Sahel drought

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The Sahel drought from the late 1960s to early 1980s created a famine that killed a million people and afflicted more than 50 million. 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.

1 Previous Sahel droughts
2 Potential factors contributing to Sahel drought
3 United Nations Sahel drought response
4 Notes
5 External links

[edit] Previous Sahel droughts

Because the Sahel's rainfall is heavily concentrated in a very small period of the year, the region has been prone to droughts ever since agriculture developed around 5,000 years ago. Some suggest this development was related to the drying of the Sahara crowding people

Records of climate in the Sahel begin with early Muslim travellers in the early Medieval Warm Period. These suggest that Sahel rainfall was relatively low in the seventh and eighth centuries and then increased substantially from about 800 AD^[1]. There was a decline in rainfall from about 1300 AD, but an increase again around 200 years later.

The first major reported drought in the Sahel occurred around 1640, and a major drought after generally wet conditions occurred, based on the reports of European travellers^[2], during the 1680s. This cycle of several wet decades followed by a drought was repeated during the eighteenth century, but around 1790 dry conditions similar to those of the late twentieth century set in^[3] and continued until around 1870. After that, a very wet period set in for around 25 years, followed by a return to drier conditions.

The first rain gauges in the Sahel date from 1898 and they reveal that a major drought, accompanied by large-scale famine, in the 1910s, followed by wet conditions during the 1920s and 1930s reaching a peak with the very wet year of 1936. 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 and many have thought it contributed to the severity of the subsequent Sahel drought

[edit] Potential factors contributing to Sahel drought

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 and poor land management.

In the late 1990s, climate model studies suggested that the drought was not only caused by humans, but also by natural large scale climate changes.

In the early 2000s, after the phenomenon of global dimming was discovered, some speculatively suggested that the drought was likely caused by air pollution generated in Eurasia and North America. The pollution 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 likely 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.^[4]. These climate model simulations indicated that the general late 20th century Sahel drying trend was attributable to human-induced factors; largely due to an increase in greenhouse gases and partly due to an increase in atmospheric aerosols. These climate change modeling studies also project that human-induced climate change could lead to a 25% reduction in Sahel rainfall by year 2100.

[edit] United Nations Sahel drought response

In 1973, The United Nations Sahelian Office (UNSO) was created to address the problems of drought in the Sahel region following the West African Sahel drought of 1968-73. In the 1990s, the United Nations Convention to Combat Desertification (UNCCD) was adopted and UNSO became the United Nations Development Programme's Office to Combat Desertification and Drought, as its scope broadened to be global rather than only focused on Africa.^[5]