 Common pool resource problems are generally solved in one of two ways: (1) by taking the resource in question out of the commons, that is by creating property rights in it, or (2) by finding ways to collectively manage the resource, for instance by regulating who can access the commons at a given time. Which approach is best suited to solving a particular problem, and what form that approach should take, depends on many factors, e.g., how excludable the resource is, whether it is stationary, and how quickly the resource can be regenerated. By providing a framework for analyzing the strategic behavior of individuals in different contexts, game theory provides a useful tool for identifying the solutions most likely to work in a given case. Here Elinor Ostrom’s work on common pool resources, which won her the 2009 Nobel Prize in Economics, has been especially influential. Ostrom used game theoretic analysis complemented by extensive field work to show that, although there is a surprising amount of diversity in the ways that communities have managed to sustainably govern common resources, the success of these approaches tends to be a function of a number of underlying principles (Ostrom 1990). Some of these principles reflect things we’ve already discussed in other contexts, e.g., the importance of monitoring and sanctions. While others are perhaps less obvious. For instance, the importance of accommodating nested or overlapping jurisdictions of responsibility. Because the ways in which these principles manifest themselves is highly dependent on context, though, rather than saying more about them here, we’ll instead turn to another problem that has received a lot of attention in environmental ethics: climate change.