In that model, China’s per capita emissions are close to the global average and rising fast. Consequently, China’s emissions rights would rise only for a short time until they hit the global average and then would need to decline along with the global average. That may not be acceptable to China and some other fast-growing countries. For them, some headroom may be needed, perhaps in the form of linking the growth in emissions allocations to GDP growth, as suggested by the Garnaut Climate Change Review (chapter 12 of the draft report). That can conveniently gel with China’s energy intensity target, mentioned in the post.

Whatever form a greenhouse gas commitment by China takes, it will have to result in comprehensive action, and it will likely need to be binding not voluntary to be successful. The Clean Development Mechanism (CDM) may have been a useful first step, but it is quite unsuitable to deliver the kind of reductions needed. Just how crucial China is for the global effort to limit climate change, and how urgent the challenge, is explained in several chapters in the China Update 2008 book