One of the most important climatic phenomena on the planet, the Gulf of Mexico Stream , which warms temperatures in Western and Northern Europe and makes the climate more moderate in those northern latitudes, has slowed in recent decades, with the As a result, its effects have been weaker than ever, at least in the last millennium .
This is the conclusion of a study led by Stefan Rahmstorf, from the Institute for Climate Impact Research in Potsdam (Germany). The gradual but accelerating melting of the Greenland ice sheet due to human-induced global warming is possibly a key factor contributing to the slowdown in the Gulf Stream . If the process continues, the impact on Europe’s marine ecosystems and sea level will be felt.
Previous research had pinned the slowdown in the so-called southern Atlantic ocean circulation as the culprit, but now there is evidence that it is the entire global ocean circulation that has weakened .
It has also been found that while the specific area in the North Atlantic has been cooling the rest of the world has been warming . The scientists relied on data from the atmospheric temperature of the sea surface and measurements on ocean currents, ice level, tree rings, corals and sediments. With these data they have been able to reconstruct the evolution of temperatures over more than a millennium.
The Gulf Stream is a large body of water about 1,000 kilometers wide that runs at the surface level , and is driven by differences in the density of ocean water. The southern water is warmer, and therefore lighter. For this reason it flows north, where the waters are colder.
Upon colliding with them, the warm current descends into the deepest layers of the ocean and then flows back south. Jason Box of the Geological Survey of Denmark and Greenland believes that fresh water coming out of the melting of the Greenland ice sheet “is probably disturbing the circulation.” With the meltwater there is less saline water on the surface, than it is the one that tends not to sink, which is why it cools the Gulf Stream more.
