Copenhagen Consensus: Climate Change Assessment, Cline

Assessment Paper

An Assessment Paper on Climate Change was prepared for the 2004 Copenhagen Consensus by William Cline. The working paper used by the Expert Panel is available for download here, the finalized paper has been published in Global Crises, Global Solutions by Cambridge University Press.

Short Summary

This paper examines the issue area of abatement of greenhouse gas emissions to limit future damage from global warming. Three policy strategies are evaluated: a) an optimal, globally-coordinated carbon tax; b) the Kyoto Protocol; and c) a value-at-risk strategy setting carbon taxes to limit exposure to high damage.

First, however, a considerable portion of this paper must be devoted to the conceptual framework and key assumptions used in modeling costs and benefits from abatement of global warming.

The paper briefly reviews the state of play in the scientific and international policy deliberations on global warming. It summarizes the key findings of the 2001 review of the Intergovernmental Panel on Climate Change (IPCC) and reviews the status of the Kyoto Protocol. It also discusses crucial methodological components that can drive sharply contrasting results in cost-benefit analyses of global warming abatement, including especially the question of appropriate time discounting for issues with century-scale time horizons.