How Climate Change Affects Our Food Supply

Wheat is one of the grain crops with yields expected to decrease under climate change. Andy Sacks/Stone/Getty

The Intergovernmental Panel on Climate Change (IPCC) published its fifth Assessment Report in 2013-2014, synthesizing the latest science behind global climate change. Here I summarize the highlights of the chapter examining the effects of climate change on food security:

  • While the net effect is negative, climate change can have both positive and negative impacts on food production. Negative impacts have been seen on wheat and corn. Effects on rice and soybeans gave been small, and some positive effects on crop production have been observed in some regions at high latitudes.
  • Wild fish and seafood have been negatively affected by climate change. Ocean fish are seeing range shifting towards the poles, and fisheries associated with coral reefs are in decline. Sea level rise, polar ice melting, changes in precipitation, and ocean acidification all are likely to disrupt wild fish populations and their associated fisheries. Harmful algal blooms are more prevalent, and they either affect shellfish directly or render them improper for consumption.
  • Scientists are documenting important damage to crops during extreme heat events, which are becoming more prevalent. Crops like grains and rice are vulnerable, although the various interactions with changes in precipitations make local predictions difficult.
  • Weeds are benefiting from increased carbon dioxide concentrations, making them more competitive against crops. In addition, warmer temperatures help pests survive winter temperatures and expand their geographic range. At the same time, there’s been a documented decline in herbicide efficacy with increased carbon dioxide levels.
  • Since global crop yields are expected to be negatively affected by climate change, and the human population is expected to continue to grow, food prices will increase. More frequent extreme weather events also increase food prices. Other drivers of food prices, including agricultural policy, technology, and fuel costs, prevent reliable estimates of the magnitude of the increase in food prices.
  • Beyond food production, other important aspects of food security are negatively affected by one or more elements associated with climate change. For example, food processing often needs large amounts of potable water, which is predicted to increasingly vary in availability. Food transportation and distribution can be impacted by floods and other climate-related disasters. Food storage will face increased populations of pests.

Adaptations to climate change have the potential to reduce the negative effects discussed. In fact, many adaptations are already implemented with success. Since most of the world’s crops rely on rainfall, adjusting irrigation techniques or grazing intensity to better match precipitation patterns would be beneficial. Adjusting to changes in temperatures can be done by choosing better plant breeds or species, or adjusting sowing and harvesting schedules. Outside of adapting for better production of food, issues associated with food security could be lessen by better distribution and reduced waste of food.

Here again those in the most precarious economic situations will have the most difficult time taking the steps needed to adapt to climate change in order to produce, process, transport, and distribute food.

Adaptation therefore includes the distribution of knowledge, technology, breeds, and other resources across food producing regions.

Find highlights from the IPCC’s Fifth Assessment Report’s conclusions about:


IPCC, Fifth Assessment Report. 2014. Impacts: Food Security.