The ocean warming is well explained. It’s the result of removing sulfur compounds from ship fuels. This change reduces could cover and increases the flux of solar radiation into the ocean causing heating. This is well agreed upon by scientists and not controversial. Cloud cover reduction is measurable and clearly visible in pre and post 2021 satellite imagery where shipping lanes have cloud trails before the change and do not have cloud trails now.
Presumably for the same reason the Gulf of Mexico doesn't show up despite having six of the ten largest US ports. I'd guess they only tracked the open ocean, but whether that's a design decision or those types of clouds don't form over certain bodies of water I couldn't say.
Either way, much of the traffic in the Pacific comes from or ends at China, I don't think anyone is denying that.
So the change in regulation happened in 2020. How then does this hypothesis explain changes in ocean temperature before then? What is the relative magnitude of the correction vs CO2-only-based models?
It doesn't. This model isn't an alternative to CO2 based atmospheric warming models, it just explains a very recent trend in ocean temperature. This branched off a discussion about recent temperature trends. Everyone asking questions about general long term trends either aren't reading or are starting a different conversation.
GP explicitly referenced this phenomenon in an unqualified manner when addressing ocean warming. If they wanted to be understood the first time, they should have clarified the context.
Ship tracks are concentrated to an from that continent. So the effect of the clearing of those tracks was concentrated on those oceans. The fact that they could warm more easily than expected, only mattered when they started to warm. And then a sufficient area warmed sufficiently quickly to impact global ocean temperatures.
That's the problem with snarky dismissals like the one that you just gave. Often they are missing some important point that will move the think you are ridiculing from ridiculous, to surprisingly reasonable. And if that happens, you're the one who looks bad.
As an alternative, I would suggest curiosity questions. If there is no good answer, your point is still made. And if there is one, you will still look good. The only disadvantage is that you don't get the pleasure of that "gotcha" moment.
We don't know that they did. It takes satellites to get a representative measure of ocean temperatures worldwide. There's some noisy data from ships dipping mercury thermometers into the oceans, but this was hardly a widespread practice.
Over the long-term, yes. But the very recent, very acute 1.5 degree warming is unexpected against pure CO2-based models. I've read a bunch of theories (reduction in certain type of emissions from ships being a prevalent one), but nothing conclusive
We are increasing the energy imbalance in the earth system. A large part of that energy is absorbed by oceans. And at the same time our temperature buffers like the arctic sea ice, are disappearing.
I think we're seeing the same thing that is always seen when a complex system is sufficiently perturbed. Loss of stability, chaotic behaviour, and eventual collapse.