I just had a cappuccino with Brazil's Ambassador of Climate Change Sergio Barbosa Serra, a top negotiator in the Brazilian delegation. We discussed what's going to get hashed out in the next 36 hours of the conference. He boiled the challenge down to this: World leaders will be trying to define and make sense of the "transparency" that the U.S. is demanding of China and other participating nations. It's a departure from the verifications known as MRVs (as in, "measurable, reportable, and verifiable") that have discussed at past COPs. China and others are worried that "transparency" opens them up to intrusive scrutiny and unwanted policy prescriptions.

Some excerpts from the interview follow:

Are you and other leaders of developing-nations buoyed by Clinton's big promise today to commit 100 billion a year by 2020 to developing nations to mitigate and adapt to climate change?

It's a fair commitment. These are not the figures that would really solve the problem, but it's a good start. Until now we only had the announcements of probably commitments regarding a few billion dollars. This is more in the line of what we would be expecting in terms of mid-term and long-term financing.

Is China justified in resisting Clinton's demands for transparency?

They have a point. The agreement in Bali was on MRVs. Now the discussion is about "transparency" -- It depends on the wording, really. it has to be something that is effective but on the other hand is not seen as too intrusive. It can't be someone telling you Look you have to change your policy here and there. Yes, you have to report, and there could be a discussion on numbers. But I don't think the US would like to see, in the case of its own transparency or its own actions, someone from a foreign country or institution saying You shouldn't be doing this you should be doing something else. We can reach a wording on the question of transparency that could be suitable to everyone. The methods [of transparency] have to be negotiated -- [a clear definition] would make everyone more at ease.

Is a weak deal better than no deal?

No. You always have expectations for a good agreement. Without a certain degree of commitment, or it will undermine the credibility [of these negotiations]. I think we can reach a good agreement event if it's not complete. You can leave some detailing and secondary matters to be discussed later, but you have to fix a date for that before the next COP in December -- it should be before that.

...This is the most important act of global diplomacy in a century, maybe--certainly since global arms control. There is no threat more universally shared than climate change. I just don't see anything more threatening.