Desertification

The world's drylands, contrary to popular misconceptions of being barren unproductive land, contain some of the most valuable and vital ecosystems on the planet. These dryland environments have surprising diversity and resiliency, supporting over two billion people, approximately thirty-five percent of the global population (UNEP, 2003). In fact, approximately seventy percent of Africans depend directly on drylands for their daily livelihood (UNEP, 2003). However, these precious and crucial areas are at a crossroad, endangered and threatened by the devastating process of desertification. There are over one hundred definitions for the term Ð''desertification', however the most widely used and current definition is as follows: desertification refers to the land degradation in arid, semi-arid and dry sub-humid regions due to human activities and climate variations, often leading to the permanent loss of soil productivity and the thinning out of the vegetative cover (UNCCD, 2003). It is important to note that desertification is not the expansion and contraction of deserts or hyper-arid territories, which grow and decrease both naturally and cyclically. French ecologist Louis Lavauden first used the term desertification in 1927 and French botanist Andre Aubreville, when witnessing the land degradation occurring in North and West Africa in 1949 popularized this term (Dregne, 242). The causes of desertification include overgrazing, overcultivation, deforestation and poor irrigation practices. Climatic variations, such as changes in wind speed, precipitation and temperature can influence or increase desertification rates, but they are not catalysts to the process- it is the exploitative actions of humans that trigger desertification (Glantz, 146). The most exploited area historically has been Africa. In the Sahel (transition zone between the Sahara and the Savanna) of West Africa during the period of 1968 to 1973, desertification was a main cause of the deaths of over 100,000 people and 12 million cattle, as well as the disruption of social organizations from villages to the national level (USGS, 1997). As a result of the catastrophic devastation in the Sahel, the United Nations Convention to Combat Desertification (UNCCD) was held in Nairobi, Kenya in 1977, where an agreement was reached to eradicate desertification by the year 2000. Obviously this goal was not achieved. Countries and organizations, notably in the industrialized world, have been unwilling to provide significant and sufficient financial and economic aid to countries most impacted by this issue (Mainguet, 2003). Consequently, desertification is out of control, threatening the sustainability of the world's environment, disrupting social structures and well-being, and impairing economic growth. This crisis reaches beyond the local, directly affected communities, impacting and jeopardizing world stability. Environmentally, desertification reduces the world's freshwater reserves due to water over consumption and irrigation mismanagement, decreases genetic diversity through soil erosion and plant destruction, and also accelerates the carbon exchange process by damaging carbon Ð''sinks'. Socially, desertification causes population displacement as people search for better living conditions, often leading to conflicts and wars. Another social consequence is a dramatic reduction in the world's food supply due to the depletion of vital dryland vegetation and a decline in crop yields. Desertification is also linked to a number of health issues such as malnutrition, as clean water and sufficient food resources are extremely scarce. Economically, income potential is lost because land is unproductive, and monetary funds are devoted towards combating desertification, compromising economic growth and development. Crisis management becomes more important than achieving economic goals. Furthermore, increasing levels of poverty have resulted due to dire economic conditions. The international body must devote more time, resources and energy to find effective and long-term solutions that will benefit not only directly-affected areas, but the world at large. The devastating environmental, social and economic ramifications of desertification must be addressed immediately, cooperatively and without hesitation, before the window of opportunity is lost.

Desertification has created and encouraged a number of major environmental problems, and has endangered the sustainability of a diverse and clean global environment. Through the use of poor irrigation practices and exploitative human actions for profit, water has been over consumed and desertification has occurred near areas surrounding fresh water supplies, reducing or depleting these reserves. In the desertification process, the shorelines and the aquatic land and soil becomes eroded, salinized and degraded. Thus, feeder rivers decline in quantity and supply, river flow rates decrease and ultimately freshwater reserves are polluted and/or reduced. The reduction of river flow rates and the lowering of groundwater levels leads to the "silting up of estuaries, the encroachment of salt water into water tables, and the pollution of water by suspended particles and salination" (FAO, 2003). These problems are particularly evident in the Aral Sea in Asia, which at one point was the fourth largest lake in the world (Aral Sea Homepage, 2002). During the Soviet era in the 1960's and 1970's, the communist central planners had little regard for water conservation, and over consumed this resource. In order to meet the demand for agricultural irrigation the Union of Soviet Socialist Republics (USSR) "diverted water from rivers that flowed into the Aral Sea" (Pacific Island Travel: Desertification, 1999). These exploitative actions dropped water levels by one-third because feeder rivers could no longer replenish the large lake, as illustrated in Appendix 1 (Pacific Island Travel: Desertification, 1999). Not only has the shorelines of the Aral Sea declined, but Lake Chad in Africa has followed a similar fate. Desertification in the Lake Chad region has dropped water levels far below the average dry season amount of "10,000 square kilometers to only 839 square kilometers" (Earth Crash Earth Spirit, 2001). The reduction of water levels in Lake Chad and the Aral Sea decreases their ability to moderate the local climate, resulting in more extreme variations in temperature and precipitation. Therefore, local ecosystems are disrupted and even destroyed, as the climate becomes more continental in nature, and vital water supplies are scarce or depleted.

Desertification reduces the biodiversity and genetic diversity of dryland ecosystems, impairing the sustainability of plants, animals and even humans in these regions. As a consequence of desertification, the soil