[bradclark1]

Changes to ocean currents in the Atlantic may cool European weather within a few decades, scientists say.
http://news.bbc.co.uk/2/hi/science/nature/4485840.stm

Further down the page.

The NOC researchers admit that the case is not yet proven.
The analysis involves only five sets of measurements, made in 1957, 1981, 1992 and 1998 from ships, and in 2004 from a line of research buoys tethered to the ocean floor

Michael Schlesinger from the University of Illinois at Urbana-Champaign, a leading expert in models of climate and ocean circulation, believes that even with these caveats, the NOC team has probably come up with a link to human-induced climate change.

Essentially it's a theory that needs more research.