What is being done to make shipping cleaner?

That’s interesting info that l didn’t know. Do you have a link? It is definitely a valid question.

I would like to see some other comparative numbers.

We know that pollution-per-ton-carried is pretty high for truck transportation.

Pollution-per-ton-carried for rail delivery is about 1/50th as much as it is for trucks. But of course, one train can only run a couple of hundred containers, if that.

Cargo ships, especially the big ones, can carry between 15,000 to 20,000 cargo containers. If you do the long division, the pollution-per-ton-carried has got to be considerably smaller for cargo ships than even for railroads.

You can’t just say “ships pollute” – I think you have to do a comparison with other types of freight delivery and see where cargo shipping lands.

My guess is that you will find that ocean cargo shipping is considerably cleaner than any alternative on a pollution-per-ton basis.

Here’s information on pollution by ships.

Even more interesting is comparing the different modes of shipping.

”...if I’m understanding the numbers correctly, over a five-year time frame the world’s ships cause enough cooling to offset the total warming caused by every car, plane and bus combined.”

Fascinating question @FireMadeFlesh. Apparently, anything from 1500 to 10,000 shipping containers are lost overboard each year too. That’s a lot of junk landing in our oceans. And who knows what’s inside those containers.

I’ve done some more reading, and it seems I was mistaken. The pollution in question, where the 15 largest ships match all the cars in the world, is sulphur dioxide and particulates, not greenhouse gasses. See here and here. Much of this is due to the use of poor quality fuels that are not allowed to be used on land. It appears some technologies can dramatically improve this figure for less cost than similar reductions on land (http://www.cleanshipping.org/download/111128_Air%20pollution%20from%20ships_New_Nov-11(3).pdf). It is harder to find data on greenhouse gas emissions from shipping.

@elbanditoroso You are correct, shipping is very efficient. However not all the goods transported need to be transported. A resurgence of local manufacturing could reduce our dependence on shipping. A focus on reusable products rather than disposables could also reduce the total quantity of cargo. And just because it is more efficient than trucks, trains, and aviation, doesn’t mean it can’t do better. Are their diesel-electric hybrid ships? Is there a role for a return to wind power, with engines as backup propulsion? I’d like to see information on that.