The 1970s saw one of the most severe droughts in sub-Saharan Africa's Sahel region, a semi-arid belt just south of the Sahara Desert. Lasting roughly from 1968 to 1975, this drought had profound implications for the region's ecology and its inhabitants.

The primary cause was the Sahel's natural climate variability, which periodically witnesses cycles of droughts and wet periods. However, the 1970s drought was particularly extreme in its intensity and duration. Human activities like overgrazing and deforestation worsened the natural variability. As livestock overgrazed, vegetation cover reduced, making the land more susceptible to desertification. Concurrently, deforestation for firewood and agriculture led to soil degradation, amplifying the effects of the drought.

The repercussions were vast and multi-faceted. Widespread famine ensued, affecting tens of millions, especially in Chad, Ethiopia, Mali, Mauritania, Senegal, and Burkina Faso (known as Upper Volta until 1984). It's estimated that in these countries alone, over 100,000 people succumbed to starvation, malnutrition, and associated diseases.

The drought also devastated Sahelian economies, primarily centered on agriculture and pastoralism. As crops failed and livestock perished, local economies collapsed, depriving families of their primary means of subsistence. Consequently, many residents of the Sahel region migrated, seeking better conditions. This mass movement resulted in significant internal displacements, with a majority relocating to urban areas, while some even crossed borders.

The prolonged absence of rainfall combined with these human activities turned vast tracts of the Sahel barren, accelerating desertification in the region. The international community took note of the Sahel's plight, and various humanitarian organizations, governments, and United Nations agencies initiated relief efforts, providing essential food, water, and medical aid. Though these measures saved countless lives, the sheer scale of the disaster often rendered assistance inadequate.

In the aftermath of this drought, many Sahelian nations, along with the broader international community, recognized the necessity for sustainable agricultural practices, water conservation, and reforestation. The lessons learned from this tragic period spurred initiatives like the Great Green Wall, which aimed to plant a vast belt of trees across the Sahel, to combat desertification and mitigate the impacts of potential future droughts.

Overall, the Sahelian drought of the 1970s serves as a poignant reminder of ecosystems' fragility and human societies when faced with climatic changes and unsustainable land use.