Green Corner: Sustainable Travel – cruise ships

Pia Amberger, Environmental Management Division, USAG Ansbach DPW

ANSBACH, Germany (Aug. 1, 2017) — To bring our segment on sustainable travel to an end, there is one last form of transportation we have yet to talk about: cruise ships.

Around 24 million passengers took a cruise on the world’s oceans last year (up from 19 million in 2010). While they are an exciting and relaxing way of travel to some of the most exotic and beautiful places on earth, to the areas they travel through cruise ships represent an enormous environmental strain.

The majority of cruise ships are powered by one of the cheapest types of fuel: heavy oil, which is a highly toxic waste product of the petrochemical industry and has a sulfur content of up to 3.5 percent. Depending on the size of the ship and the duration of the cruise, each trip burns between 150 and 400 tons of heavy oil. One cruise emits as many pollutants as 5 million cars for the same route. Only a few ships use particulate filters like the ones built into cars as there are no legal obligations for that on the open sea.

Cruise ships consume the energy of a small town. Around 40 percent of a trip is spent docked in various ports. Even then, the engines are kept running to continue regular operations like catering, lighting and air-conditioning. Only a handful of cruise ships are capable of using shore power, and most often they decline to do so as it is more expensive. Studies show that ports used by cruise ships have a 50 to 80 percent higher fine-dust pollution than in heavy-traffic areas.

Cruise ships are also responsible for a number of waste streams that are discharged into the marine environment. That includes sewage, greywater, some hazardous wastes, oily bilge water (a mixture of fresh water, sea water, oil, sludge, chemicals and various other fluids), ballast water and solid wastes. Most often these get dumped straight into the ocean. When these wastes are not properly treated and disposed of, they present a significant source of pathogens, nutrients and toxic substances that have the potential to threaten human health and damage aquatic life.

Cruise ships especially have a large impact on the environment because they tend to use the same routes in specific coastal areas and dock in the same ports repeatedly (e.g. Florida, California, New York, the Caribbean or the waters of Alaska). Therefore, they also have a significantly large cumulative impact on a local scale.

If you don’t want to forego a cruise, there are three things you can do before booking a trip. There are several websites like ATMOSFAIR where you can compensate the CO2 emission that your cruise trip has and donate money to various climate-protection projects all over the world. You can also look at the annual NABU (German Nature and Biodiversity Conservation Union) cruise ship ranking for European cruises to find out which ship has the smallest environmental impact. A similar list that ranks non-European cruises is available at And lastly, don’t fly to the port where the ship is docked. Get there by public transportation like a train or bus. As shown in the June edition of this newsletter, they emit much less CO2 than the plane.

Check out Part 1 of this column HERE.

Check out Part 2 of this column HERE.

Check out the August 2017 environmental newsletter HERE.

Check out more environmental news from the Environmental Management Division HERE.

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