Effects on food supply

During the past 10 000 years - which have been relatively stable in climatic terms - farming methods have evolved and improved, enabling more food to be produced. Local climatic limitations on crop growth have been overcome through irrigation, fertilization, mechanization and the breeding of varieties adapted to local conditions. During the past five decades, the food requirements of a rapidly expanding population, combined with a worldwide shortage of new tracts of arable land, have led to an unprecedented reliance on yield improvement.

Climate change could affect food production through:

• geographical shifts and yield changes in agriculture;

• a reduction in the quantity of water available for irrigation;

• loss of land through a rise in sea level and associated salinization; and

• effects on the productivity of fisheries through a rise in sea level and changes in water temperatures, currents, flows of fresh water and nutrient circulation.

Predicting the effects of climate change on crop and livestock yields is complex. Agricultural production is sensitive to the direct effects of climate, especially extreme weather events. It is also sensitive to the indirect effects of climate on soil quality, on the incidence of plant diseases and on weed and insect (including pest) populations. In particular, irrigated agriculture would be affected by changes in water resources. The Intergovernmental Panel on Climate Change has reviewed assessments of the impact of climate change on agricultural productivity (6).

The modelling exercises reported to date have often not attempted to incorporate social and economic responses. It is assumed that farmers will adapt to changes in climate by, for example, changing crop varieties or dates of planting. Human societies would clearly respond to significant changes in food supplies by such means as migration. The complex political, economic and technological influences on world food production are difficult to quantify. These influences include the rapid commercial and political changes that have encouraged the production of standardized crops for unseen, remote markets using large-scale, heavily mechanized agricultural production methods. This has occurred to the extent that food has gradually become an international commodity rather than a source of nutrition for local populations.

In Europe, the regional assessment by the Intergovernmental Panel on Climate Change concludes that crop mixes and production zones will be redistributed (8). Subsequent changes in food prices are highly dependent on world markets and the adaptive actions taken by producers. Relatively few studies, however, have addressed vulnerability to food shortages in Europe, and the assessment of the Intergovernmental Panel on Climate Change does not identify vulnerable groups. Several regional assessments for Europe have also been undertaken (48). These studies focus on model simulations for changes in crop yield and agricultural risk.

The political implications of climate change must also be considered. As land areas suitable for the cultivation of key staple crops or productive fishing grounds undergo geographical shifts in response to climate change, they may become the subject of political conflict. Conflicting demands for water may also cause problems, especially in Israel, Turkey and other semi-arid countries (106).

Was this article helpful?

0 0
Guide to Alternative Fuels

Guide to Alternative Fuels

Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.

Get My Free Ebook

Post a comment