Originally a comment by Pliny on Stuck.

WooHOO!, a discussion about ships, something this old salt can contribute to. Carbon footprint wise, it’s hard to compete with these giants on an emissions per cargo ton carried level. They are extremely efficient which is why there has been a move to larger and larger ships – fewer sailors and lowered fuel costs per ton. Remember, the construction and operating costs of these ships pencils out in a global marketplace. It’s part of the reason you can buy less expensive goods manufactured overseas.

If you want to rail against emissions, it’s better to go after interstate trucking in the USA. Compared to rail transport, semis double the carbon footprint per ton carried. They also suck when following too closely during rush hour.

As for nuclear power, only one civilian transport has ever been nuclear powered under a US flag – the Savannah. Why? Construction costs and maintenance are at least 50-100% higher. There are restrictions on access to ports. Even the profligate US Navy can only afford nuclear power for carriers and subs because the mission effectiveness value is felt to justify the cost, but only just. Most other navies build less expensive non-nuclear subs but since the USN tactical doctrine involves forward deployment, diesel-electric (Or AIP) subs are less effective in that role.

And of course if something goes wrong – well, if a diesel engine leaks fuel it can be bad – if a reactor does, they call it a meltdown…