"China's emissions of carbon dioxide have shrunk by 17 per cent since the mid-1990s," the Lawrence Berkeley National Laboratory in California said in an April report, the daily says.

"There is a good basis to argue that China has done more to combat climate change over the past decade than has the United States," said another report by the Natural Resources Defence Council, also cited by the daily.

China is the second-largest carbon dioxide producer after the US and had been expected to become the world leader by 2020, a prospect that in light of the new reports appears to have been put off by years or decades.