Scientists detect disastrous trend in North Atlantic waters

Scientists have detected evidence that global warming is affecting currents in the North Atlantic. These currents are responsible for delivering heat to western Europe from the Caribbean, and without them, the region will become much colder. Scientists are monitoring the alarming changes. 

Scientists have detected a weakening of the current that brings warmth to western Europe.

Highlights

By Marshall Connolly (Catholic Online)
Catholic Online (https://www.catholic.org)
4/19/2018 (7 years ago)

Published in Green

Keywords: North Atlantic, current, circulation, global warming, heat, warmth, Western Europe

LOS ANGELES, CA (California Network) - There is a conveyer belt of warmth under the North Atlantic. Known as the Atlantic meridional overturning circulation (AMOC), this network of undersea currents transfers warmth from the Caribbean to the North Atlantic where it is responsible for the warming western Europe and the British Isles in particular. 

If this current should weaken or fail, western Europe would soon become more frigid than at any time in recorded human history. The impacts would be devastating. North America would also suffer from higher sea levels and the shifting of fish stocks farther away from the coast. 

There are several currents involved in AMOC, including the Gulf Stream, which circulates warm water around the Atlantic, the North Atlantic Current, which diverts a portion of the Gulf Stream's warm waters north towards the British Isles, and the North Atlantic Deep Water, which recycles the spent North Atlantic Current and brings the now cold waters back south to be warmed again in the Gulf Stream. 

Essential to the ability of these waters to transfer heat is salt. Saltwater holds warmth better than freshwater and freezes at a lower temperature, around 28.4 degrees Fahrenheit. 

Global warming is diluting the saltwater. As Greenland's glaciers melt and more rain falls in the North Atlantic, the quantity of freshwater being added to the sea is enough to dilute the saltwater, hampering the current's ability to transfer heat. 

The AMOC is weakening, and that may have disastrous consequences in Europe.

Concern over this possibility was first raised in the 1980s, but there was no data to assess the situation. However, in the past decade, new sensors placed in the Atlantic have revealed what scientists feared, the current is weakening. 

To better understand the situation, scientists looked at paleoclimate data. That's data taken from the prehistoric past to determine what conditions were like centuries, even thousands of years ago. The assessments were simple since warmer waters mean different organisms and stronger currents deposited larger grains of sediments. The results were startling. 

The AMOC is the weakest it has been in 1,600 years. And at least one other study has affirmed this conclusion. 

There is no proof yet that global warming is causing the AMOC to weaken, although that is the prevailing hypothesis. It also makes sense, since the quantity of freshwater in the North Atlantic is increasing. Further study is necessary. 

The AMOC transfers the planet's heat from the tropics to the temperate regions. It's essential to having bearable winters in western Europe. If scientists are correct, and the current is weakening, then Europeans can expect shorter summers and colder winters. The east coast of North America can expect higher sea levels and the shifting of fish stocks. And this is just one piece of the global climate puzzle. There's no telling yet what the global impact will be as the AMOC weakens.