Scientists warn that no protective measures can save Venice, as the rising sea level threatens to engulf the city. Thus, the Serenissima may be forced to relocate in the future as scientists desperately try to save it from the growing threat of flooding.
A new report, published in the journal Scientific Reports, and cited by Euronews, assessed the existing and potential protection strategies for the Italian city, based on sea level rise projections included in the UN’s Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report.
Venice, a UNESCO World Heritage Site, has experienced increasing floods over the past 150 years. Last summer, heavy storms swept through the area, causing drainage systems to overflow and streets to turn into raging rivers.
In 2019, severe floods caused the death of two people and damage worth hundreds of millions of euros, including in the tourist area of St Mark’s Basilica. Glass barriers and a €3.3 million restoration plan were revealed in 2023 to protect the 900-year-old church, which remains at the mercy of the tides.
Scientists have now outlined three possible protection strategies for Venice, warning that immediate, rapid action is “necessary”. The study’s authors argue that Venice is an example of the challenges that many low-lying coastal areas will face due to sea level rise in the coming centuries, including the Maldives and the Netherlands.
Possible relocation of Venice
The authors predict that dikes may be needed in the event of a sea level rise of more than 0.5 meters – something that could happen by 2100, even if emissions remain low – with an estimated cost of between 500 million and 4.5 billion euros.
These are artificial embankments, usually made of soil, sand or rocks, along the coast or rivers and act as a barrier against possible floods.
The closure of the lagoon with a wide reinforced dike could also be viable in the event of a sea level rise of more than 0.5 meters and protect the city from a sea level rise of up to 10 meters. However, the initial cost for such a project is estimated to exceed 30 billion euros.
As a last resort, the study states that the relocation of the city, its residents, and its historical landmarks may be necessary if the sea level rises above 4.5 meters, which is expected to happen after 2300, while the related cost is estimated to be up to 100 billion euros.
The study’s authors warn that the construction of large-scale interventions, such as permanent dams, can take anywhere from 30 to 50 years, which means that timely planning is necessary.
“There is no best strategy for Venice”
“Our analysis shows that there is no optimal strategy for Venice,” says Professor Robert Nicholls of the Tyndall Centre for Climate Change Research at the University of East Anglia.
“Any approach adopted must balance multiple factors, such as the well-being and safety of the inhabitants of Venice, economic prosperity, the future of the lagoon’s ecosystems, the preservation of the region’s cultural heritage and traditions and culture,” he adds.
According to him, all low-lying coastal areas should recognize the challenge of long-term sea level rise and “start examining the effects of climate change now”.
“Given the high cultural value of Venice, these costs are clearly insufficient and no protection measure can preserve the Venice we see today in the long term,” he claims.
Why is the sea level rising in Venice?
Venice is already at risk during high spring tides due to its location in a shallow coastal lagoon.
According to the Royal Museums Greenwich, the sirocco seasonal winds can cause “storm surges”, carrying water through the Adriatic Sea towards the lagoon and the city. When tides and storm surges collide, flooding can be extreme.
Global warming also accelerates the rise of sea levels worldwide due to the combination of melting glaciers and thermal expansion of seawater as it warms.
Even worse, the ground level of Venice is sinking by about 1 millimeter per year due to natural soil shifts. This phenomenon has been exacerbated by human activity, such as pumping groundwater from beneath the lagoon. However, this is now prohibited.
