PARIS, Feb. 2 - The first IPCC report, an overview of the science of global warming, said that it was "very likely", or at least 90 percent certain, that mankind was to blame for most of the warming in the last half century.

The previous report in 2001 had put the probability at "likely", or at least 66 percent. The new report projected a "best estimate" that temperatures would rise by 1.8-4.0 degrees Celsius (3.2-7.2 Fahrenheit) this century.

BRUSSELS, April 6 - The second report said that rising temperatures were already changing the face of the globe and could lead to more hunger, water shortages and extinctions.

It projected that crop yields could drop by 50 percent by 2020 in some countries. More than 1 billion people may face shortages of fresh water by 2050, especially in Asia. By the 2080s, millions of people will be threatened by floods because of rising sea levels, especially in the mega-deltas of Asia and Africa and on small islands.

BANGKOK, May 4 - A draft of the third report obtained by Reuters, "Mitigation of Climate Change", highlights two scenarios saying that the costs of limiting emissions of greenhouse gases could mean a loss of just 0.2 or 0.6 percent of global gross domestic product (GDP) in 2030.

And the toughest scenario assessed, demanding that governments ensure that global greenhouse gas emissions start falling within 15 years, would cost 3 percent of GDP by 2030.

VALENCIA, Spain, Nov 16 - A fourth "Synthesis Report" will sum up all the findings.

PAST IPCC REPORTS -- 2001, 1995, 1990

- The 2001 study said there was "new and stronger evidence" linking human activities to rising temperatures.

- In 1995, the IPCC report concluded that "the balance of evidence suggests a discernible human influence on global climate". That report helped pave the way to the UN Kyoto Protocol in 1997, which obliges 35 industrial nations to cut greenhouse gases to 5 percent below 1990 levels by 2008-12.