Global warming worser than anticipated

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Future Looks Hot

 

U.N. Panel Says Warming Is Worse Than Previously Believed

 

By H. Josef Hebert

The Associated Press

 

W A S H I N G T O N, Oct. 26

 

New evidence shows man-made pollution has “contributed substantially”

to global warming and the earth is likely to get a lot hotter than

previously predicted, a United Nations-sponsored panel of hundreds

of scientists finds.

 

The conclusions by the Intergovernmental Panel on Climate Change,

the most authoritative scientific voice on the issue, is expected to

widely influence climate debate over the next decade.

 

The report’s summary, a copy of which was obtained by The Associated

Press, was being distributed to government officials worldwide this

week.

 

It is the first full-scale review and update of the state of climate

science since 1995 when the same panel concluded there is “a

discernible human influence” on the earth’s climate because of the

so-called “greenhouse” effect caused by the buildup of heat-trapping

chemicals in the atmosphere.

 

Panel Revises Assessment

The panel says in its new assessment that now “there is stronger

evidence” of the human influence on climate and that it is likely that

manmade greenhouse gases already “have contributed substantially to

the observed warming over the last 50 years.”

 

And the scientists, in revised estimates, conclude that if greenhouse

emissions are not curtailed the earth’s average surface temperatures

could be expected to increase from 2.7 to nearly 11 degrees Fahrenheit

(1.5 to 6 Celsius) by the end of this century, substantially more than

estimated in its report five years ago.

 

It attributes the increase — from a range 1.8 to 6.3 degrees Fahrenheit

(1 to 3.5 Celsius) warmer in the 1995 assessment — mainly to a reduced

influence now expected to be played by sulfate releases from industry

and power plants. Such releases, which tend to have a cooling

influence, will likely dramatically decline in industrial countries

because of other environmental concerns, the scientists maintain.

 

“What this report is clearly saying is that global warming is a real

problem and it is with us and we are going to have to take this into

account in our future planning,” said Kevin Trenberth, head of climate

analysis section at the National Center for Atmospheric Research.

 

“It definitely reinforces what we were able to say in 1995,” added Tom

Wigley, a climate scientist at the center in Boulder, Colorado. “It

shows the previous projections (in 1990 and 1995) were conservative.”

 

Wigley, who did not participate in crafting the latest findings, was a

key author of the 1995 report’s section about the human impact on

climate.

 

Others were less certain.

 

Some Scientists Still Skeptical

 

Michael Schlesinger, a climatologist at the University of Illinois at

Champaign-Urbana said despite the new information there is still

insufficient knowledge about natural climate variables such as solar

radiation that could change the assessment.

 

Comparing studies of climate to listening to noise radio transmissions,

Schlesinger said in an interview, “Science has moved closer to the

radio transmitter, so the signal is higher and more apparent against

the background noise. But the background noise has not diminished.

There

are still uncertainties and there may be very large surprises ahead.”

 

The IPCC’s third assessment report is expected to get final approval at

a United Nations conference early next year. While some wording will

certainly be changed by government policy-makers, the central

scientific conclusions may not be altered, several scientists who have

been involved in the process said Wednesday.

 

Michael Oppenheimer, an atmospheric physicist at Environmental Defense,

said the latest assessment “reinforces the mainstream scientific

consensus” about global warming. Its new estimates of warming poses “a

risk of devastating consequences within this century.”

 

Major Polluters Ignore Kyoto Accord

 

Three years ago industrial nations tentatively agreed to curtail the

release of greenhouse gases — mainly carbon dioxide from burning fossil

fuels — to below 1990 levels as a first step to address global warming.

 

But none of the major industrial countries has yet ratified the

agreement, crafted in Kyoto, Japan in 1997. Skeptics argue that the

science has yet to be conclusive and that computer models used to

predict future climate is not reliable enough to warrant a dramatic,

and possibly very expensive, shift in energy use to curtail carbon

emissions into the atmosphere.

 

The issue also has crept into the presidential campaign. Vice President

Al Gore has argued the science is clear and steps need to be taken soon

to begin reducing greenhouse emissions. His Republican rival, Texas

Gov. George W. Bush, has not dismissed global warming, but urges a

cautious approach and believes the science still needs to be proven.

 

The IPCC panel’s summary of a voluminous technical report covering 14

chapters attempts to provide the most current state of scientific

understanding of the climate system and potential for future warming.

 

While there are still uncertainties, the IPCC scientists say that there

is an “increasing body of observations” that provide a “collective

picture of a warming world” that cannot be solely explained by

natural forces.

 

“Emissions of greenhouse gases and aerosols due to human activities

continue to alter the atmosphere in ways that affect the climate

system,” the report says.

 

Various findings of the last five years have reinforced the IPPC’s 1995

determination that climate change warrants top-level attention by

government policy makers.

 

 

 

 

 

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