Nature magazine has a chilling article [1] in this issue tracking the enui that seems to be overtaking the Gulf Current. [2]

It seems that as the ocean warms, it also becomes less active. Thus, the Gulf Stream might ultimately stop flowing north, while the once-icy Arctic waters will stop flowing south. This might be "Good for Canada" (see next post), as Newfoundland suffers less the effect of the Arctic backflow, but it could equally be devastating for much of Northern Europe, which depends on the warm Gulf waters to moderate its climate.