Climate change, impacts and vulnerability in Europe ... - MemoFin.fr

Changes in the climate systemPast trendsAnnual precipitation records averaged acrossEurope show no significant changes since 1950according to the E-OBS dataset (Haylock et al., 2008),based on the European Climate Assessment dataset(Klok and Klein Tank, 2009). At the sub-continentalscale, the trend in precipitation is most significantin north-eastern and south-western Europe. Themajority of Scandinavia and the Baltic States haveobserved an increase in annual precipitation ofgreater than 14 mm per decade, with an increaseof up to 70 mm per decade in western Norway. Incontrast, annual precipitation has decreased in theIberian Peninsula, in particular in north-westernSpain and in northern Portugal (Map 2.5). Whilethere is some evidence linking land use, in particularforest cover, to local and regional precipitationpatterns (Millán, 2008), it is not clear if the relativelyminor land-use changes since 1950 have influencedthe observed precipitation trends.ProjectionsSeasonal mean precipitation values and inter-annualvariability is better reproduced by an ensembleof RCMs than by any single RCM (Beniston et al.,2007; Tapiador, 2010). Recent work, building onthe two EU-funded research projects PRUDENCE(Christensen et al., 2002) and ENSEMBLES (van derLinden and Mitchell, 2009) has shown that RCMshave a reasonably strong consensus across Europein predicting changes in seasonal average rainfall(Tapiador, 2010). These projections indicate a generalincrease in annual precipitation in northern Europeand a decrease in southern Europe. The change inannual mean between 1961–1990 and 2071–2100according to the ENSEMBLES project (van derLinden and Mitchell, 2009) varies between 10% and20 % in northern Europe and between – 5 to – 20 %in southern Europe and the Mediterranean (Map 2.6left). Projections for summer precipitation showa decrease over southern, central and northwestEurope, which can reach of up to 60 % in parts ofsouthern Europe. Precipitation is projected to remainconstant or to increase slightly in northeast Europe(van der Linden and Mitchell, 2009; Tapiador, 2010)(Map 2.6 right).Map 2.570N60N50N40N30N1 2001 000800600Note:Total precipitationDrier– 87.5– 7015W 0 15E 30E– 52.5– 35PRCPTOT (mm)Trends in annual precipitationacross Europe (1960–2012)Change in annual precipitation (PRCPTOT, mm/decade)– 17.5017.5Trend: – 35.99 mm per decade (– 59.30 to – 10.14)Trend: 30.10 mm per decade (12.60 to 46.56)3552.570Wetter87.51955 1965 1975 1985 1995 2005 2015The trends are calculated using a median of pairwiseslopes algorithm. Black dots represent high confidencein the sign of the long-term trend in the box (if the5th to 95th percentile slopes are of the same sign).Boxes which have a thick outline contain at leastthree stations. Area averaged annual time series ofpercentage changes and trend lines are shown beloweach map for one area in northern Europe (blueline, 5.6 to 16.9 °E and 56.2 to 66.2 °N) and one insouth‐western Europe (red line, 350.6 to 1.9 °E and36.2 to 43.7 °N).Source: HadEX dataset, updated with data from the ECA&Ddataset.66 Climate change, impacts and vulnerability in Europe 2012