1. 2016-01-28 A Swedish perspective on adaptation to Climate Change Jörgen Nilsson Swedish Meteorological and Hydrological Institute Norköping

2. 2016-01-28 Nordic hydropower in % of total electricity production Norway 100%123 TWh Sweden 45% 66 TWh Finland 12% 8 TWh (approximate figures)

3. 2016-01-28 Inflow to the Swedish hydropower reservoirs in relation to the average for the period 1950-2006 (TWh/year) Source: Svensk Energi

4. 2016-01-28 We need regional information Source: Monitor No. 18, 2003 300x300km 50x50km

5. 2016-01-28 Precipitation change downscaled by the regional RCO: HadAM3H ECHAM4/OPYC3 Emission scenario A2Emission scenario B2

6. 2016-01-28 Annual runoff change (mm) Hadley/A2 Annual runoff change (mm) Echam/A2 Annual runoff change (mm) Hadley/B2 Annual runoff change (mm) Echam/B2

7. 2016-01-28 National hydrograph for Sweden 1961-1990 vs 2071-2100

8. 2016-01-28 Future production potential in Swedish rivers 1961-1990 vs 2071-2100

9. 2016-01-28 Implications: Less demand for heating … but more for cooling CDD HDD 1961-1990 2011-2040 2041-2070 2071-2100 Heating degree days per year, T<17 o C Cooling degree days per year, T>20 o C A2

10. 2016-01-28 Swedish guidelines on hydrological design of dams

11. 2016-01-28 Upgrading of dam safety, new spillway for the Håckren dam

12. 2016-01-28 Impacts on design floods in Sweden % change in design flood peak, 1961-1990 vs 2071-2100

13. 2016-01-28 Changes in 100-years floods according to E/A2 and E/B2 scenarios

14. 2016-01-28 Changes in 100-years floods according to H/A2 and H/B2 scenarios

15. 2016-01-28 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)

16. 2016-01-28 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

17. 2016-01-28 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

18. 2016-01-28 Future flood risks around the big Swedish lakes Stockholm Gothenburg Karlstad Mälaren Hjälmaren Vänern Vättern Göta älv Örebro

19. 2016-01-28 Stockholm 1924

20. 2016-01-28 Stockholm in April 2003 Foto: Sten Bergström, SMHI

21. 2016-01-28 Lake Mälaren and Stockholm, summary of the problems 1.Decree for regulation in 1943 2.Pressure on exploitation, shore lines are not secure under today’s 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

22. 2016-01-28 Uplift of land in Sweden (mm per year)

23. 2016-01-28

24. Large land slides in the Göta älv valley 1: Jordfallsskredet 1150, 65 har 3: Intagan 1648-07-10, 27har 6: Ballabo mars 1733, 3 har 9: Utby 1806-12-21, 4,5 har 10: Västerlanda ca 1830, >5 har 12: Surte 1950-09-29, 24 har 14: Göta 1957-06-07, 32 har 15: Agnesberg 1993-04-14, 0,25har 16: Ballabo 1996-04-16, 0,7 har Source: Statens Geotekniska Institut

25. 2016-01-28 Inundated areas at peak level if Climate Change is considered will be about 50 cm higher than today

26. 2016-01-28 Change in 100-year levels(cm)New return periods RCAO – H/A2+ 3725 RCAO – H/B2+ 2140 RCAO – E/A2+ 985 RCAO – E/B2+ 5712 Changes in the 100-years levels and return periods for Lake Vänern according to climate scenarios

27. 2016-01-28 Tunnel?

28. 2016-01-28 Attractive near-shore developments in the city of Karlstad Foto: Sten Bergström, SMHI

29. 2016-01-28 Vänern- Göta älv, summary of the problems 1.Decree for regulation in 1937 2.Pressure on exploitation, shore lines are not secure under today’s climate 3.Hydropower in the river 4.Important shipping 5.Unstable geology limits discharge in the river. Land slides may risk water supply for 700 000 citizens 6.Sea levels hinder discharge 7.Climate change increases the problems

30. 2016-01-28 Conclusions Big lakes mean big problems in metropolitan areas Today’s flooding problems will be aggravated by climate change in western Sweden Stockholm can be secured by a doubling of the discharge capacity of Lake Mälaren There is no simple solution for Lake Vänern and River Göta älv. A combination of measures will be needed. Cautious physical planning is necessary to avoid future problems everywhere

31. 2016-01-28 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!