Norway's environment minister called the United Nations climate negotiations starting today in Copenhagen "the most difficult talks ever embarked upon by humanity." They are also probably the most important; at stake in this gathering of 190 nations intended to draft a successor to the Kyoto Protocol are the future of human civilization and the survival of countless plant and animal species threatened by climate change. Yet even at a time when unity of purpose is crucial, global warming deniers have stepped up their dirty tricks campaign and scored their biggest victory to date.
Hackers last month illegally intercepted hundreds of e-mails from scientists at a prominent British climate research center, a few of which show signs of ethical lapses. In some, researchers discuss withholding data or manipulating them in ways that, the deniers claim, show the scientists hyping the threat of global warming. In others, they discuss boycotting journal editors they believe are too accommodating of the work of climate skeptics. The content of many of these messages has been distorted or taken out of context -- for example, one of the correspondents, Pennsylvania State University professor Michael E. Mann, has said he was merely criticizing a journal editor who was notorious for publishing studies that didn't meet minimal scientific standards. Still, some climate scientists appear to have crossed the line that separates objective observers from advocates, undermining their credibility.

