Climatic Change

, Volume 109, Issue 3–4, pp 815–825

Correlation between climate sensitivity and aerosol forcing and its implication for the “climate trap”

A Letter
Letter

Abstract

Climate sensitivity and aerosol forcing are dominant uncertain properties of the global climate system. Their estimates based on the inverse approach are interdependent as historical temperature records constrain possible combinations. Nevertheless, many literature projections of future climate are based on the probability density of climate sensitivity and an independent aerosol forcing without considering the interdependency of such estimates. Here we investigate how large such parameter interdependency affects the range of future warming in two distinct settings: one following the A1B emission scenario till the year 2100 and the other assuming a shutdown of all greenhouse gas and aerosol emissions in the year 2020. We demonstrate that the range of projected warming decreases in the former case, but considerably broadens in the latter case, if the correlation between climate sensitivity and aerosol forcing is taken into account. Our conceptual study suggests that, unless the interdependency between the climate sensitivity and aerosol forcing estimates is properly considered, one could underestimate a risk involving the “climate trap”, an unpalatable situation with a high climate sensitivity in which a very drastic mitigation may counter-intuitively accelerate the warming by unmasking the hidden warming due to aerosols.

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Institute for Atmospheric and Climate Science, ETH ZurichZurichSwitzerland
  2. 2.CICERO (Center for International Climate and Environmental Research – Oslo)OsloNorway
  3. 3.IIASA (International Institute for Applied Systems Analysis)LaxenburgAustria
  4. 4.MPI-M (Max Planck Institute for Meteorology)HamburgGermany

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