In 2006 China set a target of a 20% cut by 2010 of its energy intensity (the amount of energy consumed per unit of GDP).

ECONOMIST: Pollution in China

China, now the world's biggest emitter, and so the country in the spotlight, has committed itself to cut the carbon-intensity of its economy by 40-45% by 2020.

ECONOMIST: The Copenhagen Summit

China, India and other developing countries have already promised to cut the energy or carbon intensity of their expanding economies.

ECONOMIST: Climate-change talks