Nairobi, Kenya ? A long-awaited report by an international scientific network will offer “much stronger” evidence of how man is changing Earth’s climate, and should prompt reluctant governments into action against global warming, the group’s chief scientist said Monday.

The upcoming, multivolume U.N. assessment – on melting ice caps, rising seas and authoritative new data on how the world has warmed – may provide “just the right impetus to get the negotiations going in a more purposeful way,” Rajendra K. Pachauri told The Associated Press midway through the annual two-week U.N. climate conference.

The Indian climatologist is chairman of the Intergovernmental Panel on Climate Change, a global network of some 2,000 scientists who regularly assesses research into how carbon dioxide and other heat-trapping gases produced by industry and other human activities are affecting climate.

In its pivotal Third Assessment in 2001, the panel concluded that most global warming – temperatures rose an average 1 degree in the past century – was likely the result of such manmade greenhouse gases.

In its Fourth Assessment, to be issued in installments beginning in February, “there’s much stronger evidence now of human actions on the change in climate that’s taken place,” Pachauri said.

“It’s bound to have a major impact,” he said.

He said the detailed document will offer more evidence on sea-level rise, melting glaciers and the growing scarcity of water. He didn’t discuss those details, because the Fourth Assessment Report is in the draft stage. But it is likely to cite such recent research findings as:

l World temperatures have risen to levels not seen in at least 12,000 years, propelled by rapid warming the past 30 years.

l Greenland’s ice mass has been melting at what NASA calls a “dramatic” rate of 41 cubic miles per year, far surpassing the gain of 14 cubic miles per year from snowfall.

l The levels of oceans, expanding from warmth and from land-ice runoff, have risen at a rate of about 2 millimeters a year between 1961 and 2003, and by more than 3 millimeters a year in 1993-2003.