VIENNA - Mankind is to blame for climate change but governments still have time to slow accelerating damage at moderate cost if they act quickly, a draft U.N. report shows.
Underlining the need for speed, it says a European Union goal of holding temperature rises to a maximum 2 Celsius (3.6 Fahrenheit) above pre-industrial times is almost out of reach.
The 21-page study, due for release in November, lays out possible responses to global warming but cautions that some impacts are already inevitable, such as a gradual rise in sea levels that is set to last for centuries.
The report gives a first overview of 3,000 pages of research by the U.N.'s climate panel already published in three instalments this year about the science, the likely impacts and the costs of slowing climate change.
The authoritative summary, obtained by Reuters and meant to guide governments in working out how to slow warming, reiterates that humans are to blame for climate change but that clean technologies are available to offset the most harmful emissions.
"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (from human activities) greenhouse gas concentrations," it says.
"Very likely" means at least 90 percent probability, up from 66 percent in a previous report by the U.N.'s Intergovernmental Panel on Climate Change (IPCC) in 2001 when the link was only judged "likely". The IPCC draws on work by 2,500 scientists.
The report shows a table indicating worsening damage such as bleached corals, coastal flooding, increasing costs of treating disease, deaths from heatwaves and rising risks of extinctions of species of animals and plants.
But it says: "Many impacts can be avoided, reduced or delayed" by cutting greenhouse gas emissions.
