Acting as the backbone for global trade, shipping provides essential products, materials, and services to millions around the world. However, the environmental effects of shipping are highly detrimental to the environment with the industry being responsible for more than 18% of some air pollutants.
Alongside this, The International Maritime Organisation has estimated that CO2emissions from shipping were equivalent to 2.2% of the global human-made emissions in 2012, which are expected to rise...
https://www.ship-technology.com/features/maersks-methanol-mission-a-greener-future-for-shipping/