The global shipping industry is facing calls to follow the example of the car industry and cut its carbon emissions.
The International Maritime Organisation's environment committee is meeting in London this week to try to agree a global plan for reducing emissions levels.
Without a clean-up there are warnings that shipping could account for almost a fifth of carbon emissions by 2050.
Container ships use fuel that has 3,500 times more sulphur than car diesel.
International shipping carries about 90% of world trade but there has been no regulation of carbon emissions.