In recent years, Southern California has witnessed drought-fueled wildfires, the southern Appalachian Mountains endured a devastating hurricane, and New England suffered catastrophic floods. These increasing climate disasters reveal the staggering economic toll exacted by climate change. Efforts by governments worldwide to recover from and safeguard against such extreme weather events are escalating, yet the challenge of holding fossil fuel companies accountable remains a complex legal frontier.
Amid numerous lawsuits seeking compensation from fossil fuel producers, a persistent obstacle in court cases has been the difficulty of establishing direct causality between a company’s greenhouse gas emissions and specific climate-related damages. The scientific ambiguity in tracing the fingerprint of individual emitters on targeted climate catastrophes has long been a stumbling block. However, a recent groundbreaking study published in Nature offers a new scientific framework that could fundamentally shift this landscape.
The study introduces a methodologically rigorous framework that marries sophisticated climate modeling with publicly available emissions data to compare the contemporary climate—exposed to a firm’s greenhouse gases—with a hypothetical climate scenario absent those emissions. Known as the “but for” causality standard, this approach asserts that a climate disaster likely would not have occurred but for the emissions of a particular fossil fuel company. This methodological advance brings a new degree of precision to climate data attribution that could empower legal systems worldwide.
Led by Justin Mankin, an associate professor of geography at Dartmouth College, the research team elucidates a calculus of climate liability grounded in empirical evidence. Mankin claims that the scientific question posed back in 2003—whether emissions from individual companies could ever be conclusively linked to climate change—now finds a clear affirmative. His work signals a closing of the scientific chapter on climate causation, even as legal proceedings interpret and act on these findings.
Using this framework, co-author Christopher Callahan, now a postdoctoral scholar at Stanford University, demonstrates causal estimates of regional economic damages attributed solely to extreme heat resulting from the emissions of individual fossil fuel firms. Their analysis reveals that from 1991 to 2020, extreme heat fueled by carbon dioxide and methane from just 111 companies cost the global economy a staggering $28 trillion. Remarkably, the top five emitters alone account for $9 trillion of this burden, underscoring the outsized contribution of a small group of fossil fuel producers.
One particular investor-owned company stands out as bearing between $791 billion to $3.6 trillion in heat-related economic losses during the same timeframe. These numbers articulate a profound linkage between corporate emissions and tangible financial impacts, underscoring the grave responsibilities borne by these entities. The research thereby constructs an evidentiary basis that could redefine how courts evaluate corporate accountability for climate-related harms.
This breakthrough takes climate attribution science beyond traditional atmospheric concentration metrics, which rely on parts per million measurements that are notoriously difficult to attribute to individual emitters. Instead, Callahan and Mankin simulate emissions directly through their novel model, tracing warming patterns and associated economic losses downstream to specific corporate sources. This fine-grained modeling represents a critical leap forward in environmental forensics.
Building upon prior work quantifying global economic losses from heat waves and cross-border climate damages, their latest study focuses on extreme heat as a particularly cogent indicator of anthropogenic climate change. Extreme heat events, intimately connected to rising global temperatures, pose immediate and documented financial threats, making them an ideal case study for the application of this novel attribution methodology.
This research arrives at a moment when legal strategies globally increasingly invoke “polluter pays” principles, exemplified by legislative initiatives such as Vermont’s 2024 Climate Superfund Act. This law empowers the state attorney general to hold fossil fuel companies financially liable for climate damages verifiably linked to their emissions. The Nature study informed parts of Vermont’s groundbreaking legislation, providing scientific validation for legal claims in unprecedented ways.
Yet challenges remain. Vermont’s legal actions face pushback challenging the state’s capacity to utilize climate attribution science accurately and its authority to impose such liability. The scientific clarity provided by this study may prove pivotal in court, addressing skepticism by demonstrating traceable causal chains between emissions and climate-induced economic effects.
The researchers emphasize that their analysis is retrospective, not predictive. Their modeling documents the losses that have already transpired due to historical emissions, offering an evidentiary foundation for liability claims rather than forecasts of future climate impacts. This retrospective approach strengthens the immediacy and relevance of their findings for current legal and policy debates.
By integrating decades of climate impact data, socioeconomic variables, and advances in physical climate science, this framework transcends earlier attribution models, which lacked the granularity or scope to assign corporate responsibility definitively. The study’s rigorous scientific underpinning offers a robust toolkit for legislators, courts, and regulators striving to implement accountability frameworks in the fossil fuel industry.
Ultimately, this research reframes the climate responsibility discourse, stressing that the prosperity derived from fossil fuel consumption does not absolve companies from the harm their products have caused globally. The analogy to pharmaceutical liability is poignant: just as a drug manufacturer cannot evade responsibility for side effects based on therapeutic benefits, fossil fuel corporations should not be exonerated for climate damages despite economic gains.
As climate disasters intensify and demand for justice escalates, this innovative scientific framework may become a cornerstone for holding corporate emitters accountable under legal and regulatory regimes. It embodies the convergence of rigorous scientific inquiry and urgent societal imperatives, charting a new path toward addressing the enormous costs of anthropogenic climate change.
Subject of Research: Not applicable
Article Title: Carbon majors and the scientific case for climate liability
News Publication Date: 24-Apr-2025
Web References: https://www.nature.com/articles/s41586-025-08751-3
References: DOI 10.1038/s41586-025-08751-3
Keywords: Climate change, Fossil fuels, Carbon emissions, Climate modeling, Economics research, Greenhouse gases, Methane emissions, Climate change effects, Methane, Extreme weather events, Scientific approaches, Anthropogenic climate change, Environmental issues, Greenhouse effect, Climate data, Research methods, Environmental impact assessments, Climate monitoring, Environmental methods
