Scientists are increasingly convinced that human activity is behind the increase in global temperatures since the 1950s, which has boosted sea levels and the odds of extreme storms, according to a leaked draft of an upcoming U.N. report.

“It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951 to 2010,” according to a summary of the draft obtained by CNN. “There is high confidence that this has warmed the ocean, melted snow and ice, raised global mean sea level and changed some climate extremes in the second half of the 20th century.”

That conclusion comes from the upcoming report of the U.N. Intergovernmental Panel on Climate Change, the fifth in a series of multiyear reports seen as a benchmark on the subject. The panel’s last report, in 2007, concluded that it was 90% certain that rising temperatures were due to human activity; the new draft raises that figure to 95%.

The science of global warming is politically controversial but generally accepted as fact by most researchers, who point to heat-trapping carbon emissions from the burning of fossil fuels as the major cause. A May study of research papers published between 1991 and 2011 found that more than 97% of those that expressed an opinion on the cause of increasing temperatures supported that consensus.

The panel’s report is slated for release in sections, starting in September.

http://www.cnn.com/2013/08/20/world/un-climate/index.html?hpt=hp_t2