Impacts of Climate Change on Food Production and Supply

Overall, climate change, including global warming and increased climate variability, could result in a variety of impacts on agriculture.? Some of these effects are biophysical, some are ecological, and some are economic (UNFCCC Climate Change Information Kit). ?

They include:

A shift in climate and agricultural zones towards the poles

Changes in production patterns due to higher temperatures

A boost in agricultural productivity due to increased carbon dioxide in the atmosphere

Changing precipitation patterns

Increased vulnerability of the landless and the poor.?

Rosenzweig and Hillel (1995) explain these and other ideas in Potential Impacts of Climate Change on Agriculture and Food Supply.

In the early 1990's in a study sponsored by EPA, agricultural scientists in 18 countries estimated potential changes in national grain crop yields using crop models and the GCM scenarios at 112 sites worldwide (Rosenzweig and Parry, 1994) (Figure 3). The results of this global assessment suggests that a doubling of the atmospheric carbon dioxide concentration will lead to only a small decrease in the global crop production.? However, it appears that developing countries in lower latitudes will bear the brunt of these problems.

Several factors contribute to the latitudinal differences in simulated yields. In high latitude regions, increased temperatures benefited crops otherwise limited by cold temperatures and short growing seasons.? The climate change induced warming at low latitudes brought greater heat and water stress, resulting in greater yield decreases than at higher latitudes.

In addition, in Rosenzweig et al., Climate Change and Extreme Weather Events; Implications for Food Production, Plant Diseases, and Pests, the authors found that global food supply may be affected by an increase in extreme weather events and climate variability associated with global warming.? Altered weather patterns can increase crop vulnerabilities to infection, pest infestations, and choking weeds.? This will not only decrease yields of crops, but also force farmers to apply harmful and expensive pesticides and herbicides.? The increase in extreme weather events will affect both developed and developing countries, although developed countries have more resources to deal with vulnerabilities

Source : http://www.climate.org/topics/agricul/index.shtml