EARLY this month, a team of geoscientists discovered a lost continent beneath the island of Mauritius, which they believe was submerged 84 million years ago.
Live Science reports that small, shiny flecks of rocks known as zircons from Mauritius date back billions of years, to one of the earliest periods in Earth’s history, the researchers found. Other rocks on the island, by contrast, are no more than 9 million years old.
From this, the team concluded that Mauritius is all that remains of the much larger, submerged continent.
But disappearing shorelines may not be the stuff of ancient history climate change is threatening the future of many African cities.
An estimated 55 million African live in vulnerable, low-lying coastal zones (where the altitude is 10 metres or less above sea level), and this figure is projected to rise to over 100 million by 2030.
Madagascar – an island – has the longest coastline of any country in Africa. On the mainland, the beach view is longest in Somalia, South Africa, Mozambique and Egypt.
Already, coastal erosion has reached dramatic levels in Togo, where the former capital city, Aneho, dozens of surrounding villages, along with the main road that links the west African country to Benin, are likely to disappear from the map by 2038 if nothing is done to reverse the erosion that is currently eating away between six and 10 metres of coastal land each year.
By one estimate, Banjul, the capital of The Gambia, could disappear in 50-60 years through coastal erosion and sea-level rise.
Another threatened city is Mauritanias capital Nouakchott, which was vulnerable to flooding even before climate change became a factor.
According to recent studies commissioned by Mauritanian authorities, 79% of the overall surface area of Nouakchott could be under water in fewer than 10 years and in 20 years at most.
The worst-case scenario projects the disappearance of the city around 2050.
With a one-metre rise in sea level, it is estimated that 34% of the Nile Delta would be inundated, putting more than 12% of Egypts best agricultural land at risk. The coastal cities of Alexandria, Idku, Damietta and Port-Said would be directly affected, displacing roughly seven million Egyptians or 8.5% of the population, according to data published in the Africa Water Atlas.
In the extreme case of a five metre sea-level rise, more than half (58%) of the Delta would flood, devastating more than a third of Egypts agricultural land and displacing roughly 11.5 million people from over 10 major cities.
Along with the direct effect on peoples livelihoods, Egypts economic growth will also feel the repercussions. A one-metre rise would incur a 6% drop in GDP while a three-metre rise would result in a 12% drop, the UNEP report states.
COMPARATIVE LENGTH OF COASTLINES OF AFRICAN COUNTRIES
|RANK||COUNTRY||LENGTH OF COASTLINE (Km)||OCEAN/SEA ALONG WHICH IT RUNS|
|3||South Africa||2,798||Atlantic and Indian Ocean|
|5||Egypt||2,450||Mediterranean Sea and Red Sea|
|7||Morocco||1,835||Mediterranean Sea and Atlantic Ocean|
|8||Libya||1,770||Atlantic Ocean and Mediterranean Sea|
|14||Cape Verde||965||Atlantic Ocean|
|16||Sudan||853||Red Sea and Indian Ocean|
|22||Cote dâ€™Ivoire||515||Atlantic Ocean|
|24||Sierra Leone||402||Atlantic Ocean|
|28||Equatorial Guinea||296||Atlantic Ocean|
|29||Sao Tome and Principe||209||Indian Ocean|
|35||Democratic Republic of Congo||37||Atlantic Ocean|