The Gulf Stream, together with its northern extension, the North Atlantic Drift, is a powerful, warm, and swift Atlantic ocean current that originates in the Gulf of Mexico, exits through the Strait of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean.
At about 30 degrees West, 40 degrees North, it splits in two, with the northern stream crossing to northern Europe and the southern stream recirculating off West Africa.
The Gulf Stream influences the climate of the east coast of North America from Florida to Newfoundland, and the west coast of Europe.
There is some speculation that global warming could decrease or shutdown thermohaline circulation and therefore reduce the North Atlantic Drift.
The timescale that this might happen in is unclear; estimates range from a few decades to a few hundred years.
This could trigger localised cooling in the North Atlantic and lead to cooling (or lesser warming) in that region, particularly affecting areas that are warmed by the North Atlantic Drift, such as Scandinavia and Great Britain.
The chances of this occurring are unclear.