Global Warming 'already changing world'
Pastor Dale Morgan
Global Warming 'already changing world'*
By Richard Black
Environment correspondent, BBC News website, Brussels
A woman walks through flood waters
Societies in many countries face increased risk of flooding
Climate change is already having major impacts on the natural world, a
UN report is set to announce.
The Intergovernmental Panel on Climate Change (IPCC) believes there is
also a discernible, though less marked, impact on human societies.
The IPCC is due to release the summary of its report on Friday, and
talks look set to go on until the last minute.
Draft versions seen by BBC News warn it will be hard for societies to
adapt to all the likely climate impacts.
The report is set to say that a temperature rise above 1.5C from 1990
levels would put about one-third of species at risk of extinction.
Adaptation alone is not expected to cope with all the projected effects
of climate change
IPCC draft
More than one billion people would be at greater risk of water
shortages, primarily because of the melting of mountain glaciers and ice
fields which act as natural reservoirs.
The last-minute wrangling is likely to affect the degree of certainty in
the final version, but not the overall direction.
The scientific work reviewed by IPCC scientists includes more than
29,000 pieces of data on observed changes in physical and biological
aspects of the natural world.
Eighty-five percent of these, it believes, are consistent with a warming
world.
Growing certainty
Since the IPCC's last global assessment in 2001, the amount of
scientific work on observing and collating changes to the natural world
has vastly increased.
In parallel, computer models which project the Earth's climatic future
have grown ever more sophisticated, though there are still uncertainties
in their forecasts and they remain unable to model some physical
processes accurately.
The combination of more observational evidence and better models allows
scientists to paint a much more detailed picture of what is happening in
different regions of the world, and what they believe is likely to
happen in the future.
"What we find is that evidence of the impacts of climate change is much
sharper, much more reliable," said IPCC chair Rajendra Pachauri.
"Many of the uncertainties have been resolved; and they confirm that the
poorest of the poor are most likely to be hit by the impacts of climate
change."
Fresh water is perhaps the most serious issue for human societies.
The world's great mountain ranges, such as the Himalayas, Rockies, Andes
and Alps, act as natural reservoirs, trapping winter rain and snowfall
as ice, and releasing it gradually in the summer.
Evidence suggests that glaciers are shrinking in all of these ranges.
One recent study predicted that 75% of Alpine glaciers would have
vanished by the end of this century.
A fisherman drags fish at the drying Dongting Lake on January 11, 2007
Countries supplied by glacier melt could face more droughts
As the ice disappears, spring and autumn floods become more likely, with
an increased risk of drought in summer. The IPCC is expected to say
there is "very high confidence" that these trends are already occurring.
It will also project a higher risk of flooding for many major cities on
or near the coast.
Another significant human impact projected in the drafts is a reduction
in agricultural output for most regions of the world.
Africa, most of South America, and Asia are likely to see crop yields
and livestock productivity falling.
Temperature rises of about 1C would benefit agriculture in some regions,
such as New Zealand and the northern portions of Russia and North
America; but greater rises would damage output in all parts of the world.
Carbon cuts
Some observers of climate issues have long maintained that action on
climate change should focus on protecting societies and natural systems
against impacts such as floods and drought, rather than on curbing
greenhouse gas emissions.
The IPCC, however, is set to conclude that "adaptation alone is not
expected to cope with all the projected effects of climate change, and
especially not over the long run as most impacts increase in magnitude".
Dealing with drought
Poorer societies are likely to be hardest hit, as they lack the
resources to set up protective measures and change their economic base.
Adapting to climate impacts, in the IPCC's view, should go hand in hand
with reducing emissions.
The report has already led to an exchange of words between the European
Union and the US, with Europe's Environment Commissioner Stavros Dimas
on Monday condemning the US's "negative attitude" towards international
climate treaties, and saying that a change of stance was "absolutely
necessary".
The US ambassador to the EU, Boyden Gray, responded that trans-Atlantic
differences were "not that great", even though President Bush,
commenting on a Supreme Court ruling that his administration had a duty
to regulate vehicle emissions, maintained the US was "doing enough" and
saw no need to change policy.
This is the second in a series of IPCC reports coming out this year,
together making up its fourth global climate assessment.
The first element, on the science of climate change, was released in
February, concluding it is at least 90% likely that human activities are
principally responsible for the warming observed since 1950.
The third part, which comes out in May, will focus on ways of curbing
the rise in greenhouse gas concentrations and temperature.