In 1973, the Italian government established a legal framework for safeguarding Venice and its lagoon. Construction of the flood protection system started in 2003 and was used for the first time in October 2020 . This system of mobile barriers  closes the lagoon inlets to avoid floods when needed, while under normal conditions they lay on the seabed, thus allowing ship traffic and the exchange between the lagoon and the sea . To prevent flooding of the central monument area, additional measures have been proposed including inlets, expansion of salt marshes and pumping seawater into deep brackish aquifers to raise the city's level .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report