Regional Climate model estimates for changes in Nordic extreme events

Abstract

Changes in extreme weather events with climate change were estimated for northern Europe by Rossby Centre coupled atmosphere – Baltic Sea regional climate model simulations. Two driving global climate models and two forcing scenarios were used. The estimates were made by comparing, at each grid point, 50-year return values for the simulation periods of 1961–1990 and 2071–2100. The most significant predicted changes in the study area are in the extremes of maximum and minimum air temperatures. The increase in the extreme surface wind speed is mostly small. The 50-year return value for the precipitation amount in five days is predicted to increase by over 50 % in many areas. The extreme snow water equivalent is predicted to decrease very significantly in most of the study area but increase in some highland areas. Very heavy snow fall will become generally more frequent. From the point of view of adapting structural design and community planning to climate change, the results suggest that the emphasis should be in the design practices in regard to flooding. The estimated changes in other structural design criteria are generally less significant or favourable. Key words: Climate change, extreme weather, regional climate modeling, adaptation to climate change, risk management of structures, probabilistic design