Droughts in the Sahel
The Sahel region is a climate zone sandwiched between the Sudanian Savanna to the south and the Sahara desert to the north, across West and Central Africa.
[2] The economies, agriculture, livestock and human populations of much of Mauritania, Mali, Chad, Niger and Burkina Faso (known as Upper Volta during the time of the drought) were severely impacted.
The Sahel is marked by rainfalls of less than 1,000 millimetres or 40 inches a year, almost all of which occurs in one continuous season, which can run from several weeks to four months.
), similar in timing to the Little Ice Age (LIA, 1400 to 1850 CE), a well-known interval when Northern Hemisphere temperatures were cooler than at present.
[12] The 1740s and 1750s was recorded in chronicles of what is today Northern Nigeria, Niger and Mali as the "Great Famine", the worst for at least 200 years prior.
It caused massive dislocation of the Sahelian states of the time, but also disrupted the Trans Saharan trade routes to North Africa and Europe.
Historical records suggest this drought caused a large-scale emigration from the Bornu Empire, contributing to its rapid decline in the 19th century.
The 1940s saw several minor droughts — notably in 1949 — but the 1950s were consistently wet, and expansion of agriculture to feed growing populations characterised this decade.
Grazing became impossible and this triggered a large-scale famine that led to the first mobilization of external aid and the creation of the International Fund for Agricultural Development by United Nations.
[19] A literature review from the African Journal of Ecology summarized the environmental changes that species faced after the late 20th century droughts, some of which includes (but is not limited to) severe declines in biodiversity and increases in other disturbances, such as fires.
[23] Niger reported diarrhoea, starvation, gastroenteritis, malnutrition and respiratory diseases killed and sickened many children July 14.
The new military junta appealed for international food aid and has taken serious steps to calling overseas help since coming to office in February 2010.
[26][27][28] Originally it was believed that the drought in the Sahel primarily was caused by humans over-using natural resources in the region through overgrazing, deforestation[29] and poor land management.
[33] In 2002, after the phenomenon of global dimming was discovered, a CSIRO study[34] suggested that the drought was probably caused by air pollution generated in Eurasia and North America, which changed the properties of clouds over the Atlantic Ocean, disturbing the monsoons and shifting the tropical rains southwards.
In 2005, a series of climate modeling studies performed at NOAA / Geophysical Fluid Dynamics Laboratory indicated that the late 20th century Sahel drought was probably a climatic response to changing sea surface temperature patterns, and that it could be viewed as a combination of natural variability superimposed upon an anthropogenically forced regional drying trend.
A study published in 2013, done at the University of Washington, suggests that atmospheric aerosols caused a downward shift in the Intertropical Convergence Zone.
