By Nick Cumming-Bruce, The New York Times, November 28, 2012
GENEVA — This year
has ranked among the nine warmest since records began more than 160 years ago,
continuing a trend for the planet that is increasing the dangers of extreme
weather events, according to United Nations meteorologists.
“It confirms the trend towards a warmer planet,” Michel Jarraud, head
of the World Meteorological Organization at the United Nations, said in Geneva
on Wednesday as he delivered a provisional assessment intended to inform policy
makers and negotiators attending the U.N. Climate Change Conference in Doha,
Qatar.
The final judgment on 2012 will come in March, but Mr. Jarraud said
that meteorologists were not observing any major events that would greatly
alter the preliminary findings.
“Climate change is taking place before our eyes
and will continue to do so as a result of concentrations of greenhouse gases in
the atmosphere, which have risen constantly and again reached new records,” he
added in a prepared statement.
Among the most conspicuous evidence of climate change associated with
global warming was the “alarming” rate at which Arctic ice had melted during the summer
months, he said. The melting this year occurred at a much faster rate than in
2011 and outpaced the predictions of climate experts on the Intergovernmental
Panel on Climate Change, he said.
By September, the level of Arctic ice was the lowest since satellite
records began and had shrunk by nearly half — an area nearly the size of India
— below the average minimum level in the 20 years before 2000, the organization
reported.
The ice will reform in the winter but will be thinner than before and
more vulnerable to further melting, Mr. Jarraud warned. “The trend is not only
continuing but accelerating,” he said. “The more it melts, the faster it will
melt.”
The ice melt will contribute to rising sea levels that are already 20
centimeters, or nearly 8 inches, higher than a century ago, Mr. Jarraud said,
posing added risks in the event of extreme weather. Hurricane Sandy would have had less impact on
New York if it had occurred 100 years ago when sea levels were lower, he said.
After a chilly start to 2012, average temperatures from January to
October were 0.45 degrees Celsius, or 0.81 degrees Fahrenheit, above the
average from 1961 to 1990, according to the World Meteorological Organization’s
findings. A rise of only one degree Celsius was sufficient to increase the
frequency of extreme weather events, Mr. Jarraud said.
The above-average temperatures experienced in 2012 had been marked by
record temperatures in areas like Greenland, Siberia and central China, the
World Meteorological Organization reported.
Much of the United States, together with parts of Europe, western
Russia and southern China, had suffered severe drought, while parts of West and
sub-Saharan Africa had experienced severe flooding.
Meteorologists
have been at pains to make clear that no major weather event was the result of
a single cause, but research into climate change was establishing clear links,
Mr. Jarraud said, citing the results of research into the extreme heat wave in
Russia in 2010. “Without climate change, this episode would have been very
unlikely,” he said.
No comments:
Post a Comment