Container shipping accounts for ~2.2% of CO2 emissions: https://en.wikipedia.org/wiki/Environmental_effects_of_shipping https://en.wikipedia.org/wiki/Environme

Container shipping accounts for ~2.2% of CO2 emissions: https://en.wikipedia.org/wiki/Environmental_effects_of_shipping https://en.wikipedia.org/wiki/Environmental_effects_of_shipp... You're probably thinking of other emissions. They burn heavy fuel oil, so they emit a lot of sulfur.