[LeifCarrotson]

> if we were to replace all of the world's fleet to be more energy efficient (which would almost by definition mean larger/longer ships, since they benefit from hydrodynamic efficiencies)

The hydrodynamic efficiencies are a small part of the problem, there are many other things that can be done. You don't need to scrap a perfectly good hull, you can simply choose to run slower, burn higher-quality fuels, or strap on an oxidation catalyst (DOC) to cut CO, particulate filter (DPF) to reduce particulate emissions, or add selective catalytic reduction (SCR) to reduce NOx emissions.

But until regulation and the market catch up, old ships will choose to run too fast, to burn whatever's cheapest, and to vent their exhaust directly into the atmosphere.

[LargoLasskhyfv]

Hrrm. Do you know why I am aware of

https://www.cma-cgm.com/news/2749/world-premiere-launching-o... and

https://www.cma-cgm.com/news/3379/world-premiere-bunkering-o... and

https://en.wikipedia.org/wiki/CMA_CGM_Jacques_Saad%C3%A9 and

https://en.wikipedia.org/wiki/Jacques_Saad%C3%A9-class_conta... ?

Because I've been curious after I've seen them coming into or leaving port while walking along the river.

Like: "Huh? LNG Powered? What does that even mean? Where would they store it?"

Several times. Business as usual now, it seems.

As is https://en.wikipedia.org/wiki/Slow_steaming

[AYBABTME]

You're entirely right, I just wanted to provide rough perspective on the complexity of actually overhauling the world's fleet.