U.N. Says Humans Are 'Extremely Likely' Behind Global Warming

STOCKHOLM—A much-anticipated United Nations report issued Friday reaffirmed growing belief that human activity is the dominant cause behind a rise in global temperatures, but presented a more moderate estimate on rising temperatures.

A summary of the report, the work of more than 800 scientists working for the U.N.'s Intergovernmental Panel on Climate Change over several years, said there is a 95% likelihood that humans are behind global warming, up from the 90% level reported in a similar 2007 report. The IPCC noted that air and oceans are getting warmer, ice and snow is less plentiful, and sea levels are rising.