The Obama administration has rejected a UN scientific panel’s call for a 40 percent reduction of greenhouse gas emissions by 2020. On Tuesday, US climate envoy Todd Stern called the UN Intergovernmental Panel on Climate Change’s target “not necessary,” “not feasible” and “not in the cards.” Stern made the comments at international talks in Mexico ahead of the December global climate summit in Copenhagen.

US climate envoy Todd Stern: “These are hard issues, and I think that we are just — you know, we’re working through it and making progress. I do think that we will have a successful agreement in Copenhagen, but it would be — we just say, in the context of any kind of negotiation like this, it would be incredibly unusual.”