Air Emissions

Air emissions, including sulfur dioxide and nitrogen oxide, are regulated at the international, federal and state levels, and sometimes even at individual port levels. According to the International Convention for the Prevention of Pollution from Ships (MARPOL Annex VI), cruise ships in operation are issued an International Air Pollution Prevention Certificate, attesting to the fact that they meet the standards. The certification is conducted by port states, including the EPA and the U.S. Coast Guard. Similarly, going beyond what is required by regulators, new technologies being tested and used by cruise lines further and drastically reduce sulfur dioxide and nitrogen oxide emissions.

The cruise industry's emissions of carbon dioxide and other air emissions, on a per passenger basis, have been reduced in recent years. This has been the result of more fuel efficient ships coming into service and new technologies and energy management programs that reduce emissions. Some improvements on many ships include:
  • New engine designs, including diesel electric engines that allow much of the engine power to shut down when power demand is less
  • Highly sophisticated and optimized power management systems
  • Optimized hull designs to create smoother, more hydro-dynamically efficient hulls
  • Efficient heating, ventilation and air conditioning systems
  • Waste heat recovery and reuse systems
  • LED and compact fluorescent lighting

The cruise line industry has committed significant financial resources to developing and implementing new technologies that will further enhance performance. These include:
  • Alternative fuel options
  • Testing and applying alternative/renewable energy options (such as solar panels and onboard wind turbines)
  • “Slick” hull coatings (which reduce ship drag and thus also reduce fuel usage and emissions)
  • Interceptor plates (designed to “lift” the aft-body of the ship which reduces propulsion power demand and energy consumption) and “duck tails” (lengthening of the aft ship, reducing resistance, propulsion power demand, and energy consumption)
  • Window coatings (which prevent the sun's heat from penetrating glass, thus reducing air conditioning needs and saving energy)
  • Water use minimization (low flow showers and faucets, next generation icemakers, vacuum toilets, etc.)

Though it is still early in terms of its deployment at cruise ports, our industry is supportive of the potential benefits of shore-based power, also known as cold-ironing or alternative marine power, provided the power is cleaner than that which the ships generate. The industry is engaged at the international level in discussions regarding the adoption of a standard for cold-ironing connections and other technical elements, so that every ship fitted for shore-based power could connect at any equipped port around the world.

We are also optimistic about innovative “exhaust scrubber” technologies that reduce particulate matter and sulfur oxide gas (SOx) emissions to nearly zero. An in-depth feasibility study is underway, in cooperation with local regulatory agencies, the EPA and the British Columbia Clean Air Research Fund, to develop and test a stack emission scrubber for possible use on board cruise ships. The system uses the natural chemistry of seawater to remove sulfur oxide (SOx) as well as reduce particulate matter emissions. The sea water is then treated to remove harmful components prior to being discharged.

Shore PowerScrubber
Shore Power                                                                  Scrubber

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