I'm not an expert on global warming, but I do think that of all the fossil fuels, burning coal is the worst for our environment, and China is burning a buttload of coal!
While coal consumption in the rest of the world grew somewhat slowly over the last 12 years, consumption in China more than doubled. China now burns almost as much coal as the rest of the world combined:
(clic the pic for an even more smoky image)
China is both the biggest coal producer AND the biggest coal importer.
Can it be that the biggest single problem facing the world is the need to find a much cleaner energy source for the developing world?
One thing is for sure: a rich world carbon tax is not going to do much, if anything at all, for the environment. Unlike acid rain, carbon dioxide emission is a global externality, not a local one.