European Commission proposals to bring shipping into the bloc's carbon market contain exclusions for small commercial and military vessels that would leave millions of tons of carbon dioxide emissions unregulated, a study by a nongovernmental organization showed on Thursday.

With about 90% of world trade transported by sea, global shipping accounts for nearly 3% of the world's carbon dioxide emissions. So far, the industry has avoided the EU's system of pollution charges.

Under proposals announced in July 2021, shipping would be added to the European Union Emissions Trading System (ETS) from 2023 phased over a three-year period, a move designed to spur emissions cuts from the sector.