A climate change expert has expressed scepticism about the role that feed additives will have in reducing greenhouse gas emissions from agriculture.

At the National Sheep Association AGM on Tuesday, Professor John Gilliland questioned who will pay for methane inhibitors if the technology becomes available to farmers.

“Are retailers going to put their hand in their pocket and pay for it because I know farmers won’t,” he said at the meeting near Ballymena, Co Antrim.

Gilliland described methane inhibitors as “win-lose” because the technology aims to reduce greenhouse gas emissions from livestock without any other benefit to farmers or the environment.

He argued that existing “win-win” measures, which lead to various environmental gains and improved farm profitability, should instead be encouraged on farms.

The example of multispecies swards was given, with research suggesting herbal leys can help increase biodiversity, improve soil structure, build soil carbon, reduce fertiliser use and improve animal performance.

“I would much prefer it if farmers were paid to do this because this will deliver far more benefit than some synthetic chemical that you put down the throat of a ruminant,” he said.

Gilliland argued that calculations on greenhouse gas emissions from farming should include the carbon dioxide that is removed from the atmosphere and stored in soils, trees, and hedgerows.

He presented figures for host farmers Roger and Hilary Bell which shows their farm emissions are 60% lower when “gross sequestration” is accounted for.

Research from the ArcZero project has found that 51,507 tonnes of carbon is stored on the Bell farm and 98% of this is found in the soil.

By improving efficiencies on their sheep and beef farm, the Bell family have been able to reduce the carbon footprint of production by 28% over the past two years.

“We are on a journey. There are some farms that are already at net zero and there are others who are moving towards it,” Gilliland said.