UN: global warming unprecedented

A UN report on climate change is to be unveiled in Shanghai (China) next Monday. It reportedly indicates that global warming has occurred at an unprecedented rate over the past century and says that strong evidence now exists that human activities are to blame. UPI news agency has managed to obtained a copy of the summary of the most recent version. In the report, which will be formally presented to policymakers at a meeting of the IPCC Working Group, scientists say the average surface temperature of the Earth has increased by 0.6 degrees Celsius since 1861, the earliest date for which accurate measurements are available. The figure, which was calculated over the past five years from research on climate change, is 0.15 Celsius higher than the estimate presented in a report released in 1995 by the IPCC. "The rate of and duration of [global] warming in the 20th century has been much greater than in any of the previous nine centuries," the report stated. "Similarly, it is likely that the 1990s have been the warmest decade and 1998 the warmest year of the millennium." Among the key findings of the report: recent satellite data indicates that the world's snow cover has declined 10 percent since the late 1960s and there has been a "widespread retreat" of mountain glaciers in non-polar regions over the past 100 years. The global average sea level rose between 0.1 meters and 0.2 meters (0.65 feet) during the 20th century. The report says research on atmospheric conditions and greenhouse gases reveals that the concentration of carbon dioxide has risen 31 percent since 1750. About three quarters of the manmade CO2 emissions over the past 20 years are attributed to the burning of fossil fuel, changes in land-use, and widespread deforestation.