This post orginally appeared in the Opinio Juris  blog.
Oh, how much difference a year — and lower expectations — make!
The BBC report  on the Cancún meeting declared that “if Copenhagen was the Great Dane that whimpered, Cancún has been the Chihuahua that roared.” Never mind that the Great Dane’s whimper was about the same decibel level as the Chihuahua’s roar. Last year, expectations were sky high for a new legal agreement that would extend, complement or replace the Kyoto Protocol, so the non-binding Copenhagen Accord was a major disappointment. This year expectations for the Cancún Conference were extremely low, so an outcome that essentially incorporates the Copenhagen Accord into the UNFCCC process is seen as a big win.
Frankly, I was doubtful that the Cancún Conference would be able to accomplish this much. Last year, a small group of countries successfully blocked the COP’s adoption of the Copenhagen Accord, leaving its status within the UNFCCC process uncertain. Since Copenhagen, the big developing countries such as China and India voiced at best tepid support for the Copenhagen Accord. So I had thought it likely that Cancún would produce a weaker result.
But the Mexican chair, Secretary of Foreign Affairs, Patricia Espinosa, did a masterful job in creating a negotiating atmosphere in which countries had confidence, and in putting pressure on Venezuela and its allies not to sink the meeting. (Reportedly, President Calderon personally called Hugo Chavez in an effort to dissuade Venezuela from blocking, as it did last year.) In the end, when only Bolivia objected to the adoption of the text, Espinosa was able to simply note the Bolivian objection and then gavel the decision through, to widespread applause.
The Cancún Agreements  reiterate all of the key elements of the Copenhagen Accord, including:
But the Cancún Agreements do not simply bring the Copenhagen Accord into the UNFCCC process; they elaborate and operationalize the three page Copenhagen Accord in thirty pages of decision text. Among its key elements, the Cancún decisions:
In Cancún, the growing splits among developing countries were on even clearer display than in Copenhagen. India played a very constructive role (and in particular, Environment Minister Jairam Ramesh), introducing a proposal on ICA that was very forward-leaning and suggesting that it could accept binding commitments. The small island states continued to push for negotiation of a new protocol that would address emissions from countries without Kyoto targets. And China found itself under increasing pressure from its fellow developing countries to accept some limits on its emissions.
Going forward, the Cancún decisions under both the UNFCCC and the Kyoto Protocol leave open the question of legal form — that is, whether there should be a new legal agreement under the UNFCCC, a second commitment period under the Kyoto Protocol, or both. The COP decision extends the mandate of the Ad Hoc Working Group on Long-Term Cooperative Action (AWG-LCA) for another year, and requests that it “continue discussing legal options with the aim to complete the agreed outcome” on the Bali Action Plan, and the parallel decision on the Kyoto Protocol calls on the AWG-KP to complete its work next year, so that there is no gap between commitment periods.
But whether or not next year’s UN Climate Change Conference in Durban, South Africa is able to translate the Cancún Agreements into legal form, the Cancún outcome represents a significant achievement, which shows that — with proper management — the UNFCCC process is still able to move the ball forward.
Dan Bodansky is Lincoln Professor of Law, Ethics, and Sustainability at Arizona State University's Sandra Day O'Connor College of Law. He is a guest contributor to Climate Compass and author of several Pew Center reports, including The Evolution of Multilateral Regimes: Implications for Climate Change , which was released at the Cancún climate talks.