Some 112,000ha of grassland currently used for beef, sheep and dairy production would need to be rewetted, if models used by the Climate Change Advisory Council (CCAC) to set its carbon budgets for Ireland are adopted. That’s in addition to 62,600ha of peatland.

Modelling by researchers at the University of Limerick shows that this scale of rewetting, along with a massive increase in afforestation is needed to meet a 51% reduction in greenhouse gasses from the land use, land use change and forestry (LULUCF) sector.

The CCAC’s technical report also shows that 46,500ha of new forestry planting would be needed between 2021 and 2025, followed by 92,500ha between 2026 and 2030.

LULUCF is separated from agriculture, even though farmers are responsible for most land use in Ireland outside of forestry. This is contentious with farmers because alternative land uses were seen by farmers as a means of offsetting or mitigating some of the emissions from their farming activity.

The report identifies how LULUCF will contribute to offsetting 51% of emissions by 2030.

Among the measures that will be required are a combination of rewetting of peatlands, improved management of mineral and organic soils under grasslands, cropland management, and increased afforestation. These will require action by Government that effectively encourages these land uses.

Table 1 below identifies the increase in forestry, grassland re wetting and peatland rewetting that is required to deliver a 51% reduction by 2030

The University of Limerick General Overview for a Back-casting approach of Livestock Intensification (GOBLIN) model is used in the report to identify a route to a 51% reduction of the 4.8mt CO2eq that came from LULUCF in 2018.

Forestry

This involves planting 46,500ha of forestry between 2021 and 2025, followed by 92,500ha between 2026 and 2030 – meaning that by 2030 there would be an additional 139,000ha of Irish land under forestry compared with 2021.

The extent of this increase is reflected by the fact that just 3,550ha of forestry was planted in 2019, so to meet the target, planting will have to increase by just under three times current levels up to 2025 and over five times current levels in the period 2026 to 2030.

Rewetting land

The report identifies the need to rewet 112,601ha of grassland between now and 2030, achieving 43,601ha of this by 2025 and the remaining 69,000ha between 2026 and 2030. In addition, 62,637ha of peatland is allocated for rewetting, again divided between 27,839ha up to 2025 and 34,798ha from 2026 to 2030. This would mean that 90% of peatlands that are currently used for peat harvesting would be rewetted.

Ireland has in total 4.9m hectares of land in agricultural use and the combined rewetting of grassland and peatland identified in the report would amount to 3.6% of agricultural land in the Republic of Ireland.

Not spread evenly

However this does not mean that rewetting would take place equally across the country, it would be concentrated in areas of what is considered more marginal farmland. The report quotes Teagasc research that identifies 40% of organic grassland is farmed under specialised cattle systems (sucklers/beef), 30% sheep, 25% dairy and just 5% in tillage. The report accepts that agriculture in these areas is low intensity and could continue at a reduced level. It also proposes that policy will “have to consider compensating farmers and land owners for income forgone from rewetting”.

The report also recognised the need for public and community engagement to deliver this major change of land use as it will be concentrated in specific areas such as the midlands. It also suggests support for sustainability measures could be an alternative income for farmers.