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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