The signals are clear – but contradictary. China has embraced the concept of climate change and is allowing officials to discuss the risks openly. Two weeks ago Zheng Guogang, head of the Chinese metereological administration warned of droughts, rainstorms and the threat to major infrastructure projects. He could not have spoken without permission.

But at the same time economic growth remains the prime objective of Chinese policy and growth requires the consumption of ever greater volumes of primary energy, led by coal.

Demand may have slipped by a small amount last year but new coal plants are still being opened. Coal consumption in China has doubled in the last ten years. China is now the world’s largest economy and consumes more than half of all the coal used worldwide each year. Within two decades, even on quite modest assumptions about economic growth it will have an economy twice the size of the US with personal living standards equivalent to those of the US in 1980. But it will still be an economy powered by coal – with demand on current policies up by another 20 to 25 per cent according to the forecasts produced by the International Energy Agency.