You may have heard that the ice is melting in the Arctic. There have been many media reports about this in recent years. That the ice cover is shrinking is perhaps not so surprising. Scientists have long seen that the temperature rises much faster here. In fact, twice as fast as the average for the rest of the world. But what about the water under the ice? Studies of ice and air have received a lot of focus. But not as much research has been done on the state of the water masses in the Arctic Ocean. – How big the warming is in the Arctic compared to the rest of the world, it has not been quantified before, says Marius Årthun. Difficult to stop the changes Årthun is a researcher at the Bjerknes Center for Climate Research. He is behind the study together with Chinese and German researchers. They have found out a lot of exciting things: The upper 2,000 meters of the Arctic Ocean are heating up 2.3 times faster than the global average. The Barents Sea will have the largest future temperature increase. Here, the temperature will increase by more than five degrees in this century, if we do not succeed in taking action. Major changes are therefore imminent for everything that lives in the northernmost waters. The fact that the temperature in the air in the Arctic increases much faster than elsewhere in the world is due to a phenomenon called “Arctic Amplification”. The term refers to the mechanisms behind it. WILDLIFE: Walrus in its element. Photo: Sebastian Gerland, Norwegian Polar Institute For example, loss of sea ice means that less of the sunlight is reflected. When more of the energy does not “bounce” back, but remains in the Arctic, it contributes to the warming only going even faster. This melts even more ice. And that’s how you get a self-reinforcing effect. – What we see is that we also have an arctic strengthening in the sea, says Årthun. Temperatures outside of normal have already been recorded. – Even if you turn off all the taps today, the changes will continue for several decades. Increased transport of heat So what is actually happening? Yes, what the researchers have found is that there is an increased transport of heat. From southern latitudes and into the Arctic. BEHIND THE STUDY: Marius Årthun is a researcher at the University of Bergen and the Bjerknes Center for Climate Research. Photo: Ingrid H. Onarheim The researchers call it an “Atlantification” of the Arctic. The sea gets warmer and then more heat is transported in. This is how you get this mechanism called arctic amplification. – The effect will increase to a great extent, into the future, says the researcher. At the same time, you have a mechanism that works against. Which tries to get rid of the extra heat. Among other things through extra heat loss to the atmosphere. – But this heat loss is not enough to compensate for increased heat from the sea via ocean currents from the south. The ice is shrinking Five degrees warmer water in the northern Barents Sea is not good news. – It is quite extreme, and will cause the sea up there to become quite a different place if this prediction holds true. The prediction is based on a “business as usual” scenario, explains the researcher. – What is called a “strong emission” scenario. Correspondingly, that we do not manage our emissions. At the same time, that is where we are heading right now. We have had a taste of the consequences. – The summer ice is on its way out already. We also see major changes in the middle of the darkest winter, says Årthun. With less ice, the stage is also set for geopolitical challenges. Interest in resource extraction is increasing. Sea ice at Svalbard. Photo: Jonathan Rheinlænder / Bjerknesenteret – Those who think that the changes are happening far away, and who may not be so worried. What would you say to them? – There are good reasons to think that what happens in the Arctic does not stay in the Arctic. Changes in the sea ice cover have been linked to changing weather patterns in Europe and Asia. – You are changing a fairly important part of the climate system. How it affects other parts of the climate system is not as easy to predict. Worried Randi Ingvaldsen works at the Institute of Marine Research. She has a good understanding of climate effects on marine species and ecosystems. She explains that when the ice disappears, it affects all the species that live in connection with the ice. It includes everything from plankton to polar cod, seals and polar bears. – What will a five degrees warmer Barents Sea mean? ECOSYSTEM EXPERT: Researcher Randi Ingvaldsen at the Institute of Marine Research. Photo: Sveinung Åsali / news – You get a completely different system in the northern parts. Warmth-loving species move north, while the arctic species may disappear in the worst case. – The entire Arctic will move north. Warming can mean that the fish find new spawning grounds. – The heat-loving commercial species are also dependent on the arctic species in the north. This may affect commercial stocks. – Are you worried? – I am quite worried about the Arctic part of the Barents Sea. If we are to have an arctic part, we cannot have such warming. Then we have to do something to stop it.
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Study warns against “extreme” warming – news Nordland
