Global warming could cause the giant network of ocean currents that disperses heat to Northern Europe to cease temporarily in the next 100 years, according to new research.
The North Atlantic Current transports warm water from the Gulf of Mexico towards Europe, providing much of the north-western parts of the continent with a relatively mild climate.
But meltwater from Greenland and excessive rainfall caused by climate change could interfere with this ocean current, otherwise known as the Atlantic Meridional Overturning Circulation.
Using simulations, scientists in the Netherlands predicted a 15 percent likelihood that there will be a ‘partial collapse’ of the huge current network in the next 100 years.
‘The oceans store an immense amount of energy and the ocean currents have a strong effect on the Earth’s climate,’ said Professor Fred Wubs at the University of Groningen.
Previous research has shown that increased meltwater – water released by the melting of snow or ice – from Greenland coupled with rainfall has the potential to slow down or even reverse the North Atlantic Current, blocking the movement of heat to Europe.
While the chance of a total collapse of the North Atlantic Current within the next thousand years was found to be insignificant, a temporary interruption in the delivery of relatively warm water to north-western Europe is much more likely, according to the researchers.
The team, which has been studying ocean currents for about 20 years, based their research on complex equations describing fluid flows of the huge current system, described in Scientific Reports.
The North Atlantic Current shows non-linear behaviour, meaning that small changes can have large effects.
Such temporary transitions could cause colder spells in the North Atlantic, although this needs to be verified by further studies.
The model also does not take into account considerable changes in freshwater in the North Atlantic, which can be caused by the melting of ice sheets.
‘Confirming our results through simulation with a high-resolution climate model will be the next challenge,’ said Professor Wubs.
The North Atlantic Current has experienced a weakening of around 15 per cent since the mid-twentieth century, according to a study published in Nature last year.
According to the Met Office, a weaker North Atlantic Current will bring less warm water northwards, and this will partly offset the warming effect of the greenhouse gases over Western Europe.
However, the gradual weakening of the current could cause havoc in other regions and would not be enough to prevent an overall warming caused by climate change.