National Academy of Science Confirms Climate Attribution Science Can Now Assign Responsibility for Climate-Related Extreme Weather Damage
FOR IMMEDIATE RELEASE
A new report affirms that attribution science can quantify climate change’s contribution to specific extreme weather events — giving insurers, investors, and courts another tool to assign responsibility and price climate risk accurately.
MEDIA CONTACT: Ryon Harms, [email protected], (310) 730-9407
EL CERRITO, CALIFORNIA — July 21, 2026 — As You Sow, the nation’s leading shareholder representative, today welcomed the release of Attribution of Extreme Weather and Climate Events and their Impacts, a landmark consensus report from the National Academies of Sciences, Engineering, and Medicine. The peer-reviewed report, developed by a committee of 14 independent scientists, concludes that attribution science can now provide increasingly confident metrics about how human commercial activity has contributed to climate change and specific extreme weather events, including heat waves, floods, wildfires, and droughts.
“The financial market depends on accurate pricing of risk, full stop,” said Andrew Behar, CEO of As You Sow. “This report helps provide critical information about the cost of climate change. As You Sow urges corporate boards, insurers, and asset managers to treat the report as what it is: an authoritative signal that climate risk is now measurable, attributable, and financially material.”
For the insurance industry, the implications are immediate. Insurers face a deepening climate-driven crisis: catastrophic losses are rising, premiums to their customers are climbing, and providing coverage is becoming unprofitable in more areas in the U.S. The ability to attribute a measurable share of a disaster’s damages gives insurers a scientifically grounded basis to price policies accurately and, through subrogation, to recover costs from the parties responsible for contributing to climate change rather than passing the entire burden onto homeowners.
“For years, the link between any individual disaster and climate change was too uncertain to act on,” said Danielle Fugere, President and Chief Counsel of As You Sow. “The National Academies’ report has closed that gap. Insurers like Travelers and Chubb now have a tool that, combined with existing source attribution science, allows them to seek reimbursement for the costs of certain climate change related damages. Homeowners are now unfairly shouldering that burden.”
The new report gives courts a defensible, scientific basis for assigning responsibility. Every dollar invested in high-carbon activity now carries a measurable and growing exposure that company boards can no longer ignore.
As You Sow has pressed this argument directly with major insurers this proxy season. As an organization, we filed a shareholder proposal asking Chubb to assess if and how pursuing subrogation claims against high-emitting companies could reduce losses and help preserve affordable homeowner insurance; it filed a separate proposal asking Travelers to disclose how rising climate catastrophe losses affect its ability to sustain its business over time as homeowner insurance becomes unaffordable and whole areas of the U.S. become unprofitable to insure. A companion proposal at Wells Fargo asked the bank to evaluate its growing exposure to climate-related litigation risk from its financing of high-carbon activities.
The report updates a 2016 National Academies assessment and reflects a decade of advances in observational data, satellite measurement, and modeling that have, according to the committee, , substantially increased confidence in attributing the impact of climate change on weather related events.
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As You Sow is the nation’s leading shareholder representative, with a 30+ year track record promoting environmental and social corporate responsibility. As You Sow addresses a range of issues that affect shareholder value including climate change, ocean plastics, toxins in the food system, biodiversity, racial justice, and workplace diversity. See As You Sow’s shareholder resolution tracker.