May 13, 2002 -- According to the new European Climate Assessment report, precipitation in Europe shows a tendency towards more wet extremes.
This is seen in particular at locations where the annual amount of rainfall has increased. Also, systematic changes in temperature extremes have been documented for the first time using observational records from all over Europe.
These results are obtained in a comprehensive investigation of daily series of observations at more than 200 meteorological stations in Europe and the Middle East. The investigation, initiated by the Europe Climate Support Network, was a co-operative activity of 34 countries and coordinated by the Royal Netherlands Meteorological Institute.
Today, the report is presented to the directors of Meteorological Services at the World Meteorological Organization in Geneve, Switzerland. It is the sequel to the first assessment report of Europe's climate that was issued in 1995.
A decreasing number of frost days and to a lower extent an increasing number of summer days accompanied the observed warming trend. Throughout the year, the frequency of days that are much colder than normal has decreased and the frequency of days that are much warmer than normal has increased.
Remarkably, these trends are not always in balance: during the warm recent decades the number of 'cold extremes' decreased at a lower rate than the increase in the number of 'warm extremes'. Future research should deal with the causes for the observed trends and with projections of future climate extremes.
In the present study, daily series have been analyzed that started around 1950. They cover a period of roughly half a century. This is long enough to describe trends in extreme events that occur several times a year. Events that are much more extreme, for instance events leading to catastrophic flooding, are so rare that the observational series are too short to detect changes.
The conclusions are in line with recent findings of the Intergovernmental Panel on Climate Change (IPCC) and satisfy the wish of more knowledge on regional climate variations and extremes. They will be discussed at the IPCC-meeting on changes in extreme weather and climate events to be held in China from 11 to 13 June.
The full report is available at http://www.knmi.nl/voorl/.
