There was a palpable sense of expectation around the world that the December 2009 Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) held in Copenhagen, Denmark, would result in a binding agreement among governments to substantially reduce pollution-causing climate change. In contrast to that expectation, the outcome of the conference was little more than voluntary agreement on principles--albeit important ones, in the form of the Copenhagen Accord--and general consensus that a binding agreement might be achievable in time for the next Conference of the Parties in Cancun, Mexico, in December 2010. Many observers, and indeed some government officials in the West, blamed China for the failure of the Copenhagen meeting, in particular for China's opposition to a binding agreement to reduce global emissions of greenhouse gases (GHGs) by 50% by mid-century. China was especially strident in opposing any binding cuts in GHGs for developing countries, although it pledged voluntary efforts to improve its own energy efficiency. Whether China is to blame for the outcome at Copenhagen remains subject to debate, and of course the Chinese strongly deny the accusation. What is beyond question is that China is now the largest national source of pollutants causing global warming, thus making its policies and actions central to efforts by governments, industry, and individuals to limit and cope with climate change.