With the recent big ocean current changes, I finally see a mechanism. First, there is a Pacific shift, and the warm water goes south. Then that causes the Arctic ice to build up, and that throws down a big current to the Atlantic belt. That forces the Atlantic water to go south.
I was looking for another mechanism to lock things in, and I finally found it. The Arctic ice becomes so thick that the coastal areas are no longer 'warm' at -30c. Thus, the Arctic ice becomes the first of the major ice advance
With the Arctic ocean sealed up, we can easily hit -50 for the whole place. If the highlands were totally popped up, then we would have multi-year ice all over.
This is the only 'feedback mechanism' I've ever seen in this. The Arctic ice is white and cools the whole place down. No ocean currents are pumping heat up North. We are locked in ice.
I would never argue this with the super-PR people. The way to handle it with the 'Scientific Method' is to do more physics in the field and lab. No 'computer models' affected by 'Garbage In, Garbage Out'. When all the warmies are frozen, then it might be time to do something. :)
ps. I still can't see the mechanism from the Atlantic to the Pacific to lock things in below the equator. I can see the mechanism to close the ice age loop, when the Arctic ice becomes thick enough to stop the flow of saline water down Greenland. I don't like the idea of the Pacific being a clock on its own.
ps. I may see the Pacific feed-back, but we'll have to wait. The extreme cold of the Arctic could be sufficient to suppress the North Pacific current with cold water from the Bering Sea. We can wait to see if cold water flowing down the North America west coast could interfere with the formation of the Pacific warm-water belt. We'll start to see all this in the next few years, if we are tipping into a major ice age. Otherwise, it all clears up in 20 years.
pps. This is the North Pacific circulation.
There is no water coming from the Bering Straight, quite amazing. There is some coming from the Bering Sea over the Alaskan chain, but little. The big mass is below the chain, and it is moving. If it got a lot colder then this would move. You can also see the edge of the North Pacific current, which has no heat.