10/06/2021 at 4:03 PM CEST
A new report highlights the strong environmental impacts generated by tourist cruises, authentic floating cities brimming with travelers that move from one point to another on the planet. Only the Mediterranean recorded in 2019 a traffic of 30.7 million passengers aboard cruise ships. The study carried out by researchers from the Universities of Exeter (United Kingdom) and Girona reveals that these ships pollute the air, sea and soil in a very noticeable way, and can endanger human health. A single cruise ship emits as much CO2 as thousands of cars, but the list of hits is much longer.
The study was based on more than 200 research articles about the impacts on the environment and also the health of people and has been published in the journal Marine Pollution Bulletin. This is the most complete work done so far on the pollution generated by cruise ships.
One of the main impacts is the emission of carbon dioxide, CO2, by the powerful engines that drive these boats. The authors note that a large cruise ship can have a carbon footprint greater than 12,000 cars.
Passengers on an Antarctic cruise, for example, can produce as many CO2 emissions during a seven-day voyage as the average European in their daily lives for an entire year.
In the Mediterranean Sea, it is estimated that CO2 emissions from cruise ships and ferries account for up to 10 percent of all emissions from existing ships, despite the fact that its fleet is relatively small.
A 2007 study already showed that emissions from cruise ships sailing through New Zealand were at least three times higher than emissions from international aviation. In addition, the energy consumption of an overnight cruise is 12 times greater than that of a hotel on the mainland.
But large amounts of Sulfur oxides (SOx) and Nitrogen oxides, as well as heavy metals. “Acid rain caused by SOx and NOx emissions can travel long distances from the point of their emission and have a potential for a greenhouse effect in coastal areas, as well as erode facades and sculptures,” the study notes.
In addition, these oxides have the ability to contribute to the acidification of the oceans through the alternation of the PH of their waters.
Another toxic component emitted by cruise ships, the authors add, are the ultrafine particles, a kind of soot that comes out of chimneys and that when inhaled by passengers it can be dangerous. The concentrations of these particles on the deck of these ships “is comparable to the concentrations measured in polluted cities, including Beijing or Santiago de Chile,” the study points out.
“Each of the gases and particulate compounds from cruise ship pollution can be detrimental to human health. In particular, SOx and NOx can cause premature death, including lung cancer and cardiovascular disease, ”the scientists warn.
A ton of trash a day on a single cruise
The document also addresses the generation of solid waste. The total amount of garbage produced by a cruise ship carrying 2,700 passengers can exceed one tonne per day. Although these types of ships represent only a small percentage of the global shipping industry, it is estimated that around 24% of all waste produced by maritime transport comes from this sector.
When studying the cruise trips to Southampton (United Kingdom) during August 2005, the study indicates that 75% of the garbage generated by the passengers was incinerated and disposed of at sea.
Also, the wastewater discharge from these vessels it entails the release into the sea of numerous fecal and pharmacological substances dangerous for the marine environment. In addition, these ships also release ballast water, used for the ship’s maneuverability, which may contain oils, sewage, microplastics and even invasive species, which are thus released to a medium other than their own.
The study also highlights the strong impact caused by Light pollution emitted by these ships, often provided with excess lighting at night, causing problems in the migration of some species and putting them in danger.
“We need global legislation to minimize damage to both our oceans and our health & rdquor ;, warns the first author of the study, the researcher at the University of Girona Josep Lloret.
Professor Lora Fleming from the University of Exeter added that “without new, strictly enforced national and international standardized rules, the cruise industry is likely to continue to cause these serious health and environmental hazards.”
The employer announces improvements
On the other hand, the employers’ association that groups the large cruise companies, CLIA, assures that the companies are making a great effort to reduce their environmental impacts. “Cruise lines work with scientists and engineers to develop cutting-edge and sustainable environmental innovations and practices, investing $ 1 billion in new technologies and cleaner fuels,” notes the CLIA website.
Among other things, it refers to the installation of cleaning systems for polluting gases on ships to reduce emissions by up to 98% in the case of sulfur oxides. They also announce the upcoming construction of ships powered by liquefied natural gas. In fact, the first of them has been operating since 2019. According to the employer, the energy efficiency design standards “will reduce CO2 emissions by 30% by 2025.”
Regarding waste, this business organization ensures that “waste management professionals on cruise ships recycle 60% more waste per person than an average person who recycles on land every day.” “Cruise lines recycle 80,000 tons of paper, plastic, aluminum and glass every year,” he adds.
Reference study: DOI: 10.1016 / j.marpolbul.2021.112979
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