Peatlands
Project Drawdown defines peatlands as: the protection of carbon-rich peatlands, leading to reduced degradation rates and the safeguarding of carbon sinks. This solution replaces the destruction of non-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 management plans for already degraded peatlands. The peatlands solution projects adoption of protection of non-degraded peatlands.
Methodology
Total Land Area [1]
Total land allocated for the peatlands solution is 369 million hectares, comprising global peatlands. [2] The total land area available for this solution was modeled using the annual rate of peatland degradation (e.g. from deforestation and mining): 0.52 percent. Future degraded and non-degraded areas were calculated, and the projected future non-degraded, non-protected area was set as the total available area for protection. Current adoption [3] of peatlands is estimated at 3.3 million hectares (Silvius, 2006).
Adoption Scenarios [4]
Seven custom adoption scenarios were developed based on commitments such as those of the Irish Peatland Conservation Council (2017), using the linear growth curve. 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.
Impacts of increased adoption of peatlands from 2020-2050 were generated based on three growth scenarios, which were assessed in comparison to a Reference Scenario where the solution’s market share was fixed at the current levels.
- Plausible Scenario: This scenario results in the protection of 246.3 million hectares of unprotected peatlands by 2050.
- Drawdown Scenario: This scenario intensifies adoption based on aggressive adoption scenarios, and results in the protection of 341.6 million hectares of peatlands by 2050.
- Optimum Scenario: The most aggressive adoption scenario results in the protection of 344.2 million hectares of peatlands by 2050.
Full 100 percent protection of unprotected peatlands was limited by the continuous annual rate of peatland degradation (0.52 percent), even under the most aggressive adoption scenarios.
Emissions and Sequestration Model
Peatland sequestration rates are set at 1.4 tons of carbon per hectare per year, based on 20 data points from 6 sources. Emissions reductions are set at 41.2 tons of carbon dioxide-equivalent per hectare per year, while nitrous oxide reduction is 2.9 tons of carbon dioxide-equivalent per hectare per year. The value for carbon dioxide-equivalent is based on meta-analysis of 104 data points from 32 sources, while nitrous oxide uses 25 data points from 7 sources. Emissions from peat extraction were not modeled.
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. This study assumes that all peatland is on forested land. Peatland protection is the top priority for forested land.
Results
Total adoption of peatlands in the Plausible Scenario is 246.3 million hectares in 2050, representing 66.7 percent of the total suitable land. Of this, 243 million hectares are adopted from 2020-2050. The emissions impact of this scenario is 21.6 gigatons carbon dioxide-equivalent by 2050. Total carbon protected is 335.8 gigatons carbon dioxide-equivalent. Financial impacts are not modeled.
Total adoption in the Drawdown Scenario is 341.6 million hectares in 2050, representing 92.5 percent of the total suitable land. Of this, 338.3 million hectares are adopted from 2020-2050. The impact of this scenario is 33.5 gigatons carbon dioxide-equivalent by 2050. Total carbon protected is 465.8 gigatons carbon dioxide-equivalent.
Total adoption in the Optimum Scenario is 344.2 million hectares in 2050, representing 93.2 percent of the total suitable land. Of this, 344.2 million hectares are adopted from 2020-2050. The impact of this scenario is 36.6 gigatons carbon dioxide-equivalent by 2050. Total carbon protected is 469.4 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. The Drawdown model calculates emissions reduction of 1.3, 1.9, and 2.0 gigatons carbon dioxide-equivalent per year by 2050 in the Plausible, Drawdown, and Optimum Scenarios, respectively. 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 2014 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.