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Posted on Fri, Feb. 02, 2007
By SETH BORENSTEIN
The Associated Press
Blunt Climate Report Says Humans Cause Global Warming
It says humans 'very likely' cause warming that can't be controlled. Some experts disagree.
PARIS | Global warming has begun, is 'very likely' caused by humans and will be unstoppable for centuries, the world's leading climate scientists say in a report being released today.
The scientists - using their strongest language yet on the issue - said higher temperatures and rises in sea level would continue no matter how much humans control their pollution.
The report also linked the warming to the recent increase in stronger hurricanes.
The report was prepared by the Intergovernmental Panel on Climate Change - hundreds of scientists and representatives of 113 governments.
The phrase 'very likely' translates to a more than 90 percent certainty that global warming is caused by burning of fossil fuels.
The panel predicted temperature increases of 2 to 11.5 degrees Fahrenheit by 2100. Its best estimate was for temperature increases of 3.2 to 7.1 degrees Fahrenheit, the panel said.
On sea levels, the report projects rises of 7 to 23 inches by the end of the century. An additional 3.9 to 7.8 inches are possible if melting of polar ice sheets continues.
Several scientists from the Midwest were involved in different aspects of preparing the report, from researching to reviewing.
One of the 2,500 worldwide reviewers of the report was Tony Lupo, associate professor of atmospheric science at the University of Missouri-Columbia.
Lupo said Thursday that he didn't think evidence of global warming had changed enough in recent years to warrant such strong language in the report. Lupo said there are political reasons for such language.
"The idea is to push policymakers into addressing the issue," Lupo said. He said he thinks that the planet is warming, but he is skeptical about how much is caused by human activity.
But Charles Rice, a Kansas State University agronomy professor who is a lead author in an upcoming section on how to reduce greenhouse gases, said he thinks that the report's conclusions are valid.
"There is still some uncertainty over how much is natural cycles and how much is human-induced," Rice said. "But certainly the climate is changing. Most people would agree with that and certainly agree we?ve affected the carbon dioxide level."
Johannes Feddema, an associate professor of geography at the University of Kansas, wrote a summary in the IPCC report of his study on how land cover such as forests and crops can cool the air. Deforestation of the Amazon, he found, appears to affect surface temperature of the tropical Atlantic and Pacific oceans.
Feddema said the global panel's conclusions about climate change are not too strong.
Michael J. Hayes, climate impact specialist and associate director at the National Drought Mitigation Center in Lincoln, Neb., said he didn't know if there was enough data yet to show that global warming 'very likely' is causing stronger hurricanes.
However, he said that much more evidence had been falling into place to support the theory that humans are a factor.
"It is a very tough issue, a touchy issue," Hayes said. "It is political, and the words, however you phrase them, can mean so many different things to so many different people."
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