The AMOC (Atlantic Meridional Overturning Circulation) is weakening. This climate caused problem is one that we can see immediately with our own eyes in the behavior, direction of severity of weather events.
The AMOC is, in very simplistic terms, both a planetary temperature modulator and driver of the atmosphere. It exchanges warmer ocean water in the tropics with cooler arctic water in a sort of serpentine loop. The AMOC is heavily dependent upon 2 factors. The salinity and temperature of the water.
This ocean conveyor utilizes both ocean depth and the lateral current to travel from the tropics to the poles.
What occurs on, and under the surface also happens in the sky. The ocean current also drives atmospheric movement and direction. If the AMOC is steady and strong, it creates movement along more predictable patterns... ie, the Earth as we know it and our various wet and dry regions.
But what happens if the AMOC were to weaken or fall apart? Well.... a number of things. None of them good.
Think about driving your car down the road, when all of a sudden the steering wheel pops off, coolant stops circulating and the engine goes into low power mode for safety. You can't control the car, the engine is overheating and you can barely creep down the road.
This is exactly what is happening to the weather. Weather systems stall. So you get longer high pressure, dry and hotter events. Or a storm system stalls over a region dumping flooding rain for days or weeks. Or they might wander. With no atmospheric driver you may see rare weather events in totally unexpected areas. Finally with a weakened AMOC, northern cooler areas and southern hot areas cannot modulate.
The climate crisis is no joke. It might be harder to see sea level rise or overall temperature rise. But severe weather events are in your face type of stuff. Exactly what we're experiencing now... and it's only going to get worse.
Quite a stew we've cooked up for the planet. Let's hope there are some miracle solutions on the horizon.