The carbon footprint of farming is fundamentally misunderstood, US-based scientist Dr Frank Mitloehner told an IFA conference on climate change and agriculture.

The self-syled GHG guru explained how livestock production differs from fossil fuel usage in that the methane produced by livestock is part of a cycle that is in balance as long as numbers are not increasing.

Mitloehner holds that the vast majority of the methane output from grassland livestock production is re-absorbed by grassland in a “biogenic carbon cycle”. He said the total global production of methane from livestock was 560m tonnes. While 550 million tonnes are absorbed in a process called hydroxo oxidation, “methane is destroyed as well as being produced”. This leaves net emissions at only 10 million tonnes, less than 2% of gross emissions. Mitloehner said the carbon cost of a person’s meat consumption was half that of a single transatlantic flight.

Food waste

He also raised the issue of the vast proportion of food that is wasted, which he put at 40% of all production globally, describing it as costly to the environment.

He said pasture land captures as much carbon as forestry, to loud applause.

Earlier, Prof John Fitzgerald, the chair of the Climate Change Advisory Council, had expressed the belief that forestry supports rural economies to the same extent as agricultural production. He maintained that a cull of the national herd is necessary for agriculture to reach its targets.

Mitloehner did counsel against an increase in livestock numbers, saying that “an increase in livestock numbers is an increase in carbon output”.

Cattle numbers

Teagasc’s Frank O’Mara said Ireland had “stabilised” cattle numbers in the last couple of years. While there was an increase in overall livestock numbers immediately after the ending of milk quotas, extra dairy cow numbers are being offset by reducing suckler numbers.

We are not the problem but we definitely can be part of the solution

O’Mara outlined the main planks of the Marginal Abatement Cost Curve carbon roadmap, including the use of protected urea, low-emission slurry application at times of optimum nutrient usage, particularly early in the growing season, and more utilisation of clover in pastures.

IFA president Joe Healy highlighted how Ireland had increased its food output by 45% since 1990, with only a 1% increase in emissions.

Closing the conference, incoming IFA president Tim Cullinan described “a clear science gap in the counting of carbon from agriculture”.

“We are not the problem but we definitely can be part of the solution,” he concluded.

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Cut suckler cows or hold what we have? IFA climate conference debate