Climate change caused by carbon dioxide (CO2) and other manmade greenhouse gases is one of the most pressing problems facing society today.1United Nations International Panel on Climate Change, Climate Change 2014 Synthesis Report Summary for Policymakers, 2014. https://www.ipcc.ch/site/assets/uploads/2018/02/AR5_SYR_FINAL_SPM.pdf. In total, the world emits 35 billion tons of carbon dioxide per year. These emissions have had wide-ranging effects on the climate, such as rising sea levels and more frequent extreme weather events.2UN IPCC, 3. Growing public concern has led 139 countries and over 700 corporations to make net zero emissions pledges, in which greenhouse gas emissions are lowered or offset.3Net Zero Tracker, accessed April 4, 2023, https://zerotracker.net/. Many of these pledges rely on the purchase of carbon offsets to reach net zero.
Carbon offsets are purchased through carbon markets where offset dealers sell credits that most often represent one ton of CO2 reduction or sequestration. Carbon markets rely on economic principles, namely that allowing markets to incentivize CO2 reductions will lower emissions. Most carbon offset credits today are generated by emissions reductions, in which a firm reduces its own emissions and then sells those reductions as offsets.4Kelley Hamrick and Melissa Gallant, Voluntary Carbon Market Insights: 2018 Outlook and First Quarter Trends, Forest Trends Association, July 27, 2018, https://www.forest-trends.org/publications/voluntary-carbon-markets/. Some credits also come from sequestration projects, where CO2 is captured from the atmosphere through either manmade or natural processes and sold as offsets.
Unfortunately, carbon markets have yet to be effective in creating large-scale reductions in CO2. Several barriers prevent markets from working well, most notably the high cost of measurement, reporting, and verification of carbon reductions and sequestration, as well as the high initial costs of projects and lack of reliable information. The current carbon market does not provide a high enough price to incentivize large amounts of high-quality carbon reduction or sequestration projects.
Despite this, physically sequestering carbon in the natural landscape should still be pursued for its CO2 reductions and numerous other environmental services. In particular, private agricultural lands could provide enough carbon sequestration to more than offset the emissions from food production.5Evich Helena Bottemiller and Ryan McCrimmon, “Biden Wants to Pay Farmers to Grow Carbon Capturing Crops. It’s Complicated,” POLITICO, June 29, 2021, https://www.politico.com/news/2021/06/29/biden-climate-farmers-carbon-496843. Several different land management practices can be used to sequester carbon including reforestation, regenerative agriculture, and adaptive multi-paddock grazing, with each practice also providing co-benefits such as cleaner water, healthier soil, and improved wildlife habitat.
This paper examines some of the key approaches for sequestering carbon on private agricultural lands and the barriers that exist in carbon markets. It provides evidence that carbon payments themselves are insufficient to incentivize uptake, but that additional payments based on the co-benefits created by these land management practices may be enough to overcome the costs of implementation, including measurement, reporting, and verification.
How to Capture Carbon: Costs and Conservation
Terrestrial carbon capture, or carbon farming, is the process of using plants to sequester carbon in the soil. Through changes in land management, carbon is drawn from the atmosphere by growing plants and stored in their roots, stems, and leaves. As humans use the plants for timber, crops, or forage, much of the carbon remains underground in the roots, where they gradually decompose and improve the soil organic matter (SOM).
Increased SOM improves the fertility of the land and, depending on the region and practice, carbon can be held underground for decades or even centuries.6Judith D. Schwartz, “Soil as Carbon Storehouse: New Weapon in the Climate Fight?” Yale Environment 360, March 4, 2014, https://e360.yale.edu/features/soil_as_carbon_storehouse_new_weapon_in_climate_fight. Healthier soils have several co-benefits including improved water retention, reduced soil erosion and water pollution, and improved wildlife habitat.7Ryan McGuire, et al., “Potential Co-Benefits and Trade-offs Between Improved Soil Management, Climate Change Mitigation and Agri-Food Productivity,” Food and Energy Security 11, no. 2 (2022): e352, https://doi.org/10.1002/fes3.352; Holly Fretwell and Harrison Naftel, “Western Rumination: Cows and Conservation,” Forthcoming, The Center for Growth and Opportunity.
Several agricultural land management methods can be implemented to sequester carbon. These methods rely on the principle of improving soil health by minimizing soil disturbance and improving SOM. The simplest of these methods are reforestation and afforestation. These processes either allow forests to grow back naturally or establish new forests.
Trees are the most effective plant for carbon sequestration; the world’s existing forests capture 1.5 times the amount of total US carbon emissions each year.8Nancy Harris and David Gibbs, “Forests Absorb Twice as Much Carbon as They Emit Each Year,” World Resources Institute, January 21, 2021, https://www.wri.org/insights/forests-absorb-twice-much-carbon-they-emit-each-year. In addition to having extensive root systems that store carbon, wood is 50 percent carbon by weight and any durable goods made from timber, such as homes and furniture, can be viewed as long term sequestered carbon. The timber industry is one of the only carbon sink industries in the US, capturing the equivalent of 12 percent of annual US emissions.9David N. Wear and Ann Bartuska, “Forest Carbon 201: Land Use Effects of Wood Product Markets,” Resources for the Future, March 8, 2021, https://www.rff.org/publications/explainers/forest-carbon-201-land-use-effects-of-wood-product-markets/.
Forest sequestration also faces challenges. Measuring carbon levels in soil requires taking a core sample that reaches the roots of the sequestering plant, which in the case of trees can be 10 or more feet below the surface. Many core samples must be taken throughout a forest, as the amount of sequestered carbon can vary across short distances.10Pete Smith et al., “How to Measure, Report and Verify Soil Carbon Change to Realize the Potential of Soil Carbon Sequestration for Atmospheric Greenhouse Gas Removal,” Global Change Biology 26, no. 1 (2020): 219–41, https://doi.org/10.1111/gcb.14815; Raisa Mäkipää, Margareeta Häkkinen, Petteri Muukkonen, and Mikko Peltoniemi, “The Costs of Monitoring Changes in Forest Soil Carbon Stocks,” Boreal Environment Research 13 (2008): 120–130, http://www.borenv.net/BER/archive/pdfs/ber13/ber13-B120.pdf. In addition, the accuracy of these core samples is still questioned in the literature.11Jean-Nicolas Poussart, “Verification of Soil Carbon Sequestration – Uncertainties of Assessment Methods,” Lund University, 2002 https://lup.lub.lu.se/luur/download?func=downloadFile&recordOId=1333028&fileOId=1333029.
Establishing a new forest can also be expensive. A Congressional Research Service review of carbon sequestration through forests found that carbon offset prices would need to be above $91 per ton to be profitable, far more than current offset prices of $3–6 per ton.12Ross W. Gorte, “U.S. Tree Planting for Carbon Sequestration,” Congressional Research Service,” May 4, 2009, https://climatechange.lta.org/wp-content/uploads/cct/2018/03/R40562_2009.pdf; Hamrick & Gallant, Voluntary Carbon Market Insights.
In addition to creating or reestablishing forests, current timber management practices can be altered. Single stand forests, such as the vast pine forests of the Southeast, have been shown to be effective at capturing carbon and may even capture more carbon than natural forests under the right conditions.13K.H. Johnsen, et al., “Meeting Global Policy Commitments: Carbon Sequestration and Southern Pine Forests,” Journal of Forestry 99, no. 4(2001): 14–21, https://academic.oup.com/jof/article. Typically, mixed stand forests made up of many ages and species of trees are the best management option for environmental benefits. However, mixed stands require single tree harvesting which is more expensive and time consuming than harvesting in single stands.14“How Forests Store Carbon,” Penn State Extension, September 24, 2020, https://extension.psu.edu/how-forests-store-carbon. Other practices can also be used to improve carbon sequestration, including longer rotations between harvests, harvesting timber in winter, and growing trees that are slow to mature, all of which add additional costs.15“How Forests Store Carbon,” Penn State Extension.
Another method of carbon farming is regenerative agriculture. The goal is to capture carbon by improving soil health through farming practices such as minimum or no-till, cover cropping, and crop rotation. Each of these methods improves soil fertility by either minimizing soil disturbance or actively promoting more soil organic matter.16“What is Regenerative Agriculture?” Regenerative Agriculture Initiative at California State University, Chico and The Carbon Underground, February 16, 2017, https://regenerationinternational.org. If done on a large scale, regenerative agriculture has the potential to capture six to nine percent of US carbon emissions annually, enough to more than offset emissions produced by the agricultural industry.17Serge Wiltshire and Brian Beckage, “Soil Carbon Sequestration through Regenerative Agriculture in Vermont,” PLOS Climate 1, no. 4, (April 11, 2022), https://journals.plos.org/climate/article?id=10.1371/journal.pclm.0000021; Bottemiller and McCrimmon, “Biden Wants to Pay Farmers.” These practices also improve water retention, reduce soil erosion, and limit fertilizer runoff.18“Regenerative Agriculture 101,” Natural Resource Defense Council, November 29, 2021, https://www.nrdc.org/stories/regenerative-agriculture-101.
Despite the benefits of regenerative agriculture, only about 12.5 percent of farmers use these methods.19A. Kassam, T. Friedrich, and R. Derpsch, “Global Spread of Conservation Agriculture,” International Journal of Environmental Studies 76, no. 1 (January 2, 2019): 29–51, https://doi.org/10.1080/00207233.2018.1494927. The profitability of these practices is debated in the literature. Some work indicates that fewer inputs and increased soil fertility increases profit, while other work shows reduced yields. One reason for this debate is the large overlap in organic and regenerative practitioners.20Clair E. LaCanne and Johnathan G. Lundgren, “Regenerative Agriculture: Merging Farming and Natural Resource Conservation Profitably,” PeerJ 6 (February 6, 2018), https://doi.org/10.7717/peerj.4428; Alon Tal, “Making Conventional Agriculture Environmentally Friendly: Moving beyond the Glorification of Organic Agriculture and the Demonization of Conventional Agriculture,” Sustainability 10, no. 4 (April 2018):1078, https://doi.org/10.3390/su10041078.
Most organic farmers use regenerative and organic practices together. While there is no problem with this, regenerative agriculture allows for the use of conventional tools such as synthetic pesticides and fertilizer that organic farming prohibits. Unfortunately, this means it is difficult to gauge the true profitability of regenerative agriculture alone. There are also important differences in both crops and geography that affect the economic viability of these practices.
Despite the difficulties of showing profitability, the sale of carbon offsets may still offer another income source for farmers under the right circumstances and encourage wider adaptation.
Prospective regenerative farmers around the world must take on initial costs that can range from $3 to $130 per acre depending on the country, farm, and practice. Costs include capital expenditures in new equipment and variable costs like seed for cover crops and increased labor costs associated with learning and implementing new practices.21Kai Tang, Marit E. Kragt, Atakelty Hailu, and Chunbo Ma, “Carbon Farming Economics: What Have We Learned?” Journal of Environmental Management 172 (May 1, 2016): 49–57, https://doi.org/10.1016/j.jenvman.2016.02.008. Studies that looked specifically at American agriculture found even higher costs with a minimum of $20 per acre.22John M. Antle, Susan M. Capalbo, Keith Paustian, Md. Kamar Ali, “Estimating the Economic Potential of Soil Carbon Sequestration in the Central United States Using an Aggregate Econometric-Process Simulation Model,” Climatic Change 80, no. 1(January 1, 2007): 145–171, https://link.springer.com/content/pdf/10.1007/s10584-006-9176-5.pdf.
Regenerative farmers also must deal with carbon measurement and verification challenges similar to those faced by the timber industry. Although these might be lower because core samples are not required to go as deep, the process is still expensive and time consuming.
Rangeland covers about one-third of the US and can also be used for successful carbon sequestration. By mimicking the mob grazing patterns of wild herds, some ranchers argue they have been able to greatly improve the health of their rangeland.23Holistic Management Case Studies, Profiles, and Articles, The Savory Institute, https://savory.global/wp-content/uploads/2017/02/Holistic-Management-Case-Studies-Profiles-Articles.pdf. Adaptive multi-paddock grazing (AMP), also known as holistic or intensive rotational grazing, divides the land into many paddocks through which the herd is rotated with the goal of using the herd to control invasive grasses and encourage vigorous plant growth. After sufficient grazing, the paddock is given time to recover and native plants regrow stronger than before, including in their roots. Improved root growth increases SOM and sequesters carbon underground.24Fretwell and Naftel, “Western Rumination.”
There is significant disagreement in the literature on the benefits of AMP grazing, with many studies finding little improvement in yields of forage or beef. However, conservation ranchers continue to swear by the practice and some analyses of landscape changes after adoption of AMP grazing show significant improvement in conservation value.25Rachel Lawrence et al., “Short Duration Rotational Grazing Leads to Improvements in Landscape Functionality and Increased Perennial Herbaceous Plant Cover,” Agriculture, Ecosystems, and Environment 281 (September 1, 2019): 134–144, https://www.sciencedirect.com/science/article/pii/S0167880919301185. In spite of this, there is solid evidence that these methods do sequester additional carbon, even if they do not improve yields.26Samantha Mosier et al., “Adaptive Multi-Paddock Grazing Enhances Soil Carbon and Nitrogen Stocks and Stabilization through Mineral Association in Southeastern U.S. Grazing Lands,” Journal of Environmental Management 288 (June 15, 2021): 112409, https://doi.org/10.1016/j.jenvman.2021.112409.
Numbers on current AMP grazing practice are hard to come by, but according to the Iowa Beef Center survey only 16 percent of Iowa farmers used seven or more paddocks on their grazing land. Similarly, the Savory Institute, a nonprofit that advocates for holistic grazing, estimates that their practices are used on less than one percent of the world’s rangelands.27“Iowa Cattle Grazing Survey: Part 1 Results,” Cows & Plows, Iowa Beef Center and Iowa State University Extension, October 2007, https://www.iowabeefcenter.org/CowsPlows/Iowa2007GrazingSurvey1.pdf; Holistic Management Case Studies, The Savory Institute. Large-scale adoption of AMP grazing faces barriers like those found in the timber and crop industries, including measurement and verification difficulties, labor inputs, and high initial costs. In particular, the cost of creating paddocks can add up quickly, with costs up to $10 per acre.28Fretwell and Naftel, “Western Rumination.”
While landowners face significant economic barriers in establishing terrestrial carbon farming on their land, other challenges also exist. Climate politics is divisive and massive swings in government policy can occur with each new election. Concern over frequent changes in government policy is one concern pointed to by farmers.29Kragt, Marit E, Nikki P. Dumbrell, Louise Blackmore, “Motivations and Barriers for Western Australian Broad-Acre Farmers to Adopt Carbon Farming,” Environmental Science & Policy 73 (July 2017): 115–123. https://doi.org/10.1016/j.envsci.2017.04.009.
While carbon markets are largely not government controlled in the US, nations like Australia have experienced this more directly, with continual changes in government policy increasing the risk facing carbon farmers. Reliable information is also a challenge for prospective carbon farmers with limited data on carbon prices, the cost of practices, and the effect on business.30Kragt et al; Megan C. Evans, “Effective Incentives for Reforestation: Lessons from Australia’s Carbon Farming Policies,” Current Opinion in Environmental Sustainability 32 (June 2018): 38–45. https://doi.org/10.1016/j.cosust.2018.04.002. Once a farmer has overcome these economic barriers and invested in carbon sequestration, carbon markets present their own set of challenges.
Carbon Market Challenges
There are two main types of carbon offset markets: compliance and voluntary. Compliance markets function under government regulations that cap the amount of carbon a firm can emit and allow for the purchase of offsets and trading of carbon allowances. Voluntary markets function without government mandates and are where most companies currently purchase offsets as part of their net-zero goals. Emerging voluntary markets face a lack of regulation and oversight, allowing for both innovation and fraud. Concerns over offset market effectiveness relate to three main areas: additionality, verification, and measurement of sequestration.31Robert Mendelsohn, Robert Litan, and John Flemming, “How to Repair the World’s Broken Carbon Offset Markets,” Yale Environment 360, November 18, 2021, https://e360.yale.edu/features/how-to-repair-the-worlds-broken-carbon-offset-markets; Mark Hafstead, “The Role of Voluntary Carbon Markets in Achieving Net-Zero Goals,” Resources for the Future, July 13, 2022, https://www.resources.org/common-resources/the-role-of-voluntary-carbon-markets-in-achieving-net-zero-goals/.
Additionality requires that a conservation project provide environmental value beyond what was already provided before the project. For example, selling offsets for carbon sequestered by an existing forest would not lower carbon levels.
Figuring out whether an offset project is additional, however, can be challenging. Carbon sequestration occurs all the time from normal land management practices (e.g., traditional farming, grazing, and forestry). Determining additionality requires comparing it to the hypothetical scenario where carbon offset revenue was not available.32D. Broekhoff, M. Gillenwater, T. Colbert-Sangree, and P. Cage, “Additionality” in Securing Climate Benefit: A Guide to Using Carbon Offsets, Stockholm Environment Institute & Greenhouse Gas Management Institute, November 13, 2019: 20–25, https://www.offsetguide.org/wp-content/uploads/2020/03/Carbon-Offset-Guide_3122020.pdf. In other words, if the project was not undertaken for the sole purpose of selling carbon credits, it does not provide additionality.
The issues of measurement and verification come from the difficulty and costs associated with measuring carbon. Not all offsets are created equal, and buyers want high-quality offsets that will last for long periods of time and reduce greenhouse gases. Ensuring this requires intensive tests to establish baseline carbon levels and continued monitoring to ensure that the project sequesters carbon. Due in part to this complexity and associated costs, investors have been wary of carbon farming and sequestration on agricultural lands.33Oscar J. Cacho, Leslie Lipper, and Johnathan Moss, “Transaction Costs of Carbon Offset Projects: a Comparative Study,” Ecological Economics, Transaction Costs and Environmental Policy, 88 (April 1, 2013): 232–43, https://doi.org/10.1016/j.ecolecon.2012.12.008; G. Cornelis van Kooten, Sabina Lee Shaikh, and Pavel Suchánek, “Mitigating Climate Change by Planting Trees: The Transaction Costs Trap,” Land Economics 78, no. 4 (November 1, 2002): 559–72, https://doi.org/10.2307/3146853. In total, only two percent of all carbon sequestration projects come from agriculture.34“Chapter 2: Conceptual Issues” in Economics of Sequestering Carbon in the US Agricultural Sector, USDA Economic Research Service, 4, https://www.ers.usda.gov/webdocs/publications/47467/17114_tb1909c_1_.pdf?v=0.
This is due in large part to the high transaction costs associated with carbon farming. Accurate soil carbon testing requires large numbers of samples from a single property as the amount of carbon sequestered can vary greatly even over a single farm. In addition, direct soil tests are not always simple and may require expensive equipment depending on the type of sequestration practice and the depth of the roots.35Pete Smith et al., “How to Measure, Report;” Raisa Mäkipää et al., “The Costs of Monitoring Changes in Forest Soil Carbon Stocks,” Boreal Environment Research 13 (November 25, 2008): 120–30.
Even though direct soil tests are the most accurate method, there is disagreement over their precision in the literature, which disincentivizes both investors and landowners from participating.36Jean-Nicolas Poussart, “Verification of Soil Carbon Sequestration – Uncertainties of Assessment Methods,” Lund University (2002), https://lup.lub.lu.se/luur/download?func=downloadFile&recordOId=1333028&fileOId=1333029. In total, transaction costs—which also include insurance and regulatory approval—add up quickly and can make up anywhere from 25–75 percent of the total cost of a sequestration project. One analysis suggests up to 270 percent of anticipated income from offset sales goes to transaction costs.37Christopher S. Galik, David M. Cooley, and Justin S. Baker, “Analysis of the Production and Transaction Costs of Forest Carbon Offset Projects in the USA,” Journal of Environmental Management 112 (December 15, 2012): 128–36, https://doi.org/10.1016/j.jenvman.2012.06.045; Timothy R. H. Pearson, Sandra Brown, Brent Sohngen, Jennifer Henman, and Sarah Ohrel, “Transaction Costs for Carbon Sequestration Projects in the Tropical Forest Sector,” Mitigation and Adaptation Strategies for Global Change 19, no. 8 (December 1, 2004): 1209–22, https://link.springer.com/article/10.1007/s11027-013-9469-8.
The current structure and requirements of carbon markets are likely insufficient to meet the challenges of large-scale carbon farming. In the future, carbon offsets may become more valuable and encourage investors to take on the higher costs and risks associated with carbon farming, but until then, terrestrial carbon sequestration will require additional incentives to be viable.
Valuing Co-Benefits as a Solution
Carbon farming faces many barriers, but capturing the value of its co-benefits through incentives beyond carbon markets may help overcome those barriers. The literature on co-benefits points to important non-market values for many conservation activities, including reduced soil erosion and degradation, cleaner water, and better wildlife habitat.38Mikael Karlssonl, Eva Alfredsson, and Nils Westling, “Climate Policy Co-Benefits: A Review,” Climate Policy 20, no. 3 (February 10, 2020): 292–316, https://doi.org/10.1080/14693062.2020.1724070. In effect, the seller of a carbon offset is generating a positive externality. Thus, the price offered for carbon is lower than the true value of the practice, given its external benefits.
This market failure could be addressed by including co-benefits in offset prices or by creating and expanding markets that trade each co-benefit separately. While including the value of these co-benefits in payments to farmers would incentivize more uptake of carbon farming, measuring co-benefits is often as difficult as measuring carbon.
One option is expanded government support for carbon farming. Because the effects of conservation practices are complex and the benefits wide ranging, this may be the simplest option. American agriculture is already supported by the US government. Farmers received about $22 billion in subsidies in 2019 through a wide array of programs frequently adjusted to encourage different outcomes in the industry.39Dan Charles, “Farmers Got Billions from Taxpayers in 2019 and Hardly Anyone Objected,” NPR, December 31, 2019, sec. The Salt, https://www.npr.org/sections/thesalt/2019/12/31/790261705/farmers-got-billions-from-taxpayers-in-2019-and-hardly-anyone-objected. Moreover, programs such as the Conservation Reserve Program (CRP) and Environmental Quality Incentives Program (EQIP), offer billions more to farmers each year. Utilizing some of these dollars to support more carbon farming, is one option for policymakers to consider.
In 2021, the Biden administration supported more regenerative agriculture through increased spending in a cover cropping program as well as an initiative to quantify climate effects of the CRP.40Bottemiller and McCrimmon, “Biden Wants to Pay Farmers;” Department of Agriculture, “USDA Announces New Initiative to Quantify Climate Benefits of Conservation Reserve Program,” USDA Farm Service Agency, May 25, 2021, https://www.fsa.usda.gov/news-room/news-releases/2021/usda-announces-new-initiative-to-quantify-climate-benefits-of-conservation-reserve-program. The Senate also passed a bipartisan bill the same year to support carbon farming through the creation of a USDA advisory board that will recommend methods of overcoming measurement and verification challenges.41“S.1251 – 117th Congress (2021–2022): Growing Climate Solutions Act of 2021,” Congress.gov, June 24, 2021, https://www.congress.gov/bill/117th-congress/senate-bill/1251.
Policy changes like these are good but remain in the early stages. One easier option may be the use of a certification program, like the USDA certified organic, to allow farmers to sell “carbon neutral” products at a premium. This type of certification could help cover the high costs of establishing carbon farming practices.
Farmers are also concerned about the lack of reliable information and the USDA and state extension offices can help overcome this barrier by providing information through its agents. Local extension agents are some of the most trusted government officials in agriculture and would be an excellent way of disseminating these practices to the industry.42Megan Jenkins, Jennifer Morales, Rebekah Yeagley, and Sarah Bennett, “Cooperative Conservation: Determinants of Landowner Engagement in Conserving Endangered Species,” The Center for Growth and Opportunity at Utah State University, November 29, 2018, https://www.thecgo.org/research/cooperative-conservation-determinants-of-landowner-engagement-in-conserving-endangered-species/.
Some states, such as Iowa, have already started using their extension programs for just this purpose.43Iowa State University Extension and Outreach, Carbon Science for Carbon Markets: Emerging Opportunities in Iowa, Iowa State University Extension and Outreach, (January 2022): 281, https://store.extension.iastate.edu/product/16214. Research shows that farmers may even be more interested in the co-benefits of carbon sequestration for the health of their land than possible income from carbon markets. Simply providing free and reliable information through extension offices may be enough to encourage more farmers to take on carbon farming practices for their own sake and without the added income from offset sales.44Kristall A. Miller, Stephanie A. Snyder, and Michael A. Kilgore, “An Assessment of Forest Landowner Interest in Selling Forest Carbon Credits in the Lake States, USA,” Forest Policy and Economics 25, (December 1, 2012): 113–22, https://doi.org/10.1016/j.forpol.2012.09.009.
Innovation is needed to overcome the main issues in carbon farming: the difficulties and costs of measurement and verification. Fortunately, some current carbon offset traders are attempting to solve this problem through innovative technological solutions, including the use of machine learning models that can better estimate sequestered carbon.45Gabriel Popkin, “Is Carbon Sequestration on Farms Actually Working to Fight Climate Change?” GreenBiz, April 16, 2020, https://www.greenbiz.com/article/carbon-sequestration-farms-actually-working-fight-climate-change. Current research is also working to improve the accuracy of other methods of estimation, such as eddy covariance, which measures infrared light reflection from soil, as well as carbon budgeting, which predicts soil carbon levels based on pre-measured sequestration capacity of individual plants and land management practices.46Pete Smith et al., “How to Measure, Report;” Michael L. Goulden, J. William Munger, Song-Miao Fan, Bruce C. Daube, Steven C. Wofsy, “Measurements of Carbon Sequestration by Long Term Eddy Covariance: Methods and Critical Evaluation of Accuracy,” Global Change Biology 2 (June 1, 1996): Michael Goulden et al., “Measurements of Carbon Sequestration by Long-Term Eddy Covariance: Methods and a Critical Evaluation of Accuracy,” Global Change Biology 2 (June 1, 1996): 169–82, https://doi.org/10.1111/j.1365-2486.1996.tb00070.x.
More research is needed in these areas, but combining different estimation methods with effective computer models may help reduce verification costs.
Agriculture has latent potential to contribute to lowering greenhouse gas levels, but current incentives do not allow for large-scale implementation. To change this, the best options will be to either value the co-benefit environmental services in a market or use government dollars to help lower initial and transaction costs.
Although carbon farming cannot solve climate change by itself, it is a key piece of the carbon emissions puzzle. The adoption of carbon farming practices would also increase the conservation value of millions of acres of agricultural land and the environmental sustainability of the nation’s food system.