An important tactic for slowing climate change is for private companies to reduce their greenhouse gas emissions, but knowing exactly how much they’re emitting can be a challenge.
To address this need, researchers in the College of Agriculture and Life Sciences (CALS) have developed an online greenhouse gas (GHG) emissions accounting tool, , to help quantify these emissions in crop production.
Walmart Inc. is using the tool as part of its initiative, aimed at working with suppliers to avoid 1 gigaton of GHG emissions from the global supply chain by 2030. In September, Walmart made the new tool available to its suppliers.
The research team developed FAST-GHG as a public good, meaning the tool will soon be made publicly available. The methodology behind it has been carefully and transparently documented to allow any individual to implement the method.
Large supply chains often receive limited information about the emissions created in the production of the products they sell. This is especially true in the food sector, where, until now, supply chains lacked simple, scientifically rigorous tools for greenhouse gas accounting.
To help solve this problem, three CALS researchers – Peter Woodbury and Dominic Woolf, senior research associates in soil and crop sciences, and Christina Tonitto, research associate in the Department of Global Development – developed a scientifically rigorous calculator to quantify how soil health management practices can reduce greenhouse gas emissions in crop production. The researchers developed the online calculator with Cornell Atkinson Center for Sustainability, in partnership with Walmart, Environmental Defense Fund and The Nature Conservancy.
“Rapid and ambitious action is required if we are to maintain a habitable Earth,” Woolf said. “One of the ways that we can drive rapid change is by supporting climate action initiatives within the private sector. Reducing the climate footprint of large supply chains can potentially have a rapid and scalable impact, provided that it is based on sound science.”
The calculator focuses on emissions from the production of three major U.S. crops: corn, soybeans and wheat. It allows food companies to quantify how much supplying farmers have reduced greenhouse gas emissions through improved tilling and cover cropping – the practice of planting alternate crops to slow erosion, improve soil health and help control pests and diseases. The calculator also accounts for how improved nitrogen fertilizer management reduces greenhouse gas emissions.
The tool allows companies to report net avoided greenhouse gas emissions due to any combination of these practices.
“Supply-chain companies participating in voluntary sustainability programs, such as Project Gigaton, often do not have a close relationship with commodity producers,” Tonitto said. “Creating an accounting tool for a user community with limited knowledge of field-level or farm-level management at a specific site was a primary design challenge for FAST-GHG development.”
The team combined a detailed understanding of carbon and nitrogen management with broadly available input data to quantify the aggregate greenhouse gas benefit of agricultural practices across supply chains.
“The tool is easy for companies to use because it pulls realistic default figures from a geospatial database behind the scenes,” Woodbury said. “It allows for a single crop field or multiple crop fields. And it is able to calculate improved results when farmers input more data.”
The research team was supported by an advisory council that included representatives from Environmental Defense Fund, The Nature Conservancy and other CALS faculty. Together, they were able to share resources and provide scientific peer review that allowed for the development of a scalable, credible tool.
Many agricultural practices have GHG impacts beyond the production site that are not accounted for by other calculators. Such impacts are referred to as leakage. “It is extraordinarily difficult to put a precise value on leakage, and that has led a lot of others in the past to simply ignore it,” Woolf said. “However, with the FAST-GHG tool we have been able to use values that represent the average amount of carbon storage that could be delivered wherever these crops are grown in the world.”
The tool also addresses issues of permanence, a critical challenge for nature-based solutions to reducing GHG emissions.
Reducing net GHG emissions through practices that build soil organic carbon results in GHG benefits, as well as improved soil health and reduced erosion, but this increase in soil organic carbon stocks is reversible if the management practices are not maintained. FAST-GHG explicitly accounts for the risk of reversal due to the abandonment of soil-health practices.
Clear accountability, standard yardsticks, reduced costs and opportunities for optimization are all needed to ensure benefits for producers. The contributions many farmers are beginning to make to support climate-smart agriculture also need to be counted.
“This tool and the collaborative effort that led to its development is a model for integrating these principles into a sustainability accounting framework, and could be replicated by businesses aiming to advance environmental, social and corporate governance,” Woolf said. “Looking beyond this specific partnership, other organizations could build upon this process for more types of agricultural products and in different parts of the world.”
Sheri Hall is a freelance writer for the Cornell Atkinson Center for Sustainability.
