One of these things is not like the others. Read on to find out why...

It's not easy for me to admit this, but it's awfully embarrassing to be an American in the international climate arena. Because, like it or not, the international community still views the United States as the biggest obstacle to a fair, ambitious, and binding global climate treaty. From what I saw on the ground this Fall at the "intersessional" meetings in Bangkok and Barcelona --where all the proposals, submissions and "non-papers" were supposed to be wrestled down to a manageable negotiating text--it's hard to fault the world for having such an impression.

Forget the fact that Americans are still, by an enormous margin, the world's largest per capita emitters of greenhouse gasses. Perhaps the biggest source of frustration has been the United States' reluctance to "put numbers on the table," or to actually lay out commitments for a couple of the most essential points of negotiation. These are the amounts and timelines for greenhouse gas emissions reductions and levels of finance for developing countries' mitigation and adaptation efforts. Or more simply put: how much and how quickly will the U.S. cut emissions, and how much cash will we pony up to help out poor countries.

Without these American numbers, it's been virtually impossible for the negotiations to begin in earnest. "We need a clear target from the United States in Copenhagen," urged Yvo de Boer, who's charged with steering this UNFCCC (United Nations Framework Convention on Climate Change) process to some kind of December resolution, in Barcelona. "That is an essential component of the puzzle." Countries simply can't make their moves until the world's largest greenhouse gas emitter shows at least some of its hand. (There's an interesting story floating around, actually, about how Chinese President Hu Jintao had two speeches in his pocket for the September U.N. meetings in New York; one had hard Chinese targets, the other had some more hollow rhetoric. After Obama's speech came up short of delivering actual numbers, Hu grabbed the noncommittal speech.)

Now there was a perfectly good political reason why the U.S. has been holding out. The State Department hasn't wanted to write a check that our domestic politics can't cash. If Kyoto taught us anything, it's that nobody can trust the U.S. until they see what's actually written into domestic law. (Quick history lesson-the U.S. signed the Kyoto Protocol back in 1998; eleven years later, it still hasn't been ratified. At least 185 countries have ratified the Protocol, from Russia to Rwanda to Australia to Iraq. Iraq! In the photo above, black signs are for the official Parties to Kyoto, and white signs signify observer status.)

So there's a massive trust gap. To be a credible player going into Copenhagen, the U.S. has to show something concrete coming from the home front. U.S. Lead negotiatior Jonathan Pershing has not been at all coy about the fact that he needs to bring home a treaty that will be signed and ratified.

The problem is, the rest of the world doesn't work this way. Every other country in the world plans to bring home the international treaty and create domestic law to match it. The U.S., looking for some special treatment, has been insisting on doing the reverse. World leaders, though, have grown impatient with this case of American exceptionalism, and not-so-subtle diplomatic shaming has been growing. In Barcelona, De Boer openly praised some key developing nations, thanking China, India, Mexico and Brazil for bringing their respective and ambitious goals to the table. "Today, already China is the world leader in terms of reducing emissions," de Boer offered. "The world is lacking similar clarity from industrial nations." It was clear who he was referring to. Piling on, the Chair of the COP15 talks, Danish minister for climate and energy Connie Hedegaard, added that "[it's] hard to imagine how the American president can be receiving the Nobel Peace Prize on Dec. 10 in Oslo, 100 kilometers from Copenhagen, and at the same time send an empty-handed delegation to Copenhagen."

To some degree, the shaming has worked. Just last week, when President Obama announced that he'd be going to Copenhagen, he said that he'd be doing so with numbers in hand. It's a huge turning point, but it's likely that the commitments themselves will be underwhelming. As I get ready to head to Copenhagen to face friends and colleagues from around the world, I hope I'm wrong.