Human activities, such as burning fossil fuels and deforestation, have increased global greenhouse gas concentrations; atmospheric carbon dioxide levels have risen from 280 parts per million (ppm) in the late 1700s to today’s level of about 400 ppm. Concentrations continue to rise, though future levels depend on choices and development pathways yet to be determined. Additionally, the future condition of the food system depends upon socioeconomic trajectories that are external to the food system itself. For these reasons, a range of possible emissions futures and socioeconomic pathways have been considered by this assessment.
The Climate Change, Global Food Security, and U.S. Food System assessment represents a consensus of authors and includes contributors from 19 Federal, academic, nongovernmental, and intergovernmental organizations in four countries, identifying climate-change effects on global food security through 2100, and analyzing the United States’ likely connections with that world.
The assessment finds that climate change is likely to diminish continued progress on global food security through production disruptions leading to local availability limitations and price increases, interrupted transport conduits, and diminished food safety, among other causes. The risks are greatest for the global poor and in tropical regions. In the near term, some high-latitude production export regions may benefit from changes in climate.
As part of a highly integrated global food system, consumers and producers in the United States are likely to be affected by these changes. The type and price of food imports from other regions are likely to change, as are export demands placed upon U.S. producers and the transportation, processing, and storage systems that enable global trade. Demand for food and other types of assistance may increase, as may demand for advanced technologies to manage changing conditions.