well, i've seen studies that freshwater influx can shut off the nadw (north atlantic deep water) formation and others that say all they do is slow it down unless a really immense shock (like from a glacial dam giving way and letting a lake drain rapidly) comes by and knocks it off. i'd guess that an ice shelf falling off a continent into an ocean could do it as well, but most of what's up around the north atlantic is in interior greenland, and can't 'fall-in', so to speak. CO2 is high as well... if those scary model forecasts aren't overdoing things by orders of magnitude then the climate over much of the northern hemisphere is due to warm tangibly in the next couple of decades. and those model forecasts don't really scare me, come to think of it. ice ages are scary... interstadials are much better to live in.
just recently, though, i haven't seen any really huge cold sst anomalies in the north atlantic. it's been persistently warmer than the long term average (long term to us doesn't mean a lot in the grand scheme of things, though) for the last few years. if i had to make a forecast for the UK for the next decade, i'd say it'll be warm if anything. maybe some relation of vince will make a pass at them, who knows?
HF 0553z04december