PARIS - The world's leading climate scientists said global warming has begun, is "very likely" caused by man and will be unstoppable for centuries, according to a report obtained today by The Associated Press.

The scientists - using their strongest language yet on the issue - said now that the world has begun to warm, hotter temperatures and rises in sea level "would continue for centuries" no matter how much humans control their pollution. The report also linked the warming to the recent increase in stronger hurricanes.

"The observed widespread warming of the atmosphere and ocean, together with ice-mass loss, support the conclusion that it is extremely unlikely that global climate change of the past 50 years can be explained without external forcing, and very likely that is not due to known natural causes alone," the report states.

The study was produced by the Intergovernmental Panel on Climate Change, a group of hundreds of scientists and representatives of 113 governments that periodically report on changes in climate.

The phrase "very likely" translates to a more than 90 percent certainty that global warming is caused by man's burning of fossil fuels. That was the strongest conclusion to date, making it nearly impossible to say natural forces are to blame.

'We Have This Nailed'

What that means in simple language is "we have this nailed," said top U.S. climate scientist Jerry Mahlman, who originated the percentage system.

The report, which is due to be officially released today, represents the most authoritative science on global warming.

The panel predicted temperature rises of 2 to 11.5 degrees Fahrenheit by the year 2100.

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 recent, surprising melting of polar ice sheets continues.

The report said that an increase in hurricane and tropical cyclone strength since 1970 "more likely than not" can be attributed to man-made global warming.

The scientists said global warming's connection varies with storms in different parts of the world, but that the storms that strike the Americas are global warming-influenced.

That's a contrast from the panel's last report in 2001, which said there was not enough evidence to make such a conclusion. And it conflicts with a November 2006 statement by the World Meteorological Organization. The meteorological group said it could not link past stronger storms to global warming.

Barbados delegate Leonard Fields, who comes from a country in the path of many hurricanes, said the new wording was "very important." He noted that insurance companies, which look to science to calculate storm risk, "watch the language, too."

"There's no question that the powerful language is intimately linked to the more powerful science," said one of the study's many co-authors, Andrew Weaver of the University of Victoria, Canada. He said the report was based on science that is rock-solid, peer-reviewed and consensus.

"It's very conservative. Scientists by their nature are skeptics."

The scientists wrote the report based on years of peer-reviewed research and government officials edited it with an eye toward the required unanimous approval by world governments.

Wording Brings Little Debate

In the end, there was little debate on the strength of the wording about the role of man in global warming.

The panel quickly agreed Thursday on two of the most contentious issues: attributing global warming to man-made burning of fossil fuels and connecting it to a recent increase in stronger hurricanes.

Negotiations over a third and more difficult issue - how much the sea level is predicted to rise by 2100 - went into the night Thursday with a deadline approaching for the report.

"I hope that policy-makers will be quite convinced by this message," said Riibeta Abeta, a delegate whose island nation Kiribati is threatened by rising seas. "The purpose is to get them moving."

The Bush administration acknowledges that global warming is man-made and a problem that must be dealt with, Bush science adviser John Marburger has said. However, Bush continues to reject mandatory limits on so-called "greenhouse" gases.

But this is more than just a U.S. issue.

"What you're trying to do is get the whole planet under the proverbial tent in how to deal with this, not just the rich countries," Mahlman said. "I think we're in a different kind of game now."

The panel, created by the United Nations in 1988, releases its assessments every five or six years. The reports are released in phases - this is the first of four this year.

The next report due in April focuses on the effects of global warming.

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http://www.glennbeck.com/2006news/newsweek-coolingworld.pdf