UN Panel Blames Humans for Warming
    By Alister Doyle
    Reuters

    Thursday 01 February 2007

    Paris - The U.N. climate panel agreed in its starkest warning yet on Thursday that human activities are causing global warming that may bring more droughts, heatwaves and rising seas, delegates said.

    The report, due for release on Friday and bolstering conclusions from a 2001 study, may put pressure on governments and companies to do more to curb greenhouse gases mainly from burning fossil fuels in power plants, factories and cars.

    Scientists and government officials in the Intergovernmental Panel on Climate Change (IPCC), the most authoritative group on global warming, agreed it was "very likely" that human activities were the main cause of warming in the past 50 years, delegates said.

    In IPCC language, "very likely" means at least 90 percent probability and is the strongest link to human activities since the IPCC was set up in 1988. The previous study in 2001 said a link was "likely," or 66 percent probable.

    IPCC officials declined comment, saying that the report would be issued on Friday at 0830 GMT. "Nobody's challenging the scientific findings, just the wording," one delegate said, adding the talks might last until early Friday.

    The Eiffel Tower, near the meeting hall, and some French homes shut off lights for five minutes on Thursday night in an action to highlight energy waste and global warming, briefly cutting France's power consumption by one percent.

    The IPCC, grouping 2,500 scientists from 130 countries, is also set to say that oceans will keep rising for more than 1,000 years even if governments stabilize greenhouse gas emissions.

    The report is the first of four this year by the panel that will outline threats of warming.

    Delegates said the Paris meeting, looking at the science of global warming, agreed a "best estimate" that temperatures will rise by 3 Celsius (5.4 Fahrenheit) by 2100 over pre-industrial levels, the biggest change in a century for thousands of years.

    More Rain, Less Ice

    It says bigger gains, of up to 6.3C in one model, cannot be ruled out but do not fit well with other data. The world is now about 5C warmer than during the last Ice Age.

    The draft accord projects that Arctic ice will shrink, and perhaps disappear in summers by 2100, while heatwaves and downpours would get more frequent. The number of tropical hurricanes might decrease but the storms would become stronger.

    The Gulf Stream bringing warm waters to the North Atlantic could slow, although a shutdown is highly unlikely, it says.

    And sea levels are likely to rise by between 28 and 43 cm (11-17 inches) this century, a lower range than forecast in 2001. Rising seas threaten low-lying Pacific islands and low-lying coastal nations from Bangladesh to the Netherlands.

    A group of scientists from the United States, Germany, France, Australia and Britain cautioned in the journal Science on Thursday that sea level rises in the past decade had outpaced previous IPCC forecasts.

    "The data now available raise concerns that the climate system, in particular sea level, may be responding more quickly than climate models indicate," Stefan Ramstorf of Germany's Potsdam Institute for Climate Impact Research and co-authors wrote.

    Many experts hope the IPCC report will spur stalled talks on expanding the fight against global warming.

    Thirty-five industrial nations aim to cut emissions of greenhouse gases to 5 percent below 1990 levels by 2008-12 under the U.N. Kyoto Protocol and want outsiders such as the United States, China and India to do more.

    Last week President George W. Bush said climate change was a "serious challenge." But he has stopped short of capping emissions despite pressure from Democrats who control both houses of Congress - arguing Kyoto would damage the economy.