A Swedish perspective on adaptation to Climate Change Jrgen Nilsson Swedish Meteorological and Hydrological Institute Norkping Nordic hydropower in % of total electricity production Norway 100%123 TWh Sweden 45% 66 TWh Finland 12% 8 TWh (approximate figures) Inflow to the Swedish hydropower reservoirs in relation to the average for the period (TWh/year) Source: Svensk Energi We need regional information Source: Monitor No. 18, x300km 50x50km Precipitation change downscaled by the regional RCO: HadAM3H ECHAM4/OPYC3 Emission scenario A2Emission scenario B2 Annual runoff change (mm) Hadley/A2 Annual runoff change (mm) Echam/A2 Annual runoff change (mm) Hadley/B2 Annual runoff change (mm) Echam/B2 National hydrograph for Sweden vs Future production potential in Swedish rivers vs Implications: Less demand for heating but more for cooling CDD HDD Heating degree days per year, T20 o C A2 Swedish guidelines on hydrological design of dams Upgrading of dam safety, new spillway for the Hckren dam Impacts on design floods in Sweden % change in design flood peak, vs Changes in 100-years floods according to E/A2 and E/B2 scenarios Changes in 100-years floods according to H/A2 and H/B2 scenarios The Nordic energy sector is very sensitive to global warming: It effects production (inflow to hydropower, wind, biomass) It effects consumption (heating) It effects safety (storms, dam safety) It effects distribution (storms) The most evident impact is that on hydropower, impacts on wind power are more inconclusive Hydropower production is expected to increase The annual rythm in river flow will be more favorable Impact on dam safety is not self-evident and has to be analysed carefully, case by case The development of the future European energy market will have strong impact on the Nordic hydropower industry The Swedish Commission on Climate and Vulnerability Addresses impacts, vulnerability, responsibilities and costs due to climate change Sub-report on flooding, November 2006 Final report, October 2007 Future flood risks around the big Swedish lakes Stockholm Gothenburg Karlstad Mlaren Hjlmaren Vnern Vttern Gta lv rebro Stockholm 1924 Stockholm in April 2003 Foto: Sten Bergstrm, SMHI Lake Mlaren and Stockholm, summary of the problems 1.Decree for regulation in Pressure on exploitation, shore lines are not secure under todays climate. Important downtown infrastructure is at risk, including the subway 3.Important shipping But 1.No river downstream hinders discharge 2.Sea level rise is compensated by uplift of land 3.Climate change does not seem to increase the problems Uplift of land in Sweden (mm per year) Large land slides in the Gta lv valley 1: Jordfallsskredet 1150, 65 har 3: Intagan , 27har 6: Ballabo mars 1733, 3 har 9: Utby , 4,5 har 10: Vsterlanda ca 1830, >5 har 12: Surte , 24 har 14: Gta , 32 har 15: Agnesberg , 0,25har 16: Ballabo , 0,7 har Source: Statens Geotekniska Institut Inundated areas at peak level if Climate Change is considered will be about 50 cm higher than today Change in 100-year levels(cm)New return periods RCAO H/A RCAO H/B RCAO E/A RCAO E/B Changes in the 100-years levels and return periods for Lake Vnern according to climate scenarios Tunnel? Attractive near-shore developments in the city of Karlstad Foto: Sten Bergstrm, SMHI Vnern- Gta lv, summary of the problems 1.Decree for regulation in Pressure on exploitation, shore lines are not secure under todays climate 3.Hydropower in the river 4.Important shipping 5.Unstable geology limits discharge in the river. Land slides may risk water supply for citizens 6.Sea levels hinder discharge 7.Climate change increases the problems Conclusions Big lakes mean big problems in metropolitan areas Todays flooding problems will be aggravated by climate change in western Sweden Stockholm can be secured by a doubling of the discharge capacity of Lake Mlaren There is no simple solution for Lake Vnern and River Gta lv. A combination of measures will be needed. Cautious physical planning is necessary to avoid future problems everywhere How to handle all that unavoidable uncertainty? Use ensembles of climate models and scenarios Develop flexible adaptation strategies Add safety margins wherever reasonably possible Communicate!