IPCC’s announcement: How a warmer sea will affect life in the Nordic region

20 August, 2021

“In the early 1900s, the oceans were able to absorb about 90 percent of the carbon dioxide we emitted. Today, they take up 26 percent. This actually means that the oceans today absorb a larger amount of carbon dioxide than they did before, although it is less in percentage terms because we now emit more,” says Jonathan Havehand, a researcher and marine ecologist at the University of Gothenburg.

But it is unthinkable that the oceans will continue to absorb carbon dioxide at the same rate, says Havehand.

“Their ability to absorb more carbon dioxide decreases every year,” he says.

On August 9, the Intergovernmental Panel on Climate Change released a new report on the effects of global warming on the earth. The report itself does not really present any new research, but it is a compilation of recent years’ research on the climate. Specifically, it is the result of 14,000 different studies, conducted by 234 researchers from 66 different countries.

There is a lot to focus on in the report and one of the big conclusions is that the earth has not been this warm for 6500 years. But also that we can reach a 1.5 degree increase in the average temperature on Earth already within 20 years. It is now also beyond doubt that human emissions are the cause of global warming.

When the countries of the world signed the Paris Agreement in 2015, it was agreed to limit warming to 1.5 degrees and certainly not exceed two degrees. However, if we continue with today’s emission levels, we will go over both of these benchmarks, unless drastic measures are taken soon.

The oceans have historically helped us limit emissions, sequestering not only carbon dioxide, but also heat. They have actually stored as much as 90 percent of the heating that took place between 1971 – 2010. But warmer oceans are also taking up more space, and according to the IPCC’s summary, sea levels on Earth are now rising three times as fast as they did 50 years ago.

“We are taught in school that the water cannot be compressed. But that’s not entirely true. When water gets warmer, it swells, and that is one of the reasons why the water level is now raised. At the same time, we have glaciers that are melting, which contributes more water,” says Jonathan Havehand, who has been researching life below the surface for more than 35 years.

There are reports of coastal cities and even islands that will disappear as a result of sea level rise if we continue to emit as much greenhouse gases as we do now. But in the Baltic Sea, the change will not be as dramatic.

“Firstly, the inflow of water into the Baltic Sea is not as large. But we also have a parallel land uplift in the Nordic countries. At the rate at which sea levels will rise, so will the land level rise in parallel. But how big that difference will be depends of course on how big the warming will be and where in the Nordic countries you are.

But this does not mean that the Baltic Sea remains unaffected.

“The IPCC will see increased rainfall, which means that the Baltic Sea will have more fresh water. How much fresh water it gets depends on how hot we let it get. But if the precipitation increases enough, there are some animals that will not thrive as well in the Baltic Sea.

But it doesn’t have to be a negative thing, says the researcher.

“At the same time, we may get new species here, we don’t know, but the question is whether we will appreciate them as much as we appreciate cod.

Floods Gävle
Photo: Andreas Bardell / Aftonbladet / TT

The jet stream weakens

Another consequence of the earth warming up is, among other things, that we will experience extreme weather more and more often, even here in the Nordic countries. When the ice in the Arctic melts, there is not as much white ice that reflects off the sunlight, but there are larger areas of dark sea that absorb heat. As the oceans get warmer, so does the air. This, in turn, affects the polar jet stream, the air corridor that is in the atmosphere and that controls large parts of our weather. Havenhand describes how it works:

“An air corridor is similar to when you walk into a department store through sliding doors like that. Outside it is cold, when it goes in it blows a little, and then you are met by warm air. Similarly, it works with the jet stream. It has locked in the cold air in the north and contributed to us having a more stable and reliable weather here in the Nordic region.

But when the air in the Arctic now gets warmer, it affects the jet stream, which in turn will affect our weather.

“That’s why this summer it’s suddenly 20 degrees three days in a row in Greenland, or why we can have severe heat waves or freezing cold all of a sudden. The weather will not be as reliable, quite simply.

And it is precisely the reliability and stability of the weather that Havenhand believes is one of the major concerns with the climate crisis.

“Our entire society is built on eco-sewing services. We expect that it will rain at a certain time of the year, or that the fish will be at a certain coastal strip. But when the earth’s temperature changes so quickly, ecosystem services will change. And the question is whether our society has time to adapt to that.

Never has the warm-up gone so fast

There was a time when the Earth was significantly warmer than it is today. Then there was not even any ice on the poles. Why, then, should we be worried now?

“It is absolutely true that it has been warmer on earth. There was even a time when there was no oxygen in the oceans. But that warming took hundreds of thousands of years. Today, this change has passed in just a few decades. It has never happened so fast before. And if we look evolutionarily, few species are able to adapt in just a few decades.

Havenhand has devoted much of his research to understanding what happens to the ability of animals to reproduce as the oceans become more acidic and warmer. He believes that really, global warming does not have to be such a big problem for the ocean, but it is the sum of all human activities that makes him worried.

“The problem with what happens in the sea is that there are several stresses happening simultaneously. The oceans are acidifying because they absorb more carbon dioxide, while at the same time they become warmer. In addition, they become sweeter due to an increased rainfall and ice melting. All of these effects alone might not affect the oceans very hard, but it’s when they happen at the same time that it gets really bad. Then they can make each other worse. And that’s exactly what’s happening now.

Havehand says coral bleaching in Australia is a good example of how the effects reinforce each other.

“Coral bleaching is actually something that has happened from time to time for a long time. Most corals are usually able to recover after a while, but now the corals do not have time to recover. The marine heat waves are coming more and more often, at the same time as the sea is becoming more acidic. If you then have a species like the coral that is already exposed, it will be much more difficult for it to withstand more stresses. Especially if the stresses happen more and more often.

The oceans are an important source of oxygen for both humans and animals. Every second breath we take today comes from the sea. How does global warming actually affect the oceans’ ability to produce oxygen?

“We don’t have a clear answer to that, which is quite worrying. Imagine if you were sitting in a space capsule and you know that your tube that gives you 50 percent of your oxygen will be affected by external factors. Then you would have liked to know exactly how it will change, right? That’s something we should be looking at more, especially given that our other oxygen sources on land are being cut away at a furious rate.

“Climate is not a scientific issue anymore”

Jonathan Havenhand is not really very concerned about the well-being of the oceans, he believes that the seas will always survive. But the big question is whether we as humans will be able to adapt to the change that is taking place beneath the surface.

According to him, the climate is no longer a scientific issue – it is a political issue.

“We know we have the technology and the money to solve the problem. What is lacking is the political will and it does not get any easier with fossil fuel companies continuing to lobby for the status quo. I’m not an environmental economist, but I think most economists would agree with me that it’s cheaper to fix the problem now than late.

He himself mentions several measures that could mitigate the effect of warming.

“We know that other factors reinforce each other. If we can then make sure to reduce other human impacts on the oceans, then we can make the ocean more resilient. For example, we could switch to more sustainable fishing and reduce eutrophication. We can do this today, locally, while working for common changes globally.

But despite the alarming numbers, Havenhand still feels hope for the future.

” I have to feel hope, the alternative is not even worth thinking about. I think we can influence the world with how we think and with our attitude. We know that change can happen quickly if we want to. It has in the past. It’s been less than 20 years since we got smartphones. Check out how it has changed our society! It can go fast if we make up our minds.

Text: Fanny Jönsson
Photo: TT News Agency

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