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Report on climate change faults the role of humans

NEW YORK -- The latest United Nations assessment of the role of humans in global warming has found with "high confidence" that greenhouse gas emissions are at least partly responsible for a host of changes already underway, including longer growing seasons and shrinking glaciers.

A summary of the working draft of the report, to be released tomorrow in Brussels, was provided yesterday by several people involved in reviewing it.

It is a detailed follow-up to a February report by the United Nations group, the Intergovernmental Panel on Climate Change, which was the fourth assessment since 1990 of the basic science that points to a human hand on the planet's thermostat.

That report said there was at least a 90 percent chance that most warming since 1950 had resulted from a continuing buildup of heat-trapping emissions in the atmosphere.

The new report describes the specific effects of climate changes on people and ecology; identifies those species and regions at greatest risk; and describes options for limiting risks.

It finds that global warming caused by humans has almost certainly contributed to recent shifts in ecosystems, weather patterns, oceans and icy regions, and that it will have large and lasting effects on human affairs and on the planet's web of life in this century.