It's too early to say whether the Cancun climate change summit will be deemed a success or not. By keeping expectations low, the myriad bureaucracies involved will be able to term any agreed string of words a victory. One thing though is certain: in any meaningful sense, Cancun will fail. How can I be so sure? For one thing, it is not concerned with climate change: it is entirely preoccupied with (1) political jockeying and finger-pointing, and (2) greenhouse gas emissions. For another, any agreement or commitment (or, more accurately, declared commitment) will be based on current science; it will not have the capacity to adapt to our rapidly expanding scientific knowledge. Bureaucracies understand top-down, one-size fits all, centralised decision-making. They don't understand diverse, adaptive approaches, and they certainly don't like relinquishing control to people who might be better at actually getting things done than government agencies or their pals who run gigantic corporations. Their real expertise at the international level is in making declarations of intent and organising the transfer of large sums of cash from taxpayers in the rich world to such corporations and third-world elites.
So is there anything positive I can suggest? I've talked and written about Climate Stability Bonds for many years now. As far as I know, nobody's thinking about issuing them. Yet they are the only instrument that I've heard of that can address the doubts (genuine or otherwise) about whether climate change is happening, the huge uncertainties over its likely effects and the best ways of dealing with it, and our rapidly expanding scientific and technological knowledge. Even more important, they are the only suggestion I've seen that will subordinate all policies and all activities and intervention to what we actually want to achieve, rather than to the supposed means of reaching it: a stable climate. That's a versatile and adaptive goal, which can encompass plant, animal and human health, and physical, social and financial targets and ranges.
Current policy, including Cancun, will focus on net emissions of those gases thought to be greenhouse gasses. That's not the same as climate stability. So, in the unlikely event of an agreement in Cancun with which the signatories will actually comply, you can be sure that in any meaningful terms the summit will fail.