This should'nt be a shock:
http://news.bbc.co.uk/2/hi/asia-pacific/7347638.stmChina has already overtaken the US as the world's "biggest polluter", a report to be published next month says.
The research suggests the country's greenhouse gas emissions have been underestimated, and probably passed those of the US in 2006-2007.
The University of California team will report their work in the Journal of Environment Economics and Management.
They warn that unchecked future growth will dwarf any emissions cuts made by rich nations under the Kyoto Protocol.
The team admit there is some uncertainty over the date when China may have become the biggest emitter of CO2, as their analysis is based on 2004 data.
Until now it has been generally believed that the US remains "Polluter Number One".
Next month's University of California report warns that unless China radically changes its energy policies, its increases in greenhouse gases will be several times larger than the cuts in emissions being made by rich nations under the Kyoto Protocol.
The researchers say their figures are based on provincial-level data from the Chinese Environmental Protection Agency.