Food systems contribute 19%–29% of global anthropogenic greenhouse gas emissions, releasing 9,800–16,900 megatonnes of carbon dioxide equivalent in 2008. Agricultural production, including indirect emissions associated with land-cover change, contributes 80%–86% of total food system emissions, with significant regional variation. The impacts of global climate change on food systems are expected to be widespread, complex, geographically and temporally variable, and profoundly influenced by socioeconomic conditions. Low-income producers and consumers of food will be more vulnerable to climate change owing to their comparatively limited ability to invest in adaptive institutions and technologies under increasing climatic risks. But promising interventions, such as agricultural intensification or reductions in waste, will require careful management to distribute costs and benefits effectively.