onsdag 31 augusti 2022

The climate threat Doomed zombie ice will raise the water level at least 27 cm

Doomed Zombie Ice Shock Raises Sea Levels

Of: 

Paula Westerberg 

Published: Today 13.35 

Updated: Today 15.48 

NEWS 

Scientists have for the first time been able to establish a minimum level for how much the water level will rise due to climate change. 

That will be 27 centimeters – or three times more. 

And it all has to do with something called zombie ice. 

Greenland's ice sheet is melting. We have known that for a long time. But we didn't know how much, until now. 

A study by the Geological Survey of Denmark and Greenland (GEUS) was published on Monday. Scientists have used a new method and concluded that 3.3 percent of the Greenland ice sheet will melt. That's 110 trillion tons of ice. 

According to the study, this is unavoidable, the ice is doomed, and has been called "zombie ice". 

As the zombie ice melts, sea levels will rise by an average of 27 centimeters across the globe. However, it will vary regionally, and in some areas the levels will be lower, in others even higher. 

- And 27 centimeters is only from Greenland's ice. And it is only one of several components that lead to increased water levels, says Andreas Peter Ahlstrøm, chief research consultant at GEUS.

It was, among other things, by looking at the balance of the ice that the researchers arrived at their results. Nina Kirchner, docent in glaciology at Stockholm University and director of the Tarfala research station, explains: 

- It snows in the winter, and then the glacier gets added. Then it melts in the summer. You can compare it to a bank account. And at the end of the year, you check whether you went minus or plus. A glacier always wants to be in balance. 

Andreas Peter Ahlstrøm, Geological Survey of Denmark and Greenland.

Andreas Peter Ahlstrøm, Geological Survey of Denmark and Greenland. Photo: Andreas Peter Ahlstrøm

Nina Kirchner, docent i glaciologi vid Stockholms universitet och föreståndare för Tarfala forskningsstation.

Nina Kirchner, docent in glaciology at Stockholm University and director of the Tarfala research station. Photo: Nina Kirchner 

Reaction to what has already been 

But because ice is an inert material, there is a delay in how it is affected by climate change. 

- It lags behind. What is happening now, the ice sheet will react to in many, many years, says Nina Kirchner. 

The researchers behind the study calculated how the ice balance will be affected by how the climate has been over the past 20 years. And that is precisely why they can say that this will definitely happen, because it is a reaction to climate change that has already happened. 

- So it is completely regardless of what the climate will look like in the future, says Andreas Peter Ahlstrøm. 

What this research doesn't show, however, is time. An answer to when the ice will melt and thus the water level will rise, is not given. It says in the study that it will happen in this century, which the authors have been criticized for because it is not supported by research. One of the authors has explained that it was a "qualified guess", AP writes. 

Arkivbild.

Archive image. Photo: Felipe Dana / AP 

27 cm is only the lowest level 

A water rise of at least 27 centimeters would have a major impact on society. 

- Everyone living in coastal areas would be affected. And the infrastructure in the big cities is not adapted for this. In addition, we know that extreme weather events are becoming more extreme and happening more frequently because of climate change. That together with a 27 centimeter higher water level is not so fun, says Nina Kirchner. 

And 27 centimeters is just a minimum scenario. According to the study's worst-case scenario, the water level rises by 78 centimeters. 

Are you worried? 

- No. I work with this so I have to keep distance from it. But as a private person, I am, says Nina Kirchner. 

She explains that it is a matter of us having to reverse the trend and that many and large efforts will be required. 

Do you think we will succeed? 

- I hope so. We have to.

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