Climate attribution science has matured, National Academies report says

The science used to assess how climate change affects specific weather disasters has become more reliable over the past decade, according to a new report from the U.S. National Academies of Sciences. The finding matters for public safety planning, infrastructure rules and court fights over who may bear responsibility for climate-related losses.

The report, released Thursday, says researchers now have stronger tools to estimate how human-driven warming changes the odds or severity of some extreme events. It also says the field still faces limits, especially where weather records are thin or the event unfolds at a scale too small for current climate models to capture well.

How attribution studies work

Climate attribution research compares the world as it is now with a modeled version of the world without human greenhouse gas emissions. Scientists then examine how often the conditions behind an event appear in each case, producing an estimate of how warming affected the event’s likelihood or intensity.

The National Academies report says the field has benefited from better climate models, broader observations, improved statistical methods and a clearer physical understanding of weather extremes. It says those advances have expanded the range of events researchers can assess.

The report describes two main approaches. Probabilistic studies focus on how climate change has shifted the odds of an event like the one observed. Storyline studies examine the particular weather setup behind an event, an approach the report says can be useful for tropical cyclones and other rarer hazards where specific atmospheric conditions may be easier to analyze than overall frequency.

Strongest findings for heat and rain

The report says confidence is highest for attribution involving extreme heat and heavy precipitation. Scientists have a stronger grasp of how warming affects temperature and rainfall extremes than they do for some other hazards.

Confidence drops for phenomena such as wildfires, severe storms and tornadoes, according to the report. The National Academies also says “compound events,” such as fires that coincide with extreme dryness, are harder to interpret because several hazards interact at once.

Data gaps remain a major barrier. The report says weather monitoring before the satellite era was uneven, and many parts of the global south lack records detailed enough to establish long-term probabilities for some extremes. It says small-scale events also pose a problem because even advanced climate models commonly use grid cells far larger than the thunderstorms or tornado dynamics scientists may need to study.

The National Academies recommends improving records in under-observed regions, using non-instrument evidence where possible, and investing in higher-resolution modeling. The report also calls for more attention to human influences beyond greenhouse gases, including aerosols, irrigation and land-use changes.

Legal and political stakes

The report also reviews extreme event impact attribution, which attempts to connect climate-driven changes in an event to consequences such as deaths or property damage. The National Academies says those analyses remain uneven by hazard, region and impact type, and it urges researchers to be clear about uncertainty while building tools useful for disaster preparedness.

Politico has reported that fossil fuel interests see the growing field as a legal threat because attribution studies could be used in lawsuits seeking damages from oil and gas companies. Ars Technica has reported that Republicans in Congress and state governments have threatened the National Academies’ funding amid disputes over climate science and the courts.

The National Academies report does not say attribution can answer every question about every disaster. It says the field has become a mainstream scientific tool with higher confidence in some areas and clear work still ahead in others.

This story draws on original reporting from Ars Technica.