Attribution Science: Why Fossil Firms May Owe Trillions in Climate Damages

Can science link fossil fuel companies to climate damages, and enable lawsuits? 

Summary  

A new study published in Nature (April 2025) finds a strong scientific link between major fossil fuel emitters and specific climate-related damages, like extreme heat. The researchers demonstrate a method for assigning real economic losses (in the hundreds of billions to trillions) to emissions from individual companies. This could unlock legal and financial accountability mechanisms, fundamentally reshaping how markets and courts respond to climate risk. 

Why This Matters 

• If emissions can be traced to specific companies, the courts could hold fossil firms legally responsible. 

• If Chevron’s emissions caused up to US $3.6 trillion in tropical heat damage, then accountability moves from theory to finance. 

• Scenario: A city hit by deadly heat waves could seek damages from high-emitting companies using this framework. 

• If investors face legal risk tied to emissions, then fossil investments may decline sharply. 

• As courts adopt science-based models, companies’ climate liabilities become quantifiable, and investors must reassess balance sheets. 

What is Attribution Science? 

Researchers Christopher Callahan and Justin Mankin built an “end-to-end attribution framework” that: 

• Uses emissions data (Scope 1 & 3) from large fossil firms. 

• Applies climate modeling to compare heat extremes with and without emissions. 

• Provides reproducible methods that courts could use to determine liability between emissions and damages. 

Challenges and Considerations 

While the science behind this study is strong, using it in real-world court cases won’t be simple. Different legal systems have their own rules about what counts as proof, and some might not accept this kind of climate modeling as evidence—at least not right away. It also takes a lot of data and technical skill to link a specific company’s pollution to a specific climate impact, like a heatwave or flood. On top of that, fossil fuel companies and their insurers may push back hard against these claims, making the legal process slow and difficult. Finally, investors who own shares in these companies could also face financial risk if lawsuits succeed or new regulations are introduced. This means everyone—from businesses to policymakers—needs to start thinking seriously about how to prepare. 

Accelerate Your Climate Strategy: Action Items 

To manage growing legal and financial risks tied to emissions accountability, companies and investors can: 

• Assess Emissions Liability Exposure: Review emissions data (Scope 1 and 3) and evaluate which historical activities could be linked to climate damages. 

• Strengthen Disclosure Practices: Use trusted reporting frameworks like the ISSB and CDP to ensure emissions data is transparent and legally defensible. 

• Engage Legal and Risk Teams: Build internal capacity to understand how new science could shape future lawsuits or financial disclosures. 

• Reevaluate Investment Strategies: Reduce exposure to high-emitting companies and sectors that could face litigation or regulatory fines. 

Companies across industries—energy, insurance, manufacturing, and finance—can stay ahead of the curve by acting now. Those that lead on transparency and emissions responsibility will be better equipped to manage climate litigation risks, maintain investor confidence, and respond to evolving regulatory standards. 

Bottom Line  

This study solidifies the scientific case that fossil fuel companies can be held accountable for real-world climate damages. By linking emissions to financial harm, it shifts liability from abstract risk to tangible responsibility—forcing a rethink in investment, legal, and regulatory arenas.