Uncertainty analysis of climate change and policy response

Mort Webster, Chris Forest, John Reilly, Mustafa Babiker, David Kicklighter, Monika Mayer, Ronald Prinn, Marcus Sarofim, Andrei Sokolov, Peter Stone, Chien Wang

Research output: Contribution to journalArticle

168 Scopus citations


To aid climate policy decisions, accurate quantitative descriptions of the uncertainty in climate outcomes under various possible policies are needed. Here, we apply an earth systems model to describe the uncertainty in climate projections under two different policy scenarios. This study illustrates an internally consistent uncertainty analysis of one climate assessment modeling framework, propagating uncertainties in both economic and climate components, and constraining climate parameter uncertainties based on observation. We find that in the absence of greenhouse gas emissions restrictions, there is a one in forty chance that global mean surface temperature change will exceed 4.9°C by the year 2100. A policy case with aggressive emissions reductions over time lowers the temperature change to a one in forty chance of exceeding 3.2°C, thus reducing but not eliminating the chance of substantial warming.

Original languageEnglish (US)
Pages (from-to)295-320
Number of pages26
JournalClimatic Change
Issue number3
StatePublished - Dec 1 2003


All Science Journal Classification (ASJC) codes

  • Global and Planetary Change
  • Atmospheric Science

Cite this

Webster, M., Forest, C., Reilly, J., Babiker, M., Kicklighter, D., Mayer, M., Prinn, R., Sarofim, M., Sokolov, A., Stone, P., & Wang, C. (2003). Uncertainty analysis of climate change and policy response. Climatic Change, 61(3), 295-320. https://doi.org/10.1023/B:CLIM.0000004564.09961.9f