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

†

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.