Serious about the environment.

Bush-administration officials privately threatened organizers of the U.N. Climate Change Conference, telling them that any chance there might’ve been for the United States to sign on to the Kyoto global-warming protocol would be scuttled if they allowed Bill Clinton to speak at the gathering today in Montreal, according to a source involved with the negotiations who spoke to New York Magazine on condition of anonymity.

Bush officials informed organizers of their intention to pull out of the new Kyoto deal late Thursday afternoon, soon after news leaked that Clinton was scheduled to speak, the source said.

Here's a story on what Clinton said. Bottom line, he said Bush was "flat wrong."

And NYTimes confirms the walkout, not the reason.