According to the National Oceanic and Atmospheric Administration, the winter of 2014-15 was one of the warmest since records began. However there is one area of the North Atlantic which bucks the trend, writes Jamie Hacking for The Westside Story.

Gulf Stream Slowed By Melting Greenland Ice Sheet

Gulf Stream slowing down

Data collected from across the North Atlantic shows that there is one area in which temperatures are 3.6 degrees Fahrenheit colder than average. A new study now claims that the cold patch could provide evidence of a worrying slowdown in the Gulf Stream, which moves large amounts of warm water from the equator towards the North Pole, moving up the East Coast of the U.S. before heading into the North Atlantic.

If the Gulf Stream were really to be slowing down, it would add weight to the argument that global warming could trigger “tipping points” in Earth’s weather systems which would set off a series of irreversible changes. According to the U.N. Intergovernmental Panel on Climate Change, there is a 10% chance that the Gulf Stream will simply shut down by 2100, while other experts believe that the probability is even greater.

Study co-author Stefan Rahmstorf, a climate scientist at the Potsdam Institute for Climate Impact Research in Germany, wrote that “evidence is mounting that the long-feared circulation decline is already well underway.”

Rising sea levels and changing weather patterns

A slowdown in the Gulf Stream is an phenomenon that has not been experienced in hundreds, or maybe thousands, of years. It is believed to be linked to another climate tipping point, namely the melting of the Greenland ice sheet, which causes huge amounts of fresh water to enter the ocean.

This fresh water tends to sit on top of the water column as it is lighter and colder than the salty sea water. Over time this increasingly thick layer of fresh water interferes with the currents of sea water, slowing down the Gulf Stream and affecting ocean circulation as a whole.

It is thought that a rapid slowdown of the Gulf Stream could lead to a faster rate of sea level rises along the East Coast of the U.S., a lot of which is densely populated, and cause colder weather conditions than normal in northern regions of the U.S. and Europe.