The long-awaited Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) is undergoing a final review by scientists and bureaucrats this week before the landmark study is released on Friday.
Already, the chairman of the Panel, which is made up of representatives of 130 countries and 2500 scientists, has called on governments to take decisive action to counter global warming and its problems forecast in the report, Reuters reports.
They are said to include more intense storms, a greater incidence of floods, heatwaves and drought, and rising sea levels.
"I hope policies and action will be formed to address the problem," said Rajendra Pachauri, the IPCC chairman, at a news conference on Monday as the review got under way. "I think, based on the awareness that is growing very rapidly in every part of the globe, you will see a certain political resolve developing."
The IPCC reports every five years or so and since the last report in 2001 the body of scientific evidence pointing to far-reaching climate change, with significant human causes, has strengthened considerably.
Drafts of the report have already been revealed showing that the expected average global temperature increase by the end of this century is in the range of 2 to 4.5 degrees Celsius, compared to 1.5 to 5.8 degrees in the 2001 assessment. Crucially, however, the best estimate within that range is expected to be a rise of 3 degrees. A number of scientists believe that a 2-degree rise would be enough to push climate change to a tipping point, beyond which no level of human counter action could forestall it.