Ruminants contribute to Greenhouse effect

Press, 8 June 1989, Page 38

Ruminants contribute to Greenhouse effect

NZPA Sydney The world’s three billion sheep, cattle and goats make a big contribution to one of the main causes of the greenhouse effect, according to scientists. By emitting 80 billion tonnes of methane a year, exhaled as a product of digestion, ruminants are responsible for about 20 per cent of the methane liberated into the atmosphere every year.

The concentration of methane in the atmosphere was growing at the rate of 1 per cent each year and helping to change global climate, a scientist with the United States Environmental Protection Agency, Dr Michael Gibbs, said. Dr Gibbs, who has been working on the greenhouse effect with Australian scientists and environmental groups, said there were several main

sources of methane emissions. Other sources related to human activity included rice paddies, forest and crop burnings, coal mining, landfills, and venting and flaring in oil exploration. Natural sources included swamps, lakes and peat bogs. “Reducing emissions from one or two sources would do little to stabilise methane concentrations in the atmosphere,” Dr

Gibbs said. "Instead small reductions in each of the main sources, including ruminants, is desirable.” According to Dr Gibbs there is considerable scope for reducing the amount of methane an animal produces. One option he suggested would be to change the fermentation processes that take place in animals’ digestive tracts.