SEATTLE--The chief science adviser to British Prime Minister Tony Blair appears ready to tone down a controversial statement on climate change he made last month in Science (9 January, p. 176). But it took a forgetful press aide to bring the matter to light.

Lowering the temperature. The value of comparing terrorism and climate change was "highly questionable," a private memo for David King said. CREDIT: JOHN BELL PHOTOGRAPHERS, LONDON

David King, who gave a well covered plenary lecture and held a press conference here at the annual AAAS meeting--publisher of ScienceNOW--triggered an intense debate in the U.K. press after he asserted last month that "climate change is the most severe problem we are facing today more serious even than the threat of terrorism." On 3 February Blair tried to tamp down the controversy during a Parliamentary committee meeting by saying that although terrorism and global warming are both of "critical urgency, I think you can get into a rather cerebral debate about which is more important than the other." But the issue was sufficiently flammable that Blair's principal private secretary Ivan Rogers advised King in a 10 February memo to "decline [interview requests from] the U.K. or U.S. national media" during his visit to Seattle.

That memo and several other documents related to the controversy were on a computer disk obtained by Science after it was inadvertently left in the AAAS pressroom. King's personal press secretary, Lucy Brunt Jenner, has confirmed that the material on the disk is authentic.

In his plenary speech, King criticized the Bush Administration for its failure to sign the Kyoto Protocol, an international agreement to reduce industrial emissions. Although King was prepared to clarify his position on the global warming/terrorism comparison at the press conference, the issue wasn't brought up, Brunt-Jenner says. But the internal memos, dated 3 days before his lecture, contain mock exchanges that suggest King was ready to tone down the rhetoric. In one exchange, King was prepared to say, "the value of any comparison [between the number of deaths caused by climate change and terrorism] would be highly questionable, [because] we are talking about threats that are intrinsically different." If pushed to compare the two issues, King was ready to answer, "both are serious and immediate problems for the world today."

The Rogers memo informs King that "this sort of discussion does not help us achieve our wider policy aims" and "distracts from our wider efforts to engage the U.S. on climate change." But the memo from 10 Downing Street "did not muzzle" King, says Brunt Jenner. "Sir David had three opportunities to meet with the media and he spoke freely with them," she says.

--MICHAEL MARTIN