The impacts of climate change
2007-03-14 09:14
Here are some of the projected
regional impacts of global warming in a draft UN report by the
world's top climate scientists. The report will be presented in
Brussels on April 6 after a final review:
Asia
Glacier melt in the Himalayas is "virtually certain" to
bring more floods, rock avalanches, and disrupt water resources.
Coastal areas, especially heavily populated river delta
regions in south, east and southeast Asia, are likely to be at
greatest risk of increased flooding.
Projected rises in temperature and shifts in rains are
likely to bring declines in crop productivity "that will
increase the risk of hunger especially in developing countries".
Africa
"Large rises in numbers of people at risk of water scarcity"
are likely because of shortages and rising demand for water. An
"increased risk of hunger" is likely because of factors
including cuts in the area suitable for farming and crop yields.
Projected sea level rise will threaten large cities. Coral
reefs and mangroves will be further degraded. There may be lower
fish catches from large lakes.
Europe
In the south "climate change is likely to have negative
impacts by increasing risk to health due to more frequent heat
waves, reducing water availability and hydropower, endangering
crop production, and increasing the frequencies of wildfires."
In the north, climate change is likely to bring benefits
such as less cold, increased crop yields, increased forest and
fish productivity, and more hydropower potential.
By the 2020s, there is likely to be increased risk of flash
floods throughout Europe. Coastal flooding is likely to threaten
up to an extra 2.5 million people each year by 2080.
North America
"Projected warming in the western mountains is very likely
to cause reduced snowpack, more winter floods, reduced summer
water flows, exacerbating competition for over-allocated water
resources."
Forests will suffer more from pests, disease and fire.
"Cities with a history of heat waves are likely to suffer
many more, with potential for adverse health impacts," it said.
"Population growth and development in coastal areas are very
likely to increase risks and economic losses from sea level
rise, severe weather and storm surge. Current adaptation is
uneven and readiness for increased exposure is low," it said.
Latin America
Tropical forest could be replaced by savannah in eastern
Amazonia because of higher temperatures and less soil water. In
northeast Brazil and northern Mexico, semi-arid vegetation is
likely to be replaced by arid-land vegetation.
In drier areas, climate change could lead to desertification
of farmland. Yields of some crops could fall, but soybean yields
are likely to increase in temperate zones.
Sea temperature rises could damage Central American coral
reefs and shift southeast Pacific fish stocks.
Australia and New Zealand
Water security problems are projected to increase in
southern and eastern Australia and parts of eastern New Zealand.
Further loss of biodiversity is likely in sites including the
Great Barrier Reef and Alpine national parks.
Coastal communities in places such as the Cairns region or
southeast Queensland, are very likely to face risks from sea
level rises and more severe storms.
Some areas will benefit from up to about 1-2 Celsius global temperature rise, such as New
Zealand and parts of southern Australia. Benefits include longer
growing seasons, less frost risk, reduced winter energy demand.
Polar regions
Likely projected losses in the thickness and extent of ice
and changes in permafrost will have "detrimental effects on
migratory birds, mammals and higher predators."