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By Charles Clover, Environment Editor, in The Hague
The
world has not warmed since 1940, according to tree rings,
coral reef and ice core boreholes, one of the world's leading
"global warming" sceptics told a meeting at the
climate change conference.
Prof Fred Singer, a meteorologist at the University of Virginia,
used temperature data assembled by James Hanson of Nasa,
who first highlighted the problem of climate change, to
challenge the findings of the Inter-governmental Panel on
the subject which underpin the Kyoto climate treaty.
He said:
"The climate has warmed in the last century but this
took place before 1940. The hottest years in America were
around 1940. We don't know the cause of the warming but
we don't think it was human activity."
Mr Singer
says he has found no evidence suggesting future extreme
weather events, such as severe storms or droughts, increases
in infectious diseases, or changes to forests and other
ecosystems. He accepts there has been an increase in greenhouse
gases but believes this has led to "a greening of the
planet, improved agricultural yields and more vigorous forest
growth".
He also
accepts evidence from temperature records all over the world
that there appears to have been a pronounced warming since
1975, with some of the hottest years in the 1990s. But he
says that satellite records of the temperature three miles
up, which should show a warming, do not show a warming at
all.
He said:
"One explanation is that the satellites are wrong.
The other explanation - that is my hypothesis - is that
the surface appears to be warming but isn't really warming
at all."
Bob
Watson, chairman of the IPCC, has used the surface temperature
records of the past 20 years to claim that the 20th century
is the warmest for 1,000 years, but Mr Singer disagrees.
He places greater faith in the "proxy" records
of temperature, contained in tree rings, ocean sediments,
ice cores and so on, which he says show no warming since
1940.
He said:
"Thermometers may not be quite correct. Proxy records
say the global temperature has not increased in the past
20 years." He believes that "heat islands"
caused by urbanisation have distorted thermometer readings.
He produced graphs from research conducted by the University
of East Anglia and analysis of Greenland ice cores over
100,000 years published in scientific papers to support
his point.
Mr Singer
is one of several scientists to challenge the broad conclusions
of the IPCC, a distillation of the work of 3,000 scientists
from most of the leading meteorological institutes. He shared
a platform with Richard Coutney, from Britain's Institute
of Economic Affairs, who suggested that the summary and
conclusions of the IPCC's assessment of the climate had
been manipulated by politicians.
Geoff
Jenkins, head of the Met Office's Hadley Centre for Climate
Prediction and Research, and a leading figure in IPCC, said:
"To say that politicians wrote the summary report of
the Inter-govermental Panel on Climate Change is rubbish."
As to satellite data, he said neither this, nor balloon
data, showed the expected warming in the upper atmosphere.
"There
is warming but the models say it should be the same as the
surface. Prof Singer has an issue here that we need to resolve.
We don't believe it invalidates the model's predictions
of the future. But it's a weakness and we need to sort it
out."
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