Climate Change: impacts and adaptation - IPCC · Climate Change: impacts and adaptation Lučka...
Transcript of Climate Change: impacts and adaptation - IPCC · Climate Change: impacts and adaptation Lučka...
g IPCC Fourth Assessment Report
Climate Change:
impacts and adaptation
Lučka Kajfež Bogataj
University of Ljubljana IPCC WG2 vicechair through AR4
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..)
Leaf unfolding dates in EuropeLeaf unfolding dates in Europe
Muir Glacier, Alaska, August 13, 1941, photo by W.O. Field
Muir Glacier, Alaska, August 31, 2004, photo by B.F. Molnia
UTC
13:00
Heat stress
Cold stress
light
extreme
high
moderate
light
comfortable
moderate
high
extreme
Heat wave of 2003, the largest humanitarian
natural catastrophe in Europe for centuries
15,000
†
15,000
†
7,000
†
7,000
†
4,000
†
4,000†
2,000
†
2,000
†2,000
†
2,000
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4,000
†
4,000
†
Perceived Temperature on 8 August 2003 and excess mortality
Source: German Weather Service, 2004
Climate change impacts transpire gradually from the natural environment into the economies and society
Water
Soil
Nature
Air
Biodiversity
Ecosystem
Water
Projected impacts of climate change
1°C 2°C 5°C4°C3°C
Sea level rise
threatens major cities
Falling crop yields in many areas, particularly
developing regions
FoodFood
WaterWater
EcosystemsEcosystems
Risk of Abrupt and Risk of Abrupt and
Major Irreversible Major Irreversible
ChangesChanges
Global temperature change (relative to pre-industrial)0°C
Falling yields in many
developed regions
Rising number of species face extinction
Increasing risk of dangerous feedbacks and
abrupt, large-scale shifts in the climate system
Significant decreases in water availability in many areas, including Mediterranean and Southern Africa
Small mountain glaciers disappear – water supplies threatened in several areas
Extensive Damage
to Coral Reefs
Extreme Extreme
Weather Weather
EventsEvents
Rising intensity of storms, forest fires, droughts, flooding and heat waves
Possible rising yields in
some high latitude regions
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
Critical thresholds
Major impacts of climate change on crop and
livestock yields, and forestry production by 2050
Agriculture
Yield fall, droughtS Europe
Increased crop varieties & yields, but more disease
N America, Europe, Rus.
Increased disease; lower yields, droughtsAfrica
Increased storms; lower yields; increased drought
S America & Caribbean
Increased flooding; increased drought; increased disease
S Asia
Increased storm activity & intensityEast Asia
Worse droughts; desertification of farmlandAustralia
ImpactsRegion
Globally there will be some gains in potential agricultural land by 2080,
but losses of up to 9% in sub-Saharan Africa.
More extreme weather events
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.
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
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.
Extreme > 1 million;
high =1 million – 50,000;
medium 50,000 – 5000.
Population potentially displaced by
current sea level trends to 2050
Regions most affectedRegions most affected Vulnerable systems and sectorsVulnerable systems and sectors
• The Arctic
• Sub-Saharan Africa
• Small islands
• Asian megadeltas
• Some ecosystemsCoral reefs; sea-ice regionsTundra, boreal forests,
mountain and Mediterranean regions
• Low-lying coasts
mangroves & salt marshes
• Water resources in mid-
latitudes & dry Tropics
• Low-latitude agriculture
• Human health where adaptive capacity is low
Increased water
availability(2070 ca.↑1/5)
Increased forest growth
(only in the beginning?)
Increased
yields(only in the beginning? )
Decreased
yields
Decreased water
availability( 2070 ca.↓1/3)
Increased fire risk
S EuropeN Europe
Europe
North ↔ South differences
Adaptation will be necessary
to address unavoidable impacts
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
A global shift southward
PRUDENCE project; Results based on HadRM3H
SUMMARYhuman development tipping points
� Reduced agricultural productivity
� Heightened water insecurity
� Increased exposure to extreme weather
events
� Collapse of ecosystems
� Increased health risks
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.