Every year, the mainland releases 20 billion cubic metres of coalbed methane (CBM) into the atmosphere - the energy equivalent of 26 million tonnes of coal or the annual output of the Three Gorges Dam.
Aside from the environmental considerations - methane is about 20 times as noxious as carbon dioxide - it is a massive waste of energy which the mainland is belatedly trying to harness.
Historically, CBM was viewed as an unwelcome by-product of coal mining and used to be treated as hazardous waste product. More recently, the increased demand for natural gas, improved extraction technology and higher gas prices have led to the commercial exploitation of CBM.
CBM is found in the seams within coalbeds and is responsible for the frightful carnage caused by gas explosions in the mainland's coal mines every year.
With 36 trillion cubic metres of proven reserves, China has the third-highest reserves in the world after the United States and Canada. The bulk of these reserves are in Shanxi province, Inner Mongolia and Shaanxi province, accounting for 55 per cent of the total, with the northern parts of Xinjiang accounting for 23 per cent.
But development of the resource has been slow as a result of the low levels of investment, lack of infrastructure and cumbersome bureaucratic procedures for getting licences and other legal problems.