Global warming may lead to big chill threat


Britain could have a climate like Iceland’s within the next 100 years, a scientist has warned. The change would come about as a result of global warming, with the Gulf Stream being suddenly cut off. They say the process may have already begun because of changes caused by global warming.
The Gulf Stream carries ocean heat past Britain’s shores, ensuring that the climate stays mild. If it was not there, temperatures in the UK would plunge. The Iceland Britain scenario is investigated on the Big Chill, broadcast on BBC 2’s Horizon tonight.

Expert Terry Joyce, from Woods Hole Oceanographic Institute in the US says: “The likelihood of having an abrupt change is increasing because global warming is moving us closer and closer to the brink. We don’t know where it is, but we know one thing, we’re moving closer to the edge.

“And so I’d say that within the next 100 years it’s very likely, in other words a 50% probability that this might happen.” The change would come almost out of the blue. “It will be quick, and suddenly one decade we’re warm, and the next decade we’re in the coldest winter we’ve experienced in the last 100 years, but we’re in it for 100 years,” he says.

Dr Bill Turrell, from the Fisheries Research Service in Aberdeen, has been measuring the salt content of the Gulf Stream current flowing north of Scotland. If salinity is dropping, it is a sign that the driving force behind the Gulf Stream is weakening.

Global warming threatens the Gulf Stream because it is predicted to produce more fresh water, which would dilute the salty waters of the current. This in turn would stop it sinking, and if this happened the heat it carries would be cut off.

Dr Turrell’s measurements show that the Gulf Stream’s salinity is indeed dropping. “It’s the most fundamental change I’ve observed in my career,” he tells the programme. “We were really worried when we saw these results. We’d never seen a change like this before.”