Methane emissions – cited as a major contributor to rising greenhouse gases – are being overestimated by over 9 per cent, according to Teagasc, the Agriculture and Food Development Authority.
The national body, which provides research, advisory and training services to the agriculture and food industry and rural communities, has carried out research which has found that methane emissions, specifically from dairy cows, is being overestimated by around 9%. The findings were discussed at Teagsac’s Signpost conference in Clonmel, Tipperary, at the end of last week, the Irish Farmers Journal reports.
The colourless, odorless gas occurs abundantly in nature and as a product of certain human activities, and globally, it is the second most important greenhouse gas (GHG). Its contribution to global warming is estimated at 28 times that of carbon dioxide, over a 100 year period, and once produced, methane persists in the atmosphere for around 12 years after which it is eventually broken down into carbon dioxide and water.
Dr Hazel Costigan from Teagasc told the conference that based on the research, emissions had been “overestimated” and that methane conversion factors “vary greatly across the year.” She noted how enteric methane makes up just over 60 per cent of greenhouse gas emissions.
“When a country doesn’t have enough of their own data, they have to use an internationally derived methane conversion factor. Based on some of the research we have done, our methane is being overestimated,” the post-doctoral researcher said.
“The methane conversion factors vary greatly across the year. They are particularly much lower in spring time and they are about 9% lower across the year.
“What we are trying to do is refine these methane conversion factors so that they are more applicable to grazing dairy cows, their genetic makeup and the forage they’re consuming,” Costigan said.
In April, the Joint Committee on Environment and Climate Action, heard that changes in cattle breeding would help to reduce methane emissions. Calls were made for changes in the agriculture sector to reduce the methane emissions associated with the production in beef and dairy farming, citing research. Environmental campaigners have highlighted methane as the second most significant contributor to greenhouse gas emissions in Ireland, saying this is due to the large population of cattle.
However, in 2023 estimated emissions of CH4 were 15,914.6 kt CO2eq, indicating an decrease of 3.7% on the 1990 level of 16,534.2 kt CO2 equivalent, the Environmental Protection Agency (EPA) states.
Proposals to cull 200,000 cows to combat climate change and meet climate deadlines of reducing agricultural emissions by 25% by 2030 have been met with strong pushback. Irish farmers have voiced strong opposition and joining a string of protests last year, with a petition against the move gathering thousands of signatures.
Those opposed to the move, including a number of TDs, have said that the proposals are unnecessary and that an emphasis on more sustainable farming practices as well as financial assistance to support the move to more sustainable farming would be more beneficial for the sector.
Costigan said that the main focus of the new research is to find a feed additive that is compatible with Irish grazing systems, while at the same time not affecting animal performance or food safety, the Irish Farmers Journal reports.