Ai Guangzeng, 60, says the biogas she has been fueling her home with since 2006 is "good stuff."

"It's much cleaner burning than coal or firewood," she says, pointing to the blue flame on the stove in her home in a remote village in Guizhou Province.

Ai sees only two other significant aspects to the methane gas: it has cut her coal consumption by half and spares her the arduous chore of chopping firewood.

However, Ai Xinglong, energy office chief of Guizhou's Kaiyang County, sees a direct link from the gas stove to the United Nations climate change conference, which opened Monday in Copenhagen.

He is anxious that the conference participants keep pushing forward the Cleaner Development Mechanism (CDM), an arrangement under the Kyoto Protocol that allows industrialised countries with greenhouse gas reduction commitments to invest in ventures that cut emissions in developing countries as an alternative to more expensive emission reductions in their own countries.

Ai Xinglong is responsible for the local methane program and has been busily encouraging local farmers to build biogas generating pools, also called the methane digesters, to reduce the consumption of coal and wood, so limiting carbon dioxide emissions.

He wants to know whether the Copenhagen conference will keep endorsing the CDM, so the biogas farmers in Kaiyang can be "rewarded" with money by selling the amount of emissions reduced by using methane.

"The money can be used as a follow-up fund for our methane program. It's very important," he says.