A 'climate tipping point' has been reached in the Barents Sea

Posted Jun 27, 2018 by Karen Graham
Climate change involves huge and complex processes and they can be cumbersome, sometimes taking many years before we even realize a change has occurred. However, when sudden shifts in these processes occur, we call it a "tipping point."
Nordkapp or North Cape is the point where the Norwegian Sea  part of the Atlantic Ocean  meets the B...
Nordkapp or North Cape is the point where the Norwegian Sea, part of the Atlantic Ocean, meets the Barents Sea, part of the Arctic Ocean. It was was named by the Englishman Steven Borough, captain of the Edward Bonaventure, which sailed past in 1553 in search of the Northeast Passage.
Harvey Barrison from Massapequa, NY, USA
As the world knows, the Arctic region has undergone some dramatic changes as the climate has warmed. Besides the warmer temperatures observed across the region, there has been an ongoing decrease in sea ice. But the greatest temperature increases observed have been in the northern Barents Sea.
In a new study published in the journal Nature Climate Change, Norwegian researchers found that warming conditions and decreasing sea ice volume “may soon” see the Barents Sea complete a transition from cold, fresh Arctic waters to a warm, salty Atlantic regime.
Map shows the location of the Barents Sea north of Russia and Norway  and the surrounding seas and i...
Map shows the location of the Barents Sea north of Russia and Norway, and the surrounding seas and islands.
The Barents Sea, hemmed in by Russia and Scandinavia to the south, the island of Svalbard to the northwest and Russia’s Novaya Zemlya archipelago to the east, has been a "buffer" holding back the warm, salty waters of the Atlantic Ocean from the much colder waters of the Arctic Ocean.
The Barents Sea has always been divided further - with the waters in the northern region of the sea being cold, fresh and often covered in ice, while the southern region of the sea was mixed with the warm waters from the Atlantic Ocean. This region was usually ice-free.
We've observed the tipping point in action
We have known that in the Earth's past, there were certain events that were tipping points for the climate, but accurately determining the length of time it took for the event to take place has been hard to reconstruct with any great accuracy.
Lind et al. (2018)
But the Norwegian research team is saying we have been watching a tipping point take place, right before our eyes - and it is taking place in the Barents Sea today. Basically, the buffer between the Arctic and Atlantic Oceans is disappearing at an alarming rate.
There have been a number of studies in recent years that have documented the “Atlantification” of the Barents Sea. Digital Journal reported on one study published in April 2017 that showed that warm waters are flowing into the into the ocean north of Scandinavia and Russia, altering ocean productivity and chemistry, causing the sea ice to recede and "kickstarting" a feedback loop that will eventually make summer sea ice a thing of the past.
The research team used a compilation of hydrographic observations from 1970 to 2016, along with other climate data to investigate the link between changing sea-ice import and this Arctic warming hotspot. One important thing they found was that not only were atmospheric temperatures warmer, but warmer temperatures also extended all through the water column.
Main bathymetric/topographic features of the Arctic Ocean
Main bathymetric/topographic features of the Arctic Ocean
There began a sharp increase in temperatures and salinity in the Barents Sea in the mid-2000s that can be clearly linked to a decrease in sea ice extent and increasing salinity. To check their observations, the team also examined precipitation levels on the surrounding islands bordering the Barents Sea, such as Svalbard and Franz Josef Land, to confirm that the loss of fresh water came down to loss of ice and not a change in weather patterns.
“Increased Atlantic Water inflow has recently enlarged the area where sea ice cannot form, causing reductions in the sea-ice extent,” the team writes. “The entire region could soon have a warm and well-mixed water-column structure and be part of the Atlantic domain.”
What does this all mean?
Well, first, let's talk about the Barents Sea. The influx of warmer, saltier Atlantic waters will result in weakened ocean stratification, enhanced vertical mixing and increased upward fluxes of heat and salt that prevent sea-ice formation and increase ocean heat content.
Melting sea ice in the Arctic produces fresh water  slowing the circulation of denser salt water and...
Melting sea ice in the Arctic produces fresh water, slowing the circulation of denser salt water and thereby slowing warming currents
How soon will this particular "tipping point" be completed? It will happen much sooner than we may think - perhaps within the next 20 years or so. ad author Dr Sigrid Lind, a researcher in physical oceanography and climate science at the Institute of Marine Science and the University of Bergen in Norway told Carbon Brief: “If the decline in freshwater content in the upper 100 metres during 2000-16 continues, the freshwater content will be zero – meaning no stratification – around 2040.”
As for the ecosystem changes that are expected to take effect, they could be profound and dramatic. Dr. Lind says, “The Arctic ecosystem in the northern Barents Sea have species that are adapted to the cold, stratified and sea-ice covered Arctic climate, including ice-associated marine mammals.”
Prof Igor Polyakov of the International Arctic Research Center, who was not involved in the research, agrees that the impacts could be considerable. He tells Carbon Brief: “The discussion presented in the manuscript rightly states that this region may soon be transferred from an Arctic to an Atlantic type of climate. Consequences of these changes may be widespread and dramatic.”
Will we see more climate tipping points? Perhaps, but maybe not as dramatic as this one. But it is fair warning as to what is happening before our eyes.