The Sahel context
12 countries, ~3m kmΒ², 400-600 mm rainfall, ~150m people. The world's largest desertification hotspot.
The Sahel is a semi-arid belt across 12 African countries from Senegal in the west to Eritrea in the east. Key facts:
| Feature | Value |
|---|---|
| Area | ~3 million kmΒ² |
| Population | ~150 million |
| Rainfall | 400-600 mm/yr (variable, marginal for agriculture) |
| Countries | Senegal, Mauritania, Mali, Burkina Faso, Niger, Nigeria (north), Chad, Sudan, South Sudan, Eritrea, Ethiopia, Cameroon (north) |
| Economic context | GDP per capita ~$500-1,500; among world's poorest |
| Livelihoods | ~70% rural; subsistence farming + pastoralism |
The Sahel sits at the climatic transition between Sahara (north) and savanna (south). Rainfall depends on the Inter-Tropical Convergence Zone (ITCZ) shifting north each summer. Even small rainfall reductions trigger major vegetation + agricultural losses.
Why this matters for desertification impacts.
Because the Sahel is:
- DRY enough for vegetation to fail in droughts,
- POPULATED enough that lots of people are affected,
- POOR enough that there's no economic cushion,
- WEAKLY GOVERNED enough that institutions cannot buffer the shock,
...desertification causes catastrophic + cascading impacts. The Sahel is the world's largest case-study of how a fragile environment fails under combined climate + human pressure.
Recent timeline.
- 1968-1985: Sahel drought, rainfall fell ~20-30%. Tens of thousands of deaths from famine.
- 1980s onward: incremental Lake Chad shrinkage continues; out-migration accelerates.
- 2005: Niger famine, ~3m affected.
- 2010-12: Sahel food crisis affecting ~18m people; livestock losses ~30-50%.
- 2009-present: Boko Haram insurgency in NE Nigeria + Lake Chad basin escalates.
- 2012-present: Mali insurgency, Tuareg uprising.
- 2014: Lake Chad Basin Commission emergency declaration.
- 2017: Great Green Wall pledges ~$33bn at One Planet Summit.
- 2020-24: Continued ~3m displaced people; ~50m food-insecure annually; coups in Mali, Burkina Faso, Niger.
This timeline shows desertification is not a single 'event' β it is a SUSTAINED + DEEPENING CRISIS spanning generations.
Examiner tip. Always frame Sahel desertification impacts in terms of the SHARED case study (12 countries, ~150m people, marginal climate + governance) rather than isolated facts. The 4GE1 Section C mark schemes reward integrated case-study knowledge.
- Sahel: 12 countries, 3m kmΒ², 400-600 mm rain.
- ~150m population; ~70% rural; GDP/capita $500-1,500.
- Sits on Sahara-savanna climate boundary; ITCZ-dependent.
- Sustained crisis since 1968-85 drought; deepening through 2020s.
- Combined climate + governance + population pressures drive cascading impacts.