On December 31, 2012, the Kyoto Protocol’s first commitment period will expire. Unless states agree to a second commitment period, requiring a further round of emissions cuts, the Protocol will no longer impose any quantitative limits on states’ greenhouse gas emissions. Although, as a legal matter, the Protocol will continue in force, it will be a largely empty shell, doing little if anything to curb global warming.

This discussion paper analyzes the options going forward for the Kyoto Protocol, including adoption of a legally-binding second commitment period, a “political” second commitment period, or no new commitment period. It also considers the legal implications of a gap between the end of Kyoto’s first commitment period and the adoption of a new legal regime to limit emissions, the prospects for the Clean Development Mechanism in the absence of a second Kyoto commitment period, and the relationship between the Kyoto Protocol negotiations and the emerging regime under the Cancun Agreements.

Daniel Bodansky is Lincoln Professor of Law, Ethics and Sustainability, at Arizona State University’s Sandra Day O’Connor College of Law. This paper is based on a presentation made to a workshop organized by the Pew Center on Global Climate Change in Konigswinter, Germany in June 2011. The paper is published in Viewpoints, a publication of the Harvard Project on Climate Agreements.