Great Green Wall in Sahara

Thursday 02nd Feb 2012 by theWeather Club

An area of fertile land the size of England is being lost to the advancing Sahara desert every year but ambitious plans are afoot to stop the sands of time. The Great Green Wall project plans to introduce a belt of vegetation to halt the southern spread of the Sahara by planting a tree barrier nine miles wide and 4,831 miles long passing through 11 countries from east to west, from the Horn of Africa to Senegal.

The trees would be drought-adapted species, preferably native to area, that will slow soil erosion; slow wind speeds; and help rain water filter into the ground, to stop the desert from growing. The outcome would be a richer soil content that will help communities across the Sahel who depend on land for grazing and agriculture. More than 70% of Africa's poor depends on farming, according to the UN's Intergovernmental Panel on Climate Change (IPCC). The UN fears that over the next 25 years land degradation could reduce global food production by as much as 12% leading to a 30% increase in world food prices.

In many central and West African countries surrounding the Sahara, climate change has slowed rainfall to a trickle, according to the IPCC. Crops have died and soils have eroded—crippling local agriculture. If the trend continues, the UN forecasts that two-thirds of Africa's farmland may be swallowed by Saharan sands by 2025. Drought, desertification, and other climate-related disasters are already forcing many farmers to abandon their lands, spurring a heavier flow of immigrants out of central and North Africa.

The trees in the Great Green Wall act as natural windbreaks against sandstorms, and their roots improve soil health—especially by preventing erosion. The lush channel through the desert would help farmers already displaced by drought—and may even stem the exodus of environmental refugees.

The gigantic tree barrier would also trap some atmospheric carbon dioxide, a greenhouse gas, and produce a refuge for native animals and plants. Some of the trees themselves may become valuable crops. The native acacia tree, a staple plant in the Great Green Wall, produces a gum which is an ingredient in consumer products such as cosmetics and soft drinks. Senegal also plans to dig rainwater reservoirs along its portion of the wall—virtual lifesavers in a region where rain falls only three months out of the year.

Overall though, the Great Green Wall is an extremely bold undertaking but sometimes thinking big is what is needed to draw attention to a problem.