As the prospects of significantly mitigating climate change through emissions reductions become dimmer, the critical necessity of adaptation has become clearer, with failure-to-adapt litigation possibly playing an important role in bringing adaptation measures to pass. Based on a review of every adaptation-related case in the U.S. Climate Litigation Database maintained by the Sabin Center for Climate Change Law, this Article offers the first comprehensive assessment of failure-to-adapt litigation in the United States. It finds that such cases have proliferated in this country over the past decade, but that the lawsuits so far filed have sought specific, incremental, and relatively small-scale adaptation measures rather than systemic, large-scale, coordinated action. The Article’s central finding is that failure-to-adapt litigation in the United States has so far been only modestly successful: most suits have failed, but a significant minority have succeeded. Failure-to-adapt litigation succeeds frequently enough to make it an important, and perhaps underutilized, tool for bringing about much-needed adaptive measures in the United States.

In May 2024, the International Tribunal for the Law of the Sea (ITLOS) issued a landmark advisory opinion on climate change under international law. It unanimously determined that State Parties to the United Nations Convention on the Law of the Sea have specific obligations to take all necessary measures to prevent, reduce, and control marine pollution from anthropogenic greenhouse gas emissions. ITLOS noted that these obligations are ones of due diligence, and the standard of due diligence is “stringent,” given the high risks of serious and irreversible harm to the marine environment due to climate change; but it does not clarify what “stringent” due diligence means. This Comment provides an initial understanding of stringent due diligence by referencing the precautionary approach and the International Law Commission’s Draft Articles on Prevention of Transboundary Harm From Hazardous Activities.