Updated · The Equation - Union of Concerned Scientists · Jul 9
2025 Studies Link Carbon Majors to 231 Heatwaves, Chevron to $3.6 Trillion in Losses
Updated
Updated · The Equation - Union of Concerned Scientists · Jul 9
2025 Studies Link Carbon Majors to 231 Heatwaves, Chevron to $3.6 Trillion in Losses
1 articles · Updated · The Equation - Union of Concerned Scientists · Jul 9
Summary
Two 2025 attribution studies tied emissions from major fossil-fuel and cement producers to extreme heat, with one tracing 231 heatwaves to Carbon Majors and another linking Chevron alone to $791 billion-$3.6 trillion in heat-related losses over 31 years.
The heatwave study found Carbon Majors caused about half the increase in heatwave intensity over the past 120 years and that 16 to 53 of the 231 events would not have occurred without emissions traced to those companies.
Researchers said extreme event attribution is strongest for heatwaves, where the climate signal is clearest, while more complex events such as hurricanes, heavy rain and wildfires are harder to isolate with the same confidence.
The report said attribution science now underpins IPCC assessments and is increasingly relevant for litigation, planning and accountability, even as studies remain concentrated in the Global North because long-term data are scarcer elsewhere.
As climate lawsuits target major emitters, can science prove who is responsible for a specific hurricane or heatwave?
With a new US report validating climate attribution, will courts finally make fossil fuel giants pay for weather disasters?
Attribution science focuses on the Global North. How can developing nations use it to demand climate justice?
Landmark 2025 Study Links 180 Carbon Majors to Half of Global Heatwave Severity, Paving Way for Legal Accountability
Overview
A landmark study published in Nature in 2025 made a major breakthrough by directly linking the carbon emissions of the world’s largest fossil fuel companies—known as 'carbon majors'—to deadly heatwaves. Using advanced attribution science developed over the past two decades, the study systematically traced hundreds of extreme heat events back to these companies’ historical emissions. This clear scientific connection marks a significant advancement in understanding how specific corporate actions drive the climate crisis. The findings are being hailed as a leap forward, providing powerful evidence for legal efforts to hold major oil companies accountable for climate damages.