Looks like another intermediate option is bio-methanol. But, both options are very rare, with diesel being the overwhelming majority of international shipping.

Shifting to either would be a very significant improvement over the status quo. Whether that meets EU requirements is another matter.

https://www.reuters.com/markets/commodities/maersk-buy-bio-m...

Yep, everything is on the table. All done through complete lifecycle well to wake calculations to prevent hiding emissions in intermediate steps.

Works by forcing say 2% green fuel in 2028 and then a market for shipping companies to buy and sell rights. The requirement will increase every couple of years.

Which means old ships will continue to operate but will have to pay for their emission to greener vessels. Thus we have a very direct gain from going all the way rather than half hearted attempts, allowing modern green vessels to make a business case on selling their credits by being over performers.