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CNNU.N. officials are pleading for immediate economic assistance for four African countries where people are facing malnutrition in the wake of a drought last year.
The coming weeks ahead will be the toughest for these countries in the Sahel -- the stretch of African countries including Niger, Chad, Mali and Mauritania -- as they make their way into the rainy season and scrape by with the little food they have since last year's harvest, officials said.
"Niger is the center of this crisis, it is a country by far the worst affected, some 7 million people are suffering from severe or moderate food insecurity and that's almost fifty percent of the country's population," Holmes said.
Over 10 million people in the Sahel are at risk for food shortages, according to the U.N., and their situation is unlikely to improve until the coming harvest in October.
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http://www.cnn.com/2010/WORLD/africa/07/20/un.africa.food.crisis/index.html?eref=rss_world&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2Fcnn_world+%28RSS%3A+World%29
"Recent work by meteorologists and oceanographers has shown that much of the recent year-to-year changes in Sahel rainfall are forced by changes in sea-surface temperature in the Gulf of Guinea (on the equator near the prime meridian) and by El Niño in the Pacific. When the gulf is warm, the Intertropical Convergence Zone shifts south away from the Sahel reducing the African monsoon that draws moist air into the Sahel. Longer term changes in rainfall from decade to decade are forced by changes in sea-surface temperature in the western Indian and tropical Atlantic oceans. When these areas are cool, Sahel rainfall increases."
"The oceanic forcing of Sahel rainfall is amplified by land-atmosphere feedbacks. As the land dries out, there is less vegetation, less evaporation from the land, and more sunlight is reflected from the land. These processes further weaken the monsoon. This positive feedback also involves land degradation due to human interactions with the land."
In other words, the combination of global warming and deforestation has rendered the Sahel particularly susceptible to increased desertification and drought.
http://oceanworld.tamu.edu/resources/environment-book/desertificationinsahel.html