Extreme Behavior

Global warming is expected to have a large effect on the amount and distribution of precipitation, with wet areas projected to become wetter and dry areas drier, and an overall increase in total rainfall. Another important aspect of these predicted changes is the frequency of extreme rainfall events, because the impact of a few heavy rain events is very different from that of many more moderate ones. Allan and Soden  (published online 7 August) use satellite observations and model simulations to evaluate how climate warming is affecting the frequency and strength of rain events. Heavy rains are occurring with increasing frequency when it is warm and less often when it is cold, and these extremes are happening more frequently than models have suggested they should. This implies that the impacts of precipitation changes due to global warming could be greater than have been assumed.

---