[Reply to “Did the Italian Government approve an obsolete project to save Venice?” by P.A. Pirazzoli] Obsolete? No. Necessary! Yes. The gates will save Venice



We are confused by Paolo Antonio Pirazzoli's argument in these pages that the proposed sea gates to protect Venice from flooding by exceptional tides will not work in the event of sea-level rise. In fact, the two case studies he provides show that they would protect the city. In his examples, Pirazzoli arbitrarily adds a very large, 50-cm sea-level rise to the peak level of the October 1976 flood, which was a week-long event. A 50-cm rise in sea level corresponds to the Intergovernmental Panel on Climate Change's central value within an extraordinary range that he cites as 9-88 cm of sea-level rise at the end of 100 years. Even if one accepts this number, given the range of uncertainty, recall that it is the assumed sea-level rise at the end of 100 years.