Possible Causes
A drought induced famine occured in Africa's Sahel region and many parts of the neighboring Sénégal River Area and Horn of Africa.
Sahel Famine
The Western donor nations once theorised 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.
Lake Chad is economically important because it provides water to more than 20 million people living in the four countries that surround it (Chad, Cameroon, Niger, and Nigeria) and the plant Typha Australis (big cattails) was cutting off the water supply to those countries making people die of thirst or crops die from lack of water.
high population numbers are putting further strain on natural resources, food supplies, fuel supplies, employment, housing, etc
International Response
Results
France, Schegal, and Gambia gave them food.
The UK, Gordon Brown, and The EU gave them cash
Charities and NGO's gave them mixed goods, expert advisors and cash.
The international Red Cross gave them food and expert advisors.
The United States gave them food and cash
There were 9 confirmed deaths, 42 indirectly, 20 unconfirmed, and 17,800,000 people were in immediate risk of starvation
Prevention
They developed food security plans and managed their water supplies better.
Photo based on: 'horizon' by pierreyves @ flickr