Climate Change: impacts and adaptation - IPCC ?· Climate Change: impacts and adaptation Lučka Kajfež…

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  • g IPCC Fourth Assessment Report

    Climate Change:

    impacts and adaptation

    Luka Kajfe 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

    1C 2C 5C4C3C

    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)0C

    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.

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