Head of the US climate change delegation, Jonathan Pershing, explains how this first meeting is about process and building on the successes of Copenhagen, in the run-up to Cancun. Countries differ in perspectives on the Accords, but he points out that, for the first time, the vast majority of emissions are included, the two-degree target is set, structures are in place for technology and market agreements. Success in Cancun will depend on firstly moving the actions in the Accords through to implementation, and secondly, by elaborating on rules for reporting, verification and monitoring, financing, reduced emissions from deforestation. He is optimistic that process can be made to overcome dissent between parties.