In a recent conference (Nov 2025) Jim Hansen opined that some of the so-called tipping points are simply reversable phenomenon which would reverse if we were to decrease the green house gasses in the atmospheres (my thought: they might show hysteresis and so on a human time line would look like tipping points). However he did say that he thought that the AMOC shutting down would be a genuine tipping point. So what would the consequences be. It has often be suggested that Europe would become quite a bit cooler as heat was no longer transferred from the tropics by the surface current and that hurricanes in the south would be stronger due to the extra heat left in tropical waters, But what else could happen.
Up to now, the heat differential between the Arctic and the tropics has been decreasing as the Arctic heats faster than the rest of the world. Now with Northern areas cooling and southern areas warming, the heat differential would increase and perhaps even exceeds the heat differential that used to exist. What are the possible consequences of this.
*With the heat differential re-established, the Hadley cells should speed up to their previous intensity causing the jet stream to increase to its previous speed and to stop waving back and forth, North and South so much. At present this is resulting in long periods of drought or precipitation as loops in the Jet steam get stuck in place. Weather patterns should return to their previous more orderly march Eastward instead of getting stalled.
The colder temperatures in the north should cause whatever snow falls on Greenland to stay there instead of melting and flowing to the sea. If the effect is intense enough, it might even lead to the accumulation of snow on the high lands of Baffin Island (where the continental glaciers begin to accumulate) Sorry, forget this last one. It is pulling a very long bow.
The Sea Ice in the Arctic should form earlier, melt later and increase in thickness over the winter, allowing the native people to utilize the ice as they did before the present melting occurred.
Agricultural zones, which have been creeping North for a few decades, should return south although they might be narrower than they were before the warming began. The more regular march of weather patterns, mentioned above, should favor dry land agriculture as rain followed sunny, followed rain, follows sunny.
With the accumulation of snow on Greenland, sea level might stop rising although if the new regime results in more melting in the Antarctic, it could overpower this effect.
There is no way of telling if any of the above will come to pass until the AMOC shuts down and it does or does not occur.
