IPCC Fourth Assessment Report - Climate Change: impacts and adaptation
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..)
9. 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 andRisk of Abrupt and
Major IrreversibleMajor 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
ExtremeExtreme
WeatherWeather
EventsEvents
Rising intensity of storms, forest fires, droughts, flooding and heat waves
Possible rising yields in
some high latitude regions
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
12. Major impacts of climate change on crop and
livestock yields, and forestry production by 2050
13. 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.
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.
Extreme > 1 million;
high =1 million – 50,000;
medium 50,000 – 5000.
Population potentially displaced by
current sea level trends to 2050
18. Regions most affectedRegions most affected Vulnerable systems and sectorsVulnerable systems and sectors
• The Arctic
• Sub-Saharan Africa
• Small islands
• Asian megadeltas
• Some ecosystems
Coral reefs; sea-ice regions
Tundra, 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
19. 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
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.