From Encyclopedia of Food Issues

Climate change is a fact. According to the Intergovernmental Panel on Climate Change Fifth Assessment Report, published in September 2013, average global temperatures have risen by approximately 0.120C per decade since 1950, and are predicted to rise at nearly twice that rate over the next few decades.

There are regional variations, and a well-publicized “pause” from 1995 to 2012 (which, as the report’s authors point out, is a statistical artifact due to the occurrence of a strong El Niño effect at the beginning of this period). But the main facts are clear, and the effects of temperature increases on the global production of some basic crops are already beginning to be noticed. Production of maize and wheat, for example, declined by 3.8% and 5.5% respectively between 1980 and 2008, relative to the yields that might have been expected in the absence of global warming. These percentage declines are equivalent to losing the whole of the annual production of maize in Mexico and wheat in France.

Global warming, and the predicted consequential changes in global weather patterns, will affect all aspects of food supply. It is not just a matter of food production, where temperature changes can affect the length of a growing season, and changes in rainfall patterns can affect yields. Climate change will also affect other aspects of food availability, such as distribution and exchange. It will affect access to food (affordability, allocation, and preference). And it will affect the utilization of food (nutritional and societal values and food safety).

Sophisticated computer modeling has shown that the negative effects of these changes will impact most strongly on those who are least able to cope – the countries of the third world, especially those of Southern Africa and South-East Asia. The poverty and lack of infrastructure in these countries means that they have limited capacity to cope with the short-term shocks of drought or flooding, or to adapt their agricultural and farming methods to the weather changes and other long-term stresses associated with climate change. Affluent Western countries will be relatively unaffected, at least over the next few decades.

These predictions raise serious social and moral issues in themselves, but there are yet more questions. Changes in the food supply can be a critical driver for social change, from the peaceful reorganization of an agricultural system to outright revolution and war. There is clear evidence of a link between climate change and conflict, and conflict at a local or national level can have a disastrous effect on food supplies.

The eventual answers must be political, but to be effective they must address the key practical issues. Many groups of scientists throughout the world are now using computer modeling to help predict scenarios and to identify the issues that need to be addressed if the worst scenarios are to be avoided.


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