OVER THE MOO-N WITH METHANE REPORT

(Published 27 May 2011)

A study has revealed that cows in Australia are burping less planet warming gas than previously feared.

Cattle, sheep and other ruminant livestock produce large amounts of methane, which is about 20 times more powerful at trapping heat than carbon dioxide. One cow can produce about 1.5 tonnes of greenhouse gas emissions a year.

Half of New Zealand's greenhouse gas emissions come from agriculture and most of that is from sheep and cattle. Most of the cattle and sheep emissions are, contrary to popular belief, from burping.

Scientists at Australia's state-backed research body, the CSIRO, say the amount of methane from cattle fed on tropical grasses in northern Australia could be nearly a third less than thought.

The findings were based on results from specially built respiration chambers using Brahman cattle fed tropical grasses and challenge old calculations used by the government to estimate emissions from cows.

About half of Australia's approximately 27 million head of cattle are in the north, with the northern cattle herd accounting for about 4.5 percent of the nation's total greenhouse gas emissions.

A 30 percent reduction in emissions would total about 7.4 million tonnes, or roughly the amount of a large coal-fired power station.

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