Read here. The long and wide acceptance of the oceans' conveyor belt theory was, until recently, a confirmed scientific consensus. The conveyor belt theory was also a foundational cornerstone of all climate models. But, as oceanographers did more research and scrutinized the empirical evidence, they determined the popular, consensus conveyor belt theory was no longer sustainable, nor valid.
Where's that leave the IPCC's climate models then? Up a certain creek, without the proverbial paddle.
"Here is a list of recent discoveries that have shaken the foundation of the conveyor belt theory.
- Most of the subpolar-to-subtropical exchange in the North Atlantic occurs along interior pathways.
- The deep deep western boundary current (DWBC) breaks up into eddies at 11°S.
- There is little meridional coherence in the overturning transport from one gyre to the next.
- Wind forcing, rather than buoyancy forcing, can play a dominant role in changing the transport of the overturning.
- The southward transport of deep waters at 8°S, off the Brazilian coast, was shown to be carried entirely by migrating coherent eddies.
- Floats launched within the DWBC at 53°N do not follow a continuous boundary current, but instead take multiple paths to the subtropics, including interior pathways far removed from the DWBC.
- Two recent studies have found unexpected pathways in the upper ocean.
- A recent study shows that MOC transport in the subtropical North Atlantic is susceptible to variability in the "leakage" of warm and salty water into the South Atlantic.
- Studies showing little to no coherence across gyre boundaries have prompted interest in monitoring the overturning circulation in the South Atlantic and the subpolar North Atlantic.
- The connectivity of the overturning and, more importantly, of the meridional heat transport from one basin to the next can no longer be assumed on interannual time scales.
When all of these observations are combined, they indicate that the conventional conceptual model of ocean overturning needs revamping....."As the study of the modern ocean’s role in climate continues apace, the conveyor-belt model no longer serves the community well— not because it is a gross oversimplification but because it ignores crucial structure and mechanics of the ocean’s intricate global overturning."....."I repeat my earlier assertion: if the conveyor belt model is wrong then none of the IPCC's model results can be taken seriously.""