Global schemes to fight climate change may miss their mark by ignoring the "fundamental connections" in how food is produced, supplied and consumed, say scientists in a new paper published in the journal Nature Food. Global bodies such as the Intergovernmental Panel on Climate Change (IPCC) and the UN Framework Convention on Climate Change (UNFCCC), handle the different components of the food system separately. This includes crop and livestock production; food processing, storage and transport; and food consumption. Scientists argue this disjointed approach may harm strategies to reduce food emissions and safeguard food from climate impacts, and that a "comprehensive" and "unified" approach is needed.
Food and climate change are deeply interlinked, but food emissions need to be tracked beyond the "farm gate," that is, beyond the emissions arising from growing crops or raising livestock. Researchers are uncovering new insights on how the different subcomponents of the food system contribute to climate change mitigation and adaptation. They argue that we must understand how these components work together -- or clash in some cases -- in order to effectively address agriculture in a changing climate.
A systems approach is crucial for achieving lasting change at a large scale, and for bringing a much broader set of players into the discussion, say the authors. "Actions aimed at changing only some of the component parts of the food system are not going to solve the climate crisis," said Cynthia Rosenzweig, the lead author of the paper. "We need all actors and institutions involved in the many different parts of the food system to understand their roles and impacts, and to make the informed choices needed for widespread transformation," she explained.
Towards a unified food systems approach
The authors recommend that global reporting systems take a unified food systems approach in measuring their emissions. They argue this could improve international and national-level responses to climate change in agriculture in three important ways.
First, a systems approach would allow for much better estimates of the whole food system's contribution to total human-induced greenhouse gases. "Current best estimates of emissions from food production, related land-use changes, processing, consumption and management of food waste, range from 21 to 37 percent of all human-induced emissions," said paper co-author Tek Sapkota, a scientist with the International Maize and Wheat Improvement Centre (CIMMYT). "While this overall figure helps us recognize that the food system is an important source of greenhouse gas emissions, we need a complete accounting of emissions from all components of food systems in order to inform appropriate responses," he explained.
Secondly, a big-picture view could help us understand how growing demand for climate-friendly foods might interact with climate-efficient food production. "There is increasing awareness of the link between diets, nutrition, and climate change, informed by recent studies such as the EAT-Lancet Commission report," said co-author Prajal Pradhan from the Postdam Institute for Climate Impact Research. "Dietary changes are important, but measures need to be taken across the whole system, and must deal with production, consumption and also food loss and waste at all stages of the supply chain."
Finally, the interconnectivity of all parts of the food system means that measures in one area will have positive or negative consequences elsewhere. "We want to avoid situations where strategies to fight climate change, such as growing bioenergy crops or protecting forests, have a detrimental effect on food supply," said Luis G. Barioni, another co-author of the paper based at the Brazilian Agricultural Research Corporation (EMBRAPA). "The goal is to develop actions that strike a balance between food security, adaptation and mitigation. A food system gives us the unique vantage point to assess this," he said.
Many agricultural practices can increase yields and resilience to climate change, while also reducing greenhouse gas emissions, say the authors. Farming techniques that increase the amount of organic matter in soils -- such as leaving behind stems from harvested crops, or using livestock manure for fertilizer -- can boost the resilience of some crops to rising temperatures, without harming yields or increasing emissions. "These interactions are only clear when we look through the lens of the whole food system," emphasized Sapkota. "This kind of understanding is crucial to the success of any climate change response in agriculture."
Read more: Rosenzweig C et al. 2020. Climate change responses benefit from a global food system approach. Nature Food.
This article is a synthesis of chapter 5 of the IPCC's Special Report on "Climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems" which was contributed collectively by the authors in the manuscript.