On a global scale, the Nordic region is rich in wetlands. These lakes and wetlands maintain water quality, regulate groundwater levels and soil moisture, help mitigate floods, sequester carbon, and are habitat to rich biodiversity, such as high concentrations of birds, mammals, reptiles, amphibians, fish, and invertebrates as well as a diversity of plants. The Ramsar Convention defines wetlands as areas of marsh, fen, peatland, or open water with a maximum depth of six meters. They can be natural, artificial, permanent, or temporary, with static or flowing water, fresh, brackish, or salt water. Wetlands provide numerous essential ecosystem services such as pollution control, water purification, soil formation, nutrient cycling and recreational values. Wetlands also provide great economic benefits, e.g., water supply, fisheries, wildlife resources, transport, recreation, and tourism. Finally, wetlands have special attributes as a part of the cultural heritage and religious beliefs.
Wetlands have, through the anaerobic conditions, resulted in poor decomposition of organic material and subsequent peat accumulations, and have therefore been a significant historic carbon sink. These processes were however reversed when wetlands were drained during the last centuries, because lower water tables expose the organic matter to oxygen and thereby increase decomposition rates and CO2 emissions. The degraded wetlands cause significant environmental deprivation and socio-economic issues such as soil degradation, increased fire risks and degradation of buffer zones vital to prevent flooding. Several factors must be carefully considered though, to ensure the positive impacts from wetlands. Hambäck (2024) highlights the importance of maintaining a diversity of wetland types within different landscapes to optimize their functions and benefits. The effectiveness of these functions depends on factors like location, design, and management, which can enhance different ecosystem services while potentially disadvantaging others.
Despite their diverse use, wetlands have long been considered unproductive since agricultural and forestry cultivation of these areas was difficult. But when these carbon-rich peatlands were drained during the 1800s and 1900s, these drained peatlands became productive agricultural lands. This was during a time when there was an urgent need for increased food production due to a growing population. The only option at the time, was to increase the area used for croplands. This resulted in a rapid expansion of drainage concentrated in Europe, the United States and China, causing a 21% global loss of wetlands between the 18th century until today. Peatland drainage for forestry reasons occurred much later during the 20th century to expand the forest industry. The highest global rates of wetland area loss happened in the mid-twentieth century when governments offered subsidy programmes to encourage wetland conversion to crop- and forestland. These programmes sped up the drainage of wetlands, resulting in a 50% total loss of wetlands in Europe.
The long-term net effect of rewetting on greenhouse gas emissions is negative, meaning that carbon sequestration will offset greenhouse gas emissions when an area is rewetted. Rewetting effectively stops the emission of CO2 due to the re-establishment of anaerobic conditions, which gradually prevent the decomposition of organic matter into CO2. However, raising the water level starts the process of anaerobic decomposition, which releases methane, a greenhouse gas with much larger radiative effects than CO2 but with a shorter lifespan in the atmosphere. However, studies have shown that the radiative effects of methane emissions from rewetting do not undermine the greenhouse gas mitigation potential of peatland rewetting. Therefore, postponing rewetting efforts only increases the long-term warming effect through continued CO2 emissions.
Drained peatlands are estimated to cause 4% of global CO2 emissions. In the EU, peatlands cover 7.7% of the land surface, yet the EU is the world’s second-largest emitter of greenhouse gases from drained peatlands, producing 220 Mt CO2e/year – around 15% of global peatland emissions and 5% of the EU's total GHG emissions (in 2017). Among the top EU peatland emitters are Finland and Sweden. In most countries, drained peatlands account for over 25% of emissions from agriculture and agricultural land use. Hence, rewetting initiatives are important to reduce EU greenhouse gas emissions. According to the Convention on Wetlands (2021), meeting the Paris Agreement objectives may require rewetting of virtually all drained peatlands.
The focus on wetlands has expanded in recent years as climate change has led to severe impacts following extreme weather events in the Nordic countries, such as flash floods, extreme precipitation, or wildfires caused by long dry periods. Also, heightened awareness of the biodiversity crisis has amplified the attention on wetlands, which serve as critical habitats for aquatic and terrestrial species. This is seen through the presence of numerous wetland species on the IUCN Red List of Threatened Species. Nevertheless, different wetland functions vary in effectiveness based on location, design, and management, leading to some services being enhanced while others may be disadvantaged. While wetlands are diverse and often provide synergies between ecosystem services, it’s important to note that interests do not always overlap, and effective management will require navigating trade-offs to maximize benefits.
Rewetting policy space in the Nordics
The Nordics have a long tradition of managing water resources, and some approaches have proven harmful to the natural wetlands. Due to more than two hundred years of expansion and intensification of agriculture and forestry, the Nordic wetlands are under significant pressure. Despite a long list of regulatory global mitigation measures and international agreements and conventions, such as the Ramsar Convention, Kunming-Montreal Global Biodiversity Framework and the Bern Convention, wetlands are still highly threatened. Today, EU (European Union) laws and directives such as the Habitats Directive, the Water Framework Directive, the Land Use, Land-Use Change and Forestry regulation (LULUCF), the Common Agricultural Policy (CAP), the EU Strategy for Biodiversity and the Nature Restoration Law (NRL), form the wetland and rewetting policy space in the Nordic countries. NRL was adopted by the European Parliament in February 2024 and has been called the most significant piece of nature legislation in the EU since the 1992 Habitats Directive. The regulation is expected to significantly change rewetting policy space for European wetlands, as the targets are significantly more ambitious than previous, the legislation which will be crucial to restore biodiversity, support water scarcity and reach climate neutrality by 2050. NRL is also a key instrument to help the EU, and its member states meet international biodiversity commitments under the Kunming-Montreal Global Biodiversity Framework. As part of the legislation, each member state must within two years submit a draft national restoration plan, specifying the measures the country will put in place to fulfill the obligations and achieve the targets stated by the law. One major overall target is that at least 20% of all land and sea area should be restored by 2030, which must be specified with dedicated measures in the national restoration plan. Another major target is that all EU countries must restore at least 30% of drained peatlands on agricultural land by 2030 (of which as least a quarter should be rewetted), 40% by 2040 and 50% by 2050 (where at least one-third of the area should be rewetted).
There are diverse challenges and opportunities for rewetting drained peatlands in the Nordic region, which has encouraged the Nordic Working Group for Environment and Economy (NME) under the Nordic Council of Ministers to address the issue. This study assesses the political landscape of rewetting objectives and targets, looking into economic instruments in place and to what extent monitoring and evaluation of rewetting policy measures is conducted. By mapping and understanding the differences and similarities across the Nordics, the project aims to gain deeper insights into the region's status and knowledge of rewetting practices. The findings from this evaluation can help inform policymakers and how the Nordic countries can learn from each other and how rewetting can play a pivotal role in future environmental and climate policymaking.
The study was carried through in 2024 by Norion Consult. The authors are Linda Stafsing, Elvira Borgman, Sofie Kjøller Jørgensen, Laura Schou Bagh and Agnes Plesner Skårup. Quality assurance has been done by Rikke Fischer-Bogason.