Editor’s Note
The following brief excerpt (pp. 1633-34) from “Reference Guide on Climate Science” in the Fourth Edition of the Reference Manual on Scientific Evidence is published with permission from the National Academies of Sciences, Engineering, and Medicine.
The chapter is the subject of dispute between co-authors of the manual and a group of attorneys general led by JB McCuskey of West Virginia
Legal Applications of Climate Science
There are several ways in which climate science may factor into the resolution of climate lawsuits. First, climate science may be used to evaluate claims of causation and harm, e.g., whether the GHG emissions at issue in a case cause or contribute to public endangerment or injury to a specific plaintiff. Second, climate science may be used to evaluate whether climate-related risks or harms were or are foreseeable. Finally, climate science may be used to determine the scope of a defendant’s legal obligations and authorities with regard to GHG mitigation, climate change adaptation, climate-related disclosures, and other matters.
Causation and Harm
Disputes about causation and harm arise in different types of climate lawsuits. For example, in cases where plaintiffs are seeking to compel government regulation of GHG emissions from a sector or activity, the parties may dispute the nature and/or magnitude of harm that can be attributed to those emissions, and whether the harm is substantial enough to trigger a regulatory obligation on the part of the government defendant.278 Causation may also be an issue in cases where government agencies are defending GHG regulations against legal challenges, insofar as it may be necessary to demonstrate that those emissions cause some form of environmental or public harm in order to justify the regulatory action.279 Finally, the issue of causation and harm tends to be a major element of the standing analysis in cases where the plaintiff is alleging that they have experienced an injury as a result of the defendant’s actions or inaction with regard to GHG emissions and climate change.280
278 See, e.g., Juliana v. United States, 339 F. Supp. 3d 1062, 1096 (D. Or. 2018), rev’d and remanded, 947 F.3d 1159 (9th Cir. 2020). In the foregoing case, a group of youth plaintiffs claimed that the federal government had violated their constitutional rights by permitting, authorizing, and subsidizing fossil fuel extraction and consumption that contributed to climate change. They sought both declaratory and injunctive relief requiring the federal government to reduce emissions from fossil fuels. The district court held that plaintiffs had Article III standing because they had alleged sufficiently personalized and concrete injuries that were fairly traceable to the GHG emissions resulting from U.S. fossil fuel production and use. The Ninth Circuit reversed, holding that plaintiffs had failed to satisfy the redressability prong of standing because the injunctive relief they sought was outside the power of an Article III court.
279 These questions of source attribution may implicate questions about climate change and extreme-event attribution. For example, if a plaintiff alleges injury based on exposure to an extreme event, the court would need to refer to extreme-event attribution research to evaluate the relationship between global climate change and the extreme event (what is the attributable risk?), as well as impact attribution data to evaluate the relationship between the plaintiff’s injury and the event.
280 See, e.g., Coalition for Responsible Regulation v. EPA, 684 F.3d 102 (D.C. Cir. 2012).
National Academies of Sciences, Engineering, and Medicine. 2025. Reference Manual on Scientific Evidence: Fourth Edition. Washington, DC: The National Academies Press. https://doi.org/10.17226/15256.
