Sep 27, 2011
Increase of extreme events in a warming world
by
,
Proceedings of the National Academy of Sciences
- Develops a theoretical approach to quantify the effect of long-term trends on the expected number of extremes in generic time series, using analytical solutions and Monte Carlo simulations
- Applies the method to study the effect of warming trends on heat records
- Finds that the number of record-breaking events increases approximately in proportion to the ratio of warming trend to short-term standard deviation
- Finds that short-term variability thus decreases the number of heat extremes, whereas a climatic warming increases it
- For extremes exceeding a predefined threshold, the dependence on the warming trend is highly nonlinear
- Finds that the sum of warm plus cold extremes increases with any climate change, whether warming or cooling
- Estimates that climatic warming has increased the number of new global-mean temperature records expected in the last decade from 0.1 to 2.8
- Estimates for July temperature in Moscow that the local warming trend has increased the number of records expected in the past decade fivefold, which implies an approximate 80% probability that the 2010 July heat record would not have occurred without climate warming