In a new paper published yesterday, climate scientists described a newly discovered deep, cold current flowing off Iceland’s coast that appears to make the ocean conveyor belt that warms the northern Atlantic less sensitive to climate change than previously thought.
In other words, another one of Al Gore’s doomsday predictions has proven false.
More significantly, scientists now have no understanding why the ocean conveyor belt shut down during past ice ages, as their most favored theory now appears insufficient.
The conveyor belt exists because the northern Atlantic has a higher salt content than most of the ocean. Put more salt in water and you increase that water’s density, thus causing it to sink to the ocean floor. The dense water then flows south along the ocean floor around Africa and into the Indian Ocean, where it rises and begins its journey back north, bringing with it warm weather to the northern latitudes of North American and Europe.
The consensus theory has been that fresh water from melting Arctic glaciers — caused by man-made global warming — would lower the high salt content of the northern Atlantic Ocean, which in turn would lighten the water, stop it from sinking, and thus cause the conveyor belt to turn off. With the conveyor shut down the flow of warm surface water to the northern hemisphere would cease. Thus, you not only would get a much hotter world, global warming would make Europe much colder and less habitable.
This new data says no, Arctic glaciers don’t produce enough fresh water. The newly discovered current dominates instead, acting to stabilize the conveyor belt.
What complicates this complicated and confusing climate science is that there is evidence in the paleoclimate record that the conveyor belt has shut down repeatedly in the past. Unfortunately, scientists now have really no clear understanding why.
Not that they ever did, based on our limited present knowledge.