New Climate Report Sparks Outrage

Summary

The video examines controversy over a July report from the US National Academies of Sciences (NAS) on extreme-event attribution: estimating how climate change affects the likelihood or severity of events such as floods, heatwaves, wildfires, and hurricanes.

The speaker says critics object partly to the report’s perceived lack of objectivity and partly to the fact that some researchers involved have discussed using attribution science in climate litigation. Critics cited in the video have described the report in highly charged terms. The speaker argues that the central concern is methodological, rather than evidence of a deliberate conspiracy.

How event attribution works

Researchers define and quantify a particular weather event, then compare climate-model simulations representing conditions with global warming to simulations representing conditions without it. The difference in modeled probabilities is used to estimate climate change’s contribution to the event.

Scientific limitations raised

• Other causes may matter: Attribution can assume that global warming explains the main change in an event’s probability, even though factors such as land use and controlled burns can also affect risk, especially wildfire risk.
• Models have limitations: Some climate models may not accurately represent extreme events, making their probability estimates uncertain.
• Results depend on event definitions: Adding details to an event’s definition can make it appear less likely. With sufficiently specific definitions, the modeled probabilities in both scenarios may be effectively zero.
• Counterfactual probabilities are difficult to establish: The speaker argues that estimating whether a particular event would have occurred without climate change is mathematically ill-defined, even though climate change can affect broader trends in some types of extreme events.

The speaker says the 2016 NAS report more plainly warned that attribution results were not directly about the actual event. In the speaker’s view, the new report acknowledges that observations may not adequately validate model-based probability estimates, but does not clearly explain the underlying methodological concerns.

The speaker emphasizes that this criticism does not mean climate change is not happening, is not human-caused, or is unimportant.

Researchers, sources, and organizations mentioned

• David Zaruk — Critic of the report, described in the video as a retired professor of science communication.
• Roger Pielke — Political scientist and former professor; critic of the report.
• Judith Curry — Atmospheric scientist; critic of the report.
• Myles Allen — Researcher associated with the development of event attribution; author of a paper titled “Liability for Climate Change.”
• Friederike Otto — Climate researcher associated with World Weather Attribution; quoted discussing conversations with lawyers about attribution science and litigation.
• Steve Koonin — Critic who argues that the NAS report creates an illusion of elite scientific consensus.
• Tim Garrett — Oceanographer and retired admiral, described as having served in the Trump administration; critic of the report.
• US National Academies of Sciences (NAS) — Publisher of the report on extreme-event attribution and of a 2016 report discussed in the video.
• World Weather Attribution — Organization associated with event-attribution research.
• Bezos Earth Fund — Identified as one funder of the NAS report and a supporter of World Weather Attribution.
• E&E — Outlet for the interview with Friederike Otto cited in the video.
• Otto and collaborators — Authors of a paper cited for its assumption about the main cause of changes in event distributions.
• Twenty-five Republican state attorneys general — Said to have called for an investigation into the NAS report’s objectivity.