Meanwhile, China has unveiled its first national plan for climate change. China said it intends to reduce its energy by a fifth before 2010, but that it would not make sacrifices at the expense of economic development. China said it would not commit to any caps on greenhouse gas emissions. Many analysts believe China could overtake the U.S. this year as the world’s largest emitter of greenhouse gases. China said rich countries were responsible for most of the greenhouse gases produced over the past century and had an “unshirkable responsibility” to do more to tackle the problem.