Yeah but did they sign the kyoto treaty????
Yes, but since they are a developing country there are no emissions limits on China. This is the reason the US did not sign. All that Kyoto does is transfer emissions from developed countries to developing countries. Much of China's growth is due to the fact that Europeans and Americans don't want dirty industry.
It should also be noted that Kyoto isn't the only dirty transfer to the developing world. European recycling initiatives typically have a lot of their trash shipped to China. That way Europeans can feel happy that they are recycling material while the Chinese 'recycling' companies simply bury it in landfills.