Global warming is accelerating faster than what climatologists had calculated. In 1995, the Intergovernmental Panel on Climate change predicted that global warming would rise between 1C and 3.5C during the 21st century if the present trend continued. But if Thomas Karl, director of the National Climate Data Centre at the National Oceanic and Atmospheric Administration, USA, is to be believed the rate of warming is already 3C per century. "In other words, we are already experiencing the rate of warming projected to continue throughout the century," says Karl.