Climate change represents a global commons problem, where individuals, businesses, and nation-states all lack sufficient incentives to reduce their greenhouse gas emissions to levels consistent with meeting their collectively agreed upon mitigation goals. The current “pledge and review” paradigm for global climate change mitigation, which many see as a major breakthrough, relies primarily on moral pressure, reputational incentives, and global public opinion to foster cooperation on mitigation efforts over and above those driven by maximization of narrow conceptions of national interests. Given the scale of the emissions reductions required to meet stated mitigation goals, the substantial economic costs of deep decarbonization, and the central role of fossil fuels in the global economy, these soft factors are likely to prove too weak. Projections based on the pledges embodied in the Paris Agreement indicate that the world is not on a path to avoiding dangerous anthropogenic interference with the global climate, and there is no enforcement mechanism to assure that the commitments made in Paris are kept. These limitations suggest the need for more robust mechanisms to encourage adoption of emissions controls based on the full global costs they generate. This Article discusses four possibilities: (1) strategic emissions abatement policies; (2) linking climate change mitigation with other geopolitical issues, with a particular emphasis on trade; (3) introduction of a globally harmonized carbon price, with design features adjusted to induce reluctant countries to participate; and (4) relaxation of national sovereignty in favor of a sovereign global climate authority. Each of these options presents its own set of risks and challenges, but all must be considered in light of the importance of achieving robust global coordination on climate change mitigation and of the currently dim prospects for doing so.