Venice: Boats and Biofuels

Venice is an amazing place to visit. With its gorgeous buildings and canals, and the crazy neighborhood street design, it’s one of the most fascinating urban places I’ve ever explored.

Obviously, I’m not the only person who feels like that: it’s also probably the most touristy place I’ve ever been. HUGE cruise ships dock every day in Venice, leaving thousands of people to explore the city. Happily, though, outside of some of the key places, it’s actually pretty easy to get away from the big crowds and explore.

It’s hard to not see Venice as a deeply vulnerable place, though. It basically sits at sea level,

about 6 feet below where it used to be when people decided to build a city in the Adriatic Sea. As sea levels have risen, though, Venice now often actually finds itself below sea level when the acqua alta (high water) inundates the city during the winter high tides. The frequency of the inundation has increased over time, causing damage both to Venice’s tourist economy and, more importantly, to its infrastructure.

To address the immediate problem, government officials have decided to build huge gates along the edge of the Venetian lagoon that would presumably keep rising sea levels at bay during acqua alta events. The gates would go up during high tides and then go down when the high waters subside. Environmentalists and scientists worry that the gates will interfere with other natural processes of the lagoon, including flushing of treated sewage out of the lagoon, but it looks like construction of the gates is underway.

Speaking of sewage, Venice has a longer term strategy to address the primary cause of rising sea levels: emissions of greenhouse gases from fossil fuels. Two years ago, Venice announced plans to build a plant that would create biofuels using algae that feed on sewage. The biofuels would then be used to produce electricity and as a fuel source for motor vehicles. In many ways, creation of fuels seems like an ideal strategy for Venice, since the vast majority of motor vehicles are boats. While gondolas readily spring to mind when one thinks of boats in Venice,

motor boats are much more common in providing public transportation,

deliveries,

construction,

emergency medical services,

and, of course, gelato conveyance.

Boat engines, though, are notoriously dirty. They discharge fuels directly into the water and they emit a lot of air pollution. Plus, the extraction, refining, and transport of petroleum used in the boats contribute significant amounts of pollution. If boats in Venice were to switch to locally produced biofuels, they would reduce the petroleum-based emissions and emit fewer pollutants overall.

Venice’s algae-based biofuel plan has particular promise because it relies on sewage for fertilizer. Some lifecycle analyses initially concluded that algae biofuels grown with petroleum-based fertilizers might be worse emitters of greenhouse gases than even corn ethanol. Algae grown in sewage, in contrast, does not need additional fertilizers and it even helps with sewage processing. With the number of tourists who visit Venice every year, Venice seems to have an endless supply of fertilizer. I hope it will succeed in using it to create a more sustainable and locally produced fuel.

[All photos by Mark Riskedahl]