The report of the Intergovernmental Panel on Climate Change, released in Shanghai, predicts an increase in average global temperatures of between 1.4 degrees and 5.6 degrees Celsius in the current century. Previous projections had set the expected average increase in temperatures at between 1 degree and 3.5 degrees Celsius.
Intensive climate research and monitoring over the past few years have given scientists greater confidence in their understanding of the causes and effects of global warming, Klaus Toepfer, the executive director of the U.N. Environmental Programme, said in the report.
It said there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.
"The scientific findings being reported today," said Michael Zammit Cutajar, the executive secretary of the U.N. Climate Change Convention, "should convince governments of the need to take constructive steps towards resuming the climate change talks that stalled last November in the Hague."
Globally, it is very likely that the 1990s were the warmest decade, and 1998 the warmest year, since data were first recorded in 1861, the report said.
It said that new analyses of tree rings, corals, ice cores and historical records for the Northern Hemisphere indicate that the increase in the 20th century is "likely to have been the largest of any century during the past 1,000 years."
Toepfer said the scientific consensus in the report "should sound alarm bells in every national capital and in every local community.
"We must move ahead boldly with clean energy technologies, and we should start preparing ourselves now for the rising sea levels, changing rain patterns, and other impacts of global warming," he said.
(la/dpa)
