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Examples
of
some projected regional impacts
Africa
- By 2020, between 75 and 250 million of
people
are projected to be exposed to
increased water stress due to climate change
- By 2020, in some countries, yields from
rain-fed agriculture could be reduced
by up to 50%. Agricultural production, including access to food, in
many African countries is projected to be severely
compromised. This would further adversely affect food security and
exacerbate malnutrition
- Towards the end of the 21st century,
projected sea-level rise will affect
low-lying coastal areas with large populations.The cost of adaptation
could amount to at least 5-10% of Gross Domestic
Product
(GDP)
- By 2080, an increase of 5-8% of arid
and
semi-arid land in Africa is
projected under a range of climate scenarios (TS)
Asia
- By the 2050s, freshwater availability
in
Central, South, East and South-East
Asia, particularly in large river basins, is projected to decrease
- Coastal areas, especially
heavily-populated
megadelta regions in South, East
and South-East Asia, will be at greatest risk due to increased flooding
from the sea and, in some megadeltas, flooding
from the rivers
- Climate change is projected to compound
the
pressures on natural resources
and the environment, associated with rapid urbanization,
industrialization and economic development
- Endemic morbidity and mortality due to
diarrhoeal disease primarily
associated with floods and droughts are expected to rise in East, South
and South-East Asia due to projected changes in the
hydrological cycle
Australia and New Zealand
- By 2020, significant loss of
biodiversity is
projected to occur in some
ecologically rich sites including the Great Barrier Reef and Queensland
Wet Tropics
- By 2030, water security problems are
projected to intensify in southern and
eastern Australia and, in New Zealand, in Northland and some eastern
regions
- By 2030, production from agriculture
and
forestry is projected to decline
over much of southern and eastern Australia, and over parts of eastern
New Zealand, due to increased drought and fire.
However, in New Zealand, initial benefits
- are projected in some other regions
- By 2050, ongoing coastal development
and
population growth in some areas of
Australia and New Zealand are projected to exacerbate risks from sea
level rise and increases in the severity
and frequency of storms and coastal flooding
Europe
- Climate change is expected to magnify
regional differences in Europe's
natural resources and assets. Negative impacts will include increased
risk of inland flash floods, and more frequent
coastal flooding and increased erosion (due to storminess and sea-level
rise)
- Mountainous areas will face glacier
retreat,
reduced snow cover and winter
tourism, and extensive species losses (in some areas up to 60% under
high emissions scenarios by 2080)
- In Southern Europe, climate change is
projected to worsen conditions (high
temperatures and drought) in a region already vulnerable to climate
variability, and to reduce water availability,
hydropower potential, summer tourism and, in general, crop productivity
- Climate change is also projected to
increase
the health risks due to
heat-waves, and the frequency of wildfires Latin America
- By mid century, increases in
temperature and
associated decreases in soil
water are projected to lead to gradual replacement of tropical forest
by savanna in eastern Amazonia. Semi-arid
vegetation will tend to be replaced by aridland vegetation
- There is a risk of significant
biodiversity
loss through species extinction
in many areas of tropical Latin America
- Productivity of some important crops is
projected to decrease and livestock
productivity to decline, with adverse consequences for food security.
In temperate zones soybean yields are projected
to increase. Overall, the number of people at risk of hunger is
projected to increase (TS; medium confidence)
- Changes in precipitation patterns and
the
disappearance of glaciers are
projected to significantly affect water availability for human
consumption, agriculture and energy generation
North America
- Warming in western mountains is
projected to
cause decreased snowpack, more
winter flooding, and reduced summer flows, exacerbating competition for
over-allocated water resources
- In the early decades of the century,
moderate
climate change is projected to
increase aggregate yields of rain-fed agriculture by 5-20%, but with
important variability among regions. Major
challenges are projected for crops that are near the warm end of their
suitable range or which depend on highly utilized
water resources
- During the course of this century,
cities
that currently experience heatwaves
are expected to be further challenged byan increased number, intensity
and duration of heatwaves during the course of
the century, with potential for adverse health impacts
- Coastal communities and habitats will
be
increasingly stressed by climate
change impacts interacting with development and pollution
Polar Regions
- The main projected biophysical effects
are
reductions in thickness and extent
of glaciers and ice sheets and sea ice, and changes in natural
ecosystems with detrimental effects on many organisms
including migratory birds, mammals and higher predators
- For human communities in the Arctic,
impacts,
particularly those resulting
from changing snow and ice conditions are projected to be mixed
- Detrimental impacts would include those
on
infrastructure and traditional
indigenous ways of life
- In both polar regions, specific
ecosystems
and habitats are projected to be
vulnerable, as climatic barriers to species invasions are lowered
Small Islands
- Sea-level rise is expected to
exacerbate
inundation, storm surge, erosion and
other coastal hazards, thus threatening vital infrastructure,
settlements and facilities that support the
livelihood of island communities
- Deterioration in coastal conditions,
for
example through erosion of beaches
and coral bleaching is expected to affect local resources
- By mid-century, climate change is
expected to
reduce water resources in many
small islands, e.g. in the Caribbean and Pacific, to the point where
they become insufficient to meet demand during
low-rainfall periods
- With higher temperatures, increased
invasion
by non-native species is
expected to occur, particularly on mid- and high-latitude islands
Intergovernmental Panel on Climate Change, Fourth Assessment Report
Climate Change 2007: Synthesis Report
Summary for Policymakers
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