> Separate studies suggest that maritime carbon dioxide emissions are not only higher than previously thought, but could rise by as much as 75% in the next 15 to 20 years if world trade continues to grow and no action is taken. The figures from the oil giant BP, which owns 50 tankers, and researchers at the Institute for Physics and Atmosphere in Wessling, Germany reveal that annual emissions from shipping range between 600 and 800m tonnes of carbon dioxide, or up to 5% of the global total. This is nearly double Britain's total emissions and more than all African countries combined.[1]
> Passenger Cars: 749.4[2]
[1] https://www.theguardian.com/environment/2007/mar/03/travelse...
[2] https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100USI5.pdf
According to the data it appears I am not completely wrong. The maritime transportation sector is of roughly equal CO2 contribution to the US passenger vehicle fleet in 2007. According to the trend indicated by The Guardian in the next 15-20 years (from a 12 year old article, which would be a few years from now) maritime transportation emissions could rise by 75% while the US passenger auto fleet emissions remain flat thereby indicating a slice of tankers contribute more CO2 emissions than passenger vehicles.
These sources weren't hard to find or read, so I am not sure why you think my statement is false.