A new international study has shown that sea level along Africa’s Atlantic coast has risen by over 100 meters since the peak of the last ice age, around 30,000 years ago. Led by Professor Matteo Vacchi of the University of Pisa and published in the journal Nature Communications, the research offers the most comprehensive reconstruction to date of how sea level has changed in this region over millennia.
“Studying how sea level evolved in the past helps us better understand what’s happening now and what might happen in the future,” says Vacchi. “This is especially important for Africa’s coastal areas, which are home to millions of people and key natural environments that are increasingly threatened by rising seas.”
The study identifies three main periods of change. During the coldest part of the last ice age—known as the Last Glacial Maximum—sea level was around 100 meters lower than it is today. As the Earth warmed and the ice sheets melted, the ocean rose rapidly. This period of deglaciation caused sea level to rise at rates of up to 25 millimeters per year—much faster than today’s average.
Between about 7,500 and 1,700 years ago, sea level reached a high point, in some places even higher than it is now. It then stabilized for centuries before starting to rise again over the last 100 years due to human-caused climate change.
The findings are not just of academic interest—they have real-world importance. Coastal regions in West Africa, for example, generate over half of the region’s GDP and support a large portion of its population. But they are also among the most vulnerable to sea-level rise.
“Although Africa contributes very little to global greenhouse gas emissions,” explains Vacchi, “it will be one of the regions most affected by climate change. Our work helps show how sea level has changed in the past so we can better prepare for what lies ahead.”
The research involved scientists from several institutions, including the Earth Observatory of Singapore, Aix Marseille University in France, the University of Bologna, and Italy’s National Institute of Geophysics and Volcanology.
(Translation supported by ChatGPT-4o)