Today the Sabin Center for Climate Change Law published a report analyzing climate change lawsuits filed in United States courts while President Joseph R. Biden was in office. During the Biden administration, the federal government reversed course on the first Trump administration’s climate deregulation and embarked on a “whole-of-government approach to combatting the climate crisis.” Many states and municipalities pursued their own efforts to mitigate and prepare for climate change, while other states undertook climate deregulatory efforts. During the four years of the Biden administration, many areas of the U.S. experienced disasters linked to and intensified by climate change, including hurricanes, extreme heat, and wildfires.
The report published today analyzes the 630 climate cases filed in federal and state courts during this four-year period, with these policies and climate events as their backdrop and subject matter. All of the cases are found in the Sabin Center’s Climate Litigation Database. The report’s analysis does not assess the outcomes of the cases, many of which remain pending. Instead the report distills elements of the cases: what goals the litigation aimed to achieve, who the parties were, and the underlying subject matter and substantive law. The analysis—which builds on the Sabin Center’s reports on climate litigation during the first Trump administration (Year One, Year Two, and Full Term)—provides a quantitative overview of these characteristics of climate litigation. The report concludes with a discussion of how the trends in U.S. climate litigation may be evolving during the second Trump administration as the U.S. federal government once again reverses course on its climate agenda.
Highlights from the Quantitative Assessment
- The report assigns each case to one of six trend categories based on an analysis of the intended effect of the plaintiffs’ climate-related claims. To provide a high-level view of the landscape of U.S. climate litigation, the analysis simplifies the trend categories into four “pro” and two “con” categories, based on whether a case’s goals are oriented towards advancing climate change mitigation and adaptation or are oriented toward undermining or eliminating climate protections.
- During the Biden Years, approximately two-thirds of the climate cases filed were classified in one of the four “pro” climate categories.
- Continuing a trend seen during the first Trump administration, cases in the “Integrating Consideration of Climate Change into Environmental Review and Permitting” category predominated.
- The percentage of “con” cases increased each year, starting at 24% in 2021 and climbing to 36% in 2024 and the first 20 days of 2025.
- The volume of climate cases brought by nongovernmental organizations (NGOs) far exceeded the volume of cases brought by any other category of plaintiff. NGOs were plaintiffs in 367 of the 630 U.S. cases (58%) in the Climate Litigation Database during the four years of the Biden administration.
- During the Biden administration, cases involving fossil fuel extraction, processing, and transport (118 cases) represented the dominant category of cases. Other sectors with at least 5% of cases filed were wildlife, forest and land management, real estate development, power plants, transportation, and vehicle emissions and fuel.
Future Trends
The about-face in federal climate change policies will likely be the primary factor reshaping climate litigation trends in the U.S. during the second Trump administration. The report discusses the following potential shifts or themes:
- Invocation of constitutional arguments to defend Biden-era climate change policies. During the first months of the second Trump administration, there have been numerous lawsuits filed to defend climate change legislation and regulatory actions, including a number of lawsuits challenging the terminations of climate change-related funding awarded under the Inflation Reduction Act and other statutory authorities. Plaintiffs’ claims include that the Trump administration acted in excess of its constitutional authorities.
- A reorientation towards cases that seek transparency from the Trump administration regarding climate change information and its actions to address climate change. Lawsuits in which plaintiffs seek to compel transparency by government actors and to ensure scientific integrity are once again front and center, as they were during the first Trump administration.
- The United States moving into a role as a deregulatory plaintiff. A likely trend during the second Trump administration is federal involvement as a plaintiff or other litigation participant challenging state and local climate change policies and actions.
- Lawsuits with climate change-related deregulatory goals brought against private defendants. More lawsuits alleging that private entities violate legal obligations by taking climate change into consideration could be expected in the coming years as federal frameworks guiding companies’ actions addressing climate risk are withdrawn or abandoned and some states target ESG- and climate-focused corporate actions.
- Individual plaintiffs asserting “pro” climate claims. The number of climate washing cases brought by consumers under state consumer protection laws seems poised to increase, and potentially on the horizon are more cases in which individual plaintiffs seek compensation or other relief for noneconomic climate change-related harms.
You can read the full report here.
