Venice was underwater this week throughout consecutive days of flooding. The high-water mark reached 187 centimetres, the highest level since the record 1966 flood, causing significant damage to iconic buildings such as the Basilica di San Marco cathedral and at least one death.
According to an expert, while this week's events come as a 'perfect storm' of meteorological phenomena, climate change and rising sea levels will have catastrophic effects for the city in the long term, as the city simultaneously sinks into the wet earth it rests upon.
"The sea level is rising," says Dr Luigi Cavaleri, Venice-born oceanographer and former president of the Italian Institute of Marine Studies of the National Research Renter (Centro Nazionale per la Ricerca).
"Ice is melting in Antarctica, Greenland, but also on the Himalayas, the Alps. The water goes into the ocean and therefore the sea rises. It also rises because the water is getting warmer as the atmosphere is warming up. And by getting warmer the water expands."
Dr Cavaleri says that globally sea levels are rising by 3.5 millimetres every year, while the city of Venice is, at the same time slowly sinking by one to two millimetres in the same timeframe.
"With respect to the sea, us Venetians are 0.5 centimetres lower every year, which does not seem much but in a century it becomes half a metre. For a city existing at practically sea level, it means that in 50 years high waters will become an everyday occurrence and not an exceptional phenomenon. We will practically be underwater."
According to Dr Cavaleri, who is currently monitoring the Venice situation from Melbourne, where he is chairing an oceanography conference, there is a possible solution, which is the ongoing construction of a barrier system at the entrance of the Venice lagoon, which will shelter the city from high waters.
People walk across the flooded St. Mark's square, after an exceptional overnight "Alta Acqua" high tide water level, on November 13, 2019 in Venice. Source: AFP
The system is called MOSE ('Modulo Sperimentale Elettromeccanico' or Experimental Electromechanical Module), an integrated system consisting of rows of mobile gates installed at three lagoon inlets that are expected to isolate the Venetian Lagoon temporarily from the sea during high tides. Together with other measures, MOSE is designed to protect Venice and the lagoon from tides of up to three metres.
The project, initiated in 2003 was 85 per cent complete in 2013, but after a series of delays and scandals caused it to miss its 2018 deadline, it is now slated to be finished by 2020, according to Venetian press.
And with Italian Prime minister promising a prompt completion of the MOSE in the aftermath of the week's events, Dr Cavaleri says the project might be already partially outdated by the time it is operative.
A man pumps out water from the flooded crypt of St. Mark's Basilica after an exceptional overnight high tide water level, on November 13, 2019 in Venice. Source: AFP
"There is the problem that the size of these barriers was decided based on climatological forecasts made 50 years ago, when sea level was rising by one to 1.3 millimetres per year. Now it rises 3.5 millimetres [per year] and it is probably accelerating, therefore these barriers will not be sufficient in the space of a few decades."
