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Global
Warming:
Scientists Reveal Timetable
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by
Michael McCarthy, February 3, 2005
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A
detailed timetable of the destruction and distress that global
warming is likely to cause the world was unveiled yesterday.
It
pulls together for the first time the projected impacts on
ecosystems and wildlife, food production, water resources
and economies across the earth, for given rises in global
temperature expected during the next hundred years.
The
resultant picture gives the most wide-ranging impression yet
of the bewildering array of destructive effects that climate
change is expected to exert on different regions, from the
mountains of Europe and the rainforests of the Amazon to the
coral reefs of the tropics.
Produced
through a synthesis of a wide range of recent academic studies,
it was presented as a paper yesterday to the international
conference on climate change being held at the UK Met Office
headquarters in Exeter by the author Bill Hare, of the Potsdam
Institute for Climate Impact Research, Germany's leading global
warming research institute.
The
conference has been called personally by Tony Blair as part
of Britain's attempts to move the climate change issue up
the agenda during the current UK presidency of the G8 group
of rich nations, and the European Union. It has already heard
disturbing warnings from the latest climate research, including
the revelation on Tuesday from the British Antarctic Survey
that the massive West Antarctic ice sheet might be disintegrating
- an event which, if it happened completely, would raise sea
levels around the world by 16ft (4.9 metres).
Dr
Hare's timetable shows the impacts of climate change multiplying
rapidly as average global temperature goes up, towards 1C
above levels before the industrial revolution, then to 2C,
and then 3C.
As
present world temperatures are already 0.7C above the pre-industrial
level, the process is well under way. In the near future -
the next 25 years - as the temperature climbs to the 1C mark,
some specialised ecosystems will start to feel stress, such
as the tropical highland forests of Queensland, which contain
a large number of Australia's endemic plant species, and the
succulent karoo plant region of South Africa. In some developing
countries, food production will start to decline, water shortage
problems will worsen and there will be net losses in GDP.
It
is when the temperature moves up to 2C above the pre-industrial
level, expected in the middle of this century - within the
lifetime of many people alive today - that serious effects
start to come thick and fast, studies suggest.
Substantial
losses of Arctic sea ice will threaten species such as polar
bears and walruses, while in tropical regions "bleaching"
of coral reefs will become more frequent - when the animals
that live in the coral are forced out by high temperatures
and the reef may die. Mediterranean regions will be hit by
more forest fires and insect pests, while in regions of the
US such as the Rockies, rivers may become too warm for trout
and salmon.
In
South Africa, the Fynbos, the world's most remarkable floral
kingdom which has more than 8,000 endemic wild flowers, will
start to lose its species, as will alpine areas from Europe
to Australia; the broad-leaved forests of China will start
to die. The numbers at risk from hunger will increase and
another billion and a half people will face water shortages,
and GDP losses in some developing countries will become significant.
But
when the temperature moves up to the 3C level, expected in
the early part of the second half of the century, these effects
will become critical. There is likely to be irreversible damage
to the Amazon rainforest, leading to its collapse, and the
complete destruction of coral reefs is likely to be widespread.
The
alpine flora of Europe, Australia and New Zealand will probably
disappear completely, with increasing numbers of extinctions
of other plant species. There will be severe losses of China's
broadleaved forests, and in South Africa the flora of the
Succulent Karoo will be destroyed, and the flora of the Fynbos
will be hugely damaged.
There
will be a rapid increase in populations exposed to hunger,
with up to 5.5 billion people living in regions with large
losses in crop production, while another 3 billion people
will have increased risk of water shortages.
Above
the 3C raised level, which may be after 2070, the effects
will be catastrophic: the Arctic sea ice will disappear, and
species such as polar bears and walruses may disappear with
it, while the main prey species of Arctic carnivores, such
as wolves, Arctic foxes and the collared lemming, will have
gone from 80 per cent of their range, critically endangering
predators.
In
human terms there is likely to be catastrophe too, with water
stress becoming even worse, and whole regions becoming unsuitable
for producing food, while there will be substantial impacts
on global GDP.
