Carbon Footprint and Air Quality – United States
Decreasing emissions, increasing sequestration
For companies developing and pursuing greenhouse gas (GHG) emission reduction strategies, materials matter. Addressing greenhouse gas emissions is a major component of sustainable U.S. cotton production.
Cotton is a natural fiber harvested from plants that capture carbon dioxide – the primary GHG contributing to climate change – from the atmosphere as they grow. However, to produce healthy, abundant yields, cotton plants need additional nutrients delivered in the form of fertilizers, which can release GHGs into the environment. Cotton growers are working with researchers to optimize the amount of fertilizer required and use it as efficiently as possible. Ultimately, the U.S. cotton industry aims to decrease emissions from fertilizer and enable cotton plants and the soil in which they grow to capture and sequester more carbon from the atmosphere.
U.S. cotton carbon footprint: cradle to (farm) gate1
Ultimately, cotton fibers have the potential to capture more GHGs from the atmosphere than are generated during on-farm cotton production. In fact, the 2017 life cycle update for cotton fiber calculated that net -113 kilograms of CO2 equivalent is captured per 1,000 kilograms of cotton.2
Ambitious goal, practical actions
Overall, agriculture accounts for about 11% of total U.S. GHG emissions – significantly less than electricity, transportation or industrial processes used to produce goods and raw materials.3 The U.S. cotton industry takes an active role in decreasing its contribution to agriculture’s emissions.
The U.S. cotton industry has already reduced its GHG emissions by 25% compared to 1980. Although the rate of improvement has leveled off in the past decade,4 the industry is committed to continued progress. Growers and researchers across the country are working toward an ambitious, industry-wide goal to reduce GHGs emitted during production by 39% by 2025 as compared to 2015.5
GHG emission trends per pound of cotton, like other important metrics such as land use efficiency, are highly dependent on cotton yield; a higher yield generally means lower GHG emissions per pound of cotton. As the U.S. cotton industry has increased its overall yield without proportionally raising GHG emissions, the trendline for GHG emissions decreases. Over the past few years, the pace of yield improvement has slowed down, and that has slowed down the apparent progress in GHG emission reductions — even as growers and researchers continued to invest in new technologies and improved practices.
So, to reach the U.S. cotton industry’s ambitious GHG reduction goal, growers and researchers are implementing a full suite of climate-smart agriculture practices – practices that also help improve yields and have the potential to reduce operating costs. No-till production practices, for example, help build soil health, which enables the soil to sequester more carbon and support plant health. No-till also enables growers to use less fuel by not using tillage equipment. More efficient tractors, irrigation systems, and other equipment also cut down on energy use and thus GHG emissions.
Sustainability and agriculture experts representing the U.S. cotton industry have developed a detailed hierarchy of strategies and tactics for reducing and capturing carbon across the global cotton value chain. The hierarchy, developed using peer-reviewed literature, life cycle assessment data and basic engineering principles, serves as a set of recommendations to help the industry focus on improvements that are realistic, meaningful, and effective for the greatest number of producers and supply chain partners.
5 industry-wide approaches to mitigating cotton greenhouse gas emissions6
Reduction Approach Value Chain Actor Increase production efficiency (i.e., adopt precision ag, improve nitrogen use efficiency, increase yield) Growers, researchers Practice regenerative agriculture and increase soil carbon (i.e., adopt conservation tillage, cover crops and crop rotation) Growers, researchers Transition to renewable energy for cotton production and ginning Growers, researchers, ginners, equipment manufacturers, fertilizer producers, regional energy grids Account for biogenic carbon use and capture in cotton textiles and soils Supply chain partners, researchers Reduce energy use and CO2 equivalent emissions in manufacturing agrochemicals Fertilizer manufacturers
Increasing production efficiency
Nitrogen serves as one of the main nutrients cotton needs to grow. Cotton plants can only use so much nitrogen at a given time, however, and the amount differs depending on growth stage, rainfall, temperature and a host of other factors. If growers do not give their crop enough fertilizer, the yield will be negatively impacted. If growers improperly time their fertilizer applications or apply more than their plants can use, the excess nitrogen is lost into the water or air where it takes other forms, including the greenhouse gas nitrous oxide.
Fertilizer is a major input expense and accounts for 60% of cotton production’s total GHG emissions (due to the energy required to manufacture fertilizer and the emissions it can release once it’s in the field).7 Applying fertilizer inefficiently, then, drains farmers’ operational budgets and can lead to negative environmental outcomes. For these reasons, cotton growers focus closely on their nitrogen use efficiency – how accurately they tailor nitrogen application to their crop’s actual needs.
Achieving high levels of fertilizer use efficiency isn’t easy, but it’s incredibly important. U.S. growers have clearly prioritized this: U.S. cotton nitrogen use per pound of cotton has decreased 15% since 1990.8 The industry cannot rest on this success, though. Continued improvement is a necessity for helping curb climate change.
Due to nitrogen’s outsized impact on GHG emissions, U.S. researchers are carrying out multiple projects to better understand factors in nitrogen use efficiency and to test new precision technologies. Cotton Inc. specifically has launched a coordinated multi-state research initiative encompassing 16 nitrogen-related research projects.
The U.S. cotton industry is committed to equipping growers to act on new findings and communicates emerging research and best management practices to growers via platforms such as Cotton Cultivated, conferences and grower field days.
Nitrogen required per pound of cotton is on a downward trend in the U.S.9
Adopting precision agriculture techniques and increasing nitrogen use efficiency are two high-impact ways that U.S. cotton growers increase production efficiency – and help reduce cotton greenhouse gas emissions.
Research to refine nitrogen fertilizer recommendations
Since so many factors influence nitrogen uptake by plants, growers rely on fertilizer recommendations from industry and academic experts to optimize yield. Leading experts know it’s important to regularly reevaluate the recommended cotton fertilizer rates to adjust for higher yield goals and changing environmental factors. Even modest refinements in nitrogen applications would create significant positive impacts in terms of fertilizer emissions and growers’ operating budgets.
The Fertilizer Institute, for example, is directing research to identify the most profitable and sustainable nitrogen rate for newer cotton cultivars.10 Cotton Inc. is also leading research efforts across eight cotton-producing states. The first three years of this project focused on the research directly; the fourth year of the project (2023) was designed to focus on outreach efforts – spreading the insights and practical applications to cotton growers and their advisors around the U.S. to give them confidence in adopting the updated nitrogen recommendations.
The benefits of new precision agriculture technologies
Precision agriculture management is a boon in the effort to use nitrogen fertilizer more efficiently and thus lower the cotton carbon footprint. Cotton Inc. defines precision agriculture as a “farm management approach that uses information technology to observe, measure and respond to data to ensure that crops and soil receive exactly what they need for optimum health and productivity where and when they need it.” Ultimately, precision agriculture techniques help growers use resources in ways that support profitability and environmental sustainability.
Growers have adopted a range of technologies to better measure and predict their crop’s fertilizer needs, including an ever-increasing variety of sensors, drones, and sophisticated mapping and measurement tools. Constant advancements in computing power and machine learning have resulted in new opportunities for agricultural field robotics. Growers literally have data at their fingertips that helps them know when their plants need more nitrogen and which areas of the field need more or less nitrogen. Growers can make decisions that enable more efficient use of nitrogen fertilizer, healthier soil, and fewer GHG emissions.
Practice regenerative cotton agriculture and increase soil carbon
According to Field to Market: The Alliance for Sustainable Agriculture, regenerative agriculture uses a “systems-based perspective” that “sequesters carbon in the soil and intentionally improves soil health, biodiversity, water quality and air quality while ensuring the viability of farm production.”11 Regenerative cotton agriculture aims not to “do less harm,” but to positively influence the health of the environment. As the U.S. Regenerative Cotton Fund points out, practices like conservation tillage and cover crops regenerate the soil’s ability to function well and optimize its capacity to capture carbon.
Soil carbon is the intersection between cotton, climate change and soil health. It directly and indirectly affects field GHG emissions by keeping carbon in the soil and by helping reduce the need for nitrogen fertilizer, all while helping improve crop yield.12 Conservation management approaches to tillage, crop rotation and cover crops help improve soil organic carbon accumulation in surface soils.13
Nearly two-thirds of U.S. cotton growers report using some form of conservation tillage.14 Applying no-till practices increases the amount of CO2 captured from the air into the soil during cotton production, reaching as much as 450 kilograms of carbon per hectare per year.15
Evaluating the potential of tillage practices to store carbon in the soil
Researchers recently assessed soil organic carbon and associated soil health conditions under conservation and conventional cotton production practices in North Carolina. The data clearly demonstrates that soil carbon (and thus soil health) was enhanced in fields managed with no tillage or strip tillage on a continuous basis. Even rare instances of disk tillage in a field otherwise managed with no till or strip till reversed some of the soil health benefits. 16
There are legitimate reasons why a grower may decide to till on occasion, even if they typically practice no-till. This new insight will help growers weigh the benefits of occasional tillage (for controlling herbicide-resistant weeds, for example) against the reversal of soil health benefits.
This study also provides fresh insights for growers who practice crop rotation. Crop rotation is an important element in pest management and can be helpful for the soil – as long as the grower uses conservation or no till for the rotation, too. If they choose a high-disturbance crop such as peanuts, this study reveals, they can undo much of the soil carbon progress they’ve made when their fields are planted with cotton. Moving towards more continuous conservation-tillage management would appear to have the greatest impact on increasing soil carbon and attaining the sustainability goals set by the cotton industry.17
Measuring soil carbon throughout the southeastern U.S.
Starting in summer 2022, researchers initiated a project to build on previous studies (including the research described above) to measure cotton farms’ soil organic carbon across the entire southeastern U.S. This project will contribute valuable regional information to a national-level project assessing the potential of conservation agricultural management to sequester carbon.
Based on soil carbon and related data, the project will characterize environmental benefits from improved agricultural management as well as social and financial benefits. It aims to identify conservation practices with the greatest immediate and future potential for mitigating the Southeast’s cotton carbon footprint and boosting long-term productivity.
Creating carbon “insets”
Many companies use carbon offsets to compensate for unavoidable emissions; offsets balance those emissions with a GHG reduction activity outside of the company’s direct or indirect operations. In contrast, “insetting” is a mechanism for reducing a company’s Scope 3 GHG emissions or increasing carbon sequestration inside a company’s value chain, often through regenerative agriculture practices.18
The U.S. cotton industry and Cotton LEADS partners are considering how insetting can become an important solution in the suite of corporate climate actions. In 2021, Cotton Inc. collaborated with the Soil and Water Outcomes Fund in a pilot project creating carbon insets on cotton farms in North Carolina. The pilot engaged two cotton producers who changed practices within their operations and generated positive environmental outcomes for both soil and water quality. The practices they implemented included no-till, cover cropping and enhanced nutrient management practices. Between the two producers, 414 acres and nine fields were enrolled to the pilot program, with an estimated GHG emissions reduction of 130 metric tons of CO2 equivalent. Going forward, Cotton Inc. and Soil and Water Outcomes Fund are exploring how to scale ecosystem service markets with more U.S. cotton growers.
Growers can calculate GHG emissions and savings with regenerative agriculture practices using the Fieldprint® Calculator, a web-based tool developed by Field to Market: The Alliance for Sustainable Agriculture.
Leadership for the future
Despite slowed progress on GHG emissions in recent years, the U.S. cotton industry has made major strides in aligning around sustainability. Continuing research, grower outreach and shared insights are critical. The creation of the U.S. Cotton Trust Protocol (CTP) is an important step to engage cotton growers in accelerating progress toward the industry’s 10-year sustainability goals. The CTP helps growers measure, benchmark and track their GHG emissions through time using the Fieldprint® Calculator. Additionally, the program requires the completion of a sustainability best management practice questionnaire, a commitment to continuous improvement and third-party verification. The program aims to accelerate continuous improvement in climate-smart, regenerative agricultural practices.
The U.S. Regenerative Cotton Fund, led by the Soil Health Institute, is working in tandem with the CTP to encourage the adoption of soil health management systems across more than 1 million acres of U.S. cotton cropland. The initiative connects farmers with improved ways to boost soil health, increase yields, and measure the benefits of regenerative agriculture. Ultimately, the initiative aims to draw down 1 million metric tons of CO2 equivalent from the atmosphere by 2026.
The U.S. cotton industry is committed to leading the way in each of these areas to help sustainable cotton programs, brands and NGOs around the world align on effective, science-based climate action, on the farm and across the value chain.
1Cotton Incorporated. (2017). LCA update of cotton fiber and fabric life cycle inventory. Retrieved July 18, 2022
2Cotton Incorporated. (2017). LCA update.
3U.S. EPA. (2022). “Sources of Greenhouse Gas Emissions.” Retrieved June 16, 2022
4Field to Market: The Alliance for Sustainable Agriculture. (2021). Environmental Outcomes from On-Farm Agricultural Production in the United States (Fourth Edition). ISBN: 978-0-578-33372-4.
5Based off a 2015 baseline. See Cotton Incorporated. (n.d.). Cotton Sustainability Goals. Retrieved July 18, 2022
6Daystar, J. (April 8, 2022). “Cotton’s Role in Reducing Apparel Industry Carbon Emissions: Key strategies towards reaching net zero in the cotton industry.” Cotton Today. Retrieved June 16, 2022
7Cotton Incorporated. (2017). LCA update.
8USDA. NASS Quick Stats Chemical Use Survey data 1990 to 2021
10Steadman, J. (March 7, 2022). “Enhancing nitrogen use and effectiveness.” Cotton Grower. Retrieved June 20, 2022
11Field to Market: The Alliance for Sustainable Agriculture. (2022). “Our definition of regenerative agriculture.” Retrieved July 5, 2022
12Franzluebbers, A.J. (2021). Soil health conditions under cotton production in North Carolina. Agronomy Journal 113:2132–2149.
13Franzluebbers, A. J. (2010). Will we allow soil carbon to feed our needs? Carbon Management 1:237–251.
14Daystar, J. S., Barnes, E., Hake, K., & Kurtz, R. (2016). Sustainability trends and natural resource use in U.S. cotton production. BioResources, 12(1), 362–392.
15Franzluebbers, A. J. (2010). Achieving soil organic carbon sequestration with conservation agricultural systems in the southeastern United States. Soil Science Society of America Journal, 74(2), 347–357.
16Franzluebbers, A.J. (2021). Soil health conditions under cotton production in North Carolina. Agronomy Journal 113:2132-2149.
17Franzluebbers, A.J. (2021). Soil health conditions under cotton production in North Carolina.
18Cotton Incorporated & National Cotton Council (2022). What to know about carbon markets. Retrieved June 20, 2022