Will Venice be swallowed up by the waves in 2100? To avoid this catastrophic scenario mentioned by scientists, the City of the Doges is trying to raise awareness among younger generations about the protection of the lagoon, a very fragile ecosystem threatened by climate change.
The “acqua alta”, a particularly high tide, regularly floods the famous Piazza San Marco, a phenomenon that entertains tourists but jeopardizes the foundations of the old palaces of the Serenissima, listed as a UNESCO World Heritage Site.
If UNESCO had threatened in 2021 to put Venice on the list of world heritage in danger, the lakeside city escaped it in extremis thanks to the ban on large cruise ships entering the heart of the lagoon.
To contribute to the safeguard of Venice, UNESCO, associated with the luxury group Prada, launched an initiative on Tuesday aimed at introducing young students aged three to six to the secrets of the lagoon.
The island of Torcello, located north of the lagoon, with its salt marshes whose banks are eroded by the waves caused by motorboats, was the scene of the first outdoor lesson of this educational program called “Jardin of children of the lagoon”.
Fish made from recycled papier-mâché, samples of seawater, drawings reproducing the colors of nature… the small group of around forty enthusiastic five-year-old children tried to appropriate the lagoon .
“We want children to learn to observe nature and the lagoon, to learn to know it, to love it and to protect it better,” said Francesca Santoro, coordinator of the initiation to the ocean program of UNESCO.
Artificial dikes
This educational project is considered useful by Georg Umgiesser, director of research at the Institute of Marine Sciences of Venice (ISMAR-CNR), because “it is not enough to show simple graphs illustrating the rise in sea level”.
“As a result of the subsidence of the ground of Venice and the rise of the sea, the average sea level has risen by 30 cm in the last 150 years and is expected to rise by more than 50 cm by the end of the century “, he explains.
St. Mark’s Square, which is located in the lowest part of the city, is the first to be flooded, and “in 2100, half of Venice risks being under water”, fears this German oceanographer who lives in Venice for 40 years.
Since October 2020, a system of artificial dikes called MOSE (Moses in Italian), has been triggered as soon as the rise in the waters of the Adriatic Sea reaches an alert level of 110 cm.
This system, developed in the 1980s, before global warming accelerated, will it be sufficient to prevent the engulfment of Venice?
According to Mr. Umgiesser, this mechanism risks reaching its limits. “The MOSE was designed to shut down a maximum of 50 times a year. If the sea level rise continues at this rate, from 2100, it would have to be triggered 300 to 400 times a year”.
Biodiversity at risk
At that time, the lagoon would be effectively closed, which would prevent the exchange of water with the sea, essential for preserving biodiversity.
There remains another solution, which would consist of “raising the terrain of Venice by 30 to 50 cm by injecting seawater into its basement”, he explains. But such a scenario is still far away.
In the meantime, Jane da Mosto, director of the environmental NGO We are here Venice, is banking on salt marshes to curb theacqua-alta and attenuate currents, as natural barriers.
Restoring these wetlands, decimated by climate change and urbanization, would be, according to her, a natural solution to save Venice and its lagoon.
“Salt marshes act like sponges and can therefore slow down currents, reduce wave energy and thus reduce water levels,” explained this environmental specialist.
“It’s a race against time. We must act now. We are in a climate emergency, the disaster is already happening,” she warned.