Each country can make strong shifts which will ensure that Durban defines a clear mandate to negotiate a new legally binding agreement in the immediate future. Let's hope they take this opportunity and help the world move forward to address global warming.

The U.S. must show leadership by helping craft a path to get a new legal agreement, not throw up barriers at the outset. They need to ensure that they aren't allergic to the meal that is served, but they can't demand that everything on the menu meet their tastes at the outset.

In Durban, countries must be able to "walk and chew gum," while starting to sprint towards solutions that deliver low-carbon energy and reduced deforestation.

The countries that gathered in Cancun made progress on emissions reductions, greater transparency, forest preservation and the creation of the green fund. But we aren't done yet.