To: d[-_-]b who wrote (127582 ) 7/1/2008 12:48:15 PM From: Land Shark Respond to of 173976 No, this one:canada.com Study reveals growing evidence of global warming Margaret Munro , Canwest News Service Published: Wednesday, May 14, 2008 A vast array of physical and biological systems - from polar bears in the Arctic to tiny krill in the Southern Ocean - are showing the effect of the world's rising temperature, say scientists who analyzed more than 30,000 sets of data stretching back to 1970. Shrinking glaciers, melting permafrost, earlier spring river runoff, and warmer water bodies point to pervasive physical changes, they say. And earlier spring blossoms, bird migrations and altered distribution - salmon showing up in the Arctic, the mountain pine beetle expanding into vast tracks of Western Canada's forests - point to the many biological impacts. Polar bears walk at St-Felicien Wildlife Zoo in St-Felicien, Quebec in this March 6, 2008 file photo. Polar bears were listed on May 14, 2008 as threatened under the U.S. Endangered Species Act because of damage to their sea ice habitat, U.S. Interior Secretary Dirk Kempthorne announced. Polar bears walk at St-Felicien Wildlife Zoo in St-Felicien, Quebec in this March 6, 2008 file photo. Polar bears were listed on May 14, 2008 as threatened under the U.S. Endangered Species Act because of damage to their sea ice habitat, U.S. Interior Secretary Dirk Kempthorne announced. "Significant changes in physical and biological systems are occurring on all continents and in most oceans," the international team reported Wednesday in the journal Nature. The study builds on the work of the United Nations' Intergovernmental Panel on Climate Change, which last year concluded that human-induced climate warming is "likely" - within 66 to 90 per cent probability - having a "discernible" effect on physical and biological systems. The new study mined even more data and concludes human-influenced climate change is the main driver of the changes being observed, outstripping the more modest effects of deforestation and other land-use changes. "Anthropogenic climate change is having a significant impact on physical and biological systems globally," says the team, led by Cynthia Rosenzweig of The Earth Institute at Columbia University in New York. The team analyzed data from of hundreds of studies published in peer-reviewed journals since 1970 and is the first to "formally" link observed global changes in physical and biological systems to human-induced climate change and greenhouse, says Francis Zwiers, director of climate research at Environment Canada. "Making the link using a rigorous scientific method is a pretty big advance," says Zwiers, co-author of a commentary on the study, also in Nature. The study is not without its limitations, says Zwiers. It would be better to have evidence stretching back 50 to 100 years. But he says the new study "largely overcomes the sampling limitations because of the sheer number of changes" included in the assessment. Zwiers says scientists are now working to refine models to forecast the change that can be expected in coming years and decades, impacting everything from crop yields to hydroelectric power generation to the spread of insects and microbes associated with infectious diseases. "The more precise we can make the information the better off we will be," says Zwiers, noting that society is "going to have to be making all kinds of adaptation decisions." While it may not feel particularly warm in many parts of Canada this spring, Zwiers says the long-term trend is towards warming. Even if the world collectively managed to freeze greenhouse-gas emissions at current levels, scientists says the climate is already "committed" to significant warming for hundreds of years to come. The climate system is "a noisy chaotic system and there is a lot of natural variation," says Zwiers, cautioning against reading too much into the cold spell in Canada. "You have to very careful about local perceptions," Zwiers said in a telephone interview from the Netherlands where he is attending scientific meetings and enjoying the unusually hot weather. "People are walking around in their tank tops and restaurants are conducting business on their patios," he said, adding that it also uncomfortably warm at night in his hotel room that has no air conditioning. "And it's only May."