Analysis of Climate Policy Targets under Uncertainty

• Main Authors: Jacoby, Henry D., Prinn, Ronald G., Melillo, Jerry M., Sarofim, Marcus C., Kicklighter, David W., Wang, Chien, Schlosser, C. Adam, Paltsev, Sergey, Forest, Chris Eliot, Reilly, John M., Sokolov, Andrei P., Webster, Mort D.
• Format: Report
• Language: English
• Published: MIT Joint Program on the Science and Policy of Global Change 2009
• Subjects: Sea ice
• Online Access: http://hdl.handle.net/1721.1/49860; http://globalchange.mit.edu/pubs/abstract.php?publication_id=1989

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/). Although policymaking in response to the climate change is essentially a challenge of risk management, most studies of the relation of emissions targets to desired climate outcomes are either deterministic or subject to a limited representation of the underlying uncertainties. Monte Carlo simulation, applied to the MIT Integrated Global System Model (an integrated economic and earth system model of intermediate complexity), is used to analyze the uncertain outcomes that flow from a set of century-scale emissions targets developed originally for a study by the U.S. Climate Change Science Program. Results are shown for atmospheric concentrations, radiative forcing, sea ice cover and temperature change, along with estimates of the odds of achieving particular target levels, and for the global costs of the associated mitigation policy. Comparison with other studies of climate targets are presented as evidence of the value, in understanding the climate challenge, of more complete analysis of uncertainties in human emissions and climate system response. This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors.