Once again, I am probably wandering in the wilderness. But let's put this together. The oceans are a giant heat pump system, or cpu cooler, taking care of both solar and geothermal heat (volcanoes, plate tectonics, etc). The equatorial belt is super-hot. I was there on the equator recently, and if you have a rare blue sky at noon, you are dying. Unbelievable heat.
At 30C, the oceans start a wonderous process of shedding the heat. The equatorial belt sends off tropical atmospheric plumes. These big 'linear hurricanes' warm the rest of us up. If they are big and frequent, we have a warming cycle, and the big one is an El Nino. If they dry up, then we are cold.
Here's new physics: a strong ocean current going north can channel and fire off a plume like a rail gun. This is what used to happen when the Gulf Stream was a thing. Also, the Northern Pacific current was a real plume launcher.
Sadly, none of those currents now exist, and plume generation is a random thing. Starting last December, the El Nino was firing off a huge number of plumes. You could see them, marching like soldiers, warming us up. The soldiers have withdrawn.
(wait for a big shot of my relaxing juice)
Next morning: So, we have the ocean churning with heat, and shedding it by currents and plumes. They warm the air and cause clear-air convection which brings the heat to the top of the atmosphere. At that point, infra-red radiation sheds the heat to outer space.
There is no reason why the north has been warm since 1850. That's just the major cycle, and it is coming to an end. You can see that it is flipping, just like the magnetic field flips every tens of thousands of years.
Thus, we almost complete the hypothesis:
Every 600 years we complete a major cycle when all the equatorial heat energy flips from one hemisphere to the other (300 years in each). This cycle is so cold that it is almost sufficient to start northern continental glaciation.
Except for one more thing ---
-- to be continued