Concerns over the IPCC report. Engineer Rusconi: the continual raising of MoSE will have consequences for the Port
By Alberto Vitucci
9 July 2021
VENEZIA. Sea level rise that ranges from 43 centimeters to 84 centimeters by the year 2100, to which will be added more centimeters due to subsidence, that is, the lowering of the soil level. The scientists of the world are not lowering their guard in facing climate change. And they remember the last special report published by IPCC (the International Panel on Climate Change) on the oceans and the cryosphere at the end of 2019. That data is dramatically current, and the result of research supported by scientists from countries all over the world.
The increase in sea level continues, due to a changing climate and the melting of the glaciers. Complicated by weather and extreme events, as we saw in the lagoon on 12 November, 2019, the trend is clear. Without interventions to limit greenhouse gasses the temperature of the planet will rise by a degree within a few years, and the level of the world’s waters will rise faster, from 1.9 millimeters a year in the last century to 5.61 mm now. The result is that at the end of this century the most optimistic scenarios forecast sea level rise of 43 centimeters. The “pessimistic” scenario calls for 83 centimeters, which could be further increased by subsidence. “It means”, warns hydraulic engineer Antonio Rusconi, former director of the Bacino and Hydrographic Authority, “that in a few years tides higher than 80 cm will be a daily occurrence, even twice a day. MoSE, if it is completed and functional, would have to be raised every day, with serious consequences for the Port and the lagoon”.
The sums, after all, speak clearly. In the last decade (2010-2019) the number of tides higher than 110 cm has almost doubled, with 95 events compared to 45 in the preceding decade (2000-2009). From 1990 to 2000 there were “only” 44 tides over 110 cm.
The frequency of exceptional high tides over 140 cm is also dramatic. At that level the local defenses are no longer adequate and the city is almost completely flooded. In 2019 there were 5 tides of this type. In the previous 150 years there were 21. Also in 2019, the second highest event in history took place, with a record level of 189 cm. The three instances of tides greater than 160 cm have all taken place in the past 54 years. Ever since the tampering and excavations in the lagoon began.
A tidal alarm is growing closer and closer, threatening Venice, but also the coastal areas and the river deltas, which are also observed by the Municipal Center for Tide Prediction, directed by Alvise Papa.
The issue was also discussed during a conference for the project “Venezia 2021”, organized by Colia. The research body, chaired by an instructor at Ca’ Foscari and directed by Pierpaolo Campostrini, has collaborated for twenty years in the activities of Consorzio Venezia Nuova and the Magistrato alle Acque.
Now it has obtained 10 million Euro from the Superintendency to finance the 2021 project and collect data about the lagoon.