On the horizon, the insolent blue of the Aegean Sea, scattered rocky islets, sailboats heading towards the Greek island of Mykonos.  

But on the shore of the tiny island of Delos, a silent drama is playing out: stone walls almost two thousand years old are being destroyed by the onslaught of the sea, the level of which is rising inexorably.

In the Cyclades archipelago, the archaeological site of Delos, listed as a UNESCO World Heritage Site since 1990, risks destruction due to global warming.

“Delos is doomed to disappear in about fifty years,” says Véronique Chankowski, who directs the French School of Athens (EFA), which has been responsible for the excavations for 150 years.

“This archaeological park, which today provides us with considerable information (on the ancient world, editor’s note), we may not see it again,” she added during an interview with AFP in Athens.

Sea levels in the Mediterranean basin have risen by 2.8 mm per year over the past decades, according to the Intergovernmental Panel on Climate Change (IPCC).

Additionally, due to plate tectonics, Delos is gradually sinking.

The island, inhabited today by a handful of archaeologists in summer and two caretakers in winter, is one of the treasures of the ancient world and was a hub of trade in the Mediterranean during Antiquity.

The cosmopolitan city, which reached its peak under the Romans, had at least 30,000 people.  

Its sanctuary dedicated to Apollo, the god of arts and beauty who was born, like his sister Artemis, on Delos,  attracted pilgrims from all over Greece.

In the ancient theater, Athena-Christiana Loupou, a Greek archaeologist who guides groups through Cleopatra’s house or the Lions’ terrace, is worried.  

“All coastal cities will lose significant parts currently located at sea level,” she assures.

“We replaced plastic straws with paper straws, but we lost the war” to protect the environment, she asserts, bitterly.

To see the extent of the damage, you have to go to an area closed to visitors, cross bushes scented with oregano to reach, with your feet in the water, the shopping area.

They were places of trade and storage in the 1st and 2nd century BC.

“Every year in the spring, I notice that new walls have collapsed,” laments Jean-Charles Moretti, researcher at the CNRS IRAA and director of the French archaeological mission of Delos.

“Water enters the stores in winter, it eats away at the base of the walls,” continues this archaeologist who has been carrying out missions on the island for 40 years. “They suddenly collapse.”

In recent years, experts have noted a sharp acceleration in the rise in water levels.

“In the space of about ten years, we have on average, depending on the location of the coast, up to twenty meters of rise in sea level,” explains Véronique Chankowski.  

Emergency measures were taken with the installation of wooden props to support certain walls.

But lasting solutions are “extremely complex”, explains Véronique Chankowski. “We must work in a multidisciplinary logic” in order to design “a protection ecosystem intervening in different areas”, according to her.  

Climate change, with the occurrence of extreme weather events such as the unprecedented heatwave that Greece experienced in 2023, has an impact on cultural heritage, according to a study carried out in Greece.

“Just like the human body, monuments are built to withstand different temperatures,” Efstathia Tringa, a meteorology and climatology researcher at the Aristotle University of Thessaloniki, told the Kathimerini daily.  

Rising temperatures and higher humidity levels could seriously affect the chemical composition of certain materials used in building construction.  

In Delos, excessive tourism also poses a threat.

On summer evenings, on the bare slopes of the island, you can hear the drumming music of the open-air nightclubs of Mykonos.

And during the day, boats discharge visitors from the turbulent and eccentric neighbor which attracts more and more cruise ships.

However, heritage is subject to “continuous trampling which sometimes occurs outside the marked trails”, according to Ms. Chankowski.