Climate change effects on agriculture will have consequences for food security, both in the U.S. and globally, through changes in crop yields and food prices and effects on food processing, storage, transportation, and retailing. Adaptation measures can help delay and reduce some of these impacts.

This finding is from chapter 6 of Climate Change Impacts in the United States: The Third National Climate Assessment.

Process for developing key messages: A central component of the process was the development of a foundational technical input report (TIR), “Climate Change and Agriculture in the United States: An Assessment of Effects and Potential for Adaptation”.3baf471f-751f-4d68-9227-4197fdbb6e5d A public session conducted as part of the Tri-Societies (https://www.acsmeetings.org/home) meeting held in San Antonio, Texas, on Oct. 16-19, 2011, provided input to this report. The report team engaged in multiple technical discussions via teleconference, which included careful review of the foundational TIR3baf471f-751f-4d68-9227-4197fdbb6e5d and of approximately 56 additional technical inputs provided by the public, as well as other published literature and professional judgment. Discussions were followed by expert deliberation of draft key messages by the authors and targeted consultation with additional experts by the lead author of each message.

Description of evidence base: The relationships among agricultural productivity, climate change, and food security have been documented through ongoing investigations by the Food and Agriculture Organization959a0a29-1b2e-4b67-b6f6-8325244863cb e5be5bc9-5d60-4029-a735-5834b585ff16, as well as the U.S. Department of Agriculturea138a4bd-8005-489e-8a66-74530ab6cded, and the National Research Council06a53f5f-3202-4a61-b990-2115eb25c28f. There are many factors that affect food security, and agricultural yields are only one of them. Climate change is also expected to affect distribution of food- and waterborne diseases, and food trade and distribution.b4dfdd6a-ffce-44a3-b6b7-5770f5c70fbb a8a74c61-73ac-49d3-a832-f5179bdb24dd

New information and remaining uncertainties: The components of food security derive from the intersection of political, physical, economic, and social factors. In many ways the impact of climate change on crop yields is the least complex of the factors that affect the four components of food security (availability, stability, access, and utilization). As the globalized food system is subject to conflicting pressures across scales, one approach to reducing risk is a “cross-scale problem-driven” approach to food security.56da8899-8c9e-4ded-968a-770460ea2454 This and other approaches to understanding and responding to the complexities of the global food system need additional research. Climate change will have a direct impact on crop and livestock production by increasing the variability in production levels from year to year, with varying effects across different regions. Climate change will also affect the distribution of food supplies as a result of disruptions in transportation routes. Addressing food security will require integration of multiple factors, including the direct and indirect impacts of climate change.

Assessment of confidence based on evidence: Given the evidence base and remaining uncertainty, there is high confidence that climate change impacts will have consequences for food security both in the U.S. and globally through changes in crop yields and food prices, and very high confidence that other related factors, including food processing, storage, transportation, and retailing will also be affected by climate change. There is high confidence that adaptation measures will help delay and reduce some of these impacts.

References :

• Climate Change and Agriculture in the United States: Effects and Adaptation. USDA Technical Bulletin 1935 (3baf471f)
• A vision for attaining food security (56da8899)
• The State of Food Insecurity in the World - How Does International Price Volatility Affect Domestic Economies and Food Security? (959a0a29)
• The State of Food Insecurity in the World, 2008: High Food Prices and Food Security Threats and Opportunities (e5be5bc9)
• webpage Data sets. State fact sheets (a138a4bd)
• Understanding Multiple Environmental Stresses: Report of a Workshop (06a53f5f)
• Global food security under climate change (b4dfdd6a)
• Addressing the challenges of climate change and biofuel production for food and nutrition security (a8a74c61)