The Independent reports that the:

ocean "engine" that helps to drive the warm waters of the Gulf
Stream and keeps Britain relatively mild in winter has begun to slow
down, say scientists.

Uh oh.  This would be bad news because:

Scientists estimate that the detected 30 per cent weakening of the
Atlantic currents could lead to a fall of about 1C in Britain’s average
temperatures over the next 20 years.

Specifically, the article notes that the rate of flow has fallen 30%
from 20 million tons of water flowing per second to 14 million tons of
water flowing per second.  Continuing this process could have dire implications:

They also warn that the weakening could be the first signs of an
accelerating trend that could eventually lead to a more drastic change,
including a complete shutdown of the currents. If this were to happen,
average temperatures in Britain could fall by between 4C and 6C,
leading to winter temperatures similar to Newfoundland in Canada, which
is on the same latitude as the UK but does not benefit from the Gulf
Stream.

Such a change could also hurt New England, but Europe would bear the brunt of such a slow down in the current.

Common Dreams has another copy of the article.