I'd love to know a real world figure on improved efficiency on cargo ships.
If a "simple" innovation like that can move the needle juste by a few percent points on how much fuel we put into the transport industry, that's a very sizeable gain from a climate perspective.
Not really. The whole shipping industry accounts for 90% of the world's transportation of goods, but only 3% of greenhouse gas emissions. The problem with big ships is that they burn crude oil and create insane amounts of NOx and Sulphur pollution. Propellers won't solve that issue, only international regulations can. The industry also grows by several percent each year, so the best thing a small improvement like this could do is counter a few years of growth at best.
Thanks for pointing out it's only 3%. It's much less than I had pictured! (I also went to look it up after your comment).
Let's imagine 3% of improved efficiency (they announce between 9 and 15%, but let's be conservative) on the 3% of the world's emission, that's still almost 0.1% of the world's emission saved by only changing the propellers on cargo ships. It's still a massive improvement: 31 million tons of CO2 saved. At this scale, anything that moves the needle a little bit should be taken. But that's by plucking a number out of thin air, so I'd love to hear about it in the real world and at scale.
Regarding the rest of your message, I agree that the type of fuel that is burned is a big problem, but if changing a propeller means burning x% less of it, it's a no brainer to me!
So 0.3% of the worlds greenhouse gas emmissions by JUST replacing a few propellers doesn't seem significant to you? Can you name another measure that would reduce emmissions in a similar scale with a comparably low effort?
If a "simple" innovation like that can move the needle juste by a few percent points on how much fuel we put into the transport industry, that's a very sizeable gain from a climate perspective.