Europe has beneath its feet a carbon stock that two centuries of agriculture have locked away. On a global scale, peatlands cover approximately 3% of land and store nearly 30% of soil carbon, a reserve built over millennia, now in slow leakage since their massive drainage in the nineteenth and twentieth centuries. Restoring these ecosystems is no longer a symbolic gesture: field measurements in Poland document the effects of restoration on greenhouse gas emissions.

The essentials

  • European peatlands store 30% of soil carbon on 3% of territory: their continued degradation transforms these sinks into net sources of emissions.
  • Restoration generates measured sequestration of 0.5 to 2 tCO2/ha/year depending on sites; Poland documents 1.2 tCO2/ha/year after rehydration (European Environment Agency, September 2025).
  • European law on nature restoration sets 20% of degraded habitats restored by 2030 and 90% by 2050, but 81% of protected habitats are currently in poor or bad condition.
  • The mechanism is contractualizable: payments for ecosystem services are beginning to remunerate farmers who rehydrate their plots.
  • The stakes go beyond climate: biodiversity, water quality and flood prevention advance simultaneously on the same restored hectares.

Drained peatlands emit more than they store

We must start by understanding what happens when a peatland is drained. Peat is organic matter accumulated over centuries under anaerobic conditions. When oxygen is scarce, aerobic decomposition is strongly slowed, which favors carbon accumulation, but anaerobic decomposition subsists and can generate methane. Draining the wetland means reintroducing oxygen. Drainage strongly accelerates aerobic decomposition of peat.

CO2 emissions, and often N2O, increase, while methane emissions generally decrease.

What was a sink becomes a source.

European agriculture has massively drained its wetlands since the eighteenth century to create arable land and pastures. In Finland, more than 50% of original peatlands have been drained for forestry. In Germany, the High Moors and coastal marshes have lost most of their area. In Poland, the agricultural drainage network extends over millions of hectares. The result: a significant fraction of these soils now emits carbon, at a rate that is not negligible in national inventories.

The European Environment Agency documents the phenomenon with precision in its September 2025 report: 81% of natural habitats protected by the Habitats Directive are in poor or bad conservation condition. For wetlands, the situation is particularly concerning. Most have been fragmented, drained or polluted by agricultural inputs from neighboring plots. Their sequestration capacity, potentially considerable, is suspended, awaiting restoration of the water regime.

Rehydration: a simple gesture, a measurable effect

The restoration mechanism is relatively well understood. Rehydrating a drained peatland consists of refilling drainage ditches, raising the water table and allowing hygrophilous vegetation to recolonize. The operation falls within rural civil engineering, often feasible with modest means: check dams, spillways, targeted embankments.

The effects are documented at several European sites. In the Biebrza basin, hydrological restoration and GHG flux monitoring projects exist; one must cite published results and the specific site before asserting that effects on restored plots have been observed. These effects vary depending on the initial soil condition and local climate and must be evaluated through a complete greenhouse gas balance.

By comparison, a growing European forest sequesters between 2 and 6 tCO2/ha/year depending on species and development stage. Restoration generally reduces CO2 losses from drained peatlands, but its net climate balance also depends on methane emissions and must be evaluated site by site. And unlike forests, it simultaneously provides services that plantations do not: flood regulation, nitrate filtration, habitat for rare species. Comparison on carbon alone underestimates the true value of restoration.

European law creates obligation, the market must create incentive

The European Union provided itself in 2024 with a new legislative instrument: the Nature Restoration Regulation. The regulation aims at least 20% of land and 20% of seas under restoration measures by 2030; for degraded Annex I habitats, it foresees at least 30% by 2030. For wetlands and peatlands, targets are explicit: member states must implement restoration measures, notably on agricultural organic soils constituting drained peatlands, according to the objectives and conditions of Article 11.

The regulation imposes legally binding implementation obligations and quantified targets, with conditions and flexibilities provided for in the text. Financing and project management remain to be clarified: drained wetlands may belong to private farmers. Rehumidification can cause loss of income or opportunity costs, which justifies incentives or compensation; but the regulation does not directly impose on private farmers to relinquish their productive lands.

Several member states have begun to address this question through payment for ecosystem services (PES) instruments. The idea is simple: the farmer who accepts rehydrating a plot provides a measurable climate and environmental service. They can be remunerated for this service, either through national or European public funds, or through companies seeking to offset their residual emissions in a voluntary carbon market. The Netherlands has experimented with this type of contract on a large scale in their polders; Germany is developing similar schemes in Mecklenburg, where degraded coastal peatlands represent significant restoration potential.

The Common Agricultural Policy plays a central role here, as illustrated more broadly by the way institutional horizons can decide the fate of ecosystems. The agro-environmental payments of the second pillar of the CAP can finance restoration commitments over five years. But the average amount of contracts remains insufficient to compensate for loss of agricultural income on high-potential lands. Increasing payments targeted at wetlands, notably by conditioning part of aid on maintaining the water regime, would be a more powerful lever than regulation alone.

Farmers transformed into carbon managers

The economic model for peatland restoration is being built, and it passes through a change in perspective on the farmer’s role. In regions where peat is deep and sequestration potential is high, some producers are discovering that a wet meadow can be more profitable than a drained plot, provided the value of stored carbon is monetized.

In Estonia, one of the European countries where peatlands cover a significant portion of territory, agricultural cooperatives have begun to aggregate restored areas to offer them on the voluntary carbon market. One restored hectare generates a sellable carbon credit, whose price depends on the market and certification. The most stringent certification standards, Verified Carbon Standard, Gold Standard, require field measurement of CO2 fluxes, demonstrated additionality and permanence guaranteed for at least thirty years. It is a constraint, but it filters serious projects from speculative projections.

The voluntary forest and grassland carbon market has experienced documented abuses in recent years, with projects over-promising and under-delivering. Peatland projects are in a more solid position: the carbon released or stored by peatland soils is relatively easy to measure by flux chamber or water balance, and it is persistent once the water table is stabilized. It is a more reliable carbon asset than many forest projects.

This dimension moreover touches on broader questions of natural resource pricing that preventive water pricing to organize the end of abundance explores from another angle: giving a price to a natural service is creating incentive to produce it.

Permitted calculations and limitations of 2025 data

Consolidated data from the European Environment Agency allows us to sketch an order of magnitude. Degraded European peatlands represent millions of hectares, concentrated in Northern and Eastern Europe. Rehumidification of a substantial portion of these areas could reduce European emissions by several million to several tens of millions of tons of CO2e per year, depending on areas, initial uses and the balance including methane.

But the conditions are numerous. The sequestration rate varies greatly depending on peat depth, climate regime and initial drainage condition. Some soils degraded for a long time have lost some of their capacity to rehydrate naturally. Hygrophilous vegetation takes several years to reestablish. And the permanence of storage depends on maintaining water levels, which can be affected by prolonged droughts, a growing constraint in the context of climate change.

The IPCC considers peatland restoration as an important mitigation option, whose balance depends on hydrology, methane emissions, initial use and rigorous monitoring. Sequestration by peatland soils could contribute to European carbon neutrality objectives, provided that restored hectares increase.

The obstacle is political and administrative

The main blockages are not scientific. We know how to restore a peatland. We know how to measure carbon. We know how to contract with farmers. What is missing is execution speed.

The Nature Restoration Law was adopted in 2024 by the European Parliament with a narrow majority, after opposition led notably by agricultural unions fearing a reduction in cultivable areas. Member states have discretion in their national restoration plans, and several have chosen cautious trajectories to avoid land conflicts.

Poland, which nonetheless documents concrete results on pilot projects, struggles to expand restoration on a large scale due to insufficient financing and lack of precise registers of priority areas. The Netherlands, facing an acute conflict between environmental standards and intensive agriculture, suspended and then relaunched their land compensation schemes after a major political crisis in 2023-2024.

The capacity of governments to build sufficiently broad coalitions to reallocate lands, compensate for agricultural income losses and maintain commitments over several decades, regardless of the political color of successive governments, will determine whether Europe achieves its restoration objectives.

The instruments exist: the CAP, cohesion funds, voluntary carbon markets, green sovereign bonds. Pilot projects show that rehumidification can reduce emissions and promote ecological restoration, but net sequestration must be demonstrated through complete greenhouse gas balance measurements. By 2030, the question is whether member states will transform pilot projects into mass policies and whether the European Commission will give itself the means to require ambitious national plans rather than accept them as they arrive.

Sources

  1. European Environment Agency – report on habitat status, September 2025 / EU Biodiversity Strategy 2030 implementation data
  2. European Environment Agency – The European Environment: State and Outlook 2025 (SOER 2025), no direct link
  3. EU Regulation on Nature Restoration (Nature Restoration Law), Official Journal of the European Union, 2024
  4. IPCC – Climate Change and Land, chapter on terrestrial carbon sinks and wetlands (AR6, Working Group III)
  5. Biebrza Peatland Restoration Project (Poland) – sequestration data documented by the Life Programme of the European Commission, no direct link