Dikes Versus Windmills: Climate Treaties And Adaptation

This paper begins with a tribute to William Nordhaus, focusing on the two questions that have motivated his life’s work. The first is by how much carbon dioxide emissions should be reduced over time. The second is how to reach and enforce an agreement among sovereign nations to limit carbon dioxide emissions. Nordhaus was awarded the Nobel Prize for his efforts to answer the first question. I argue here that the answer to this question has been solved to a satisfactory extent, not only by economists, but by diplomats, and that the greatest need now is to answer the second question. I also present a simple model that extends previous research into this second question, a model in which countries choose both whether to abate and whether to adapt. Like all previous research on this topic, including Nordhaus’s own, the model doesn’t provide a neat solution, only another perspective on one of the most vexing questions in all of human history: how to prevent a tragedy of the commons of global proportions and with profound and possibly catastrophic consequences.