Shipping is a big polluter so the freight giants are trying new cargo ships powered by wind or green methanol

• The International Maritime Organization is hoping to reduce shipping's greenhouse gas emissions.
• Two cargo ships have launched in the last five weeks that could help achieve that.
• Maersk launched a methanol-powered vessel last month, and Cargill announced a wind-powered one on Monday.

Shipping is an increasingly polluting industry, responsible for 3% of the world's greenhouse gases according to research from the European Union.

The UN's International Maritime Organization announced plans in 2020 to reduce the sector's emissions by 50% by 2050.