Commercial cruise lines are some of the world's worst polluters, and Carnival is near the top of that list according to a study of European cruise line operators. Research found that Carnival alone is responsible for almost 10 times as much sulfur dioxide release as all 260 million of Europe's cars combined. The study from Transport & Environment says that the 203 cruise ships that operated in European waters in 2017 emitted a combined total of 62 kilotons of sulfur oxides (SOx), which form airborne gases known to cause lung cancer and acid rain. During the same period, Europe's 260 million known registered vehicles let out just 3.2 kilotons, the study found. Of these 62 kilotons of SOx, more than half allegedly were the product of the 47 ships operated by Carnival Cruise Lines or its subsidiaries.

Transport & Environment

Of the 20 worst offenders, seven are Carnival properties, which together made up half of the industry's SOx emissions in Europe. Carnival denied any wrongdoing when asked for comment by Fast Company, pointed the finger at the rest of the maritime transportation industry, and insinuated that the study's methodology was unscientific.

CLIA and its cruise line members are committed to a zero-emission future, as is the entire maritime sector. The cruise industry represents less than 1 percent of shipping and is making progress towards this goal, but it will take time. [...] There is further concern that the results have been published without any academic scrutiny, peer review or scientifically-robust methodology.