BRUSSELS, Belgium — An international global warming conference approved a report on climate change Friday after a contentious marathon session that saw angry exchanges between diplomats and scientists who drafted the report.

"We have an approved accord. It has been a complex exercise," chairman Rajendra Pachauri told reporters after an all-night meeting.

Several scientists objected to the editing of the final draft by government negotiators but in the end agreed to compromises. However, some scientists on the Intergovernmental Panel on Climate Change vowed never to take part in the process again.

The climax of five days of negotiations was reached when the delegates removed parts of a key chart highlighting devastating effects of climate change that kick in with every rise of 1.8 degrees Fahrenheit, and in a tussle over the level of confidence attached to key statements.

The United States, China and Saudi Arabia raised the most objections to the phrasing, most often seeking to tone the certainty of some of the more dire projections.

The final report is the clearest and most comprehensive scientific statement to date on the impact of global warming mainly caused by man-induced carbon dioxide pollution.

It predicts that up to 30 percent of species face an increased risk of extinction if global temperatures rise 3.6 degrees Fahrenheit above the average in the 1980s and 90s.

Areas that now suffer a shortage of rain will become even more dry, adding to the risks of hunger and disease, it said. The world will face heightened threats of flooding, severe storms and the erosion of coastlines.

The report will be presented at a Group of Eight leaders summit in June in Germany, which the EU will use to pressure President Bush to sign on to international talks to cut emissions.