A burgeoning field of research called attribution science is now at the heart of legal battles against fossil fuel giants.
The scientific consensus has remained unchanged for decades: since at least the 1950s. the oil and gas industry has understood that its products release carbon dioxide. fueling the melting of ice caps and rising sea levels. By 1968, studies were already warning of potentially serious environmental damage worldwide. Yet. for years. the missing link was the ability to calculate exactly how much one company’s emissions amplified a specific storm or heat wave.
That gap is now being filled by a burgeoning field known as attribution science. It has moved from theoretical inquiry to the center of high-stakes courtroom battles, most notably in *Suncor Energy Inc. v. County Commissioners of Boulder County*. As the U.S. Supreme Court heard arguments this week, the battle over this research has become a litmus test for corporate accountability.
In 2003. physicist Myles Allen posed a radical question in *Nature*: Could it be possible to sue someone for damaging the climate?. Allen. who had watched floodwaters creep within 30 centimeters of his own kitchen door in Oxford. acknowledged at the time that the models to trace greenhouse gas emissions to specific floods did not yet exist. By 2004, he had produced the first study identifying human influence on the risk of a deadly European heat wave.
The field has since splintered into distinct disciplines. Event attribution measures climate change’s role in specific disasters, such as Hurricane Katrina. While models in 2005 were limited. recent analysis from Climate Central suggests that climate change made Katrina’s ocean temperatures up to 18 times more likely and boosted its maximum sustained wind speed by 5 mph. Trend attribution, meanwhile, provides the broader context—the human fingerprint on global warming—first identified in the 2001 IPCC report.
Then came 2014, when Richard Heede, founder of the Climate Accountability Institute, introduced source attribution through his “Carbon Majors” report. Heede sought to quantify emissions attributable to individual companies over their entire history. His work revealed that Chevron, for instance, was responsible for 3.52% of all global emissions produced between 1751 and 2010. By calculating the total carbon in the products these companies sold. Heede shifted the focus away from nation-states and onto the corporations themselves.
For Heede, the industry’s resistance is a continuation of a long history. He argues that while governments and consumers play roles. these companies possessed the science for decades but chose to invest in obfuscation and denial. Today. the industry remains steadfast in its defense. arguing in legal briefs that greenhouse gas emissions cannot be unmixed and traced to specific sources. They also reject responsibility for Scope 3 emissions—the downstream use of gasoline in vehicles—which can account for 80-to-95% of a company’s carbon footprint.
This argument is being tested in Boulder’s 2018 lawsuit against Exxon and Suncor. The city and county of Boulder contend that these companies knowingly contributed to a climate crisis that taxpayers should not have to face alone. While the Supreme Court is currently debating whether the case belongs in federal or state court, the implications are vast. Chief Justice John G. Roberts Jr. noted the potential for a nationwide cascade of litigation. questioning how the court system would handle the resulting volume of claims. A ruling against Boulder could potentially halt dozens of similar suits currently pending across the country.
Despite the legal headwinds and the industry’s push to label the science as untraceable. the researchers behind these models remain undeterred. As climate impacts grow more severe. the sophisticated mapping of those damages to specific corporate coffers will only continue to sharpen. regardless of the outcome in any single courtroom.
attribution science climate litigation Suncor v. Boulder Supreme Court fossil fuels climate change