Climate Change in the Lagoon of Venice

When I last passed Fondamente Nove in a vaporetto, I noticed a group of pupils and their teachers at work on the stone barrier beneath, collecting garbage like rotting bottles and plastic bags, abandoned just where the path gets rather narrow just east of the Ospedale stop.

There are those initiatives in Venice, spontaneously organized by people living in the neighborhood, that seldom appear on social media or in the papers. This was different from the event which took place today, when people were gathering on the island Sant’Erasmo to take part in a cleaning day organized by Piero Dri (Il Forcolaio Matto), which is beautifully described by Monica Cesarato in this article on her blog.

Keeping the Lagoon healthy and clean starts with many little gestures, in which we can all lend a hand (by disposing waste in garbage cans in the first place). Keeping the Lagoon free of pollution and thus healthy also depends from other factors we cannot influence, like seaquakes, tornadoes, and excessive high tides occurring every 150 years. We saw a “mild” example of such an excessive high tide on 30 October 2018, and a really bad one on 5 November 1966. Venetians have been living with near-catastrophes for centuries, just as people in Naples know that Mount Vesuvius most probably erupts every 100 years or so. Call it the risk that comes with living in a certain place.

Chances are that in the Lagoon, like anywhere else, a healthy environment makes all the difference, and the above-mentioned small-scale initiatives come first in a chain of events: Clean islands lead to healthy sandbanks (called barene) that are able to do the work they are expected to fulfill, like absorbing CO2 and airborne toxins, and filtering polluted Lagoon water.

When no cleaning is done, toxins accumulate and dissolve, littering the soil and leaking into the Lagoon, severely damaging the plants which grow on the barene. These plants (reeds, sea grass, limonium, and herbs) do all the work to absorb toxins, so the muddy sandbanks are key when it comes to keeping the Lagoon clean and resilient. Barene are also able to absorb toxins and emissions from oil tankers and cruise ships passing in the Lagoon. Healthy barene should also help in view of rising sea levels, as they are able to soak up loads of water. The issue with barene is that during the past thirty years, their number was reduced significantly, by more than one-third especially in the southern Lagoon. In their place, industrial zones now line the Lagoon.

The International Center for Climate Change broadcast an interesting webinar four years ago, explaining how swampy areas along the coast represent the most efficient protection for cities put at risk by rising sea levels. Swamps soak up excess water masses, and this explains why swampy areas, consisting mostly of the barene in the Lagoon, must be protected, so they can counter many effects of climate change in a natural way.

To make the barene system better known, a “walk along the barene” opens to visitors on 6 April 2019 on the island Lazzaretto Nuovo, called sentiero delle barene. The new passeggiata naturalistica leads along the barene surrounding the island. The walk was created by associations, such as Archeoclub Venezia, and the Venetian Museo Naturale. The walk also tells us a story of the past: When an earlier warming of the earth took place around the year 1650, Venetian engineers recurred to the concept of creating barene as barrier, and cultivated them around most Lagoon islands. In this way, barene protected the islands from being flooded.

But is the current climate change already manifest in the Lagoon? We notice that the Lagoon flooding cycles are changing. Acqua alta (excessive high tides) happens less often during winter, while the number of serious flooding episodes is increasing. The area around the island Torcello in the northern Lagoon, that you can see above, is healthy and could become a role model for creating a sustainable Lagoonscape, capable of surviving rising water levels.

This is because Laguna Nord, contrary to what happened to the southern Lagoon, hasn’t been altered to create industrial zones (there are no casse di colmata, and no deep shipping lanes to let oil tankers and cruise ships pass). The Lagoon never looked like the deep blue waters you can see when your plane lands in Venice these days. Until 1850, you would have seen a swamp from above, with some blue patches in-between, as the Lagoon was already on its way to slowly turning into an arm of the sea. The Lagoon looked like in the photos in this post, covered with dirt-brown and yellowish marshlands (velme) and sandbanks (barene), turning purple in late summer when limonium (sea lavender) is in bloom.

We could of course argue that rising sea levels will be worse than the global warming episode occurring in 1650, after the end of the little ice age. Previsions are always difficult, but making a Lagoon more resilient and healthy should help in any case. In addition, Venetian engineers in the years following 1650 built the Murazzi stone barriers on the Lido and Pellestrina islands to protect the Lagoon from being flooded in view of rising sea water levels. They also closed two inlets and narrowed the remaining three. And they would never have allowed deep-water canals bringing in the floods.

Thus, for saving the Lagoon from rising water levels, the barene are key. Today, we still benefit from the wise work of engineers of the past, despite all those significant changes the Lagoon ecosystem underwent in the last 60 years. Below you can watch a short video of scientists, historians, and sustainability experts sharing opinions on saving the Lagoon. I find the video shows the wide spectrum of diverging opinions, even though I don’t like the title “sinking city”, because Venice doesn’t have to sink.


Climate change is also the monthly topic we will cover in the Venice Culture + Heritage Class in April 2019.

Resources for responsible visitors in this blog post:


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  1. interesting, informative and well thought out

    Posted 4.13.19 Reply
    • Iris wrote:

      Thank you! So kind of you to say. xx Iris

      Posted 4.14.19 Reply

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