First Wrongful Death Lawsuit Against Big Oil Over 2021 Heat Dome
Overview of the 2021 Pacific Northwest Heat Dome
In late June 2021, a synoptic high-pressure ridge parked over the Pacific Northwest, creating an extreme “heat dome” that shattered local temperature records. In Portland, Oregon, the mercury hit 116°F (46.7°C) and in Vancouver, Washington topped 108°F (42.2°C). Scientists using advanced climate attribution models have estimated that this event was at least 150 times more likely due to anthropogenic greenhouse gas emissions.
The unprecedented heat wave resulted in over 100 confirmed heat-related fatalities in Washington state alone, making it the deadliest weather-related event in the state’s recorded history. Among the victims was 65-year-old Juliana Leon, who succumbed to hyperthermia in her disabled vehicle.
Details of the Leon Wrongful Death Lawsuit
On May 29, 2025, Juliana’s daughter, Misti Leon, filed a civil wrongful death suit in King County Superior Court, naming ExxonMobil, BP, Chevron, Shell, ConocoPhillips, and Phillips 66 as defendants. This is the first individual climate liability action in the United States seeking damages for a personal fatality linked to extreme weather.
“The extreme heat that killed Julie was directly linked to fossil fuel-driven alteration of the climate,” asserts the complaint, which alleges that the defendants concealed internal research as early as the 1980s showing catastrophic outcomes from continued CO2 emissions.
The complaint cites a 1996 Exxon internal presentation warning of “suffering and death due to thermal extremes,” and accuses Big Oil of decades-long misinformation campaigns to delay the transition to renewable energy.
Climate Attribution Science
Attribution science combines observational data, reanalysis datasets, and high-resolution climate models (e.g., CMIP6 ensembles) to calculate the fraction of attributable risk (FAR) for specific extreme events. A 2022 peer-reviewed study published in Nature Climate Change concluded that without human-driven CO2 increases, the 2021 heat dome would have been virtually impossible.
- Methodology: Coupled model intercomparison and counterfactual scenarios.
- Result: More than 90 percent increase in frequency and intensity attributable to anthropogenic forcing.
- Conclusion: Human emissions made the heat dome 150 times more likely.
Fossil Fuel Emissions and Technical Data
The lawsuit references the carbon budgets from the Intergovernmental Panel on Climate Change (IPCC AR6) and US Environmental Protection Agency (EPA) inventories. Key figures include:
- Global CO2 concentration rising above 420 ppm in 2024.
- Annual global energy-related CO2 emissions peaking at 36.6 GtCO2 in 2023.
- Top six companies accounting for nearly 14 percent of cumulative historical CO2 emissions since 1965.
These data underpin the claim that defendants’ extraction, refinement, and sale of fossil fuels directly contributed to the atmospheric concentration driving extreme heat.
Legal Precedents and Potential Outcomes
While municipal and state governments have filed over two dozen climate damages suits, this is the first wrongful death case at the individual level. Previous cases like Multnomah County v. Chevron (2023) have been tied up in procedural appeals under the Clean Air Act preemption doctrine.
Legal experts identify several key challenges:
- Proximate causation: Demonstrating direct linkage between corporate emissions and Juliana Leon’s death.
- Statute of limitations: Varies by state; Washington allows up to three years for wrongful death claims.
- Venue selection: King County jurors have personal recollections of the 2021 heat wave, possibly favoring local accountability.
If successful, the case could set a precedent for public nuisance and failure-to-warn claims, opening avenues for climate homicide prosecutions at the state level.
Expert Opinions and Latest Developments
Aaron Regunberg, Accountability Director at Public Citizen’s Climate Program, notes:
“This lawsuit personalizes climate accountability by linking corporate misconduct to an individual life lost.”
Donald Braman, Georgetown University Law professor, comments that advances in attribution science and evolving case law could bolster plaintiffs’ arguments. At COP28 in December 2024, negotiators acknowledged the role of loss and damage funds, reflecting growing international support for climate liability.
Looking Ahead
The Leon suit is scheduled for initial hearings in late 2025. Observers will watch whether it survives motion-to-dismiss challenges under economic loss and preemption doctrines. Regardless of outcome, it marks a significant evolution in climate litigation, emphasizing individual rights in the face of global environmental harm.