Urs of the world ocean Yen may rise more than a meter by 2100
In 1984, scientists at Ohio State University found something unexpected in Antarctica. At an altitude of 1,600 meters above sea level, on the transatlantic mountain range, they found traces of algae, which are usually always found at the bottom of the sea.
Question: How could the algae get to such a height?
In 2002, the world watched in shock as the entire Larsen Glacier in Antarctica disappeared within one month. A glacier with an area of 3 thousand square kilometers melted into the sea.
At the same time, the UN International Panel of Experts on Climate Change has been criticized for the fact that existing climate models do not take into account everything that affects glaciers. It was, in particular, about observations of the breaking of glaciers in the eastern part of Antarctica in recent years. Northern Illinois University scientist and professor Reed Scherer and his colleagues now believe they have found a model that works best for the area. And the results of their work are frightening.
Big cities can be destroyed
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In the 90s, the scholar Scherer, who had a bachelor's degree at the time, followed the debate over what happened in the Pliocene era three million years ago. The line of disagreement was between those who believed that the traces of algae found at an altitude of 1600 meters were due to the fact that ice in eastern Antarctica at some time collapsed and fell down, and then was raised up, and those who believed that it is completely impossible and that, most likely, the fossils were carried by the wind to this height in the mountains.
Scherer wondered how all these processes could be connected between. But it took 20 years before a model was created that could be tested. In this he was assisted by Rob DeConto of the University of Massachusetts and David Pollard of Pennsylvania State University.
They published an article in the journal Nature, and before that the Washington Post talked about them and their models.
“In a scenario with large emissions of gases, the XXII century will turn into hell. The sea level will rise unimaginably. As a result, many large cities and some peoples will disappear from the map. This will be the centenary of the exodus from coastal areas,”says Ben Strauss, sea level program manager at the New Jersey Climate Center, in an interview with the Washington Post.
At one time, a UN group of experts on climate change suggested that if we continue to pollute the atmosphere in the same volume as now, the water level will rise to a height of 0.5 to one meter by 2100. This alone will lead to serious consequences for the whole world, in particular, some areas of the Netherlands will go under water.
But if the new model is correct, the situation could be even worse.
The new model is said to better explain the situation
All models are based on the assumption of temperatures in the atmosphere and ocean. In 2007, Norwegian climatologists also reported that the models did not match the observations.
“In recent years, there has been an increasingly intense ice splitting along the edges of Greenland and Antarctica. Many of the physical processes involved in this movement of ice are not yet fully understood. Therefore, the existing models that can describe what is happening are not realistic,”stated Ina Kindem and Sigbjørn Grønås in their commentary on forskning. no.
The main reason for the rise in seawater levels has been hypothesized to be more water in the ocean due to rising temperatures. Another important reason is the melting of glaciers far from the poles. On the other hand, the ice in Greenland and Antarctica was considered very stable.
In a material published in Nature, scientists (primarily David Pollard) showed a developed model that reproduces, in their opinion, the processes occurring during the melting of glaciers.
According to their model, Antarctica's ice will melt so that ocean levels rise by one meter by 2100 and more than 15 meters by 2500. This is at the current level of global warming.
Faulty model or data
Dagbladet got the opportunity to chat with Reed Scherer in the car on the way to the Lamont Earth Observatory, owned by Columbia University in New York. He said: “Either our data or our model is wrong. The coincidences are better now. Previous models did not include all the physics that affect ice. Not only does the ice disappear when it gets so warm that they can melt, it's all more difficult.
In 2002, water fell into the cracks of the glacier. The cracks grew deeper and deeper until the glacier split into large pieces. Thanks to this, the process is faster than with "normal" melting.
The fact is that ice melts longer than there when it falls into water. This featured the disappearance of the Larsen Glacier in 2002. It told us a lot about how the process goes and what we should pay attention to. It's not just about melting, but also about getting closer to the end point."
When the data on the algae finds in the mountains were published, Scherer, who then had only a bachelor's degree, decided to take part in the debate.
“20 years ago I could only draw something that could look like a blueprint, but now we have a model on which to test.
What is happening is a small victory for the supporters of the dynamic theory. This theory is that ice is dynamic and retreats very quickly when in contact with water, contrary to what the static theory thinks.
As the ice recedes and the pressure on the ground below it decreases, the land rises along the coast of Antarctica.
Where there used to be a sea, sediments with algae dry out, as a result of which the wind can more easily lift them off the ice.
I don't know how he will take it
Scherer looks forward to hearing from specialists.
“I don't have many answers yet. There are still some experts who believe that East Antarctica has not changed. Let's see what will be said in the coming weeks. Dave Harwood, who first found the fossil algae, said the glacier was more than three million years old. I don't know how he will take it. In this regard, I can say that he is right, but for erroneous reasons. This confirms the view that too much heat is not required for the ice to retreat strongly."
It is impossible to stop, but you can slow down
We asked Scherer about avoiding the worst effects of climate change, but his answer was not very optimistic.
“We cannot stop this, but we can slow the retreat of the ice edge,” he said.
How much better do we have to become to achieve this?
- The question is what risk you can take, hehe. We will not turn on the oil valves, and Trump also wants to increase coal production because he does not believe that climate change is due to human actions. Scientists are the first to say that we do not know everything…. But this does not mean that we know no more than … other people. The only bad thing is that there are things that I know that I do not know.
What do you usually tell people who do not believe that climate change is the result of human activities?
- First of all, I say that the climate has nothing to do with your political philosophy. The climate is what it is. And then I say that if you are sick, then you go to the best doctor with the best education, who knows the most about your disease. Not that guy at the end of the bar. So why should you trust the guy at the end of the bar more on this issue than the one who devoted his entire life to understand this issue?
Another argument from these people is that your own research says that change happens all the time. Why then do you say that this is the result of human activity?
The answer to this is that the change is happening much faster than it would on earth with less carbon dioxide. I am exploring mainly western Antarctica, not eastern, and what I see there worries me even more. But this study also shows that there is reason to be concerned about the situation in the east, not only a stable ice block.
Why are you more concerned about the western side?
- Most of the ice is below the water level and most of it is in contact with the sea, which heats it. We found fish under the ice, far from the edge of the ice, and this is very reflective. But we will talk about this in our next publication.
He is not overly optimistic about politicians and voters.
“We have to be intelligent. We had a lot of bad choices, and now we should have good ones."
The question is not that it will happen
Kerim Hestnes Nisanciogluer, professor at the Bjerknes Climate Research Center at the University of Bergen, says the UN Climate Change Panel is working to incorporate the new calculations into their models: “Antarctica is special because ice is in contact with the ocean. In warmer climates with more melting volume, melt water-filled cracks develop, causing ice along the coast to quickly break and melt. New calculations show that the contribution of the ice mantle to sea level is now greater than before. The UN Panel on Climate Change did not include these processes in their calculations, but is now actively engaged in it."
The professor says that, based on their own research in Greenland, they see that ice that is in contact with water melts faster than ice on earth. This happens because there is more melt water on the surface and cracking occurs.
“We scientists fear that what we see in Pliocene sea level data will become reality in a warmer greenhouse climate, assuming the current CO2 level in the atmosphere remains at 400 ppm,” he says in an interview. with Dagbladet. "The question is not that the water level in the ocean will rise by ten meters or more, the question is how quickly it will happen."