In 2009, the U.S. Environmental Protection Agency (EPA) published what is commonly referred to as the “endangerment finding.” Prompted by the U.S. Supreme Court’s landmark decision in Massachusetts v. Environmental Protection Agency (2007) and reflecting robust science, the finding determined that six key greenhouse gases qualify as air pollution under the Clean Air Act and pose a threat to the health and welfare of future generations. This authorized EPA to set emissions standards for motor vehicles and other major sources of greenhouse gases; however, the Agency recently announced the finding will undergo reconsideration of whether it “complies with the law and is based on sound science and policy.” On May 22, 2025, the Environmental Law Institute hosted a panel of experts to discuss the legal and scientific foundations of the endangerment finding. Here, we present a transcript of that discussion, which has been edited for style, clarity, and space considerations.