HR: 1340h
AN: U43A-0849    [Abstracts]
TI: Why is climate sensitivity so unpredictable?
AU: * Roe, G H
EM: gerard@ess.washington.edu
AF: Earth and Space Sciences, 070 Johnson Hall University of Washington, Seattle, WA 98195, United States
AU: Baker, M B
EM: marcia@ess.washington.edu
AF: Earth and Space Sciences, 070 Johnson Hall University of Washington, Seattle, WA 98195, United States
AB: Uncertainties in projections of future climate change have not lessened substantially in the last decades. Both models and observations yield broad probability distributions for long-term increases in global mean temperature expected for doubling of CO₂, with small but finite probabilities of very large increases. We show here that the shape of these probability distributions is an inevitable and general consequence of the nature of the climate system, and we derive a simple analytic form for the shape that fits recent published distributions very well. We show that the breadth of the distribution, and in particular, in the probability of large temperature increases, is relatively insensitive to decreases in uncertainties associated with the underlying climate processes.
DE: 3300 ATMOSPHERIC PROCESSES
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3310 Clouds and cloud feedbacks
DE: 3337 Global climate models (1626, 4928)
DE: 3344 Paleoclimatology (0473, 4900)
SC: Union [U]
MN: 2007 Fall Meeting