Climate scientists inform us that greenhouse gas emissions cause climate change, which in turn poses a threat to humankind. But a major tool of societies to mitigate climate change—state policies—often fail, lack ambition, and vary widely from country to country. This is puzzling: Why is it so difficult to pass meaningful climate policies even though the stakes are high? How to explain the varying responses to the same problem? What is the best way forward? In this course, students study the economic theories and political realities underlying the struggle over climate policies. In the first part of the seminar, students are introduced to various economic perspectives on climate change ranging from the neoclassical economic mainstream to critical theory. The second part of the seminar is organized around case studies of successful and failed climate policies in the United States, Germany, Denmark, the European Union, and China. In addition to the country cases, we also interrogate broader topics such as the role of finance, economic ideas, and the likely future of climate politics.