What went down at the Summit on Climate Change?

President Barack Obama speaks at the Secretary General's Summit on Climate Change at UN headquarters in New York City. (Rick Gershon/Getty Images)

The Copenhagen Climate Change Conference may not be until December, but world leaders and their top climate advisers are feeling the crunch. That's the point of New York's Climate Week and the United Nations Secretary General's Summit on Climate Change: to turn up the pressure in advance of the bureaucratic, intense December session of talks, and to give the leaders a chance to lay it out early, sans details.

While the 64th session of the U.N. General Assembly opens tomorrow, today's events were trained on climate issues -- global warming and vague ideas about emissions reductions, as well as wish lists and to-do lists for the post-Kyoto international treaty that should come out of Copenhagen.

Ban Ki-moon, the U.N. Secretary General, conceived of the summit as a means of frank discussion. While an address by one head of state to a roomful of international counterparts may not sound particularly informal, it does allow for a bit more elbow room than a U.N. treaty talk. BBC News wrote that "Mr. Ban hopes [...] that this direct, leader-to-leader contact can remove some of the log-jam."

The event also heats up a conversation that's bound to continue in the next few weeks between the G20 Summit in Pittsburgh and further rounds of negotiation in Bangkok and Barcelona -- all leading up to that Copenhagen culmination, when an actual treaty must be hammered out.

So while today was mostly a momentum-builder, short on numerical targets or specifics, it still managed to produce a few big headlines. Namely, the United States and China's vow (two famous Kyoto nonparticipants and the world's biggest carbon emitters) to work toward an international agreement -- domestic issues permitting. Such a message, even with that fairly significant caveat, would have seemed inconceivable only a short time ago.

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