Climate change is here, it's caused by humans, is probably already dangerous and is increasingly likely to be irreversible, according to a draft report from the U.N. Intergovernmental Panel on Climate Change.
The report combines three earlier documents, but the language is more stark, media report.
The report finds that past emissions, and the failure to respond to scientific warnings about the risks, have made large-scale climatic shifts inevitable.
But lowering emissions still would slow the expected pace of change, the report says, providing critical decades for human society and the natural world to adapt.
The final report will be issued after governments and scientists go over the draft line by line at an October conference in Copenhagen.