Global climate conference in Copenhagen , the largest group of developing countries, "Group of 77 and China, asked the U.S. to join Kyoto Protocol. the former United States President George W. Bush and the current president, Barack Obama have consistently rejected this proposal.

the "Group of 77 and China" (G77 and China) Sudanese President Duha Ping on the 10th a press conference in Copenhagen, said: "The United States is in history per capita (greenhouse gases) emissions the largest country; the emission reduction target of 4% would not help to save the world. "

He said the U.S. should be ambitious on reduction, "compare to the degree of the Kyoto Protocol, Annex I countries ."

Annex I countries generally refers to the industrialized countries. Signed in 1997 under the Kyoto Protocol obligations to these country-specific reduction from last year to 2012, the average must be subtracted 5.2% compared with 1990. Currently held in Copenhagen the climate change conference, one of the main work is the development of the foregoing after the expiry of the first phase of the emission reduction targets.

The U.S. Congress has refused to ratify the Kyoto Protocol. In order to bring the U.S. into the global reduction operations, in 2005, held in Montreal, Canada, the United Nations Climate Change Conference created a two-track negotiation mechanisms. on the one hand , under the Kyoto Protocol,on the other, the United Nations Framework Convention on Climate Change (UNFCCC) that is the mother structure.

Two-track system in 2007, the "Bali Action Plan" (BaliAction Plan) further confirmed that this is the current negotiating process program.

by the end of November, the United States Submitted the target that in 2020 it will make a 17% reduction than in 2005 and 83% reduction by 2050 . However, as contemplated by the Kyoto base year 1990, the United States by the 2020's target is equal to only 4%.