Australian cattle do not produce as much carbon emissions as first thought, and an adjustment to the figure could decrease the rural sector's overall contribution to greenhouse gas emissions.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 6 minutes 26 seconds 6 m Marty McCarthy reports that Australian beef and dairy cattle don't produce as much methane as first though ( Marty McCarthy ) Download 2.9 MB

That is the finding of an eight-year CSIRO investigation into the effects of the beef and dairy industries on Australia's methane emissions.

According to Dr Ed Charmley, an agriculture scientist with the CSIRO, methane emissions from cattle in Australia are 24 per cent lower than previously thought, equivalent to 12.6 million tonnes of carbon dioxide a year.

Dr Charmley said the findings would help reduce criticism of the farm sector's impact on climate change, and help farmers increase their productivity.

"It certainly helps, we have a lot more confidence in the data we have because it is based on newer methods, and it shows lower emissions," he said.

"But lower emissions means more efficient production, and so from the producers' perspective we want to see more efficient animals with less wastage going out in methane."

Meat and Livestock Australia, the nation's peak research and development body for the sheep and cattle industry, co-funded the study and has embraced the results.

Dr Matthew McDonagh, general manager of On Farm Innovation with MLA, said the findings would reduce the pressure put on primary producers for their impact on climate change.

"We already know we are not the major player when it comes to greenhouse gas emissions across the country," he said.

"But consumers are well aware of it and they know sheep and cattle produce methane, and they are concerned about any of the products they use that have an impact on the environment.

Dr Ed Charmley (right) with Greg Bishop-Hurley and Wayne Flintham were among the team of CSIRO researchers at Landsdown Station, west of Townsville in north Queensland, who have been testing methane emissions from beef cattle. ( Marty McCarthy )

"So this is just some good data that we can demonstrate to consumers that shows we have got our eye on the ball when it comes to our industry.

"We can show there had been an overestimation of sheep and cattle influence on the total greenhouse gas emissions of the country and start to tell that story to the consumers.

"We can make consumers understand that perhaps this is not the bogeyman that people once thought it was."

Methane is released through burping, and is created in the digestion process of cellulose in the rumens of livestock.

Recent advances in methane testing technology enabled researchers to more accurately test the actual amount of greenhouse gas the cows were producing.

"All the data we have used is from what we call the methane chamber technique, which is the best technology we have available," Dr Charmley said.

"It involves putting an animal in a chamber where you monitor the amount of air going in and the amount of air going out, and the concentration of methane in that.

"From that we can calculate the amount of methane that is produced by the animal, particularly in relation to the amount of food the animal is given."

The results will be used to update of the National Greenhouse Gas Inventory (NGGI), and bring Australia in line with international estimates set out by the Intergovernmental Panel on Climate Change (IPCC).

Dr McDonagh said the reason for the initial cattle emission overestimation was due to generic data being used.

Cattle herds in Australia's north were studied as part of the research. ( Virginia Tapp )

"Previously there had been estimates done using similar technology but on very different animal and feed types," he said.

"Previously they were based on dairy cattle, which aren't necessarily applicable to our grassland production systems for the majority of cattle producers.

"We basically knew that, using international data as a comparison, we were probably overestimating, but we didn't quite realise it would be by as much as 24 per cent."

Agriculture contributes more than 15 per cent to Australia's overall greenhouse gas emissions, and almost 70 per cent of that is from sheep and cattle.

Electricity contributes the most at 35 per cent, while transport contributes 14 per cent.

Dr Charmley said the 15 per cent figure for agriculture could now be downgraded as a result of the updated research.

"It will [bring it down], but at the same time there have been changes to what is known as the global warming potential of methane," he said.

"So that tends to offset some of the advantages, but if we hadn't done this work it brings down the overall agriculture emissions because methane is such a big part of that."

Dr Charmley said similar research to measure emissions from sheep was ongoing.

A national study

Around 1,000 cows were tested across the country, from north and central Queensland to northern New South Wales and Victoria.

Townsville and Rockhampton in Queensland and Armidale in New South Wales were used as the testing locations for beef cattle emissions, while the dairy data was gathered in West Gippsland, Victoria.

According to Dr Charmley, researchers were surprised to find that the amount of methane emitted was the same for animals in each location.

"That was one of the reasons for doing this study, because we thought there would be some differences between, say dairy cattle and bos indicus cattle," he said.

One thousand dairy cows as well as beef cattle were studied across the country, with researchers surprised to find that the amount of methane emitted was the same for animals at each location. ( ABC Rural: Lucie Bell )

"But what we found was that when you had a large enough data set, although there are small differences depending on where the work was done and the type of animal, the relationship was very strong."

"Per unit of dry matter intake a dairy cow emits the same amount [as beef cattle], but of course a dairy cow would consume a lot more feed than a beef cow."

Dr McDonagh said the red meat industry had been working to reduce methane emissions in livestock in recent years.

"We can already demonstrate that the amount of greenhouse gas that livestock produce, particularly cattle, over the last 30 years has reduced," he said.

"We have been able to reduce the amount of methane that an individual animal produces per kilogram of product by about 14 per cent over the last 30 years."

Dr McDonagh said there was no conflict of interest in the research, which was co-funded by MLA levy payers.

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"We certainly part-funded the research along with all of our research agency partners, led by CSIRO," he said.

"This is a published paper, which really demonstrates in the scientific literature that the data and calculations are all there, and has been critiqued by the scientific community."

The analysis of Australian cattle research data was conducted by CSIRO, the Victorian Department of Economic Development, Jobs, Transport and Resources, the New South Wales Department of Primary Industries, the University of New England and the Queensland Department of Agriculture, with technical input from the Australian Government Department of Environment.

The new method of analysing methane emissions from Australian cattle has been published in the journal Animal Production Science.