858. Feasibility of Achieving Net Negative Emissions in the Food System

To effectively combat climate change, a fundamental transformation of our systems is imperative, requiring a concerted effort to reduce greenhouse gas emissions and potentially even achieve carbon sequestration. This journey to a net-zero emissions state involves first minimizing human-caused greenhouse gas emissions as much as possible. Then, if complete elimination proves difficult, we must strive to offset any remaining emissions by removing an equivalent amount from the atmosphere. It's also possible to go beyond net-zero and enter the realm of net-negative emissions, where the overall carbon balance is negative because more carbon dioxide is absorbed than is emitted. In this context, it is crucial to address food systems, which are estimated to be responsible for nearly one-third of anthropogenic greenhouse gas emissions. We need to explore different strategies for transforming these systems to achieve net-zero or even net negative emissions.

In early September, a paper was published in PLOS Climate that presents a model-based scenario analysis that outlines potential pathways for achieving net negative emissions within the food system. 

The analysis focuses on the year 2050, when the world's population is expected to reach about one billion people. The paper examines the prospects for achieving net-negative GHG emissions from the food system through consumer choices, climate-smart agricultural technologies, and food waste reduction. Using the Global Food System Model, scenario analysis showed that a comprehensive transformation of the food system, including changes in behavior, management, and technology adoption, could theoretically result in net-negative emissions of up to 33 gigatons per year.

Among the many technologies under consideration, certain options hold particular promise for achieving net negative emissions. These include hydrogen-based fertilizer production, innovative animal feed formulations, organic and inorganic soil amendments, agroforestry practices, and sustainable seafood harvesting methods.

In terms of consumer habits, the adoption of a flexitarian diet-characterized by a predominantly plant-based diet with occasional meat and fish consumption-alone will not be sufficient to fully decarbonize the food system. However, when complemented by technological interventions, it can contribute significantly to achieving net negative emissions.

Greenhouse gas emissions require the application of a variety of technologies, and dietary shifts are expected to be particularly effective in countries characterized by ruminant production and non-intensive farming systems. It highlights the potential to achieve net negative emissions through multifaceted “cradle-to-grave” and “land-to-sea” mitigation strategies that incorporate emerging climate-smart agro-industrial technologies.

Reference

Almaraz M, Houlton BZ, Clark M, Holzer I, Zhou Y, Rasmussen L, et al. (2023) Model-based scenarios for achieving net negative emissions in the food system. PLOS Clim 2(9): e0000181. https://doi.org/10.1371/journal.pclm.0000181

Contributor: IIYAMA Miyuki (Information Program)