The details may differ, but Senator John McCain, Arizona, the presumptive Republican nominee, and the two Democrats vying for their party's nomination, Senators Hillary Clinton, New York, and Barack Obama, Illinois, all support mandatory reductions in US greenhouse gas emissions; fixed reduction targets and timetables; and a cap-and-trade program.

This means that after January 20, 2009, US climate change programs will no longer be circumscribed by the Bush administration's voluntary measures and "aspirational" goals.

In fact, earlier this week McCain took a withering shot at the Bush Administration's policy that would do credit to the administration's most ardent Democratic critics.

"I will not shirk the mantle of leadership that the United States bears," McCain said in a Portland, Oregon speech May 12. "I will not permit eight long years to pass without serious action on serious challenges."

"Instead of idly debating the precise extent of global warming, or the precise timeline of global warming, we need to deal with the central facts of rising temperatures, rising waters, and all the endless troubles that global warming will bring," McCain said. "We stand warned by serious and credible scientists across the world that time is short and the dangers are great."

McCain long ago parted ways with the Bush administration and many Republicans on climate issues. But what struck Manik Roy, director of congressional affairs for the Pew Center on Global Climate Change, as "huge" was that McCain said it in the midst of a campaign where it has received only passing attention. "The specifics are less important than the fact that he is not only standing by cap-and-trade but is campaigning on it."

The administration is trying to leave its imprint on a post-2012 agreement, when the Kyoto Protocol expires, through its major economies process involving industrial and major developing countries responsible for about 80% of global GHG emissions. The major economies meeting scheduled for July "will seek an agreement on a long-term goal for emissions reductions," Bush said in an April speech.

However, the Bush negotiating team in Poland will probably be shadowed by representatives of the next administration, which will have very different ideas about US emission reductions. The administration's delegation also may be viewed as irrelevant by the international community eagerly waiting for the new team to take charge.

A similar although more confusing situation existed at the climate talks in The Hague in November, 2000, which occurred after the US presidential election but before the US Supreme Court swept Bush into office by one vote in December. The Clinton administration, which was a driving force behind the negotiations that resulted in the Kyoto Protocol, was at the table at The Hague. However, no one knew who would succeed President Clinton just two months later: Vice president Al Gore, who supported the Kyoto Protocol; or George W. Bush, who was no fan.

The Hague talks collapsed, the first and only time the annual UN conference of the parties had to be suspended for the lack of an agreement. In March, 2001, little more than two months after taking office, President Bush rejected the Kyoto protocol on behalf of the US. The suspended Hague negotiations resumed Bonn, Germany in July, 2001, with the Bush administration firmly in place.