g IPCC Fourth Assessment Report Climate Change: impacts and adaptation

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1 g IPCC Fourth Assessment Report Climate Change: impacts and adaptation Lučka Kajfež Bogataj University of Ljubljana IPCC WG2 vicechair through AR4

2 Following addressed: Impacts observed so far Future scenarios Impacts on sectors Water Ecosystems Agriculture, forestry, fisheries Coasts Settlements and industry Health Impacts on regions (Asia, Australia... Europe..)

3 Leaf unfolding dates in Europe

4 Muir Glacier, Alaska, August 13, 1941, photo by W.O. Field

5 Muir Glacier, Alaska, August 31, 2004, photo by B.F. Molnia

6 Heat wave of 2003, the largest humanitarian natural catastrophe in Europe for centuries Perceived Temperature on 8 August 2003 and excess mortality Source: German Weather Service, ,000 2,000 15,000 7,000 Heat stress extreme high moderate light comfortable light moderate high extreme 4,000 4,000 Cold stress UTC 13:00

7 Climate change impacts transpire gradually from the natural environment into the economies and society Water Ecosystem Soil Nature Air Biodiversity

8 Water

9 0 C Food Projected impacts of climate change Global temperature change (relative to pre-industrial) 1 C 2 C 3 C 4 C 5 C Falling crop yields in many areas, particularly developing regions Possible rising yields in some high latitude regions Falling yields in many developed regions Water Ecosystems Small mountain glaciers disappear water supplies threatened in several areas Extensive Damage to Coral Reefs Extreme Weather Events Risk of Abrupt and Major Irreversible Changes Significant decreases in water availability in many areas, including Mediterranean and Southern Africa Rising number of species face extinction Sea level rise threatens major cities Rising intensity of storms, forest fires, droughts, flooding and heat waves Increasing risk of dangerous feedbacks and abrupt, large-scale shifts in the climate system

10 Impacts Marine & terrestrial ecosystems +1-2 C : negative impacts for some systems (e.g. Coral bleaching, endemic plants & fauna in S-Africa, polar systems) +2-3 C : major biome changes very likely (e.g. coral mortality, 20-80% loss of Amazonian rainforest, globally 20-30% species extinction) > +3 C : widespread, heavy impacts on biomes, globally significant extinctions

11 Critical thresholds

12 Major impacts of climate change on crop and livestock yields, and forestry production by 2050

13 Agriculture Region Australia East Asia S Asia S America & Caribbean Africa N America, Europe, Rus. S Europe Impacts Worse droughts; desertification of farmland Increased storm activity & intensity Increased flooding; increased drought; increased disease Increased storms; lower yields; increased drought Increased disease; lower yields, droughts Increased crop varieties & yields, but more disease Yield fall, drought Globally there will be some gains in potential agricultural land by 2080, but losses of up to 9% in sub-saharan Africa.

14 More extreme weather events

15 Industry and settlements The most vulnerable are those in coastal and river flood plains, those whose economies are closely linked with climate-sensitive resources, and those in areas prone to extreme weather events, especially where rapid urbanisation is occurring. Poor communities can be especially vulnerable, in particular those concentrated in high-risk areas.

16 Human health, already compromised by a range of factors, could also be further negatively impacted by climate change and climate variability Negative Impact Positive Impact

17 Vulnerability of coastal deltas Coastal wetlands including salt marshes and mangroves will be negatively affected by sea-level rise. Many millions more people are to be flooded every year due to sea-level rise by the 2080s. The numbers affected will be largest in the mega-deltas of Asia and Africa while small islands are especially vulnerable. Population potentially displaced by current sea level trends to 2050 Extreme > 1 million; high =1 million 50,000; medium 50,

18 Regions most affected The Arctic Sub-Saharan Africa Small islands Asian megadeltas Vulnerable systems and sectors Some ecosystems Coral reefs; sea-ice regions Tundra, boreal forests, mountain and Mediterranean regions Low-lying coasts mangroves & salt marshes Water resources in midlatitudes & dry Tropics Low-latitude agriculture Human health where adaptive capacity is low

19 Europe North South differences N Europe Increased forest growth (only in the beginning?) S Europe Increased fire risk Increased water availability (2070 ca. 1/5) Decreased water availability ( 2070 ca. 1/3) Increased yields (only in the beginning? ) Decreased yields

20 Adaptation will be necessary to address unavoidable impacts

21 Adaptation/Mitigation Some adaptation is occurring now, faces limitations and barriers Other stresses can exacerbate vulnerability Vulnerability depends also on development paths Sustainable development can reduce vulnerability Mitigation can reduce, delay or avoid impacts

22 A global shift southward PRUDENCE project; Results based on HadRM3H

23 SUMMARY human development tipping points Reduced agricultural productivity Heightened water insecurity Increased exposure to extreme weather events Collapse of ecosystems Increased health risks

24 CONCLUSIONS Natural and human systems are being affected by regional climate changes Impacts are expected to increase with increases in global average temperature. Adaptation can reduce vulnerability, especially in the short-term.