This post orginally appeared in the Opinio Juris  blog.
Was the Durban climate conference a success or failure? As always, the answer depends on one’s frame of reference.
As compared to the expectations going in, the outcome  was more than I think most people thought possible. In a pre-Durban paper entitled “W[h]ither the Kyoto Protocol ,” I identified three scenarios: (1) business-as-usual, with modest progress in developing the Copenhagen/Cancun framework and no political breakthroughs; (2) agreement to a “political” (not legally-binding) second commitment period under the Kyoto Protocol; and (3) agreement to a Kyoto Protocol amendment establishing a second commitment period, combined with a mandate for a new negotiating process to develop a legally-binding agreement addressing the emissions of the other major economies. Many thought that (1) was the default option, (2) represented the best-case scenario, and (3) was politically unrealistic. But the Durban outcome is in fact closest to (3):
The Durban  outcome seemed unlikely because there was little indication that China and India would agree to negotiate a new agreement to limit their emissions. Without agreement by China and India, the United States had said that it would not agree to a new round of negotiations. And without agreement by the United States, China, and India, the European Union would not agree to a second commitment period under the Kyoto Protocol. What allowed the Durban outcome was a careful compromise that gave BASIC countries, on one side, a 2020 start date for the new agreement and some ambiguity about its legal character (about which more below), and gave the EU, small island states and least-developed states, on the other side, early start and end dates for the negotiations (the negotiations will begin next year and conclude in 2015) and language that the outcome of the new negotiations will have “legal force.” Interestingly, the United States apparently played something of an intermediary role, since it had some flexibility about the issues of both dates and legal form. In the end game of Durban, India was unwilling to accept a mandate to negotiate a “protocol or another legal instrument,” and preferred the formulation “legal outcome.” The United States suggested “outcome with legal force,” India added “agreed,” and the EU said ok. Thus the deal was done.
Of course, the Durban outcomes are largely procedural. So if one’s frame of reference is what needs to be done substantively to limit temperature change to no more than 1.5 or 2 degrees C, then the Durban outcome falls far short. According to most scenarios, global emissions need to peak by 2015  in order to have a reasonable chance of limiting global warming to no more than 2 degrees. Instead, emissions rose by 6 percent in 2010 , the largest amount on record. Even if the Durban Platform  negotiations are successful, a new agreement wouldn’t kick in until 2020. Although the Durban decision calls on countries to consider raising the ambition of their existing pledges for the 2012-2020 period, these pledges are non-binding under the Copenhagen/Cancun framework. Hence the unhappiness of small island and least-developing states with a 2020 start date for a new agreement.
The Durban Platform is also pretty thin gruel as a negotiating mandate. In terms of its actual language, it is arguably weaker than the 1990 UN General Assembly resolution  that initiated the UN climate change negotiations and led to the development of the UN Framework Convention on Climate Change. The 1990 UN General Assembly resolution called clearly for the negotiation of a “convention” (albeit a “framework” agreement) “containing appropriate commitments.” In contrast, the Durban meeting was unable to agree on a mandate to negotiate a legal agreement and contains no language about commitments. The Durban platform could be satisfied by an “outcome with legal force” — a formulation that as far as I am aware does not have any precedent in international law. Arguably, “legal force” means the same thing as “legally-binding,” and the addition of “with legal force” to “agreed outcome” (the Bali Action Plan language) means that the outcome is something more than what Bali contemplated (which included COP decisions). But the inability to reach agreement on “legally-binding” suggests that at least some parties thought “legal force” might mean something less.
Moreover, the Durban Platform does not specify anything about the content of the new “protocol, another legal instrument or legal outcome with legal force.” The assumption is that it will set forth emissions limitation commitments, but the Durban decision does not say so explicitly. So, in theory, the Durban Platform negotiations could be satisfied by another framework-style agreement. In Durban, the issue was often framed as whether the BASIC countries would agree to negotiate a legally-binding agreement for the post-2020 period. But, of course, the BASIC countries are already parties to two climate change agreements, the UNFCCC and the Kyoto Protocol, one of which (the UNFCCC) already imposes general mitigation obligations on all parties, including the BASICs. So the issue is not whether China, India and the other BASIC countries are willing to become party to a legally-binding agreement, even one that imposes mitigation commitments on them. Rather, the question is whether the BASIC countries are willing to accept specific (quantitative?) obligations to limit their emissions.
The other gorilla in the room is stringency. Specific emission limitation commitments by all of the world’s major economic would be a big step forward. But whether it would be enough to prevent dangerous climate change would depend on the stringency of the commitments. Durban made little if any progress in that regard. The Durban Platform contains preambular language expressing “grave concern” about “the significant gap between the aggregate effect of Parties’ mitigation pledges … and aggregate emissions pathways consistent with having a likely chance of holding the increase in global average temperature below 2° C or 1.5° C above pre-industrial levels.” It calls on the new negotiating group to “raise the level of ambition” and launches a workplan to “enhanc[e] mitigation ambition” and to “close the ambition gap.” But efforts in Durban were completely unsuccessful to include language about when global emissions need to peak or about a long-range global emissions reduction goal (such as a 50% reduction by 2050). This suggests that even if the Durban negotiations lead to the adoption of a new legal agreement, it could fall woefully short of what is needed.
So the Durban Conference should be seen as only one step along a long path. What was remarkable about the meeting was that a coalition of small island states, least-developed countries and the European Union was successful in pushing through an outcome about which the United States, China and India were, at best, lukewarm. Whether the political pressure that led to Durban will also be sufficient to produce a strong agreement will determine whether Durban is seen by history as a significant breakthrough or a pyrrhic victory.
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.