Concrete alone is responsible for 8% of global CO2 emissions: https://www.theguardian.com/cities/2019/feb/25/concrete-the-...

Also the problem with the cargo ships isn't the CO2 - considering the amount of work they are doing they are the most efficient transport method we have. It's all about the sulfur emissions which are horrendous.

Animal agriculture accounts for 14.5% of global anthropogenic emissions, over half of which comes from cows.

http://www.fao.org/news/story/en/item/197623/icode/#:~:text=....

Fashion industry is responsible for 10% (Aviation is 2.8%)

If it was only shipping it would be small enough to not worry about. The world was slightly CO2 negative long term before modern burning of buried fuels, so a small amount (but probably not 2%) could be called useful.