Sahel droughts — LLMpedia

Sahel droughts
Name	Sahel droughts
Region	Sahel
Period	20th–21st centuries
Main causes	Reduced rainfall, land surface changes, sea surface temperature anomalies
Notable events	1913–18 famine, 1968–73 drought, 1982–85 drought, 2010–12 drought

Contents

Sahel droughts are recurrent, multi-year episodes of severe rainfall deficit and aridity affecting the semi-arid belt between the Atlantic Ocean and the Red Sea across Mauritania, Mali, Niger, Chad, Sudan, Senegal, Burkina Faso, Nigeria, and Eritrea. These events have driven famines, mass migration, and ecological shifts, prompting international responses from organizations such as the United Nations, International Committee of the Red Cross, and African Union. Scientific study involves institutions like the National Aeronautics and Space Administration, the National Oceanic and Atmospheric Administration, the World Meteorological Organization, and universities across France, United Kingdom, and United States.

Overview

The Sahel region spans the southern edge of the Sahara Desert and interfaces with the Guinea Coast and Ethiopian Highlands. Its climate is characterized by a single rainy season shaped by the northward movement of the Intertropical Convergence Zone and by variability linked to the Atlantic Multidecadal Oscillation, El Niño–Southern Oscillation, and Indian Ocean variability. Recurrent droughts since the late 19th century have altered land cover, water resources, and pastoral systems in areas such as the Lake Chad Basin and the Nile Basin, influencing political crises in countries including Sudan and Mali.

Historic episodes include late 19th and early 20th century dry spells recorded during colonial administrations of French West Africa and British Sudan. The 1913–18 famine affected populations across Niger and Mali, documented in reports by the League of Nations. The 1968–73 drought initiated wide-scale humanitarian interventions by the Food and Agriculture Organization and United Nations High Commissioner for Refugees, while the 1982–85 crisis triggered emergency aid from the United States Agency for International Development and the European Commission. The 1990s saw recurrent deficits linked to vegetation changes in the Sahelian Acacia zone; the 2010–12 drought coincided with food crises in the Horn of Africa and drew responses from Médecins Sans Frontières and the International Monetary Fund.

Droughts arise from reduced monsoonal precipitation due to shifts in the Intertropical Convergence Zone and teleconnections with the Atlantic Multidecadal Oscillation, El Niño–Southern Oscillation, and the Indian Ocean Dipole. Anthropogenic warming attributed to greenhouse gas emissions from industrial centers like Beijing, Tokyo, New York City, and London modulates these drivers. Land surface changes—deforestation around Niamey, expansion of rainfed agriculture near Bamako, and rangeland degradation in Agadez—alter albedo and evapotranspiration, interacting with feedbacks described in reports by the Intergovernmental Panel on Climate Change. Aerosol forcing from Saharan dust plumes and emission sources such as Lagos and Cairo also affect radiative balances and cloud microphysics, influencing convective rainfall processes studied by teams at the Max Planck Institute for Meteorology and the National Center for Atmospheric Research.

Human impacts include famine, malnutrition, and population displacement affecting communities in Agadez Region, Diffa Region, and Darfur, with health consequences managed by agencies like World Health Organization and UNICEF. Ecological impacts include savanna-to-desert transitions, contraction of wetlands such as Lake Chad, and species range shifts for taxa documented by the International Union for Conservation of Nature and conservation NGOs like Wildlife Conservation Society. Economic effects hit staple crop production (sorghum, millet) in agro-pastoral zones near Zinder and Maradi and reduce hydroelectric potential at projects like the Merowe Dam and irrigation schemes on the Nile River. Social consequences have intersected with conflicts involving actors such as Tuareg movements, Boko Haram, and state militaries, influencing security policies by the United Nations Security Council and regional bodies like the Economic Community of West African States.

Responses combine short-term relief—food aid coordinated by World Food Programme and cash transfers by Oxfam—with long-term adaptation strategies: drought-resistant crop trials at International Crops Research Institute for the Semi-Arid Tropics, water-harvesting and zai pit projects promoted by Food and Agriculture Organization, rangeland management by Conservation International, and transboundary water diplomacy among Chad, Nigeria, Cameroon, and Niger over the Lake Chad Basin Commission. Climate finance mechanisms from the Green Climate Fund and Global Environment Facility support resilience-building in municipal programs in Niamey and N'Djamena. National plans—such as strategies developed with the European Investment Bank and bilateral partners like France and United States—blend infrastructure, early-warning systems, and livelihood diversification.

Monitoring employs satellite platforms operated by European Space Agency and NASA (e.g., MODIS, TRMM), ground networks sustained by the World Meteorological Organization and national meteorological services in Mali and Niger, and reanalysis products from ECMWF and NOAA. Predictive efforts use seasonal forecasting models from the International Research Institute for Climate and Society, statistical indices like the Standardized Precipitation Index, and coupled ocean-atmosphere models evaluated by the Intergovernmental Panel on Climate Change and research centers including the Hadley Centre and the Lamont–Doherty Earth Observatory. Participatory monitoring integrates traditional indicators used by pastoralists in Agadez with mobile-data platforms supported by GSMA and humanitarian clusters coordinated by United Nations Office for the Coordination of Humanitarian Affairs.

Category:Climate of Africa Category:Environmental disasters in Africa