The National Academy of Sciences’ latest assessment of climate attribution science marks a turning point for the field, shifting the central question from whether human-caused warming drives extreme weather to how severe the impacts will become as disasters increasingly overlap.
The 14-author report, released by the congressionally chartered body that advises the U.S. government on science and technology, argues that extreme weather attribution research must evolve to keep pace with a warming world where heat waves, floods, and wildfires strike in close succession or across multiple regions at once.
From Single Events to Compound Climate Disasters
Attribution science quantifies how much human-caused global warming loaded the dice for an extreme event, making it more likely or more intense. Recent studies have concluded that the 2021 Pacific Northwest heat dome and this summer’s European heat wave — which killed more than 5,000 people — would have been impossible without human-caused warming.
Researchers compare an event’s intensity and likelihood in the current climate against a counterfactual world without human-caused emissions, drawing on observational data, climate models, and statistical analysis. The new report warns that methods built to detect a climate fingerprint in single, localized events struggle to capture compound climate disasters — what the authors call “more compounding, cascading, and record-breaking events.”
Standards and Rapid Studies Under Review
The panel calls on attribution scientists to develop shared standards for studying extreme events so independent research groups can compare and verify one another’s results — a move the authors see as essential as the field expands and rapid attribution studies are issued within days of major disasters.
It also recommends regular reviews of those rapid studies to ensure methods keep pace with advances in climate science, and it urges closer collaboration between scientists and local officials so attribution findings can inform disaster planning, recovery, and climate-loss estimates.
Confidence High for Heat, Precipitation, Wildfire Weather
At a webinar Thursday, panel chair James Hurrell, an atmospheric scientist at Colorado State University, said the field has surged since the National Academy of Sciences released its last attribution report in 2016. Improved models and a fuller record of climate measurements from Earth and satellites now place extremes in sharper historical context.
“A human influence has now been clearly detected in several important categories of extremes, including extreme heat, heavy precipitation and compound hot and dry events,” Hurrell said.
The report draws a clear line between areas of high confidence — heat waves, extreme precipitation, tropical storm intensity, and dangerous wildfire weather — and small-scale phenomena like severe thunderstorms and hail storms that remain difficult to model and lack robust observational records.
“Recognizing these limitations is not a weakness of attribution science; it is one of its strengths,” Hurrell said, adding that the research community has become “increasingly transparent” about where confidence is high and where more work is needed.
Wildfires Move From Hardest Case to Hallmark
The 2016 report described wildfires as among the hardest hazards to attribute because fire depends on a complex mix of weather, vegetation, and other factors. A decade later, the panel concludes scientists can confidently attribute the hot, dry fire weather that drives large wildfires, even as the behavior of individual fires remains complex.
The report identifies wildfires as a hallmark of compound climate disasters in a warming climate, with heat and drought fueling fires that trigger cascading impacts — smoke pollution, flooding, and landslides — long after the flames are out.
Skeptics Pushed Back, Mann Says Models May Underestimate
University of Pennsylvania climate scientist Michael Mann called the report “a clear, affirmative statement that human-caused climate change is indeed impacting the occurrence and intensity of extreme weather events” and said it refutes “the dismissive claims made by fossil fuel groups and right-wing think tanks.”
Mann pointed to a passage acknowledging “structural and observational” limitations in attribution modeling, arguing those weaknesses “almost certainly are leading to the models underestimating the impact climate change is having on persistent summer weather extremes.” He attributed part of that conservatism to the political atmosphere in which U.S. climate science now operates.
What Happens Next
The report’s most consequential recommendations — shared attribution standards, regular reviews of rapid studies, and tighter collaboration with local officials — will require coordination across research institutions, federal agencies, and frontline communities. The next generation of climate models capable of resolving severe thunderstorms and hail, paired with expanded observation networks in data-sparse regions, will determine how quickly extreme weather attribution can close its remaining gaps.
As compound climate disasters become the norm rather than the exception, the demand for attribution findings is likely to grow in policy, regulatory, and legal contexts — including litigation against fossil fuel companies and climate-related insurance disputes. How quickly scientists standardize their methods and translate them for decision-makers will shape whether climate attribution science keeps up with the extremes it is meant to explain.
— Rachel Greenwood, climate desk, AXO News