Summary
A White Paper on Building a Scientific Roadmap to a Carbon-Negative Agricultural System was drafted by a scientific working group of the U.S. Farmers & Ranchers in Action (USFRA), a coalition of farmer and commodity groups, agribusiness, and other organizations. At the request of the USFRA and with support from the Foundation for Food & Agricultural Research, the National Academies of Sciences, Engineering, and Medicine appointed a six-person committee to review the draft white paper by examining its clarity of key messages, effectiveness of organization, and scientific rigor. This consensus report is the committee’s critique of the draft and the product of its deliberations from November 2023 to February 2024.
The white paper describes the potential for achieving carbon-negative agriculture by combining reduced greenhouse gas (GHG) emissions from some segments of agricultural activity and increased carbon sequestration in others. It also describes research that would be needed to help meet this goal. The committee found that, as agriculture encompasses a wide variety of activities, the paper needs to define a systems boundary indicating which of those activities are included (and which are not) in the white paper’s accounting of net emissions. The boundary should include a temporal element that considers how climate change interactions with those activities will affect GHG emissions and carbon sequestration into the future. In addition, the committee suggested adding a graphic representing the system and a set of balancing equations, which will improve the foundation for the paper’s premise.
Taking these steps also would improve the cohesiveness of the report. Its chapters cover a range of subjects (crop yield, soil carbon sequestration, managing nitrogen emissions, animal production, energy efficiency, economics, and policy), and each takes an independent approach to addressing climate impacts. Each uses a different chapter structure, different assumptions about the goal (e.g., net zero versus carbon negative), and different units and terminology. Consequently, the chapters do not result in a coordinated plan for meeting the goal of carbon-negative agriculture. Making the chapters more consistent with one another, including in addressing research priorities, would strengthen their cohesion and better define the path forward. The variability between the chapters’ tones and level of detail also adds confusion about the intended audience for the white paper. Multiple audiences are possible, but they should be identified, and the paper needs to help all of them understand the significance of the material.
Many of the chapters give scarce or no attention to some of the more promising opportunities that could help meet the goal of carbon-negative agriculture. This is a limitation, considering the ambitiousness of the goal. The defined systems boundary would clarify the authors’ thinking about which activities can make the greatest contribution to the goal. In addition, the authors should think carefully about whether the scope of their analysis should include the impact of developments such as novel innovations or shifts in consumer behavior and at what level of detail the analysis should examine potential incentives to influence the adoption of agricultural practices central to achieving the goal. Some of these factors may be considered out of scope. Regardless, the authors need to explain the basis of their assumptions for the levels of adoption described in the final chapter; otherwise, the paper could be dismissed as unrealistic.
Overall, the committee finds many important ideas in the draft white paper. Although the committee is skeptical that the goal of carbon-negative agriculture can be achieved as described, it recognizes the importance of the conversation that the white paper has begun. The committee hopes that this review will strengthen the authors’ efforts to make progress on defining a roadmap for addressing carbon emissions in agriculture.
