Global Warming

Climate change challenges sinking city of Venice

The Italian city of Venice is prone to frequent flooding because it has sunk five inches over the last century, but it is also grappling with a new challenge: sea-level rise, caused by climate change, which increases the severity.

“Acqua Alta,” meaning high water, has always been a fact of life here. Several times a year, high tides and storm surges flood the city, especially the famous Piazza San Marco. The worst flood occurred in November 1966, when the Venice lagoon rose more than six feet above sea level.

Acqua Alta events are usually less than boot high, last just a few hours, and the city cleans up and goes back to normal. But floods also eat away at the soft, permeable bricks that sit above the foundations of the buildings. Over time, Venetians have raised their doorways and in some cases abandoned their ground floors. But the flooding is getting worse as the water level in the Adriatic Sea and Venice Lagoon rises due to climate change. The sea level alone has risen five and half inches since 1900, according to city officials.

The Italian government does have a plan to protect Venice. It’s called the MOSE project. Conceived in the 1970s, it’s a series of 78 underwater gates secured to the floor of the Venice lagoon. During especially high tides, they will be pumped with air and rise to the surface to block rising water from reaching the city. Four giant barriers across three inlets are scheduled to be operational by 2019.