Harvested peatlands in Ireland as seen from a drone.
Technical Summary

Peatland Protection and Rewetting

Project Drawdown defines peatland protection and rewetting as: the protection of carbon-rich peatlands, leading to reduced degradation rates and the safeguarding of carbon sinks as well as restoration (largely through rewetting) and protection of the currently degraded peatlands.  This solution replaces the destruction of non-degraded and degraded peatlands for numerous uses.

Peatlands are a hugely important stock of soil organic carbon. Despite covering only 3 percent of the global land area, they hold 30 percent of all soil carbon, amounting to at least 500 gigatons – twice the carbon stock of all forest biomass. Unlike most terrestrial ecosystems, peatlands do not reach saturation, and continue sequestering carbon in soil organic matter for centuries or millennia.

Peatlands are currently being degraded for agricultural, horticultural, forest, fuel, and infrastructural needs. An estimated 15 percent of the world’s peatlands have been degraded so far, and nearly 50 percent of that degradation is for agricultural land use.

Peatland degradation for various land uses is leading to enormous carbon emissions. Currently, peatlands are degrading at the annual rate of 0.4 million hectares per year. Moreover, global peat volume is decreasing at an annual rate of 20 cubic kilometers per year. Peatland degradation results in nearly 3 gigatons of carbon dioxide-equivalent emissions per year, equivalent to more than 10 percent of global fossil fuel emissions (Biancali and Avagyan, 2014). The rate is expected to increase in the future unless land management practices and peatland development plans are changed and reconsidered.

It is extremely important to prevent any further degradation of peatlands as well as to develop sustainable restoration plans for already degraded peatlands. The peatlands solution projects adoption of protection of non-degraded peatlands and restoration of already degraded peatlands.

Methodology

Total Land Area[1]

Total land allocated for the peatland protection  is 464 million hectares and for peatland restoration is 62 million hectares, comprising global peatlands.[2] Current adoption[3] of peatland protection is estimated at 8.84(Juffe-Bignoli et al., 2014) , while 0 current adoption is considered for peatland restoration.

Adoption Scenarios[4]

The future adoption of the peatland protection is projected based on ten custom adoption scenarios. Some of them are based on the yearly increases resulting from the historical evolution of Ramsar sites categories “forested” and “non- forested peatlands” (with management plans) combined with the degradation rate in the model and an alternative one based on the New York Declaration on Forests. Other scenarios are more aggressive in achieving higher protection trajectories. Given the small area of peatland, and the high urgency because of the degradation of unprotected peatland areas and the high mitigation efficiency of protection, several scenarios emphasized early peak adoption by 2030.

For peatland restoration, five custom adoption scenarios were developed using national peatland restoration commitments.

Impacts of increased adoption of peatlands from 2020-2050 were generated based on two growth scenarios, which were assessed in comparison to a Reference Scenario where the solution’s market share was fixed at the current levels.

  • Scenario 1: This scenario results in the protection of 266.7million hectares of unprotected peatlands and restoration of 35.16 million hectares of degraded peatlands by 2050.
  • Scenario 2: This scenario intensifies adoption based on aggressive adoption scenarios, and results in the protection of 448.6 million hectares of peatlands and restoration of 47.04 million hectares of degraded peatlands by 2050.

Full 100 percent protection of unprotected peatlands was limited by the continuous annual rate of peatland degradation (0.51 percent), even under the most aggressive adoption scenarios.

Emissions and Sequestration Model

Peatland protection sequestration rates are set at 0.51 tons of carbon per hectare per year, based on 86 data points from 16 sources. Emissions reductions are set at 38.58 tons of carbon dioxide-equivalent per hectare per year, while nitrous oxide and methane reduction are 2.25 and 3.22 tons of carbon dioxide-equivalent per hectare per year respectively . The value for carbon dioxide-equivalent is based on meta-analysis of 131 data points from 42 sources, nitrous oxide uses 40 data points from 9 sources, and methane uses 24 data points from 10 sources.

Peatland restoration emission reduction are set at 16.5 tons of carbon dioxide-equivalent per hectare per year based on 15 data points from 6 sources.

Financial Model

This study did not model financials, as costs are not necessarily carried out by the landowner or land manager.

Integration[5]

Drawdown’s Agro-Ecological Zone model allocates current and projected adoption of solutions to the planet’s forest, grassland, rainfed cropland, and irrigated cropland areas. Peatland protection is allocated on non-degraded forest, grassland, and croplands as per Leifeld 2018 estimates. Peatland protection is the top priority for all of these allocated lands. Peatland restoration, however, is allocated only on degraded forest and it is the first priority solution there.

Results

Total adoption of peatland protection and rewetting in the Scenario 1 is 301.86 million hectares in 2050, representing 57 percent of the total suitable land. Of this, 293.02 million hectares are adopted from 2020-2050. The emissions impact of this scenario is 26.04 gigatons carbon dioxide-equivalent by 2050. Total carbon protected is 1906.6gigatons carbon dioxide-equivalent. Financial impacts are not modeled.

Total adoption in the Scenario 2 is 495.64 million hectares in 2050, representing 94 percent of the total suitable land. Of this, 486.8 million hectares are adopted from 2020-2050. The impact of this scenario is 41.92 gigatons carbon dioxide-equivalent by 2050. Total carbon protected is 3206.9 gigatons carbon dioxide-equivalent.

Discussion

Benchmarks

Annual emissions from degraded peatlands today are estimated at 1.0 gigatons carbon dioxide-equivalent per year (IPCC, 2014). This will surely increase as degradation is ongoing. Griscom et al (2017)’s “Natural climate solutions” calculates 0.45-0.75 gigatons of carbon dioxide equivalent per year in 2030. The Drawdown peatland protection and restoration model calculates emissions reduction of 0.52-0.82 gigatons carbon dioxide-equivalent per year by 2030. This study is within range of this benchmark, as the degraded area will continue to grow in business-as-usual scenarios, and emissions will continue from degraded peatlands for decades or longer given the immense size of the stocks.

Limitations

It would be useful to project peatland restoration as well as protection. Projecting financials at the government or non-governmental organization level is also recommended.

Conclusions

The extremely high carbon stocks of peatlands, combined with their relatively tiny global extent, indicate that their protection should be an extremely high priority for climate mitigation.

 

[1] To learn more about the Total Land Area for the Land Use Sector, click the Sector Summary: Land Use link below.

[2] Determining the total available land for a solution is a two-part process. The technical potential is based on the suitability of climate, soils, and slopes, and on degraded or non-degraded status. In the second stage, land is allocated using the Drawdown Agro-Ecological Zone model, based on priorities for each class of land. The total land allocated for each solution is capped at the solution’s maximum adoption in the Optimum Scenario. Thus, in most cases the total available land is less than the technical potential.

[3] Current adoption is defined as the amount of functional demand supplied by the solution in the base year of study. This study uses 2018 as the base year due to the availability of global adoption data for all Project Drawdown solutions evaluated.

[4] To learn more about Project Drawdown’s three growth scenarios, click the Scenarios link below. For information on Land Use Sector-specific scenarios, click the Sector Summary: Land Use link.

[5] For more on Project Drawdown’s Land Use integration model, click the Sector Summary: Land Use link below.