Pohjola’s heater Amoc may freeze worse than predicted

In April Science Advances – the study published in the scientific journal confirms the concern that marine scientists have warned about in the past.

The sea current that warms the North may weaken much more than previously estimated. Then climate change could mean getting colder here and more drastic changes in the weather.

The Nordic climate is affected by two forces pulling in opposite directions. The second is global warming. The second is regional cooling if the North Atlantic circulation, or Amoc, weakens strongly.

In circulation, warm water travels along the surface of the sea to the north, cools, sinks deeper into the sea and flows back to the south. Golfvirta, called Pohjola’s radiator, is part of this system.

Fresh according to the study, Amoc may decline by around 50 percent by the end of the century. In llmasto models, the usual average estimate has been around 30 percent.

The researchers arrived at a new, steeper forecast by comparing the models’ predictions with observations made at sea and emphasizing the models that best corresponded to the observations.

The models that predict the strongest deterioration therefore appear to be the closest to reality.

The study does not predict that Amoc will be completely stopped, but the risk seems higher than before.

Amoc regulates heat, precipitation and weather systems over a wide area. The consequences of a shutdown could range from weather conditions in northern Europe to food production and sea level rise in the Atlantic region. For example, farming conditions may become more unstable and harder to predict.

Research manager Valentin Portman from the Inria research center in Bordeaux, France says in The Guardianthat Amoc is closer to the dangerous limit than previously estimated.

Professor at the German Potsdam Climate Impact Research Institute Stefan Rahmstorf says he is even more concerned that this limit may be reached as early as the middle of this century.

The dangerous limit referred to by the researchers is a tipping point, after which the weakening of the sea current begins to progress under its own weight. After that, the development may not be able to be stopped, even if global warming could be curbed.

Rahmstorf says Amoc’s decline by 2100 could be even more severe than the grim new estimate suggests.

“The reality can be even worse.”

The reason is that the computer models do not take into account the melting water from the Greenland ice sheet, which sweetens the seawater even more. The salinity of the water affects the operation of the cycle.

New research moves the debate away from whether the risk is only theoretical. More and more it’s about how seriously you have to prepare for it.

According to the researchers, the most important way to reduce the risk is to stop the continuous warming of the climate as quickly as possible. In practice, it means reducing emissions.

At the same time, societies should prepare for an even worse scenario.

Read more: The risk of catastrophic cooling in Finland just got closer, says a well-known researcher

Read more: A stoppage of the Atlantic seawater cycle seems more likely than before

Read more: Scientists also give Finland a serious warning: the central circulation of the Atlantic is in danger of being disrupted

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