"40% of horse-drawn carriage cargo is hay, but 50% of what we feed horses is hay".
So what?
And if I can get on my soapbox. This same problem (carrying fuel to feed the transportation unit) is well studied in medieval England because it was one of the main determinants of where cities and castles were placed (albeit unknowingly at the time). And we see what happened in England when they were able to get out from under feeding oxen.
The Tyranny of the Wagon
Example contributors as I presently understand it:
- we transport fossil fuels further around world (i.e. Middle East to the US)
- we transport most other goods some shorter distances
- iron ore transport is "up there" with fossil fuels; high ton-miles of transport.
And of course the cost of transport for a good is a function of distance, a la the rocket equation mentioned in other comments.
And the article is focused on making this point in the context of the effect of reduced demand for fossil fuels and steel (iron ore) on maritime demand. (which is interesting, and totally not what the article title was leading my brain to think about)
Edit: And then I went and actually looked at the figure at the top of the article; guess the real topic is yet a different framing than what I comment on above!
I think the problem is that, for any given sentence, it is unclear whether the author is talking about the fuel a ship is burning to move its cargo, or fuel that the ship is transporting to a destination.
I do understand that the article is making some kind of distinction between the two, but it is so terribly written that it's just impossible to figure out which one it's talking about at which point. Or at least I certainly don't care to waste my time "solving" the article like it's some kind of linguistic puzzle.
I'm not sure I've ever come across an article that needed an editor to improve its clarity more than this one.
Fossil fuels are 40% of freight tonnage, but transporting them fuels is responsible for 50% of the total freight fuel consumption.
I assume 99% of freight uses fossil sources as fuel.
> Fossil fuels are roughly 40% of maritime tonnage, but in the model they represent about half of maritime freight energy because coal, oil, and gas are mostly long-haul bulk trades. Moving a ton of scrap metal a short distance and moving a ton of oil or LNG across oceans are not the same transport-energy problem, even if both show up as one ton in a cargo table.
as being exactly what was being talked about... more fuel is spent on transporting fuel due to distance it travels.
but your comment made me re-visit (i.e. more closely skim...) the article, and it's really about: "as the demand for fossil fuels is projected to decrease, (1) less long-haul shipping is needed and (2) a greater fraction of shipping will be short-haul, which will be practical for other types of freight fueling (i.e. what's shown in the figure at the top of the article)
I have no sense of how realistic the figure is. For example, I don't know the current projections for decline of fossil fuel demand over ?? year timeframe.