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

Vulnerability to climate changeThe ClimWatAdapt project also prepared projectionsfor low flow and water stress. Map 5.2 showsannual water stress, which is calculated as theratio of water abstraction to availability for twoscenarios. Due to various uncertainties care shouldbe taken in interpreting these projections. Detailson the assumptions and models are available intheir final report (Flörke, Wimmer, Laaser, et al.,2011). In the Economy First scenario water stressshows a large increase for the 2050s across muchof Europe compared to the current situation. Theimplementation of a sustainable approach tothe management of Europe's water resources isinvestigated in a 'Sustainability First' scenario. Thisscenario sketches the transition from a globalising,market-oriented Europe to environmentalsustainability, where local initiatives are leading.A considerable reduction in annual water stress isprojected across much of Europe, compared to boththe Economy First scenario and the present daysituation (Flörke, Wimmer, Laaser, et al., 2011).Drought risks will increase throughout largeareas of the EU (see also Section 2.2.5), wherebysouthern Europe is the most vulnerable region inEurope. Increasing irrigation efficiency can reduceirrigation water withdrawals to some degree buttechnological changes will not be sufficient tosave southern Europe from water stress. Besidesagriculture, electricity production is vulnerableto climate change effects on river low flows andwater temperature for their cooling water (seeSection 4.5.3). However, the energy sector has ahigh potential to reduce water withdrawals throughtechnological improvements.Environmental flows, which are important forthe healthy maintenance of aquatic ecosystems,are threatened by climate change impactsand socio‐economic developments. Althougha Good Ecological Status is required by theWater Framework Directive (WFD), river basinmanagement plans currently do not consider climatechange impacts sufficiently and further coordinationbetween river basin management plans and droughtmanagement plans is preferable. Mandatory waterabstraction schemes are needed during low-flowperiods to protect ecosystems. Many river basinsare expected to be in the severe water stress class in2050. Competition for scarce water resources couldbe an ongoing source of tension between differentusers and in the case of transboundary river basinsbetween nations as well.Map 5.2Annual water stress for present conditions and projections for two scenariosPresent climate2050 projectionEconomy First scenario2050 projectionSustainability Eventually scenario60°60°50°50°50°40°40°40°0 500 1000 1500 km 20° 30° 40° 0 500 1000 1500 km 20° 30° 40° 0 500 1000 1500 km 20° 30° 40°Annual water stress for present conditions and projections for two scenariosLow Mild Severe Outside coverageNote: Left: present climate; middle: projection for 2050 based on Economy First scenario, median of general circulation models —regional climate models (GCM-RCM) combinations;right: projection for 2050 based on Sustainability Eventually scenario, median of GCM-RCM combinations.Yellow: low water stress (withdrawals-to-availability ratio: 0–0.2); orange: mild water stress (withdrawals-to-availabilityratio: 0.2–0.4), red: severe water stress (withdrawals-to-availability ratio: > 0.4).Source: Flörke, Wimmer, Laaser, et al., 2011.Climate change, impacts and vulnerability in Europe 2012215