Science Briefs
A Focus on Food Can Help Solve Climate Change
The global food system is extremely vulnerable to increasing droughts, intensifying heatwaves, heavier downpours, and exacerbated coastal flooding. At the same time, the food system is a major contributor to greenhouse gas emissions. Therefore, taking a global food system approach to climate change research — bringing together agricultural production, supply chains, and consumption — is a key step in both adapting to and mitigating climate change.
Food system components, linkages and outcomes.
We found that when the full set of activities of the food system are considered together, they represent 21 to 37 percent of total human-caused greenhouse gas emissions. These results appear in a new paper in the journal Nature Food.
With an international team of authors, we worked together on the Food Security chapter of the recent Intergovernmental Panel on Climate Change (IPCC) Special Report on Climate Change and Land. Together, we represent a wide range of food systems from around the world, from major commodity and livestock producers to smallholder farming systems.
The Special Report on Climate Change and Land revealed that many greenhouse gas emission sources in the food system are not well characterized. However, advanced remote sensing techniques, such as those used by NASA, can help in scaling up emissions monitoring.
In our view, the global food system approach represents a significant advance in helping producers and consumers plan effective and well-integrated climate change responses.
The approach we use brings into focus the emissions from all relevant food system activities, both within and outside the farm gate. In doing so, it breaks down the artificial separation between agriculture and related land use activities, such as deforestation, in country reports to the U.N. Climate Convention. FAO has also released new emission statistics for the period 1990-2017 that provide the shares of agriculture and related land use in total emissions from all economic sectors, for all countries.
To respond to climate change via their food systems, countries can now move beyond supply-side mitigation in crop and livestock production, which has been the traditional approach, to encompass demand side strategies, mainly dietary changes.
Synergies between mitigation, adaptation, and other co-benefits resulting from food system climate change response options.
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Plant-based diets reduce the amount of methane emissions, a powerful greenhouse gas released by ruminants. They also require less land, thus sparing areas that can be used to plant trees and store more carbon. When both these effects are combined, the maximum amount of greenhouse gas reduction achievable through dietary change is up to 8 billion tonnes of CO2e per year (total anthropogenic emissions are currently about 52 billion tonnes per year). Healthy and low-emission diets that are primarily plant-based can also reduce the burden of key non-communicable diseases, such as heart disease and diabetes.
The food system approach helps countries implement a range of context-specific responses on adaptation and mitigation, enabling them to address both sustainable development and climate challenges. This approach reveals several synergies in response options across food systems, bringing co-benefits to livelihoods and biodiversity. And in this way, these responses also help to achieve the Sustainable Development Goals. For example, increasing soil organic matter can help sequester carbon and enhance resilience to drought, as well as boost productivity and soil biodiversity.
Diversification of the food system by establishing integrated production systems and broad-based genetic resources can reduce risks from climate change. This is particularly important for smallholder farmers, who are among the most vulnerable to the effects of climate change. Reducing food loss and waste from across the entire food chain can now be considered as well, which can lead to opportunities for food systems to engage in the circular economy.
References and Links
Rosenzweig, C., C. Mbow, L.G. Barioni, T.G. Benton, M. Herrero, M. Krishnapillai, E.T. Liwenga, P. Pradhan, M.G. Rivera-Ferre, T. Sapkota, F.N. Tubiello, Y. Xu, E. Mencos Contreras, and J. Portugal-Pereira, 2020: Climate change responses benefit from a global food system approach. Nature Food, 1, no. 2, 94-97, doi:10.1038/s43016-020-0031-z.
IPCC, 2019: IPCC Special Report on Climate Change and Land
UN/FAO, 2020: FAOSTAT Emissions shares. Dataset webpage last accessed 2020-02-18.
Contact
Please address all inquiries about this research to Dr. Cynthia Rosenzweig.
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