Is Lake Chad still shrinking? The famous story, and what newer satellite work says
Lake Chad really did collapse in the droughts of the 1970s and 1980s. But a multi-satellite study found its extent has been stable for two decades and that it is not shrinking now - which is why the simple 'shrinking lake' story needs care.
Key points
- Lake Chad covered 25,000 square kilometres in the 1960s and fell to less than 2,000 in the 1980s.
- A 2020 multi-satellite study found the lake's extent has remained stable during the last two decades.
- The same study says groundwater makes up about 70% of the lake's annual water storage change, and has been increasing since the 2000s.
- Size estimates differ a lot because some count water hidden under vegetation and some count only open water.
What happened
Few African places carry a story as often repeated as Lake Chad. In the 1960s it was one of the world's largest lakes. Then came the Sahel droughts of the 1970s and 1980s, the lake split into northern and southern pools, and 'the shrinking lake' became a symbol of climate change around the world.
The trouble is that the story often stops there, in the 1980s. The lake is shallow, seasonal and covered in large areas of vegetation, so it is hard to measure from space. Newer research using several satellites at once paints a more mixed picture: a lake far smaller than in the 1960s, but not one that has kept shrinking.
Claim by claim
Why this label: From the introduction of the 2020 Scientific Reports study of the lake's hydrology.
On the ladder: a claim earns Verified from primary evidence, or from two independent sources that do not copy each other.
Why this label: The 2020 multi-satellite study directly reports the opposite for recent decades: the lake's extent has remained stable during the last two decades, despite a slight decrease of its northern pool, and it recovers seasonally. The old shrinkage was real; the claim that it continues is contested by this work.
On the ladder: credible sources conflict, so we show both workings. One side's own statement is that side's position — never proof.
Why this label: Stated in the study's abstract.
On the ladder: a claim earns Verified from primary evidence, or from two independent sources that do not copy each other.
Why this label: One of the study's main findings, from combining satellite observations of surface water and total water storage.
On the ladder: a claim earns Verified from primary evidence, or from two independent sources that do not copy each other.
Why this label: The study explains that if vegetation-covered water is counted as inundation, the total extent in October 2013 was 12,800 square kilometres, in line with other reports of about 14,000 - far above open-water-only figures.
On the ladder: a claim earns Verified from primary evidence, or from two independent sources that do not copy each other.
What we know / what we don't know yet
What we know
- The collapse of the 1970s and 1980s happened, and the lake has never returned to its 1960s size.
- For roughly the last two decades covered by the 2020 study, open-water extent was broadly stable, with the northern pool slightly decreasing.
- How you define 'the lake' - open water only, or water under vegetation too - changes the headline number by a lot.
What we don't know yet
- How the lake will behave in the coming decades, which the study says remains highly uncertain under climate change.
- A single agreed, up-to-date size figure that all research groups measure the same way.
Why it matters
About 50 million people farm, fish and keep animals around this lake. Policy built on a 1980s picture - a lake vanishing year by year - can miss what people there actually face today: a smaller, highly variable lake whose water rises and falls hard with the seasons.
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