PARIS, Feb. 2 - The first report will give evidence linking human activities, led by use of fossil fuels, to a warming in the past 50 years. It will also project likely climate changes to 2100.

A draft of the report, "The Physical Science Basis of Climate Change", says there is at least a 90 percent chance that human activities are the main cause of global warming since 1950, scientific sources say. The previous report in 2001 said the link was "likely", or at least a 66 percent chance.

It will also project a "best estimate" of a temperature rise of 3 Celsius (5.4 Fahrenheit) above pre-industrial levels. The 2001 report projected a rise of between 1.4 and 5.8 Celsius, without saying which end of the scale was most likely.

BRUSSELS, early April - The second report will detail the likely impacts of climate change around the globe and ways to adapt to warming. Australian newpaper The Age said a draft of the report, entitled "Impacts, Adaptation and Vulnerability", projects that between 200 and 700 million more people could face food shortages by 2080 and that 1.1 to 3.2 billion more people could suffer water shortages.

BANGKOK, early May - The third report, "Mitigation of Climate Change", will analyse ways to fight global warming, including options and costs for reining in emissions of greenhouse gases.