The truth about global warming
Tuesday, October 11, 2005, By Sandi Doughton Seattle Times staff reporter.
"The consensus is most clearly embodied in the reports of the 100-nation Intergovernmental Panel on Climate Change (IPCC), established by the United Nations in 1988. Every five to six years, the panel evaluates the science and issues voluminous reports reviewed by more than 2,000 scientists and every member government, including the United States.
The early reports reflected the squishy state of the science, but by 2001, the conclusion was unequivocal: "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities."
Stunned by the strong language, the Bush administration asked the prestigious National Academy of Sciences to evaluate the international group's work. The UW's Wallace served on the academy's panel, which assured the president the IPCC wasn't exaggerating.
The next IPCC report is due in 2007. Among the new evidence it will include are the deepest ice cores ever drilled, which show carbon-dioxide levels are higher now than any time in the past 650,000 years.
In the history of science, no subject has been as meticulously reviewed and debated as global warming, said science historian Spencer Weart, author of "The Discovery of Global Warming" and director of the Center for History of Physics.
"The most important thing to realize is that most scientists didn't originally believe in global warming," he said. "They were dragged — reluctant step by step — by the facts."