As he addresses a conference on climate change this morning, President Bush will face not only a crowd of skeptics but the press of time. For nearly seven years, he invested little personal energy in the challenge of global warming. Now, with the end in sight, he has called the biggest nations of the world together to press for a plan by the end of next year.

This has been a week when Bush seems to be checking boxes on the legacy list. He opened the week at the United Nations in New York, where he tried to rally support for his Middle East peace initiative and insisted his vision of a new Palestinian state is still "achievable" before the end of his presidency. And he pressed for more U.N. action against Iran, acutely aware he has less than 16 months left to stop Tehran's nuclear program.

Success in any of these areas would amount to a singular achievement and, in the view of advisers, could help rewrite Bush's place in history. No president wants to be remembered as the author of an ill-fated war and, while Iraq certainly will be at the core of the Bush administration's record, advisers hope to broaden the picture. Yet analysts said the hour is late to resolve the longstanding Israeli-Palestinian conflict on his watch, critics doubt his sincerity on climate change, and Iran remains as intransigent as ever.

"The clock is ticking, and there are certain things you want to accomplish before you go out the door," said Ron Kaufman, who was White House political director for President George H.W. Bush. "While most of these things are not new to his agenda, there may be a bit of a new urgency given the time. . . . No president wants to leave something on the table if they can get it done."

Even on Iraq, Bush clearly has an eye on the clock. While he no longer harbors hope of winning the war by Jan. 20, 2009, he wants to use his remaining time in office to stabilize the country, draw down some forces and leave his successor with a less volatile situation that would dampen domestic demands to pull out completely. If he can do that, he told television anchors during an off-the-record lunch this month, he thinks even Sen. Hillary Rodham Clinton (N.Y.), the Democratic front-runner, would continue his policy.

The goal, as national security adviser Stephen J. Hadley told the Council on Foreign Relations recently, is that "a new president who comes in in January of '09, whoever he or she may be, will look at it and say, 'I'm persuaded that we have long-term interests here. It's important we get it right. This strategy is beginning to work. I think I'll leave Iraq alone.' And so that a new president coming in doesn't have a first crisis about 'let's pull the troops out of Iraq.' "

Bush has even quietly sent advice through intermediaries to Clinton and other Democratic candidates, urging them to be careful in their campaign rhetoric so they do not limit their options should they win, according to a new book, "The Evangelical President," by Bill Sammon of the Washington Examiner. Bush has "been urging candidates, 'Don't get yourself too locked in where you stand right now. If you end up sitting where I sit, things could change dramatically,' " White House Chief of Staff Joshua B. Bolten told Sammon.

Bush is also rushing to institutionalize some of the controversial tactics he has employed in the battle with terrorists so that they will outlast his presidency. That was a major reason he agreed to put his National Security Agency warrantless surveillance program under the jurisdiction of a secret intelligence court, aides said. And that is why he has pushed to find a way to close the prison at Guantanamo Bay, Cuba, and find other ways of handling suspected terrorists, although officials increasingly doubt they will be able to do so.

White House counselor Ed Gillespie said the president's team is not panicked about dwindling time but hopes to push steadily toward some goals that will bear fruit before the end of the administration. "On some of these things we've made a lot of progress," he said. "We may not be in the red zone, but we're at a point where you don't need to throw the long ball. We can get there with three yards and a cloud of dust if we keep moving."

The focus on passing time and the coming judgment of history is common at this point in a two-term presidency, of course. In his final months in office, Bill Clinton also launched an intense effort to solve the Middle East conflict only to have Camp David talks collapse. Joel P. Johnson, who was Clinton's senior adviser in the last part of his presidency, remembers his boss holding "a whip and a chair" trying to force as much change before surrendering the Oval Office.

"It's on your mind every day because you know how long it takes to create a policy and build a campaign around it and enact it or in some way force change before your administration is over," Johnson said. "Literally on your wall and in your mind there is a calendar, and every day you see a red X and you wake up in the morning and you realize 'we only have so much time.' And what focuses your mind is you know on that last day, the story's over and you can't change it anymore."

Bolten has been trying to focus the minds of his colleagues in the Bush White House ever since taking over as chief of staff last year. He gave other top aides clocks set to show how many days and hours remain in this administration and told them to think about big things that could be accomplished in that time. Yet the most ambitious items on Bush's second-term domestic agenda have died, most notably his ideas for restructuring Social Security and immigration laws.

"They're off the table. They're done. Didn't work," said a senior official who insisted on anonymity to speak more candidly about Bush's strategy. "So he's turning to some other things."

One of the other things is climate change. Bush once expressed doubt that human activity has anything to do with warming and renounced the Kyoto treaty imposing mandatory limits on greenhouse emissions. Now he has summoned representatives from the 15 nations that produce the most greenhouse gases to this week's conference in Washington in hopes of producing a plan by the end of 2008.

While the White House points to initiatives and research Bush has sponsored over the years, he has never taken on a high-profile role in confronting the issue until now. Senior European officials said they appreciate the newfound interest. "Some months ago there was no discussion of climate. The words 'Kyoto regime' [did not come] over the lips of a government official here," German Environmental Minister Siegmar Gabriel told reporters yesterday. Alluding to Neil Armstrong's famous walk on the moon, he added, "These are big steps for us and the United States, and small steps for mankind in the international negotiations."

But Bush remains opposed to mandatory emissions caps that environmentalists and many foreign leaders such as Gabriel believe are needed. "I don't think the leopard has changed its spots," said David D. Doniger, a climate analyst at the Natural Resources Defense Council. "Or maybe the better analogy is that the only thing the leopard has changed is his spots."

One conference delegate said negotiators realize the talks will not yield a dramatic change in U.S. policy. "With this administration, we will not reach any result because the time is too short," the delegate said. "But they have the problem, not we. . . . They have the problem [of explaining] to their own people what they're going to do."