Turning China into the world’s manufacturing centre has given us a bountiful supply of dirt-cheap goods but is proving an environmental disaster. Chinese industry is overwhelmingly dependent on coal for its energy and China’s coal-fired power stations are among the least efficient in the world.

Britain’s coal plants are typically 35-40 per cent efficient, meaning that 35-40 per cent of the energy in the coal that they burn is turned into electricity and 60-65 per cent is lost in heat up the chimneys. China’s power stations are less than 25 per cent efficient.

With more than 70 per cent of its electricity coming from coal, China has one of the worst scores of any country for carbon intensity, a measure of the amount of carbon emitted for every unit of GDP.

Britain likes to boast that it has reduced its greenhouse gas emissions by 21 per cent since 1990. But we have achieved this by closing energy-hungry factories and exporting manufacturing — and emissions — to China.

However, while China now has the highest carbon dioxide emissions in the world, its per capita emissions are still only half that of Britain and a quarter of the level in the United States. China points to this difference when rejecting calls for it to set a target for cutting overall emissions.

Given that President Hu has already made clear that China would not sacrifice economic growth in the quest to prevent climate change, the best that could be hoped for from December’s Copenhagen climate summit is a cut in China’s carbon intensity. President Hu’s pledge yesterday to cut that intensity by a “notable margin” was promising, even if he failed to set any specific figure.

His statement was calculated to give the appearance that China was playing its part and to put pressure on the US to do likewise. The announcement in New York ensured maximum coverage in a country that has spent 15 years excusing its own inaction on climate change by pointing to the foot-dragging of China, India and other developing countries.

Ed Miliband, the Energy and Climate Change Secretary, said: “The fate of every nation on earth hangs on the outcome of Copenhagen. It is too important to play the cards-close-to-your-chest poker games that marked diplomacy of the 20th century.”

President Hu is like a poker player who tells his fellow gamblers that he holds a pair but refuses to say whether they are twos or aces.

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