Tudom, hogy eléggé vadul hangzik, de javaslom tanulmányozni az ehhez tartozó felméréseket, irodalmakat :)

https://www.quora.com/Is-it-true-that-the-15-biggest-ships-in-the-world-produce-more-pollution-than-all-the-cars

 

https://www.theguardian.com/environment/2009/apr/09/shipping-pollution

 

https://www.transportenvironment.org/what-we-do/shipping/air-pollution-ships

 

http://www.industrytap.com/worlds-15-biggest-ships-create-more-pollution-than-all-the-cars-in-the-world/8182

 

http://www.marineinsight.com/shipping-news/us-doj-ship-pollution-cases-paid-highest-criminal-penalties-2016/

 

Egy kicsit bulvárosabban: http://www.dailymail.co.uk/sciencetech/article-1229857/How-16-ships-create-pollution-cars-world.html