’s post I update THB analyses of where the “energy transition” actually stands.

Regular readers will recognize the approach, which is based on my 2010 book The Climate Fix. At the bottom of this post you can find a methods appendix with details on the calculations, and below that paid THB subscribers will find an Excel spreadsheet with the sources and data from each graph and table. As always, this is work in progress — Caveat lector!

There is lots to discuss, so let’s get to it . . .

Carbon-free energy is growing — slowly

Let’s start with the good news for those promoting a transition away from fossil fuels. The carbon-free share of global energy consumption — nuclear, hydro, and other carbon-free generation technologies — reached its highest level ever.

That share now sits near 14% and has climbed steadily over the past decade, but slowly with respect to aggressive targets of climate policies: net-zero means going from 14% to 100%. At the pace of the past ten years, that would take centuries.

Total energy demand continues to increase, and fossil fuels have continued to meet the majority of that growth — with global fossil fuel consumption still growing as shown below.

Global fossil fuel consumption reached a new high in 2025 — about 518 exajoules. Net-zero is further away than ever. It is essential to understand that retiring fossil fuels reduces carbon dioxide emissions; simply deploying carbon-free energy does not.

The math of a 2050 net-zero target

What would reverse that fossil fuel line and move it towards zero?

Consider the arithmetic of a net-zero-by-2050 target, measured from 2025

Reaching zero by 2050 requires retiring ~21 exajoules of fossil energy every year, starting now. That annual reduction exceeds the total energy consumption of most countries on Earth. And every year the line fails to bend down, the required rate in the remaining years grows larger, just as a matter of math.

Replacing 21 EJ of fossil energy per year, and retiring an equal amount of fossil supply alongside it, means building the equivalent of about one 1.75-gigawatt nuclear plant every day from now until 2050 — roughly 420 plants a year. Measured in wind turbines instead, at 3 megawatts and a 0.30 capacity factor, that comes to about 2,000 turbines a day, every day, for 25 years.

I’ve published this analysis for years, and net-zero isn’t getting any closer — Net-zero 2050 is infeasible, by any practical standard, but that does not mean that the aspiration of net-zero is impossible.

Consider that if the net-zero target is 2075, then the implied pace of retirement and deployment is cut in half: about one nuclear plant every two days, or 1,000 wind turbines a day. As I’ve previously noted, if the world can maintain its historical pace of decarbonization (a big ask!) then the world would hit net-zero around the 2080s.

The pie chart above shows the change in total energy consumption from 2024 to 2025. You can see that carbon-free energy made up almost half the year-on-year additions. Fossil fuels still won out.

Below, the left panel extends the comparison of carbon-free to FF year-to-year change in global energy consumption back to 2010. Fossil consumption rose in every year except the pandemic year of 2020, and was outpaced by carbon-free in only one other year.

The right panel shows what is implied by a net-zero 2050 target — on average, every year to 2050: fossil energy decreases by about 21 EJ per year while carbon-free energy increases by nearly 28 EJ per year to cover both the retirements and continued demand growth

Reasonable people can argue over the exact required amounts of annual carbon-free deployment or fossil fuel retirement — it is huge regardless of the exact methods or assumptions.

Where did fossil fuel consumption increase and decrease 2024-2025?

From 2024 to 2025, the United States and China led all countries in added fossil fuel consumption, at +1.6 and +1.1 exajoules respectively — together more than the next dozen countries combined.

After the U.S. and China is a set of fast-growing developing economies: Indonesia, Türkiye, Bangladesh, and others added smaller but steady increments of fossil fuels as their energy demand continues to climb.

The countries that cut the most fossil fuel — Japan, Russia, South Korea, Colombia — trimmed only a few tenths of an exajoule each, an order of magnitude smaller than the increases at the top of the other chart.

The additions dwarf the subtractions: the largest reduction, Japan’s, would not offset even a fifth of the U.S. increase. As long as the countries adding fossil energy add far more than the countries cutting it subtract, worldwide fossil fuel consumption keeps climbing.

Decarbonization: so far, a long, straight line

The figure below shows the carbon intensity of the global economy 1992-2025 — CO₂ per unit of GDP.

The global economy has decarbonized steadily since well before climate policy existed — back to at least the 1960s.

Two things follow.

• First, global climate policy does not drive decarbonization as the decrease in carbon intensity of the global economy long pre-dates the climate movement (which started as coordinated global policy in 1992 with the Rio Earth Summit); economies growing wealthier and using more energy more productively have driven that trend.

• Second, and less comfortably: since the climate-policy era began in 1992 the background rate shows no acceleration. Hitting deep-decarbonization targets requires this straight line to bend down. It has not done so.

Some economies cut their carbon intensity by about two-thirds since 1990 — China, the United Kingdom, Germany. Others moved the wrong way and grew more carbon-intensive, led by Iran. These differences track different starting points, energy mixes, and stages of development — not the presence or absence of climate ambition.

What actually drives decarbonization?

The figure below shows a simple Kaya decomposition of global decarbonization: Carbon intensity of GDP equals the product of two factors: how much energy the economy uses per dollar (energy intensity), and how much CO₂ that energy emits (carbon intensity of energy).

Decomposing the decline shows how much each factor has contributed to global decarbonization.

The green line — the economy becoming less energy intensive per dollar of output — accounts for almost the entire decline in CO₂ per unit of GDP. The orange line — the carbon intensity of the energy that is consumed — has barely moved in 35 years, despite the impressive growth in carbon-free energy.

How much faster can decarbonization go? I will take that up in future posts.

The decarbonization rankings tables

The first table ranks the G20 economies and the world by how much their carbon intensity of GDP — carbon dioxide emitted per unit of economic output — changed from 2024 to 2025.

India and Argentina led, each cutting emissions per dollar of output by nearly 6%, followed by China and Saudi Arabia. Most major economies decarbonized, which is common: economies tend to achieve more output per unit of energy as they grow and modernize. However, others, including the United States, saw emissions growth outpace economic growth.

The world as a whole decarbonized by about 2.3% — a fairly typical rate. Compare that to deep-decarbonization targets for 2050 which imply a sustained global rate of decarbonization closer to 8-9% per year or more.

A single year, however, tells us little, since annual figures vary with weather, fuel prices, and economic cycles. The second table takes the longer view, ranking the same economies by their change in carbon intensity across the full Paris-era decade, from 2015 to 2025.

Here the leaders are the United Kingdom, Germany, and China, each having cut carbon intensity by a third or more over ten years. Only Indonesia moved the wrong way over the decade, its emissions outrunning even its rapid economic expansion. The world decarbonized by about 19% over ten years, or a little over 2% annually .

The third table asks: did the 2015 Paris Agreement bend the curve?

It compares each economy’s annual rate of decarbonization in the decade before Paris (2005–2015) against the decade after (2015–2025), and shows the difference.

A handful of economies accelerated sharply, though the largest movers — Saudi Arabia and Brazil — did so for reasons based on their own energy and economics circumstances, rather than efforts to comply with the Paris Agreement.

Global decarbonization changed little: from ~1.9% per year before Paris to ~2.1% after. China, which dominates global emissions, actually decarbonized more slowly after Paris than before, offsetting gains elsewhere.

A change in the decarbonization rate is not sufficient to prove policy causation on its own, but the lack of meaningful change at the global level is hard to square with the frequently-expressed claims that climate policy has already achieved notable success (such as we’ve been hearing related to the retirement of RCP8.5, but I digress).

Bottom line

The 2026 update is fully consistent with the pattern I have documented here year after year. Carbon-free energy is growing. Decarbonization continues its long, slow, pre-policy downward trend. Global fossil fuel consumption continues to increase. The carbon intensity of energy has barely budged, drifting downward ever so slowly. The gap between the required rate of change to hit aggressive decarbonization targets and the observed rate in the real world widens every year.

If we are to achieve deep decarbonization this century, the lesson to take is that we should start thinking about some different options for how to get there. What we have been doing isn’t working.

Comments, critique, debate, discussion — all welcome at THB!

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Methods Appendix

Energy and emissions data. All energy consumption and carbon dioxide emissions figures come from the 2026 Energy Institute Statistical Review of World Energy, which reports data through 2025. Energy uses exajoules (EJ); emissions use million tonnes of CO₂ from energy. Non-fossil energy (nuclear, hydro, and other renewables) follows the Physical Energy Content method the Statistical Review adopted in its 2025 edition, which counts non-combustible generation at its actual energy content rather than scaling it up to a fossil-fuel input equivalent. Earlier editions used the substitution (fossil-fuel-equivalent) method; the change lowered the reported carbon-free share by several points, as discussed in the post. This basis moves the level of the carbon-free share but not the direction of the trends.

Definitions. “Fossil fuels” means oil, natural gas, and coal. “Carbon-free” means nuclear, hydroelectric, and other renewables (renewables excluding hydro), so no source double-counts. “Total energy” sums fossil and carbon-free.

Carbon-free shares. The total-energy carbon-free share divides carbon-free energy by total primary energy, from the consumption-in-EJ tables.

Decarbonization and carbon intensity. Carbon intensity of GDP divides CO₂ from energy by real GDP. GDP uses World Bank GDP, PPP (constant 2021 international dollars), indicator NY.GDP.MKTP.PP.KD, which runs through 2024. Where a 2025 value applies, 2025 GDP extends from 2024 using country real-GDP growth estimates from the IMF World Economic Outlook, October 2025; these 2025 figures remain estimates, not final actuals, and carry that label. The figures index each series to a base year (1992 = 100 for the world curve; 1990 = 100 for the country series), so only ratios of GDP enter and currency units cancel.

Kaya decomposition (Figure 9). Carbon intensity of GDP equals the product of two factors: energy intensity of GDP (primary energy ÷ GDP) and carbon intensity of energy (CO₂ ÷ primary energy). Each factor and their product index to 1990 = 100. By construction the product line equals the carbon-intensity-of-GDP series in Figure 7 rebased to 1990.

Carbon intensity change table (2024–2025). For each G20 economy and the world, the change in carbon intensity of GDP comes directly from the two growth rates as (1 + CO₂ growth) ÷ (1 + GDP growth) − 1, using EI emissions growth 2024→2025 and IMF October 2025 real-GDP growth. This approach avoids constructing absolute 2025 GDP levels. The ranking runs from the largest reduction (most negative) to the largest increase.

Country selection. The top-20 emitters and the G20 come from 2024 CO₂ emissions in the Statistical Review; supranational aggregates such as the European Union drop out of country rankings.

Approximations. No values in the figures or table approximate or interpolate anything except the labeled 2025 GDP estimates described above. All emissions and energy values match the 2026 Statistical Review as reported.

Sources and data file below.

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