Proceedings of a Workshop
Land Management Practices for Carbon Dioxide Removal and Reliable Sequestration
Proceedings of a Workshop—in Brief
Carbon dioxide removal (CDR) techniques, which aim to remove and sequester excess carbon from the atmosphere, have been identified as an important part of the portfolio of responses to climate change and have been garnering increased attention.1 The Committee on Developing a Research Agenda for Carbon Dioxide Removal and Sequestration has been convened to develop a detailed research and development agenda to assess the benefits, risks, and sustainable scale potential for CDR and sequestration approaches, as well as increase their commercial viability. The CDR approaches under consideration by the committee are coastal and land ecosystem management, accelerated weathering, bioenergy with carbon capture, direct air capture, and geologic sequestration. To aid in the development of the research agenda, each approach is being examined by the committee through a series of information-gathering workshops and webinars for open discussions with relevant communities about the current state of knowledge and research needs for understanding the potential of each approach and for deploying them at large scales.
Forests, grasslands, agricultural lands, and soils are significant reservoirs of carbon. As the amount of CO2 in the atmosphere has increased, there is growing interest in land management practices that can enhance the uptake and storage of carbon. The committee held a webinar on September 14 and a workshop on September 19, 2017, in Fort Collins, Colorado, to explore the current state of knowledge on the potential or capacity of land management practices as a CDR approach, the research that could help achieve this capacity and to estimate the impacts of land management practices across multiple scales, the state of knowledge on policies and incentives, and the socio-economic constraints on soil carbon sequestration and forest carbon storage activities. This Proceedings of a Workshop—in Brief summarizes the presentations from both the webinar and workshop.
TERRESTRIAL CARBON REMOVAL AND SEQUESTRATION POTENTIAL
Strategies for managing forests, grasslands, croplands, and soils influence their ability to absorb CO2 from the atmosphere and sequester carbon. These management strategies, which are discussed below, include reforestation, afforestation (establishing a forest on land that had no previous tree cover), reducing deforestation, improved forest management, using biomass as an energy source to substitute for fossil fuels, application of biochar2 (charcoal made from organic matter) to soil, reducing forage consumption by grazing, and employing practices that improve soil health.
1 National Research Council. 2015. Climate intervention: carbon dioxide removal and reliable sequestration. Washington, DC: The National Academies Press.
2 Biochar is produced through pyrolysis (chemical decomposition of organic [carbon-based] materials through the application of high temperature), a process that allows for the capture of carbon from biomass.
Forests constitute 90% of the U.S. terrestrial carbon sink and have the capacity to absorb 14–19% of total U.S. CO2 emissions, which is estimated to be 200 million tons of CO2e3 per year (0.2 Gt Ce per year), according to Al Sample from George Mason University. Dr. Sample noted that the U.S. forest carbon sink is projected to peak between year 2020 and 2040 and then decline due to decreased net sequestration as trees get older on land that was returned to forest; loss of forests due to land conversion; and continuing increases in wildfire and insect/disease mortality on public forest lands. Dr. Sample also highlighted the impact of forest disturbances—such as wildfires, pest infestations, and timber harvesting—on carbon storage by forests. He said that based on an analysis of data from the 2014 Forest Inventory Analysis (FIA),4 there are 7.9 million hectares of U.S. forest that remain unregenerated following disturbances (see Figure 1). It is estimated that regenerating these forest lands would remove a net of 48.9 million metric tons of CO2e per year- (0.05 Gt Ce per year).
To improve forest management practices that address carbon removal goals, Dr. Sample suggested that steps be taken to determine how to combine FIA and other data to characterize the regeneration needed and how to utilize other ground-based data to characterize the level of intervention required; set a feasible goal and timeline based on the area that is potentially deforested and the cost of intervention; identify the investments in reforestation that need to be made to remove carbon within an acceptable timeline; and create financial incentives or tax incentives (for private forests) and policies (for public forests) that would be most effective to achieve carbon removal goals through forest regeneration.
Forests can be substantial carbon sinks or sources depending on how they are managed, said Tara Hudiburg from the University of Idaho. Factors that control forest carbon storage include climatic changes, natural disturbance (e.g.,
3 Carbon dioxide equivalent (CO2e) is used to aggregate different greenhouse gases in a common unit. For any quantity and type of greenhouse gas, CO2e indicates the amount of CO2 which would have the equivalent global warming potential. Ce is a similar measure only in carbon as opposed to CO2 equivalent.
4 The USFS Forest Inventory and Analysis program is a continuous forest census taken from 105,000 field plots that projects how forests are likely to appear 10 to 50 years in the future (https://www.fia.fs.fed.us/).
fire, pests, hurricanes), human management (i.e., what to do with harvest), and policy on a global scale. Forestry activities with the potential to mitigate CO2 emissions include reducing deforestation and forest degradation; increasing forested land area through afforestation/reforestation; and increasing the carbon density of existing forests at both stand and landscape scales. Another potential option is to expand the use of forest products that sustainably replace fossil-fuel CO2 emissions, i.e., as a bioenergy feedstock. Dr. Hudiburg noted that there is uncertainty about the efficiency of bioenergy and concern that utilizing harvest residues, rather than allowing them to decompose in the forest, would impact soil fertility. She suggested that more systems-level analyses are needed to assess the use of wood products for bioenergy and long-term emission reduction.
Steven Hamburg of the Environmental Defense Fund noted that it is difficult to increase carbon density through forest management. A 30+ year whole-tree harvest experiment showed that harvesting had basically no impact on the average amount of carbon stored in the first 15 years.5 He went on to discuss other long-term experiments that indicate a shift in carbon distribution but no change in the amount of carbon stored. Dr. Hamburg believes that it is unlikely that reforestation is going to be a tool for increasing soil carbon because it is extremely difficult to increase the net carbon storage or density of soil carbon in temperate forests. It is important to maintain and improve long-term field research, he said. A lot of data from long-term field experiments are either not being collected, or not being fully maximized or mined efficiently to improve our understanding of how carbon has moved through forests and croplands. Taking additional samples and measurements in long-term study locations could augment current data on deep and surface soils, which are currently not sufficient to determine if the carbon density is evenly distributed across various soil depths, he added.
Grasslands occupy about 40% of the global land area and can sequester carbon at relatively moderate rates—theoretically greater than croplands—depending on management practices, according to Alan Franzluebbers from USDA-ARS and North Carolina State University. In discussing the results of short- and long-term studies on bermudagrass and tall fescue, Dr. Franzluebbers pointed out that soil organic carbon (SOC) accumulation was not affected by type of fertilizer used (organic or inorganic) in grazed systems; fertilization rate can have a minor effect on SOC accumulation in grazed tall fescue, particularly at the 20 cm depth; and carbon stock is significantly higher in grazed systems than in hayed systems. Data from pastures grazed for 8–15 years indicate that carbon stock is highest in spots nearest the shade and water sources, areas where animals congregated and fed, and that the carbon stock declines with distance from the shade and water source. There was also reduced SOC accumulation with increased grazing intensity. Studies also show increased SOC accumulation through cropping to pasture rotations and silvopasture (i.e., the practice that integrates trees, forage, and livestock production). Although some studies show that there are benefits of moderate grazing for SOC accumulation, its effect on SOC sequestration in different soil types and ecoregions around the United States still needs to be determined, as does the effect of the interactions between environmental conditions, plant genetics, and management practices on maximizing SOC sequestration. Dr. Franzluebbers also underscored the need for longer term studies in order to have a more complete picture of SOC sequestration over time. He noted that detecting differences in SOC accumulation at different soil depths is a big challenge.
Biological carbon sequestration can be achieved through afforestation, changes to agricultural practices, soil carbon sequestration (SCS), application of biochar to soil, and the combination of biochar addition to soil and bioenergy with carbon capture and storage (BECCS) technology, said Pete Smith from the University of Aberdeen in Scotland, UK. According to Dr. Smith, SCS has a technical potential6 of 1.3 Gt Ce per year; low impacts on land, water use, albedo, and energy; a positive impact on nutrient retention; and is low cost. Biochar has a technical potential of 1.8 Gt Ce per year; some additional land requirements and albedo impacts; a positive impact on nutrient retention and energy generation; and is relatively higher in cost than SCS. Both SCS and biochar have moderate potential for delivering negative emissions (0.4-0.7 Gt Ce per year for SCS7; 0.7 Gt Ce per year for biochar8), and afforestation and reforestation have a similar potential depending on the scale of deployment, he added. Dr. Smith further discussed, via a graph (see
5 Data after 30 years have not been collected due to lack of funds.
6 Technical potential refers to the extent that carbon can be sequestered by implementing a technology or practice that has already been demonstrated.
7 Smith, P., D. Martino, Z. Cai, D. Gwary, H. Janzen, P. Kumar, B. McCarl, S. Ogle, F. O’Mara, C. Rice, B. Scholes, O. Sirotenko, M. Howden, T. McAllister, G. Pan, V. Romanenkov, U. Schneider, S. Towprayoon, M. Wattenbach, and J. Smith. 2008. Greenhouse gas mitigation in agriculture. Philosophical Transactions of the Royal Society B 363(1492): 789–813. doi: 10.1098/rstb.2007.2184; Smith, P. 2012. Soils and climate change. Current Opinion in Environmental Sustainability 4 (5): 539–544. doi.org/10.1016/j.cosust.2012.06.005
8 Woolf, D., J. E. Amonette, F. A. Street-Perrott, J. Lehmann, and S. Joseph. 2010. Sustainable biochar to mitigate global climate change. Nature Communications 1: 56.
Figure 2), the impacts and limits (i.e., energy produced/required, relative cost, land and water requirements) of the different negative emissions technologies (NETs).
As mentioned by Dr. Smith, biochar systems can generate heat energy, create negative emissions, and sequester carbon. Johannes Lehmann from Cornell University noted that there is a lack of consensus with regard to carbon sequestration in biochar systems and there is currently no analysis that includes economic comparisons and trade-offs between different carbon sequestration technologies. Although there is a lot of research on negative priming9 with biochar, Dr. Lehman believes that there is a dearth of studies on the effect of biochar on microorganisms, water, and metal biogeochemistry that might all be relevant for CO2 removal. Dr. Lehmann identified the following basic research needs: spatial modeling, information on trade-offs and transport, benchmarking against alternatives, and techno-economic modeling. He also said that the following are needed in the area of applied research and development: industrial scale bioenergy, product consistency, energy budget at a scale of implementation, and problematic wastes. For large-scale biochar product development and distribution, more data on materials handling and soil application are needed as well as data on the fate of biochar at landscape scale, mineralization pathways above and below ground, and persistence in different environments.
Steve Shafer from the Soil Health Institute explained how managing soil health (the capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans) is very closely related to managing soil carbon: sequestering carbon involves soil health management practices (see Figure 3) and soil management influences carbon sequestration (as well as a loss of greenhouse gases; GHG). Dr. Shafer believes that there is a need for a better understanding of how managing soil health can help manage GHGs; which soil management practices capture carbon
9 Negative priming pertains to the retardation of soil organic carbon decomposition.
and enhance soil health; how to estimate the practical limits of SCS and how to factor in different soil types/environments; and how much variation is introduced by different crops and management systems. He thinks that more data is needed for establishing baselines for soil health at regional and national scales; identifying trends in changes in soil health; establishing a context to interpret soil health information; supporting selection of land management practices to improve soil health and benefit agricultural production and natural resources; and providing information to policy makers. He also sees the need for economic analyses to determine how soil health can contribute to farm profitability; effective communication to ensure that information is being used; and policies to make soil health the cornerstone of natural resource management nationwide. Current policies that affect soil health have to be identified, as well as where information on soil health can have influence (e.g., Farm Bill, state and local jurisdictions), he added.
Jean-Francois Soussana of the French National Institute for Agricultural Research (INRA) explained why SCS in croplands is a major option for climate change mitigation and food security: (1) there is 2–3 times more carbon in soil organic matter than in atmospheric CO210; (2) 1.4 billion metric tons (Gt C) can be stored annually in agricultural soils, equivalent to an annual storage rate of 0.4% in top soil11; and (3) 80% of this potential could be reached for $100 per ton of CO2, a price compatible with the 2°C global warming target.12 He also pointed out that the 0.4% SOC sequestration rate has often been exceeded in long-term arable field trials (trials lasting for more than 50 years), but the rate
10 Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp, doi: 10.1017/CBO9781107415324.
11 Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp.; Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.
12 Smith, P., D. Martino, Z. Cai, D. Gwary, H. Janzen, P. Kumar, B. McCarl, S. Ogle, F. O’Mara, C. Rice, B. Scholes, O. Sirotenko, M. Howden, T. McAllister, G. Pan, V. Romanenkov, U. Schneider, S. Towprayoon, M. Wattenbach, and J. Smith. 2008. Greenhouse gas mitigation in agriculture. Philosophical Transactions of the Royal Society B 363(1492): 789–813. doi: 10.1098/rstb.2007.2184; Franklin et al. (unpublished, cited by J.-F. Soussana)
declines as compared to the initial SOC stock13 (see Figure 4). He also noted that one limiting factor to SCS is that SOC will only increase over a finite period (30–50 years locally) until the point when a new SOC equilibrium is approached. Dr. Soussana considers the following to be challenges with SCS as a CDR approach: increasing the amount of carbon returning to soil, stabilizing fertility, and monitoring and preserving carbon stocks; and adoption and permanence of improved practices.
13 Minasny, B., B.P. Malone, A.B. McBratney, D.A. Angers, D. Arrouays, et al. 2017. Soil carbon 4 per mille. Geoderma 292: 59–86.
According to Rob Jackson from Stanford University, plants and soils offer CDR opportunities because deforestation and other land-use changes have released 150–200 Gt C into the atmosphere since 185014 and some of this carbon can be recovered; soil restoration provides erosion control, increased fertility, and other co-benefits; and land-based options are likely to be the cheapest form of CDR through 2050, possibly longer. He believes that the following are still needed: better tools for verifying soil carbon storage (to keep transaction costs down); positive but stringent assessments of efforts like the 4/1000 initiative15 for increasing soil carbon storage; new research, synthesis, and modeling efforts for root inputs as a tool for increasing SOC; and increased data collection, data mining, and use of networks (e.g., the International Soil Carbon Network, ISRIC, etc.).
PREDICTING AND ESTIMATING IMPACTS OF LAND MANAGEMENT PRACTICES TO SEQUESTER CARBON ACROSS MULTIPLE SCALES
Understanding the impacts of land management practices on SCS on the field, regional, and national level requires tools and methods for measurement and prediction. The discussion below touches on the state of science for estimating carbon and greenhouse gas emissions.
It is only possible to account for SCS if there are platforms for counting carbon, said Stephen Ogle from Colorado State University. Developing these platforms requires having models, and models require information on agricultural practices and estimates of the carbon stock changes. Models also need to be tested and parametrized by using data from controlled experiments, such as those that look at tillage practices, or changes in agricultural inputs, such as fertilization. Hence, one priority is to maintain long-term datasets; another priority is to have a federation of networks of sites that gather these long-term datasets, according to Dr. Ogle. He added that data from experiments need to be consolidated and maintained in a manner similar to FluxNet.16
Although empirical models have a lot of value, said Dr. Ogle, process-based models would allow knowledge of water dynamics, plant production, carbon and nitrogen cycling, and other processes to be used in predicting the impact on SCS in different management systems. He underscored the need to advance existing models by incorporating all of the new science into them. Model evaluation, which is often overlooked, is also important and requires independent data. More data on soil carbon are needed because the existing dataset is small, which makes maintaining existing long-term experiments a priority, he said.
Grant Domke from the U.S. Forest Service emphasized the uncertainty in the estimates of GHG emissions and removals in the U.S. land sector at the national scale and the challenge of identifying changes in GHG emissions that result from a policy or land management change. Because the intent of the national GHG inventory is to evaluate policies and management practices, reducing uncertainty in GHG estimates17 is important in determining when policies or management practices to enhance productivity or reduce CO2 through the land sector are implemented. Uncertainty in GHG estimates is also relevant to and reflected in the recent U.S. commitments to reduce GHG emissions, wherein a range was set instead of a specific target.
Dr. Domke described two inventories that could inform U.S. commitments to emissions reduction: the National Resources Inventory (NRI) of the USDA Natural Resources Conservation Service (NRCS), which is a statistical survey of land use and natural resource conditions and trends on U.S. non-federal lands; and the FIA program of the U.S. Forest Service, which provides information on the status and trends in U.S. forests. Information from NRI combined with FIA data can provide more refined estimates on land use on an annual basis, he said, but there is a growing need for more spatially and temporally resolved information. Dr. Domke believes that by combining NRI and FIA inventory observations with information from other inventories, data collected through remote sensing, structural observations from LIDAR or hyper-spectral information, and atmospheric observations, the accuracy and precision of GHG emissions and removals estimates across spatial and temporal scales could be improved.
14 Houghton, R. A. 2003. Revised estimates of the annual net flux of carbon to the atmosphere from changes in land use and land management 1850–2000. Tellus 55B:378–390; Saatchi, S., N.L. Harris, S. Brown, M. Lefsky, E.T.A. Mitchard, W. Salas, B.R. Zutta, W. Buermann, S.L. Lewis, S. Hagen, S. Petrova, L. White, M. Silman, and A. Morel. 2011. Benchmark map of forest carbon stocks in tropical regions across three continents. Proceedings of the National Academy of Sciences 108: 9899–9904.
17 This uncertainty is related to identifying sources of error in the estimates (e.g., measurements, sampling, and modeling).
POLICIES AND INCENTIVES, AND SOCIO-ECONOMIC CONSTRAINTS ON CARBON SEQUESTRATION ON FOREST AND SOILS
Carbon sequestration on forests, grasslands, and agricultural lands is possible through a range of land management strategies and could be substantial with widespread implementation. The discussion below explores the factors that complicate or deter the implementation of land management practices on a larger scale, as well as possible ways to make terrestrial carbon sequestration viable.
The technical potential of CDR practices is often discussed, but as Dr. Jackson stated, not enough time is spent on determining effective incentives for changing land management practices. He emphasized that economic factors should be considered, citing an analysis by Jackson and Baker18 using FASOMGHG19 that showed how carbon price can affect the amount of CO2 removed per year through forest management, afforestation, and forest bioenergy. This analysis, he said, showed that with a carbon price, forest offsets can be substantial; afforestation and forest management both increase with carbon price; and forest bioenergy barely nudges at $50 per ton of CO2, suggesting that it is cheaper to store carbon through land management practices.
According to Sian Mooney from Arizona State University, there is considerable technical potential to increase SCS globally but its economic potential is likely smaller than its technical potential because farmers have already chosen the practices that would maximize their profits and there are costs associated with changing land management practices, and economic potential will vary (in part) depending on the size of payments or incentives, which are required for changes in land management practices. Costs and SCS vary widely depending on the initial and the subsequent farming system and the region of analysis. Some cost estimates have shown that SCS can be economically effective and competitive with other carbon sequestration technologies, she said.
Dr. Mooney said that calculating the cost in response to land management changes requires biophysical and economic models; additional integrated modeling work is needed because current frameworks are highly specialized, not easily customizable, and not available for all regions. Such frameworks also do not incorporate change in yields and do not include full GHG accounting. Additional information is also needed to understand producer behavior and barriers to adoption, said Dr. Mooney. Economic incentives are strong motivators and they are correlated with policy design. Policy costs are dependent on the biophysical potential to sequester carbon, the economic cost to the producer, and the structure of payment design. Potential payment designs include both payment for performance and payment for practice. Research has shown that payments for performance or outcomes are more efficient than payments for practice, but transaction costs can change the efficiency of these two payment schemes. Dr. Mooney believes that incentives are required to scale up SCS in the agricultural sector, bearing in mind that the design of incentives can affect the overall cost of implementation and that co-benefits of SCS also have value. However, valuing co-benefits is difficult because they vary spatially and temporally and incentives targeted at SCS change the provision of other benefits. She also said that research is needed on societal benefits versus private cost.
Commercial crop agricultural systems can sequester carbon at a cost that is competitive with non-agricultural systems, said John Antle from Oregon State University. Implementation of SCS practices depends on the physical potential as well as the economics, behavioral factors, and institution setting and policy. Farmers’ participation in conservation reserve programs shows that providing clear and stable incentives results in effective participation; however, there is uncertainty about the key factors that drive farmers’ decisions and about policy. Socio-economic factors that constrain or complicate SCS implementation in the agricultural sector include the scale of agricultural production; farm complexity; a lack of institutions required for the functioning of markets; weak policies; property rights/ownership of land; limited ability to enforce contracts; and a lack of moral imperative to help solve a problem (i.e., climate change). Dr. Antle mentioned the importance of looking into future scenarios—not just for climate, but also future economic conditions, institutional settings, policies, and technologies, all of which can influence the outcomes of SCS implementation.
19 The Forest and Agricultural Sector Optimization Model with Greenhouse Gases (FASOMGHG) is a dynamic, nonlinear programming model of the forest and agricultural sectors in the United States. More information on FASOMGHG available at URL: https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=82963. Accessed 12-28-2017.
Farmers can engage in policies to help mitigate climate change if they are given the right financial signal, said Debbie Reed from the Coalition on Agricultural Greenhouse Gases (C-AGG).20 A financial signal can be a carbon price or other economic or financial incentive, including a tax break for land easements or equipment purchase. Market-based mechanisms that create a financial signal to the agricultural sector include conservation programs; certification programs and sustainable supply chain initiatives; payment for ecosystem service markets; and voluntary and compliance carbon-offset21 markets. Ms. Reed noted that all of these programs require similar data to measure, report, and verify what is happening at the farm-level. She emphasized the need for a national level monitoring, reporting, and verifying (MRV) system to help harmonize and track the impacts of GHGs associated with changes in practices and track changes in ecosystems. She believes that such a system would represent a programmatic investment and could also help in determining if there is double counting of activities (i.e., emissions reductions).
Ms. Reed pointed out that several economic challenges associated with carbon-offset markets still exist. There is no national level policy to provide the necessary financial signals to scale carbon offsets. The lack of a national MRV system, and the rigors of protocols and carbon-offset market requirements (including permanence and additionality), make it hard for those who seek to reduce GHG (agricultural producers) to get more payments from the sale of carbon credits.22 The hundred-year permanence requirement would be difficult to achieve in the agricultural sector (particularly for SCS) because agricultural practices change daily, weekly, or monthly, and land tenure (ownership) is an issue. The additionality requirement excludes early actors and innovators from participating in carbon markets because they were engaged in an activity before the baseline was created.
The USDA’s NRCS has developed a conservation practice toolbox (soil health building blocks) and a quantification toolbox (for evaluating SCS benefits and emissions).23 However, a strong proposal for a carbon sequestration program is still needed, said Adam Chambers of the NRCS. The NRCS is looking into investing, with a partner, in a revolving loan fund that could focus on soil carbon in order to have a program that could continually sequester carbon. However, significant work on price discovery still needs to be done. Dr. Chambers mentioned two pitfalls: there are time delays associated with implementing SCS practices because it takes time for land management practices to mature into a carbon uptake process; and payments are needed to align with practices, as certain practices will not last unless farmers are paid to employ them whereas others will stay in place for the long term with only an initial payment.
Joe Cornelius from U.S. Department of Energy Advanced Research Projects Agency-Energy (ARPA-E)24 gave an overview of ARPA-E breeding programs that aim to increase crop yield while improving soil quality: TERRA, which focuses on aboveground crop traits; and ROOTS, which focuses on belowground traits. Through these programs, cultivars are being selected to find a path for sequestering 1 Gt of carbon, with improved fertility and water use and without a decrease in yield. Dr. Cornelius also described ARPA-E’s collaboration with other agencies and organizations to make plant breeding a faster, more precise process through the use of robotic platforms and other advanced measuring/detection techniques or technologies.
According to Toby Janson-Smith from the Verified Carbon Standards Program, the three main drivers of emissions reduction and carbon removal strategies are (1) capped sectors and regulated activities; (2) carbon credit trading for other sectors or activities; and (3) non-carbon policies and incentives based on co-benefits. Looking at marginal GHG abatement cost curves and barriers, interdependencies, and co-benefits is an approach for policy makers and researchers to determine the opportunities with the greatest CDR potential. He said that the following factors should also be assessed when determining the most viable CDR opportunities: the optimal scale of implementation and monitoring; the role of market mechanisms versus regulatory pathways; and the existence of GHG methodologies for carbon accounting and crediting.
20 C-AGG is a multi-stakeholder coalition that builds capacity for the development and adoption of voluntary incentives, programs, and policies to reduce GHG emissions from the agricultural sector. C-AGG participants include agricultural producers and producer groups, scientists, environmental NGOs, carbon market developers, methodology experts, investors, and other proponents of voluntary agricultural GHG mitigation opportunities.
21 A carbon offset is a reduction in emissions of carbon dioxide or greenhouse gases made in order to make up for or offset an emission made elsewhere.
22 Having a national MRV system would harmonize the MRV systems created for individual protocols and projects, reducing the costs and burdens on protocol and project developers. Currently, about 95% of profits from the sale of carbon credits go to the middle men, e.g., a project developer, an entity that measures and monitors and verifies the changes in emissions, the verifier, and the carbon offset registry. A national MRV system would result in more payments from credits being paid to the GHG reducers (D. Reed, C-AGG, personal communication, December 1, 2017).
23 See https://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health. Accessed 12-27-2017.
24 Advanced Research Projects Agency-Energy is a U.S. government agency tasked with promoting and funding research and development of advanced energy technologies.
Mr. Janson-Smith considers high uncertainty with CDR policy, sporadic GHG monitoring and incentive flows, and intense development pressures as barriers to CDR opportunities in developing countries. He believes that in order to make CDR opportunities viable, there needs to be a mechanism for international trading of carbon, more commitment from policy makers to include the land-based sector in the compliance markets, and linking GHG crediting to carbon tax incentives. In discussing the commercial viability of CDR, Mr. Janson-Smith mentioned four drivers: (1) return on investment; (2) risk mitigation; (3) long-term sustainability; and (4) corporate social responsibility and brand positioning. He also noted that there is still a dearth of knowledge and research on the extent that individual CDR activities could generate outcomes valued by businesses and investors; the suitability of native tree species for plantations that generate carbon and other ecosystem service value; and policy and incentives around restoration of degraded lands, forests, and grasslands.
DISCLAIMER: This Proceedings of a Workshop—in Brief was prepared by Camilla Y. Ables, National Academies of Sciences, Engineering, and Medicine as a factual summary of what occurred at the workshop. The statements made are those of the rapporteur or individual meeting participants and do not necessarily represent the views of all meeting participants; the planning committee; or The National Academies of Sciences, Engineering, and Medicine.
REVIEWERS: To ensure that it meets institutional standards for quality and objectivity, this Proceedings of a Workshop—in Brief was reviewed by Mahdi Al-Kaisi, Iowa State University; Richard Birdsey, Woods Hole Research Center; Christopher Galik, North Carolina State University; Dennis Ojima, Colorado State University; and Charles Rice, Kansas State University.
Committee for Developing a Research Agenda for Carbon Dioxide Removal and Reliable Sequestration: Stephen Pacala (NAS, Chair), Princeton University, Mahdi Al-Kaisi, Iowa State University, Mark Barteau (NAE), Texas A&M University, Erica Belmont, University of Wyoming, Sally Benson, Stanford University, Richard Birdsey, Woods Hole Research Center, Dane Boysen, Modular Chemical Inc., Riley Duren, Jet Propulsion Laboratory, Charles Hopkinson, University of Georgia, Christopher Jones, Georgia Institute of Technology, Peter Kelemen (NAS), Columbia University, Annie Levasseur, International Reference Centre for the Life Cycle of Products, Processes, and Services (CIRAIG), Keith Paustian, Colorado State University, Jianwu (Jim) Tang, Marine Biological Laboratory, Tiffany Troxler, Florida International University, Michael Wara, Stanford Law School, Jennifer Wilcox, Colorado School of Mines
SPONSORS: This Workshop was supported by the U.S. Department of Energy, the National Oceanic and Atmospheric Administration, the Environmental Protection Agency, the United States Geological Survey, the V. Kann Rasmussen Foundation, and Incite Labs, with support from the National Academy of Sciences’ Arthur L. Day Fund.
For a record of presentations and additional information regarding the Workshop, including the statement of task for this study, visit http://nas-sites.org/dels/studies/cdr.
Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2018.
Land Management Practices for Carbon Dioxide Removal and Reliable Sequestration: Proceedings of a Workshop—in Brief. Washington, DC: The National Academies Press. doi: https://doi.org/10.17226/25037.
Division on Earth and Life Studies
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