Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage.

Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount.

The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. And the two big factors are the energy required to do the refining and delivering the fuel from the refinery to the gas station. Shipping the crude from the oil field to the refinery is a factor, but a small one in comparison.

This 40% is the main reason why driving an EV emits less carbon than driving an equivalently sized gas vehicle even if you're topping up that EV with the dirtiest electricity you can find.

P.S. maritime shipping typically uses very dirty fuel. We'll probably notice the reduction in sulfur pollution more than the reduction in CO2.

P.P.S 3% of a very large number is still itself a large number, so it's still worth looking for solutions.

The massive reduction in oil supply from the sudden and unexpected closure of the Strait of Hormuz, with gas prices jumping but minimal economic contraction, has been great evidence that we could perform a global energy interchange far faster than anybody ever expected without causing massive damage.

However, the pushback I've been hearing a lot is that ocean freight still needs fossil fuels, that's always going to be a blocker.

In reality, it's only ~1% of emissions, and half of it goes away when we stop other uses, so solving that 0.5% of fossil fuel use, or even still emitting it, is really a rounding error. (And methanol or ammonia as well as other synthetic fuels based off hydrogen production have a great chance of stepping into that, especially as we massively scale ammonia production from electrolyzers, which also solves the fertilizer that has been caused by closing the Strait of Hormuz).

Fossil fuel based economies are inherently fragile and bound to massive price increase cycles. Changing our economies to be powered by renewables and storage will be far more stable, cheaper, and bring a massive increase in economic output. We can't switch fast enough.

It isn’t. In the limit, if it were 100% of fuel use, then we’d be burning 1.2 gallons of fossil fuel to deliver 1 gallon, which clearly wouldn’t work.

A much better question is “what percentage of the embodied carbon for this good is from freight shipping”? The answer is almost always very low because last mile shipping dominates, and so does manufacturing the item. For fossil fuel, those things dominate, and so does the step where the customer burns the fuel.

Basically, the entire article is confused because it doesn’t start with the fossil fuel equivalent of Amdahl’s Law.

"40% of horse-drawn carriage cargo is hay, but 50% of what we feed horses is hay".

So what?