"At a major United Nations climate summit in Warsaw this week, a plan is being hammered out for negotiations on a new climate treaty to be finalized in Paris in two years’ time. Delegates from 195 nations are also seeking to obtain commitments from countries to limit their greenhouse-gas emissions between now and 2020. But the path forward is rife with disputes between rich and poor countries over funding, and how to allocate and enforce emissions reductions."

"The conference aims to outline the schedule and to set parameters for negotiations ahead of the next major climate summit in Paris in 2015, when countries hope to forge a treaty to follow the 2009 agreement settled on in Copenhagen.

At that meeting, negotiations over a formal treaty broke down, but eventually resulted in a set of non-binding pledges — the Copenhagen Accord — for emissions reductions until 2020. The accord also blurred the distinction between developed countries, which were bound by the 1997 Kyoto Protocol to reduce emissions, and developing countries, which had no such obligations. Since then, negotiators have worked on how to structure a new framework that would involve climate commitments from all countries — including China, now the world’s largest emitter, and the United States, which never ratified the Kyoto Protocol."

Jeff Tollefson reports for Nature/Scientific American November 13, 2013. [2]