An enormous lake called Mega Chad in what is now the Sahara desert took just a couple of hundred years to shrink to a fraction of its size, British scientists have found. Mega Chad was once the biggest freshwater lake on earth covering 139,000 sq miles (360,000 sq km) of Central Africa – and rapidly shrunk to a tiny fraction of its former size 1,000 years ago. The discovery sheds light on how the Amazon rain forest grows – because dust from the remains of the dried-up lake blows across the Atlantic to help fertilise the jungle.
‘A reconstructed lake level history for the ancient Lake Mega-Chad, once the largest lake in Africa, suggests that a North African humid period, with increased precipitation in the Sahara region, ended abruptly around 5,000 years ago, and that the lake’s Bodélé basin, now a large source of atmospheric dust, may not have dried out until around 1,000 years ago,’ the team wrote. But the researchers’ discovery shows this fertilisation could only have happened 1,000 years ago – leaving a riddle as to how the jungle received vital nutrients before then.
The researchers found that the change took place in just a few hundred years – much more quickly than previously considered. All that remains is Lake Chad, which at 137 sq miles (355 sq km) is still large but a fraction of its former scale. The lake, which crosses the borders of Chad, Niger, Nigeria and Cameroon, has been further reduced in size by humanity siphoning off fresh water from it.
The researchers explained the significance of the finding. The dried up remains of the lake is the biggest source of dust in the world, the Bodélé depression.
So let me get this straight: not only did Africans invent global warming, they’re also continuing to siphon off valuable water resources from Mother Gaia that could better spent on the West Side of Los Angeles, thus causing dust in the atmosphere that contributes to greenhouse gases but also helps Save the Rain Forest. Or something like that.
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