A Swedish perspective on adaptation to Climate Change
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Transcript of A Swedish perspective on adaptation to Climate Change
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A Swedish perspective on adaptation to Climate
Change
Jörgen Nilsson
Swedish Meteorological and Hydrological Institute
Norköping
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Nordic hydropower in % of total electricity
production
Norway 100% 123 TWh
Sweden 45% 66 TWh
Finland 12% 8 TWh
(approximate figures)
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Inflow to the Swedish hydropower reservoirs in relation to the
average for the period 1950-2006 (TWh/year)
Source: Svensk Energi-25
-15
-5
5
15
25
1950 1961 1972 1983 1994 2005
TWh/år
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We need regional information
Source: Monitor No. 18, 2003
300x300km 50x50km
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Precipitation change downscaled by the regional RCO:
HadAM3H
ECHAM4/OPYC3
Emission scenario A2 Emission scenario B2
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Annual runoff change (mm)
Hadley/A2
Annual runoff change (mm)
Echam/A2
Annual runoff change (mm)
Hadley/B2
Annual runoff change (mm)
Echam/B2
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National hydrograph for Sweden 1961-1990 vs
2071-2100
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Future production potential in Swedish rivers
1961-1990 vs 2071-2100
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Implications: Less demand for heating … but more for
coolingC
DD
HD
D
1961-1990 2011-2040 2041-2070 2071-2100
Heating degree days per year, T<17oCCooling degree days per year, T>20oC
A2
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Swedish guidelines on
hydrological design
of dams
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Upgrading of dam safety, new spillway for the
Håckren dam
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Impacts on design
floods in Sweden
% change in design flood peak, 1961-1990 vs 2071-2100
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Changes in 100-years floods according to E/A2 and E/B2
scenarios
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Changes in 100-years floods according to H/A2 and H/B2
scenarios
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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)
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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
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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
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Future flood risks around the big Swedish lakes
Stockholm
Gothenburg
KarlstadMälaren
HjälmarenVänern
VätternGöta älv
Örebro
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Stockholm 1924
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Stockholm in April 2003
Foto: Sten Bergström, SMHI
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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
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Uplift of land in Sweden (mm per year)
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Large land slides in the Göta älv valley
5
3
1
12215
4
14(2)
8
9
6
167, 10 13
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
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Inundated areas at
peak level if
Climate Change
is considered will
be about 50 cm
higher than today
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Change in 100-year levels(cm) New return periods
RCAO – H/A2 + 37 25
RCAO – H/B2 + 21 40
RCAO – E/A2 + 98 5
RCAO – E/B2 + 57 12
Changes in the 100-years levels and return periods for Lake Vänernaccording to climate scenarios
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Tunnel?
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Attractive near-shore developments in the city of Karlstad
Foto: Sten Bergström, SMHI
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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
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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
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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!