Desertification – Agriculturally Induced Ecological And Climatic Shifts Created The Sahara Desert

Very hot climate - Sahara Desert, Libya copy

When thinking about the Sahara do you picture a green landscape, lush with vegetation and teeming with life? Of course not! Because today the Sahara is a desert, dry and arid: a harsh and unforgiving landscape.

The ecoregion is the worlds largest hot desert, stretching across North Africa, from the Red Sea to the Atlantic ocean. Geoarcheological research by Dr. David Wright of Seoul National University has found that human driven ecological and climatic changes, brought about through the advent of agriculture, are the principle cause of the shift from the lush green landscape it once was into the ecoregion we know today.

His research has found that, as vegetation removal increased to introduce domesticated livestock, the amount of sunlight reflected off the earths surface increased, causing shifts in atmospheric conditions that resulted in reduced monsoon rainfall. This then lead to escalating vegetation loss and desertifiction, creating a feedback loop that spread across the ecoregion.

Agriculture owes its roots in shift from hunt-gatherer polycultures into the monoculture of civilisation at approximately 10,000 BC- the cradle of civilisation being the fertile crescent, which spanned from the Persian Gulf to Upper Egypt. Urbanisation and the advent of cities are other defining features of civilisation, whose origins for contemporary global civilisation are found in the fertile crescent.

When discussing the introduction of agriculture by Euroamericans in the Americas, Dr. David Wright states – “(m)ore analogous to the African context, the introduction of domesticated livestock by Euroamericans into semi-arid and arid regions of the Americas profoundly altered the ecosystem, inducing regime shifts in many regions. Grazing and browsing ungulates evolved in the Americas during the Cenozoic and were a critical component of the ecological matrix (Grayson, 2011; Woodburne, 2012). Prior to Euroamerican settlement, vast prairie grasslands spanned the interior upland regions of both North and South America. However, with the exception of Highland South America, there were no domesticated grazers present before the arrival of European settlers. Cattle (Bos taurus)  introduced a new pressure to the landscape that spatially and temporally correlates to a regime shift from grassland to scrubland (Van Auken, 2000).”

Dr. Wright’s research displays how, as well as being an immediately destructive process through the loss in vegetation, agriculture creates conditions for escalating feedback loops, with increasingly worsening results. And with the contemporary food crisis bringing about a global land grab for domestic consumption, changes in climate and soil destruction is worsening too. In Britain, soil degradation through intensive farming has gotten us to the point where we have about 100 harvests left, at current rates of consumption.

Extensive damming and draining projects are now worsening the ecological conditions of the area that once was the fertile crescent, with no efforts by the governments to reduce or reverse the damage. And given that 15% of the worlds human populations currently live in deserts, the importance of Wright’s findings are apparent because, as he states “the implications for how we change ecological systems have a direct impact on whether humans will be able to survive indefinitely in arid environments.”

 

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