 Game theory has played an important role in the moral and political analysis of climate change. In particular, it has been crucial to the analysis of why addressing climate change is difficult. Here, the consensus in the literature is that states (and other entities) interested in addressing climate change confront a massive free rider problem stemming from that fact that many of the things that can be done to prevent further climate change or mitigate its effects are either quasi-public goods or things which generate substantial positive externalities. For example, drastic reductions of carbon emissions and increased investment in carbon sequestration or alternative energy technologies are things which benefit most countries regardless of who invests in them. And, because investing in these things is costly (at least in the short term), we tend to underinvest in them, a problem that is exacerbated by the fact that the most serious costs of climate change arguably fall on future generations.