Lake Chad, once a huge lake straddling the borders of Chad, Niger, Nigeria and Cameroon, has shrunk by 95% since the mid 1960s.
The region's climate has changed during that time, with the monsoon rains which previously replenished the lake now greatly reduced.
A recent study blamed human activities combined with local weather changes, not global warming. It said overgrazing had destroyed the savannah vegetation which itself influenced the weather patterns.
As the climate has become drier, the demand for water to irrigate food crops has increased – quadrupling between 1983 and 1994 - depleting the lake further.
Nine million farmers, fishermen, and herders in the region now face water shortages, crop failure, livestock deaths, collapsed fisheries, soil salinity and increasing poverty.