99 Nations accept Evidence of Rapid Global Warming
99 Nations accept Evidence of Rapid Global Warming
SHANGHAI, China, January 22, 2001 (ENS) - The scientific basis for the reality of rapid global warming is clear, a comprehensive new United Nations report reveals. Snow cover has decreased, the duration of lake and river ice cover is shorter, and the atmospheric concentration of heat trapping carbon dioxide has increased by a third since 1750, climate scientists say.
China's spreading Takla Makan desert
(Satellite photo courtesy NASA)
The new assessment by the
Intergovernmental Panel on Climate Change projects a
"potentially devastating" global warming of 1.4 to 5.8
degrees Celsius (2.52 to 10.44 degrees Fahrenheit) over the
coming century. This forecast is for higher temperatures
than an assessment by the same panel five years ago.
Over 150 delegates from 99 governments met in Shanghai
from January 17 to 20 to consider the new evidence contained
in the contribution of Working Group I to the Third
Assessment Report of the Intergovernmental Panel on Climate
Change, "Climate Change 2001: The Scientific Basis."
The
full report, which runs to over 1,000 pages, has been more
than three years in production. It is the work of 123 lead
authors from around the world. They in turn drew on the work
of 516 contributing authors. The report has gone through
extensive review by experts and governments.
After
line-by-line consideration, the government delegates
unanimously accepted the full report.
Dr. Robert Watson,
chairman of the Intergovernmental Panel on Climate Change,
and co-chair of Working Group I. (Photo courtesy Earth
Negotiations Bulletin)
The Intergovernmental Panel on
Climate Change (IPCC) is jointly sponsored by the United
Nations Environment Programme and the World Meteorological
Organization. The IPCC Working Group is headed by Robert
Watson, an American who is chief science adviser to the
World Bank and a former adviser on environment and
technology to the White House, and John Zillman, chairman of
the World Meteorological Organization.
Watson warned
rising temperatures will "cause decreases in agricultural
productivity in the tropics and sub-tropics ... areas where
we already have hunger."
New analyses of data from tree
rings, corals, ice cores and historical records for the
northern hemisphere show that the increase in temperature in
the 20th century is the largest of any century during the
past 1000 years.
Globally, the 1990s were the warmest
decade and 1998 the warmest year in the instrumental record
since 1861, the scientists found.
"The scientific
consensus presented in this comprehensive report about human
induced climate change should sound alarm bells in every
national capital and in every local community, said Klaus
Toepfer, executive director of the United Nations
Environment Programme and a former German environment
minister.
"We must move ahead boldly with clean energy
technologies, and we should start preparing ourselves now
for the rising sea levels, changing rain patterns, and other
impacts of global warming," Toepfer urged.
Michael
Zammit Cutajar, executive secretary of the United Nations
Climate Change Convention, said, "The scientific findings
being reported today should convince governments of the need
to take constructive steps towards resuming the climate
change talks that stalled last November in The Hague."
Key findings of the report include new and stronger
evidence that most of the warming observed over the last 50
years is attributable to human activities.
Since the
IPCC’s 1995 Report, confidence in the ability of models to
project future climate has increased. There is now a longer
and more closely scrutinized temperature record.
Reconstructions of climate data for the past 1,000
years, as well as model estimates of natural climate
variations, suggest that the observed warming over the past
100 years was unusual and is unlikely to be entirely natural
in origin.
Global Atmosphere Watch weather monitoring
station at Barrow, Alaska (Photo courtesy World
Meteorological Organization)
In the mid-latitudes and
high latitudes of the northern hemisphere, it is very likely
that snow cover has decreased by about 10 percent since the
late 1960s, and the annual duration of lake and river ice
cover has shortened by about two weeks over the 20th
century, the climate scientists agree.
In recent
decades, there has been about a 40 percent decline in Arctic
sea ice thickness during late summer to early autumn, the
researchers found.
Global warming is linked to the
emissions of six gases formed by the combustion of oil, coal
and natural gas; the major one is carbon dioxide. These
gases form a blanket in the upper atmosphere which keeps the
heat of the Sun from radiating back out into space, trapping
it close to the Earth.
Since 1750, the atmospheric
concentration of carbon dioxide has increased by 31 percent
from 280 parts per million to about 367 ppm today. The
present carbon dioxide concentration has not been exceeded
during the past 420,000 years and likely not during the past
20 million years, the scientists report.
Five years ago
the same panel predicted a rise in global temperature of 1
to 3.5 degrees Celsius (1.8 to 6.3 degrees Fahrenheit).
Scientists say the prediction of even higher global
temperatures is largely because future sulphur dioxide
emissions, which help to cool the Earth, are now expected to
be lower than forecast in 1995.
March 1997 flood, New
Richmond, Ohio, USA (Photo courtesy National Ocean and
Atmospheric Administration)
Global average water vapour
concentration and precipitation are projected to increase.
More intense precipitation - rain and snow - is likely over
many northern hemisphere’s mid-latitude to high latitude
land areas.
Sea levels are projected to rise by 0.09 to
0.88 meters (3.51 to 34.32 inches) from 1990 to 2100.
Despite higher temperature projections these sea level
projections are slightly lower than the range projected five
years ago, primarily due to the use of improved models,
which give a smaller contribution from glaciers and ice
sheets.
The Intergovernmental Panel on Climate Change
Report will include a report on the impacts of climate
change, to be finalized in mid-February, and another report
on response strategies, expected in early March.
ENDS