The record water level, the highest in 50 years, led Brugnaro to ask Italy's government for assistance and to declare a state of emergency in the city after at least two people were reported dead in the flooding.
"These are the effects of climate change," the mayor tweeted.
This week's flooding marked the second-highest water level recorded in Venice since city officials began keeping records in 1923. The first time was in 1966 when three inches of rain covered the place reaching six feet too.
⚦nbsp;Anche oggi affrontando maree che segnano record negativi. Domani dichiareremo lo stato di calamitænbsp;. Chiediamo al #Governo di aiutarci, i costi saranno alti. Questi sono gli effetti dei cambiamenti climatici. Il Mose va terminato presto. Domani scuole chiuse a Venezia e isole. pic.twitter.com/iD2Y7mbOBf
Even today, facing tides that mark negative records. Tomorrow we will declare a state of emergency. We ask the government to help us, the costs will be high. These are the effects of climate change.
The ancient cathedral St. Mark's Basilica flooded for only the sixth time in 1,200 years. However, church officials said four of those times have been in the last two decades as fossil fuel emissions and sea levels have both gone up.
"I usually associate climate change with dramatic catastrophes like hurricanes and forest fires but this is silent and creeping," one local observer wrote. "Residents are adapting by scheduling meetings earlier or later, shops place wooden barriers to block water and there are ramps in low elevation spaces but it is clear that it is getting worse every winter."
Greenpeace cautioned against dismissing the flooding as the result of Venice's location in the Venetian Lagoon. "From north to south, Italy has been impacted by a series of extreme climate events," Greenpeace Italy tweeted. "What's happening in Venice is a powerful example. This is not just 'bad weather,' this is a climate emergency."
Climate experts Katharine Hayhoe, Eric Holthaus, and Bill McKibben added that the climate crisis is worsening weather events' effects on the low-lying city.
Climate experts, including Katharine Hayhoe, Eric Holthaus, and Bill McKibben, noted that low-lying cities like Venice are becoming increasingly vulnerable to extreme weather and rising seas caused by rising global temperatures.
The Italian government announced earlier this month that school children would be required starting in 2020 to study the climate crisis as part of their curriculum, in an initiative pushed by Education Minister Lorenzo Fioramonti.