We must mitigate and adapt to climate change. On this, the international community is agreed. But exactly how to do that is still up for debate. There were high hopes that last year’s UN climate talks in Copenhagen would deliver a legally binding agreement for action on climate change. But the outcome — the Copenhagen Accord — was instead a political ‘statement of intent’ that fell significantly short of expectations. Now, after a year of interim meetings and several negotiating texts, parties to the UN Framework Convention on Climate Change (UNFCCC) are gathering in Cancun, Mexico, to try again. Their success will largely depend on settling disputes — particularly between the developed and developing world — about six key issues: shared vision; adaptation; climate finance; technology transfer; reducing emissions from deforestation and degradation; and post-2012 emissions reduction targets.