Introduction

The primary design objectives for a successor climate agreement to the Kyoto Protocol are to promote nations' participation in and compliance with a global framework for reducing greenhouse gas (GHG) emissions. If nations do not sign the treaty, or if they sign it and then honor it only in the breach, other design details are irrelevant. The treaty must also set goals that at least approximately balance the costs and benefits of action, and must provide mechanisms to reach these goals efficiently. The design of a successor agreement should be simple, so that it presents nations with a clear choice. Ultimately, solutions to the global problem of climate change will require a measure of compulsion; therefore, it is important that nations view a new treaty as fair.

Achieving this objective begins with the recognition that managing climate change is a global public good. Because nations are sovereign, the possibilities for compelling them to join an agreement—or for compelling them to comply after they have joined—are limited. This constraint makes it necessary to design an agreement so that it is in nations' interest to participate and to comply. It is also necessary to set the stage for compelling participation in the future, should this be required.