THE red meat industry has come under yet more fire, with an Australian scientist claiming cattle are a greater source of greenhouse pollution than coal.

University of Adelaide Professor of Climate Change Barry Brook said livestock were responsible for half of Australia's short-term global warming gases - more than the coal industry.

Prof Brook's claims are based on the logic that methane is 72 times more damaging than CO2 in the short-term.

The Intergovernmental Panel on Climate Change's fourth report said the real impact of methane is equal to 72 units of CO2 - rather than the 21 used by Kyoto - if the impact is measured over 20 years rather than 100, which is what Kyoto uses.

"The message is not to become a vegetarian ... I eat red meat," Prof Brook said.

"But everything in moderation."

His comments follow calls by former US vice-president Al Gore to cut meat consumption and by UK climate change report author Lord Nicholas Stern for a shift to vegetarianism.

Prof Brook said the associated emissions from a family eating 4kg of beef a week was more than three times the amount associated with driving a Ford Territory 200km a week.

And he said methane reductions offered a unique opportunity to rapidly reduce Australia's global warming footprint.

Meat and Livestock Australia climate change manager Dr Beverly Henry said MLA accepted the findings of the IPCC that the global warming effect of methane was 72 times greater than that of carbon dioxide when measured over 20 years.

But Dr Henry said some estimates of the global warming potential of livestock emissions had failed to apply the 72 factor to methane from coal mining.

Only half of man-made methane emissions came from the livestock sector, she said.

"Different time frames for different gases make valid comparisons difficult," Dr Henry said.