Climate Change, Global Food Security, and the U.S. Food System


By John Ingram, Food Systems Programme Leader, Environmental Change Institute, on the 'Climate Change, Global Food Security, and the U.S. Food System' report to which he contributed:

It is well recognised that climate change poses considerable risks to global food production: IPCC AR5 and many other analyses detail where, by how much and to what types of production system given degrees of climate change will have impact. There are, however, fewer analyses of the challenges facing the food system as a whole. While disruptions to production are clearly important, climate change – and extreme weather in particular – will impact many of the food system’s ‘post-farm gate’ activities and hence food security; food security depends on more than just food production. For instance, damage to food transport and storage infrastructure due to storms and floods causes local shortages, affecting food affordability and variety. Temperature and humidity changes can lead to numerous food safety issues, and hence both health considerations and food waste, the later also affecting availability. Consumer behaviour can also change, leading to changes in diets and hence nutrition.

So what will this mean for global food security and for individual nations? This question prompted the U.S. Department of Agriculture (USDA) to undertake a major assessment on global food security and its implications for the United States. The assessment report Climate Change, Global Food Security and the U.S. Food System[1] was launched at COP21.

The report notes that food systems in the United States benefit from a large area of arable land, high agricultural yields, vast integrated transportation systems and a high level of overall economic development. Despite these assets, U.S. food production, and the U.S. food system more generally, are not immune to climate change. Furthermore, changes in climate are expected to also affect U.S. consumers and producers by altering the type and price of food imports from other regions of the world, as well as by changing export demand, and storage and transportation infrastructure that enable global trade.

It is however clear that the nature and degree of the impacts of climate change on food systems – and hence on food security outcomes – will vary depending not only on the nature of climate futures but also on the nature of socioeconomic futures. An innovative feature of the assessment was therefore a systematic assessment of the risk to key food security elements (e.g. food affordability, safety, trade, storage and transport infrastructure) for richer and poorer nations for a range of plausible socioeconomic scenarios. Five such scenarios, called Shared Socioeconomic Pathways[2] (SSPs), were designed to span a range of societal conditions in two particular dimensions (challenges to mitigation and challenges to adaptation, defined by different combinations of socioeconomic elements).


In relation to earlier analyses[3] the report demonstrates that taking the food system (as opposed to food production) approach shows, not only how the overall risk to food security develops, but also that it is highly dependent on the socioeconomic future as much as climate change per se. The approach also indicates where adaptation interventions anywhere across the whole food system would be most effective.

[1] Brown, M.E., J.M. Antle, P. Backlund, E.R. Carr, W.E. Easterling, M.K. Walsh, C. Ammann, W. Attavanich, C.B. Barrett, M.F. Bellemare, V. Dancheck, C. Funk, K. Grace, J.S.I. Ingram, H. Jiang, H. Maletta, T. Mata, A. Murray, M. Ngugi, D. Ojima, B. O’Neill, and C. Tebaldi. (2015). Climate Change, Global Food Security, and the U.S. Food System. 146 pages. Available online at


[2] O’Neill, B. C., Kriegler, E., Kristie, E. L., Kemp-Benedict, E., Riahi, K., Rothman, D. S., . . . Solecki, W. (2015). The roads ahead: Narratives for shared socioeconomic pathways describing world futures in the 21st century. Global Environmental Change. doi: org/10.1016/j.


[3] Ingram, JSI. 2011. A food systems approach to researching interactions between food security and global environmental change. Food Security 3, 417-431.


Share this article