Norway study shows raising groundwater turns peat farmland into carbon sink

A 2022–2023 Norwegian field study at the Svanhovd research station found that raising groundwater levels to 25–50 cm below the surface sharply cut CO2 emissions, turning drained peat farmland into a net carbon sink. The low-cost intervention offers a scalable climate-mitigation pathway businesses can integrate into net-zero commitments.

A field study reported by ScienceDaily, conducted during 2022–2023 at the Svanhovd research station in Norway's Pasvik Valley, found that raising groundwater levels in drained Arctic peat soils transforms farmland from a carbon emitter into a sink. Researchers monitored carbon dioxide, methane, and nitrous oxide emissions across plots with varying groundwater depths. When groundwater was raised to between 25 and 50 cm below the surface, CO2 emissions dropped sharply, and in some cases the land absorbed more carbon than it released.

Northern and high-latitude agricultural systems, agricultural planners, and climate policymakers are the principal stakeholders, alongside businesses operating in high-latitude regions. Peatlands store vast carbon because waterlogged soils limit oxygen and slow microbial decomposition; drainage for farming reverses this, releasing centuries of stored carbon. Restoring higher water levels reduced oxygen exposure and slowed decomposition, while long Arctic summer daylight amplified photosynthesis and carbon uptake. Crucially, methane and nitrous oxide emissions remained relatively low under controlled water conditions.

Governments and agricultural planners should consider integrating groundwater management into national carbon-reduction strategies given the intervention's low infrastructure investment and scalability. The study notes crop selection and harvesting frequency influence long-term soil carbon storage, suggesting wet-adapted farming could further enhance outcomes. Businesses operating in high-latitude regions can incorporate peatland water management into climate disclosures and net-zero commitments, using this science-backed pathway to strengthen climate resilience while protecting long-term ecosystem carbon stocks.

Key figure — Optimal groundwater depth: 25–50 cm below the soil surface