Venice’s flood risk is shaped by two changes at once: the sea rises and the land can sink. That is the central question in Planet Classroom’s Net Zero Speaks conversation with University of Padova professor Marco Marani, hosted by youth climate advocate Ivan Ransom. The episode, which premiered October 1, 2026, discusses Venice, vulnerable river deltas, salt marshes and climate adaptation. Watch the episode on Planet Classroom.
What happens when the sea rises and the land sinks?
The relevant measure for a coastal city is relative sea-level rise: the change in water level compared with the land beside it. A rising ocean raises the waterline; subsidence, or downward land movement, can make that waterline rise faster locally. A global sea-level average therefore cannot, on its own, describe Venice’s changing exposure. Italy’s National Institute of Geophysics and Volcanology (INGV) identifies subsidence as an accelerator of local sea-level rise in the Venice Lagoon, and the environmental agency ISPRA likewise attributes Venice’s mean-level increase to both global sea-level rise and local subsidence.
That distinction matters when interpreting numbers. ISPRA’s Venice indicator gives a 2024 mean sea-level value of 4.1 cm on its stated ZMPS reference. This is an observed indicator value tied to that reference—not a flood depth, a yearly rise, or a projection. ISPRA’s Venice sea-level indicator provides the measurement context.
How high could water levels rise in Venice?
Available figures describe different horizons and scenarios, so they should not be read as one continuous forecast. The 2024 ISPRA indicator is an observation; the INGV figures below are scenario-based assessments with different methods and reference points.
#1 Best Overall
| Figure | What it describes | How to read it |
|---|---|---|
| 4.1 cm in 2024 | ISPRA’s observed Venice mean sea-level indicator on its stated ZMPS reference. | An observed value, not a projected rise or flood depth. ISPRA |
| Approximately 82 cm by 2100 | INGV’s 2020 release summarizing a 2019 study’s estimate of average sea-level rise in the Venetian Lagoon when climate change and subsidence are combined. | A study estimate for a specified horizon, not a certain outcome. INGV |
| 3.47 m above the Punta della Salute tide-gauge reference in a worst-case 2150 scenario | INGV’s 2025 summary of a scenario for extreme high water. | A scenario figure with a different horizon, measure and reference from the 2100 estimate; do not combine the two. INGV |
The same 2025 INGV summary gives potentially submerged areas of 139 km², rising to 226 km² under the exceptional high waters described in its scenario. These are modeled potential inundation areas under the study’s assumptions, not a map of certain future flooding. Read INGV’s scenario summary.
Can MOSE protect Venice from future high water?
MOSE is Venice’s mobile barrier system, but its protection has operating conditions and cannot be treated as an unlimited answer to rising relative sea level. INGV’s 2025 summary says the system is designed for a difference of up to 3 m between sea and lagoon and a mean sea level of 60 cm in 2100. The scenarios assessed in that summary could exceed those conditions late in the century. That is a conclusion about the scenarios studied, not a claim that a particular failure or flood date is certain. INGV’s 2025 release discusses the scenarios and their implications.
Rank #2
- Ideal for Gifting
- Ideal for a bookworm
- Compact for travelling
Barriers are one part of adaptation, not a substitute for understanding how natural systems change alongside them. The Planet Classroom episode frames the issue around the interaction between engineering and ecological processes, including the resilience of wetlands and salt marshes. Planet Classroom’s episode page outlines the conversation.
Why salt marshes matter to coastal protection
Salt marshes can buffer flood impacts and support fisheries, but their contribution depends in part on sediment accumulating quickly enough to keep pace with rising water. If relative sea level rises faster than marsh surfaces build upward, a wetland’s ability to persist and provide protection can be undermined. Marani’s discussion puts these habitats within the wider adaptation question: coastal protection is not only about structures, but also about maintaining the natural processes that sustain wetlands.
How should coastal communities compare adaptation choices?
There is no universally best option in the sources discussed here. The useful comparison is location-specific and considers both flood exposure and the ecological and geological effects of an intervention.
- Engineered barriers: Assess how much flood exposure they reduce and how their performance changes as relative sea level rises.
- Wetlands and salt marshes: Consider whether sediment delivery and marsh resilience can keep pace with water-level change, as well as their role in buffering floods and supporting fisheries.
- Managed retreat or realignment: Evaluate whether moving people or infrastructure away from exposed areas is feasible in that location.
These approaches are not interchangeable. A sound plan weighs protection, marsh and sediment dynamics, changing relative sea level and whether retreat is realistically possible, while accounting for local scientific, geological and ecological conditions.
Rank #4
Who is Marco Marani?
Marco Marani is a professor at the University of Padova whose institutional profile describes work on hydrology, coastal systems and climate impacts. In the Planet Classroom Net Zero Speaks episode, host Ivan Ransom speaks with him about sea-level rise, sinking coastal land, flood risk and adaptation, using Venice and vulnerable river deltas as examples. University of Padova profile | Episode details and video.
Quick Recap
Best Value
- It can be a gift option
- Comes with secure packaging
- Helpful in various ways
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →
