Reducing peatland emissions
Peat soils store greenhouse gases for millennia if they stay waterlogged. However, an estimated 5% of global greenhouse gas emissions are released from peat soils due to their modification by humans. Reducing these emissions will help meet climate targets, with objectives to achieve this set out in action plans by the governments of the UK. This POSTnote describes the pressures on peat soils and summarises the challenges for reducing emissions from English peatlands.
DOI: https://doi.org/10.58248/PN668
Peatland is an area with a substantial layer of partially rotted organic matter at or near the surface accumulating under waterlogged conditions, from plants such as Sphagnum mosses. This peat contains little solid matter and is around 90% water by volume when saturated. Data from existing and new UK monitoring studies have provided evidence for more accurate GHG emission estimates for the different uses and condition of peatlands. With their inclusion in the national GHG inventory in 2019, land use changed from being a net sink to a net source of emissions. UK peatland 2019 GHG emissions were estimated at 23.1 million tonnes carbon dioxide equivalent (Mt CO2e yr-1), adding 3.5% to total emissions. Only 22% of UK peatlands are considered to be in a near natural state and storing rather than emitting carbon (less than 13% in England). Nutrient poor peat bogs in upland areas waterlogged by rainfall comprise around 85% of the UK peatland resource, but England has a higher proportion of lowland peatland areas (44%) of nutrient rich fens and raised bogs than other UK nations, which account for more than 80% of its peatland emissions. GHG emissions from English peatlands are estimated to be 11.1 Mt CO2e yr-1.
All the governments of the UK have consulted on, or are implementing, restoration programmes. Under the Peatland Action Plan the Scottish Government has committed to restoring 250,000 ha by 2030, with 25,000 ha already under restoration and 6,000 ha per annum being restored at present. In line with the 25 Year Environment Plan, the 2021 England Peat Action Plan aims to restore 35,000 ha of peatland by 2025 funded with 50m from the Nature for Climate Fund (and 280,000 ha by 2050), with an annual target of 4,700 ha. Up-to-date, straightforward national guidance on evidence-based restoration techniques for the objective of reducing GHG emissions is lacking; while individual landowners, organisations and contractors may have extensive knowledge about their restoration projects, this has not been integrated into a wider understanding. Evidence suggests raising water levels is the single most important measure for reducing CO2 emissions, protecting carbon stores and restoring peat formation, but an evolving toolbox of other methods can be used depending on the type of peatland and previous use or damage. The Nature for Climate peatland grant scheme (NCPGS) requires most projects to secure 25% of funds from the private sector, and the IUCN UK Peatland Programme develop and manage the Peatland Code for accessing private finance.
Key points:
- Where waterlogging prevents the decomposition of plant matter it accumulates as a peat store of carbon.
- This stored carbon is emitted as greenhouse gases from peat soils when they are drained to lower water levels and managed for land uses such as agriculture and forestry.
- Drained lowland peat soils used for arable and horticulture crops are the largest sources of emissions from any land use in England. Climate change may increase emissions from peat soils in poor condition.
- Raising water levels and restoring peat forming conditions can reduce emissions.
- Monitoring the condition and outcomes of peatland restoration projects will be key for determining national emission reductions. At the project level, verified estimates of emission reductions from restoration are needed to access private carbon finance.
- Public grants require projects to secure partial funding from the private sector.
Acknowledgements
POSTnotes are based on literature reviews and interviews with a range of stakeholders and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including:
POST Board members*
Richard Lindsay, University of East London
Professor Chris Evans, Centre of Ecology and Hydrology
Professor Mark Reed, Scotland's Rural College and IUCN Peatland Programme*
Dr Renée Kerkvliet-Hermans, IUCN Peatlands Programme* Clifton Bain, IUCN Peatlands Programme*Dr Christian Dunn, Bangor University
Chris Dean, Peak District National Park Authority/Moors for the Future Partnership
Dr David Chandler, Peak District National Park Authority/Moors for the Future Partnership
Debra Wilson, Peak District National Park Authority/Moors for the Future Partnership
Dr Jon Walker, Swansea University
Dr Christopher Field, Manchester Metropolitan University
Dr Franziska Tanneberger, Greifswald Mire Centrum
Dr Lydia Cole, University of St Andrews*
Sophie Chapman, Defra*
Andrew Coupar, NatureScot*
Naomi Oakley, Natural England
Deborah Land, Natural England
Amanda Anderson, Moorland Association*
Dr Mark Ashby, University of Keele (provided comments via the Moorland Association)*
Dr Andreas Heinemeyer, University of York, Stockholm Environment Institute (provided comments via the Moorland Association)*
Professor Roxanne Andersen, University of the Highlands and Islands
Philippa Arnold, NFU
Brendan Freeman, CCC
Professor David Large, University of Nottingham
Dr Olly Watts, RSPB*
Dr Patrick Thompson, RSPB*
Professor Richard Brazier, University of Exeter
* denotes people and organisations who acted as external reviewers of the briefing
Correction [22/04/2022]: References 49, 50 and 51 added to final sentence of subsection on upland drainage and burning. Correction [26/04/2022]: Reference 91 amended to link to the latest 2021 version (3.0) of IUCN burning and peatlands position paper