Climate Change 2001:
Working Group I: The Scientific Basis
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Much of what climate model studies show could happen to weather and climate extremes in a future climate with increased greenhouse gases is what we would intuitively expect from our understanding of how the climate system works. For example, a warming of the surface supplies more water vapour to the atmosphere, which is a greater source of moisture in storms and thus we would expect an increase in intense precipitation and more rainfall from a given rainfall event, both results seen in climate model simulations. There are competing effects of decreased baroclinicity in some regions due to greater surface warming at high latitudes, and increasing mid-tropospheric baroclinicity due to greater mid-tropospheric low latitude warming (Kushner et al., 2001). Additionally, a number of changes in weather and climate extremes from climate models have been seen in observations in various parts of the world (decreased diurnal temperature range, warmer mean temperatures associated with increased extreme warm days and decreased extreme cold days, increased rainfall intensity, etc.). Though the climate models can simulate many aspects of climate variability and extremes, they are still characterised by systematic simulation errors and limitations in accurately simulating regional climate such that appropriate caveats must accompany any discussion of future changes in weather and climate extremes.

Recent studies have reproduced previous results in the SAR and this gives us increased confidence in their credibility (although agreement between models does not guarantee that those changes will occur in the real climate system):

Additional results since 1995 include:

Aspects which have been addressed but remain unresolved at this time include:

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