If agriculture is not granted a separate climate target for biogenic methane then the national herd could be facing a 5m cut in numbers, an internal Department of Agriculture document reveals.

The document, seen by the Irish Farmers Journal, discusses climate targets in relation to Ireland’s Climate Bill and argues that a New Zealand style model which separates overall greenhouse gas emissions and biogenic methane is necessary if net zero carbon ambitions are to be achieved.

Agriculture accounts for 34% of emissions in Ireland, with the bulk made up from biogenic methane, which is methane from livestock.

“Emissions from agriculture will never reach zero,” the document says and points to the need to establish a separate target that still aligns with international standards.

The document works to the idea that a separate target would not be granted and agriculture would be expected to reduce emissions by 7mt per annum.

This would mean either a 5m reduction in cattle numbers or a combined 150,000ha of bog rewetting and roughly an extra 700,000ha of forestry by 2050, according to the report.

Specific targets for each sector under the Climate Bill are expected to be announced this autumn, and although the “distinct characteristics” of biogenic methane are recognised, it is not clear whether it will be given a separate target.

Rewetting bogs

The issue of bog rewetting is tackled in the document and says up to half of “our farmed peatlands” would have to be rewetted by 2050.

“Under the current Climate Action Plan, there is a requirement to rewet 40,000ha of peat soils,” the document reads.

“There are approximately 300,000ha of peat soils in Ireland. If half of the peat soils were to be rewetted by 2050, this would allow a sequestration potential of 2mt/annum.”

At the moment, Bord na Móna has plans to rewet 31,000ha of bog and this has been met by concern from some farmers that their land adjoining these rewetted bogs could be flooded.

Separately, there has also been concerns raised for farm families where their turbary or turf-cutting rights are at stake.

Reducing herd size

Taking the extreme example of reaching a 7mt per annum reduction in emissions, the report says an almost corresponding reduction in the national herd size would be required.

As the bulk of emissions from the sector come from biogenic methane and nitrous oxide (fertiliser) herd size would need to be reduced from 7m to 2m animals.

It continues by saying “the economic realities” and “the low profitability in the beef sector” would mean that the remaining herd “would largely be a dairy-based herd in the south and east.”

In comparison, it points to the land where traditionally beef farming is present in the west of the country and says there would be “large tracts of land west of the Shannon planted to forestry”.

Forestry

Forestry has long been highlighted as a potential route for farming to offset emissions.

However, the report points out that current afforestation rates are around 3,500ha/year and this would have to be increased to 20,000ha/year in the run up to 2050.

Currently around 770,000ha of land in Ireland is under forestry and this would need to be doubled to 1.2m to 1.4m hectares.

“This would remove approximately 5mt CO2eq per annum in 2050,” the Department of Agriculture report says.

“It is questionable whether this level of afforestation would ever be achievable, but it is used here as a reference point to highlight the scale of the challenge…”