President Obama arrived in Copenhagen this morning to address the UN conference on climate change. In a stern speech delivered hours after his arrival, Obama told world leaders and their delegates that "the time for talk is over... All of you would not be here unless you — like me — were convinced that this danger is real. This is not fiction, it is science." The President's arrival came as any agreement on climate change remained out of reach, and China, the world’s leading emitter of greenhouse gas pollutants, was accused of holding back progress in the climate talks by French President Nicolas Sarkozy. During his address (text here, video below), Obama expressed frustration and urgency:

We are running short on time. And at this point, the question is whether we will move forward together or split apart, whether we prefer posturing to action. I’m sure that many consider this an imperfect framework that I just described. No country will get everything that it wants...

Or we can choose delay, falling back into the same divisions that have stood in the way of action for years. And we will be back having the same stale arguments month after month, year after year, perhaps decade after decade, all while the danger of climate change grows until it is irreversible.

Ladies and gentlemen, there is no time to waste. America has made our choice. We have charted our course. We have made our commitments. We will do what we say. Now I believe it’s the time for the nations and the people of the world to come together behind a common purpose.

"President Obama’s rhetoric is empty," said Friends of the Earth U.S. President Erich Pica. "The U.S. has failed to significantly improve upon the weak position it brought to these talks.This speech appears to be more of a face-saving exercise for President Obama than an attempt to unite countries around a truly planet-saving agreement."

The conference, which was scheduled to end today, has been "plagued by distrust over how nations would hold each other accountable," the Times reports. (The AP says the talks are in "serious disarray.") Upon arrival, Obama immediately went into an unscheduled meeting with a high-level group of leaders from 20 countries and organizations. Wen Jiabao, the prime minister of China, blew off that meeting and sent the vice foreign minister, "a snub that left both American and European officials seething," according to the Times.

But Wen did find time for Obama after his speech, and the two met privately for 55 minutes. They reportedly discussed emissions goals, verification mechanisms and climate financing during a meeting that one White House official described as"constructive. They took a step forward and made progress." Politico also reports that "none of the several drafts circulating in Copenhagen represented even the bones of a final deal, with many key issues still in flux and time running out. Moreover, U.S. predictions that roadblocks could be thrown up by smaller countries seemed to be coming true, with last-minute objections voiced by Venezuela, Bolivia, Sudan and Saudi Arabia."

"The situation is desperate," a top Indian negotiator told Reuters. "There is no agreement on even what to call the text — a declaration, a statement or whatever. They (rich nations) want to make it a politically binding document, which we oppose." A legally binding treaty mandating deep cuts in greenhouse gas emissions by developed nations is believed to be out of reach. (Reuters has a good overview of what's being considered.) The United Nations secretariat overseeing the summit meeting has advised negotiators to extend their stays through Sunday night, and it's unclear how long Obama plans to stay.