Republicans continue to go on a witch-hunt of climatologists that have studied and reported on global warming for years... Republican, Energy and Commerce Committee Chairman Joe Barton (Tex.) has gone on a meaningless investigation of three scientists who have charted Earth's rapid warming in recent decades. This is so ridiculous thatanother senior Republican, House Science Committee Chairman Sherwood L. Boehlert, himself has asked Barton to call off the "misguided and illegitimate investigation."
As early as 1998, the three scientists, Raymond Bradley, Director of the Climate System Research Center at the Univ. of Massachusetts at Amherst, Michael Mann, Director of the Earth System Science Center at Penn State Univ., and Malcolm Hughes of the University of Arizona reconstructed the global climate change over the last millenium (pdf; also see this graph), determining that three recent years, 1997, 1995, and 1990, were the warmest years since at least AD 1400. Using climate records culled from tree rings, glacial-ice layers and coral-growth layers, the three professors -- whose research was funded in part by the federal government -- determined in 1998 that temperatures have skyrocketed in the past century compared with the 500 years preceding it. The three men put the figures in a graph now known as the "hockey stick," and their work helped prompt the U.N. Intergovernmental Panel on Climate Change in 2001 to declare the 1990s as the warmest decade in the past 1,000 years. The work has been supported as being rigorous and probably true by a national scientific panel of specialists in the area. Elsewhere, more than 100 international experts studying climate change have said that the threat of global warming is real and getting worse and Bush administration's postion on this is 'ludicrious.'
"The Man Behind the Hockey Stick" - 2005 interview