Glacier-Like

Except there won't be any glaciers left.

A signature piece of evidence for global warming -- a compilation of data showing that a sharp rise in temperatures made the late 20th century the warmest period in 1,000 years -- is probably true, a national panel of scientific specialists concluded yesterday.

A graph of the data has become an icon of global warming and is often referred to as ``the hockey stick" because of its shape: A shaft that shows a long period of relatively little change in Northern Hemisphere surface temperatures, and then a spike upward during the last 100 years or so that resembles the blade.

Since the first version of it was published in a scientific journal in 1998, environmentalists have seized on the graph as powerful evidence of human-induced climate change, while some critics have called it alarmist, questioning its methodology and the accuracy of its temperature data.

Last year, the dispute catapulted into the national political arena after Joe Barton, a Texas Republican who is chairman of the House Energy Committee, asked the three authors of the 1998 study -- including a University of Massachusetts professor -- for a detailed accounting of their government and private funding, data, and methods. A range of scientists and other legislators blasted the request as an intimidation tactic, contending that other researchers would be reluctant to embark on such studies if they knew they would be under such scrutiny by members of Congress.