Study outlines four paths to save Venice from rising seas

Friday 17 - 08:20

By: Dakir Madiha

Study outlines four paths to save Venice from rising seas

A new European study has identified four possible futures for Venice as rising sea levels threaten the historic city, warning that without swift action the UNESCO World Heritage site could be lost within centuries.

The research, published in Scientific Reports and led by oceanographer Piero Lionello, presents a framework of “adaptation pathways” to assess which strategies may remain effective under different sea level rise scenarios outlined by the Intergovernmental Panel on Climate Change.

The study examines four main options. The first maintains the current “open lagoon” system using mobile barriers such as the MOSE system, already deployed to block high tides. The second proposes building ring-shaped levees around key parts of the city. The third suggests permanently closing the Venetian lagoon with coastal dams. The fourth considers relocating residents and cultural landmarks inland.

Researchers found that the MOSE system could manage sea level rise of up to about 1.25 meters. However, this threshold is likely to be exceeded by 2300, even under low-emission scenarios, due to both rising seas and the gradual subsidence of Venice.

More extensive engineering solutions could provide longer-term protection. Ring levees and full lagoon closure would extend resilience, with the latter capable of withstanding up to 10 meters of sea level rise. However, sealing the lagoon would end Venice’s role as an active port and carry an estimated cost of around €30 billion. Relocation, described as the most radical option, could reach €100 billion including compensation and the transfer of historic structures.

The study identifies a critical “adaptation tipping point” when relative sea level rise reaches between 0.75 and 1.75 meters. Beyond this range, existing strategies would fail to meet protection goals. Under high-emission scenarios without further measures, the current system is expected to become insufficient before the end of the century.

Each option preserves different aspects of Venice’s economic, environmental, social, and cultural value. As sea levels continue to rise, the range of viable solutions will narrow. The authors stress that planning must begin immediately, noting that large-scale infrastructure projects can take up to 50 years to move from concept to completion.

The findings reinforce calls for urgent action. The researchers warn that the future of Venice will depend on near-term decisions, including whether to pursue incremental adaptation, undertake transformative engineering, or ultimately abandon the city.