There are many feedback mechanisms in the climate system that moderate the magnitude of climate change. Positive feedbacks incite continued change, while negative feedbacks halt change. With respect to temperature, positive feedbacks tend to amplify warming, while negative feedbacks suppress it. Figure 1 illustrates two important feedback loops that moderate the climate. These feedbacks contribute to uncertainties in future climate change and make pinpointing the exact warming difficult.
General circulation models (GCMs) are used to help understand the effect of the feedbacks on the climate system. Studies that have analyzed GCM results suggest that the combined effect on the climate system of the important positive and negative feedbacks is an amplification of temperature (Randall et al. 2007). However, there is considerable spread in the magnitude of this change (Randall et al. 2007), and this remains an important area of study.
Adapted for eXtension.org by Michael Crimmins, University of Arizona
Randall, D.A., R.A. Wood, S. Bony, R. Colman, T. Fichfet, J. Fyfe, V. Kattsov, A. Pitman, J. Shukla, J. Srinivasan, R.J. Stouffer, A. Sumi, and K.E. Taylor. 2007. Climate models and their evaluation. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor, and H.L. Miller (eds.). Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
Southwest Climate Change Network
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