A new study in Scientific Reports highlights the urgent need for adaptation strategies to protect Venice from rising sea levels, as outlined in the IPCC’s Sixth Assessment Report. The city, a UNESCO World Heritage Site, has faced increasing flooding over the past century, with notable severe incidents causing significant damage, including in St. Mark’s Basilica.
Researchers have proposed three potential strategies for Venice to combat flooding, stressing that immediate action is crucial. If sea levels rise by more than half a meter, artificial levees costing between €500 million and €4.5 billion may be necessary. More robust protective measures, like "super-levees," could be viable for higher sea levels, although they would entail costs exceeding €30 billion.
In extreme scenarios, should sea levels rise by over 4.5 meters, relocating cities and historic buildings could cost up to €100 billion and may be required by 2300. The study’s authors emphasize that planning large-scale interventions is critical, taking 30 to 50 years to implement.
Professor Robert Nicholls noted that there’s no one-size-fits-all solution for Venice, as adaptation must consider the well-being of its residents, economic factors, and cultural heritage. He warned that the city and other low-lying coastal areas should start addressing these challenges now.
Venice’s susceptibility to flooding is due to its shallow lagoon setting, seasonal winds causing storm surges, and ongoing ground sinking—currently about 1 mm per year—exacerbated by historical groundwater extraction, which is now banned. Global warming is accelerating sea level rise through glacier melting and ocean expansion.
