I sin seneste studie sier FNs klimapanel, at de hittidige anslag over den
menneskeskapte globale oppvarmingen sannsynligvis er alt for små. Tidligere
har man sagt opp til 3,5 grader, nå anslås ca. 6 grader - som globalt
gjennom- snitt! Det vil bety at oppvarmingen på våre breddegrader i løpet av
hundre år kan løpe opp i 10 grader eller mer. Det sier seg selv at dette
betyr katastrofe for det meste av jorda.
Men vi kan regne det som helt sikkert at også dette vil bli bagatellisert,
fortiet og avvist av det sedvanlige hylekoret av økonomiske interesser og
pseudovitenskapelige tilhengere av den markedsliberalistiske religion.
Karsten Johansen
http://www.cnn.com/2000/NATURE/10/25/global.warming.ap/index.html
Pollution adding to severe global warming
October 26, 2000 Web posted at: 9:51 a.m. EDT (1351 GMT)
WASHINGTON (AP) -- 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.
A draft of the report 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.
Today, the panel says in its new assessment that "there is stronger
evidence" yet on 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 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
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 gong 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, Colo. "It shows the
previous projects (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.
Still some doubts
Others were less certain.
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."
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, 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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