Presented by Lini Wollenberg, CCAFS Low Emissions Development, at the GIZ expert meeting on How to realize the potential of soil carbon benefits? Practical pathways for achieving impact on 28 April 2020.
Soil carbon: Potentials recognized – but how to implement?
1. GIZ Soil Carbon Webinar, 28 April 2020
How to realize the potential of soil
Practical pathways for achieving impact
2. A Grand Challenge
Soil carbon sequestration for climate change
• An opportunity that should be “neither dismissed nor exaggerated.”
(Bossio et al. 2020)
• A live debate that is pushing our knowledge forward (Rumpel et al.
• Despite strong political will, decades of knowledge, alignment with
soil health policy, multiple SDG co-benefits, few negative impacts,
and constant flow of emerging science, implementation has been
….So what’s the problem?
3. Global estimates of soil carbon potential in
• Technical potential of 2 to
5 GtCO2 in agriculture
(Fuss et al. 2018)
• ~1.2 GtCO2e economic
potential at USD
10/tCO2e (Bossio et al.
• SOC sequestration rates
and areas vary
• Uncertainties due to land
area, depth, and soil,
subsoil and landscape
Paustian et al. 2016
4. The issues
No guarantee that what you
add will stay
• Agriculture is a driver of
soil carbon loss
• Stability of storage
• Permanence and
• Slow gains, quick losses
You can’t easily tell how
much has been stored
• 3-5 years to see change
• Activity-based indicators
• Variability over space and
Large-scale change is tough
(1) biophysical limits (water, nutrients, energy, exogenous inputs), (2)
GHG trade-offs, (3) climate change effects and (4) socio-economic
barriers (C price, need for ongoing incentives, slow policy change,
investment risk, land tenure etc), (5) context-specific solutions
5. Time to move from
Rwanda New Times Newspaper
6. Soil carbon sequestration: public policy
and private investment still small scale
• NDCs: At least 27 UNFCCC parties’ Nationally Determined
contributions refer to soil carbon and 11 have targets – more can be
done to specify targets
• Government initiatives: Australia’s Carbon Farming Initiative and
California’s Healthy Soils Program provide C market incentives and
subsidies to farmers
• Private sector initiatives Indigo’s Terraton Initiative: 1 trillion tons, 5
billion ha $12-24/ha, aim for quantification methods, technologies, and
innovative finance. Corporates: Danone, Mars, Bayer, Coca Cola,
Fonterra, Diageo and Olam
• C-Market projects: Kenya Agricultural Carbon Project (World Bank
Biocarbon Fund): 37,000 smallholders, 1 MtCO2e verified mitigation
from trees and soil in East Africa, since 2009.
7. Address barriers to implementation
Stakeholders consultation. Farmers (world, ≈ 1500)
Slide courtesy of Claire Chenu
8. Systemic transformational change
Improved advisory services, novel technologies,
strong C-market, policy subsidies and regulation, company offsets,
impact investing, farmer learning and social movements (regenerative
9. Good practice features for transformational
change (review of 24 cases)
Principles Features of successful large-scale mitigation projects
1. Strong value propositions for farmers beyond carbon payments
2. Farmer- and local government-driven decisions about practices
3. Effective technical change agents with capacity for large-scale outreach
4. Farmer access to integrated support services (on-line knowledge platforms for climate information services
and technical option feasibility and suitability analysis, ICT-based services, carbon accounting linked to project
activities, centers for input and service delivery)
Finance 1. Subsidy or credit used to catalyze new practices
2. Where offered, result-based carbon payments can create incentives for sustaining projects or incremental
3. Aggregated carbon payments to communities during times of low carbon prices to reduce transaction
costs and increase reward size
4. Public-private partnership, with public support to de-risk farmer transitions and private investment, and
private funds to drive scale
5. Low entry requirements for participation in enterprises or carbon schemes
6. Low transaction costs for finance delivery
MRV 1. Low-cost MRV methodologies specific to practices, e.g. use of existing statistics, such as fertilizer sales or
milk yields, remote sensing for agroforestry or AWD
2. Activity-based monitoring
3. Continuously improved modeling and science to verify activity data
4. Automated payments
Policy 1. National policy mandate for change in practices (not necessarily climate policy)
2. Inter-ministerial and administrative unit coordination, including between central and local government
Wollenberg et al. 2019, TCAF/World Bank
11. Global agenda for collective action on soil
Foster vision for
action, led by
through seed funding
of commercial soil
Vermeulen et al. 2019
12. Getting the balance right
Source Campbell et al. 2019
• Set standards for optimal outcomes
• Monitor for negative impacts or create safeguards/no
13. Priority actions to meet climate targets
Stop carbon loss
− Protect peatlands –32%-46% of all soil carbon (~500–700 Gt C), e.g. through
supply chain accountability and monitoring and enforcement of land use
Promote significant carbon uptake
− Identify geographic priorities, regional strategies and country champions
− Create platforms for sharing knowledge and practices among farmers, locally,
regionally and globally.
− Support public-private investment (technical de-risking, project match making)
and viable carbon-markets
− Demonstrate benefits that balance crop productivity, SOC and SDG impacts
Ambitious policy and standards
− Increase ambition and specificity for SOC targets in NDCs and other policy
− Integrate SOC sequestration into national best practice and green finance
− Develop and harmonize low-cost monitoring systems
We have a grand challenge, but we can work on it!
Action is needed on multiple fronts; it not just a technical implementation
• Set ambitious targets and work toward for large-scale, systemic change
across the public and private sector institutions, esp. incentives,
advisory services, novel technical options, political will. This will take
• Test priorities and strategies with iterative, adaptive approaches that
consider optimizing impacts and trade-offs.
• Improve understanding of mitigation potentials and implementation
successes with monitoring of networks of long-term sites on farmers
Bossio et al. https://www.nature.com/articles/s41893-020-0491-z?proof=trueNov
Rumpel et al. 2019 10.1007/s13280-019-01165-2
Soils constitute the largest terrestrial organic C pool (~1,500 Pg C to a depth of 1 m; 2,400 Pg C to 2 m depth11), which is three times the amount of CO2 currently in the atmosphere (~830 Pg C) and 240 times the current annual fossil fuel emissions (~10 Pg)9. Thus, increasing net soil C storage by even a few per cent represents a substantial C sink potential.
(An overview of 27 studies25reports that 1500 Pg C can be regarded as a rough estimate of the global SOC pool (to one meter depth; across all the world’s soils, more than 130 million km2), however with substantial variability among both spatially- and non-spatially-explicit estimates and a range of from 500 to 3000 Pg C.) An overview of 27 studies25reports that 1500 Pg C can be regarded as a rough estimate of the global SOC pool (to one meter depth; across all the world’s soils, more than 130 million km2), however with substantial variability among both spatially- and non-spatially-explicit estimates and a range of from 500 to 3000 Pg C.
Pautian et al. 2016: Soils constitute the largest terrestrial organic C pool (~1,500 Pg C to a depth of 1 m; 2,400 Pg C to 2 m depth11), which is three times the amount of CO2 currently in the atmosphere (~830 Pg C) and 240 times the current annual fossil fuel emissions (~10 Pg)9. Thus, increasing net soil C storage by even a few per cent represents a substantial C sink potential.
Proximal controls on the soil C balance include the rate of C addition as plant residue, manure or other organic waste, minus the rate of C loss (via decomposition). Hence, C stocks can be increased by increasing organic matter inputs or by reducing decomposition rates (for example, by reducing soil disturbance), or both, leading to net removal of C from the atmosphere12. However, soil C accrual rates decrease over time as stocks approach a new equilibrium. Therefore net CO2 removals are of limited duration, often attenuating after two to three decades
SOC sequestration rate in cropland of 0.37–3.67 tCO2e ha−1 yr−1, (Paustian et al. 2016
Bossio et al. 2020 About half of the SOC mitigation potential, 2.8 GtCO2e yr−1, is
considered cost-effective at US$100 (tCO2)−1 (on the basis of the
methodology of Griscom et al. 32), which is one estimate of the
amount that society is expected to have to pay to mitigate climate
change35. About one-quarter, 1.2 GtCO2e yr−1, is considered to be low
cost at US$10 (tCO2)−1.
Authors’ assessment. The mean and median global technical potentials for SCS of 4.28 and 3.677 GtCO2 yr−1 (n = 23) represent good global esti- mates of the technical global potential for SCS, with ranges of 2.91–5.65 (using mean values of range mini- mums/maximums) or 2.28–5.34 (using median values of range minimums/maximums) GtCO2 yr−1 (n = 17), providing a good estimate of the spread of literature ranges. Values below these ranges mostly consider only single practices (e.g. no tillage, agro-forestry, restora- tion of degraded land, grazing management), so do not provide estimates for full global potential for SCS, while values above these ranges (>7 GtCO2 yr−1) are char- acterized by unconstrained estimates (e.g. by assuming that high per-area estimates could be applied to all cropland/ grassland areas globally with the same effec- tiveness), so provide the very maximum, unconstrained theoretical potential that would never be achievable in reality. Based on this analysis, the best estimate (with range) of realistic technical potential is considered to be close to the median of the minimums of the ranges provided, which for SCS is 3.8 (2.3–5.3) GtCO2 yr−
Also, excellent recent summary of issues: https://e360.yale.edu/features/can-carbon-smart-farming-play-a-key-role-in-the-climate-fight
Bossio et al. 2020: only a few dozen
projects that address SOC in registered compliance or voluntary
carbon markets. Fewer than 60 projects (half of them in Australia)
provided under 50 kt of CO2-equivalent (CO2e) removals by soil
in agriculture and grassland projects per year10. This is less than
0.0001% of the estimated mitigation potential11
Australia’s , a legislated voluntary offsets scheme implemented by the Emission Reduction Fund, has awarded contracts with an approximate value of A$200 million to landholders and farmers to earn carbon credits from soil organic carbon projects on degraded land, supporting a wide range of activities from rotational grazing to reduced tillage.
Indigo Ag is launching The Terraton Initiative, an effort to sequester in soils 1 trillion tons (1 terraton) of carbon dioxide from the atmosphere.
NDCs Regulatory and voluntary – at national and sub-national levels, also provide evidence of economic viability and rapid results at the local level.
11 have targets linked to GHG emissions and removals:
Canada sets a GHG emission reduction target of 44 Mt CO2eq by 2030 to be achieved from the implementation of measures under different sectors, including stored carbon in forests, soil and wetlands.
Japan sets a GHG removal target of 7.9 Mt CO2 by 2030 to be achieved through cropland and grazing land management which includes the promotion of soil management that will lead to increase carbon stock in cropland.
Under the AFOLU sector, Namibia estimates a GHG reduction/removal target for soil carbon of 0.18 Mt CO2eq.
Quantitative indicators for a specific measure/s: Malawi estimates that mitigation measures suggested under agriculture, including soil carbon sequestration resulting from agroforestry, will contribute about 0.4 Mt CO2eq yr-1 by 2040 from the extensive implementation of climate smart agriculture.
Percentage or hectares of croplands where SOC will be preserved or sequestered: Uruguay sets an unconditional target to preserve SOC in 75% of the croplands area sequester SOC in the remaining 25% of the area.
Quantitative mitigation co-benefits of adaptation actions: Burkina Faso specifies that proposed adaptation actions should make it possible to sequester carbon in the soil in excess of 0.515 Mt CO2eq by 2030.
1. System change at national levels to achieve maximal impact at lowest costs, rather expensive replication of pilot projects
2. Building momentum for participation with low entry requirements, especially for carbon payment projects
3. Setting priorities for large-scale impacts and target countries, production systems, value chains, partners and participants where success is likely
4. Synergies across technology transfer, finance, carbon accounting and standards, and policy
5. Reduced risk and uncertainty by using improved technical information, low-cost loans, grants
6. Building on existing successful large-scale projects
7. Use of meaningful environmental and social safeguards
Zomer et al. 2017 https://www.nature.com/articles/s41598-017-15794-8
An overarching case and vision for action, led by countries that already have strong national policies on soil.
A stronger business case and track-record of success among public and private investors, for example through seed funding of commercial soil carbon initiatives.
A more compelling value proposition for farmers and land managers, which may involve benefits beyond any financial compensation for building carbon. For example, co-benefits to managing soil organic carbon on farms could include higher productivity, greater resilience to drought, and (where applicable) government support.
Vermeulen, S., Bossio, D., Lehmann, J., Luu, P., Paustian, K., Webb, C., Augé, F., Bacudo, I., Baedeker, T., Havemann, T. and Jones, C., 2019. A global agenda for collective action on soil carbon. Nature Sustainability, 2(1), p.2.
See also https://www.nature.com/articles/d41586-018-07587-4#ref-CR6
Global Soil Laboratory Network (GLOSOLAN) is working to improve matters by harmonizing protocols and standards and setting up global training programmes in soil analysis. GLOSOLAN is part of the Global Soil Partnership