Climate change will emerge in the decades ahead as one of the most significant challenges facing our Nation and the world. The evidence that human activity is altering the climate--with potentially catastrophic effects--is largely unchallenged in the scientific community, yet remains the source of significant controversy from a legal and policy perspective. This course will consider climate ethics and climate science, through readings and guest lectures, and then will focus on legal efforts to address climate change under international law and in the United States. We will examine the role of the United Nations process, culminating in the Paris Agreement, and the future of international climate mitigation efforts. We will consider legislative proposals in the United States; recent Supreme Court cases and regulatory requirements under the Clean Air Act, NEPA, the Endangered Species Act, and securities law; citizen suits to compel government action using nuisance law and the public trust doctrine; and regional state and local efforts to mitigate and adapt to climate change.