The greenhouse gas (GHG) emissions — including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), expressed in CO2e — of total shipping (international, domestic and fishing) have increased from 977 million tonnes in 2012 to 1,076 million tonnes in 2018 (9.6% increase).
Whereas in a pdf from the EPA at the bottom of this page says passenger cars and light-duty trucks produced 1,046 million metric tons of CO2 in 2021.
So to recap, all maritime shipping in the world produced only slightly more CO2 than the passenger cars and light trucks only in the United States.