In the early hours of Saturday morning in the Mexican tropical resort of Cancun, international climate negotiators from the 193 countries and observer states came to agreement on what will now be know as the 'Cancun Agreements'.  After the very public perceived failure of the Copenhagen summit last year in Denmark, it was very important that this meeting ended successfully.  I wrote last week that "A failure to come to any agreement in Cancun would probably spell the end of the UN as a negotiating forum for climate change." 
 The agreement text came out of two separate negotiating forums, the "Ad Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol" and the "Ad Hoc Working Group on long-term Cooperative Action under the Convention".  The formal agreements, to be found here and here, respectively.  There are two negotiating tracks within the UNFCCC because the parties to the Kyoto Protocol do not include all of the countries that are signatories to the UNFCCC, most notably the United States.
What to do with the Kyoto Protocol, expiring in 2012, was the source of the most contention during the summit.  I worried last week that the Cancun Summit could fail under the divide between developed and developing countries, enshrined as a part of the Kyoto Protocol.  Kyoto is fatally flawed because it asks everything from developed countries, while asking nothing from developing countries - which include many of the world's largest emitters, like China (#1), India (#4), Brazil, and Indonesia.  It was further weakened because the United States, bowing to political and economic reality, chose first not to ratify it, then to withdraw from it.  The Cancun Summit ended in success simply because it decided to 'punt' on the issue of whether to continue Kyoto after it expires in 2012. Next year's summit in Durbin, South Africa will be the last conference before Kyoto's expiration, so this question will have to be addressed by then.  
Although the Cancun Agreement dodged the question of Kyoto, there are some significant achievements of note.  It formally commits the parties of the UNFCCC to ensuring that climate change does note exceed 2 degrees of warming over this century.  On mitigation (agreements to reduce emissions), the Cancun agreement codifies the voluntary mitigation targets agreed to by signatories of the Copenhagen Accord. This is a huge milestone, because it is the first time that all major economies have pledged explicit actions in a UNFCCC document since its creation in 1992. It also made significant steps on a climate financing mechanism for adaptation and mitigation by developing countries.  It delegates to the World Bank the responsibility for creating a "Green Climate Fund" that would mobilize the pledged funding of $100 billion a year in public and private financing promised by 2020.  

In January 2010, I wrote in an IISS Strategic Comment that "the success of the Copenhagen Accord had yet to be seen".  The Cancun agreement essentially adopts the Copenhagen Accord, including the emission mitigation targets voluntarily submitted by approximately 80 countries and the measuring, reporting, and verification compromise agreements - largely negotiated between the United States and China.  The Cancun Agreements successfully brought the Copenhagen Accord into the UNFCCC negotiating process.  Therefor, upon further reflection, it seems that Copenhagen, too, was a bit of a success, had it been judged against any standard that wasn't so ambitious to say that Copenhagen as the "Summit to save the planet". 
At Cancun, negotiators yet again failed to save the planet - the mitigation targets agreed to could bring up to 3 or 4 degrees of warming over this century - but they did succeed in creating much of the global architecture that one day could help to save the planet.