Australia’s cattle methane emissions figure downsized by 24%
The finding by Csiro, Australia’s government research network, has led to the National Greenhouse Gas Inventory being updated.
It follows research by scientists and officials across Australia based on data collected over eight years that looked into ways to reduce methane emissions in livestock as part of Meat and Livestock Australia's methane abatement research programmes.
The new methodology also brings the inventory in line with the estimates of the Intergovernmental Panel on Climate Change, the leading international body on the assessment of climate change, which was established by the United Nations Environment Programme and the World Meteorological Organisation in 1988.
Csiro's Ed Charmley said the survey was conducted because of concerns about the large differential between the government emission figures and those published by the IPCC for Australian cattle.
Doubt surrounded the accuracy of previous calculation methodologies used for cattle, and northern Australian cattle in particular, which were over-estimated, he said.
"Different methods used to calculate emissions from livestock in temperate and tropical regions were based on studies done in the 1960s and 1990s, mainly with dairy cattle," Dr Charmley explained.
"The revised method, which is based on improved ways of estimating ruminant methane emissions from forage-fed beef and dairy cattle in temperate or tropical regions has been tested against international defaults provided by the IPCC and found to give consistent methane yields."
MLA’s Matthew McDonagh said the new research provided an accurate dataset: "This revelation clearly shows livestock-based emissions are nowhere near what they were thought to be and will help improve the accuracy of Australia's national greenhouse gas emissions estimates.
"This is positive news for the Australian livestock sector as it seeks to continually improve its production efficiencies and demonstrate its environmental credentials."
Tom Davison, a sustainability manager at the industry-owned livestock advocacy, said the findings also illustrated a number of simple management measures producers could implement to substantially reduce methane emissions while increasing productivity.
"Some of these are as simple as integrating leucaena into grazing systems, improving growth rates or herd reproductive performance, while other future techniques may include feeding red-algae to livestock and have been prioritised for further research," said Dr Davison.
"We look forward to continuing to make further gains in this field for the mutual benefit of both our livestock industries and environmental sustainability.”