Answer:
a cooling of the climate in northern europe.
Step-by-step explanation:
Gulf Stream determines the warming of North Atlantic waters, setting warmer temperatures for countries like Norway. In the North Atlantic, it gets colder and saltier (due to evaporation of water along the way), sinking and returning to the tropics in the form of a cold underwater current. The heat dissipation of this current is what keeps England and northern Europe relatively warm, even at a high latitude.
Since the 1980s, scientists have been postulating that global warming, by melting Arctic ice and snow, would pour large amounts of fresh water into the ocean, diluting the salt from the current and preventing it from sinking. The immediate effect would be to suspend the transport of heat to Europe, which would plunge into a kind of ice age. Observations made so far, which are sparse, have shown that since 2004, the ocean wake has been at its lowest power in the last thousand years, probably because of global warming. Some scientists fear the collapse has already begun.