Greenland is the "second coldest in the world" after Antarctica, with only snow and no rain all year round, and an average temperature of only -7°C.
Because of the harsh climate, only 56,000 Inuit and Danes live on the island. They wear tightly covered up all year round, but in recent days they have almost taken to the streets in short-sleeved shorts. Days of heat have turned the world's second coldest place upside down.
Wearing short-sleeved shorts inside the Arctic Circle? What's happening in Greenland?
Most of Greenland is located in the Arctic Circle, is a typical polar climate, the sun does not set all day in the summer half year, no solar radiation in the winter half of the polar night, and the whole island is cold all year round. Greenland is 80% ice sheet, with a total area of 1,833,900 square kilometers, making it the second largest ice sheet in the world.
Because Greenland has great research value, researchers are stationed all year round. In recent days, Kutalmersh Sayram, a Texas researcher based on the island, and his colleagues have often gone out in shirts, which is a surprising thing.
Although the coastal areas of Greenland occasionally reach temperatures above 0°C in the summer, the relatively inland areas are frozen all year round, and 0°C is a distant temperature.
However, on July 19, CNN reporter René Marsh appeared on the news wearing short sleeves:
"Greenland is hot, close to 60 degrees Fahrenheit (about 15.5 degrees Celsius), which is enough to get me out in a short-sleeved shirt. This unusually warm temperature accelerates the melting of the ice sheet. ”
This unusual situation has been happening for many days, in addition to the clothing problem, more importantly, the soft ice has caused the plane to be unable to take off and land normally.
The effects of climate anomalies are not only reflected in the impact on the lives of residents, but also in a very frightening reality, that is, the melting of ice sheets.
In fact, in the three days from July 15 to 17, about 6 billion tons of ice were lost each day, enough to fill 7.2 million standard Olympic swimming pools.
This is CNN's report on the current situation in Greenland. Experts have analyzed that if the hot weather continues and Greenland's ice sheet melts completely, then the global sea level will rise by 7.5 meters.
Such a drastic change in ice has to arouse people's deep thinking, why did Greenland, which was once proud, become devastated? Why does the Arctic, the highest latitude, get so hot?
Why is it so hot inside the Arctic Circle?
Compared with Antarctica, the Arctic Circle has a much higher average annual temperature. This is because the heat capacity of seawater is large compared to the mainland. Therefore, the Arctic Ocean's ability to store heat is relatively strong, and the rate of energy dissipation is relatively slow, so the average annual temperature in the Arctic Circle is higher than that of the Antarctic, at about 8 °C.
However, this is only the objective reason for the relatively hot Arctic Circle, and it is not the main reason for the large-scale melting of Greenland's ice, and the temperature fusion in the Arctic Circle still has to be explained from the perspective of global climate.
The high temperatures in the Arctic Circle bear the brunt of global warming.
Studies of climate drivers have shown that the increase in atmospheric carbon dioxide concentrations since 1975 has led to energy absorption by the climate system, enhancing the greenhouse effect, a process that is gradually cumulative and irreversible, predicting that by 2050, Arctic glaciers could shrink to one-sixth or less of their current area.
In addition, some scientists believe that there are other factors at play in this atmospheric change, that is, the influence of polar jets. The so-called polar jet is a jet stream that moves in a snake-like posture in the mid-latitudes, and both tropical cyclones and extratropical cyclones belong to the polar jets.
This year in Europe, there has been a rapidly moving air current in the high sky, which is 7-12 km from the ground, moving from west to east, bringing the warm and humid air flow of the Atlantic Ocean to Northern Europe, Russia and other regions. This current brings hot weather to the traditional cold regions, and the coastal countries within the Arctic Circle have rare hot weather.
Sweden's part of the Arctic Circle has soared to 30°C, and temperatures in northern Russia have reached 32°C, and the continued drought and high temperatures have not only increased the forest fire risk factor, but also the ice in the Arctic Circle has melted rapidly.
What happens when the ice melts again? Is it possible for the melted ice to recover?
If the warming situation does not diminish and the ice sheet continues to melt, then sea level rise is inevitable.
Scientists have made a prediction about the rate of sea level rise, and by the end of this century, sea levels will rise by 0.2-1 meters, which is only a conservative estimate, in fact, it may be more.
Assuming that Greenland's ice melts and the world's sea level rises by at least 7 meters, most of the world's coastal provinces and cities will be submerged without any protective measures.
In the case of China, Jiangsu, Shandong, and Guangdong, which are near the sea, will certainly be submerged, and the inland provinces and cities of Anhui and Jiangxi will also face threats.
In addition, the melting of ice is a gradual process, and the water that has melted will cut the solid glacier, and the ice will fall off and fall into the ocean, which will form the ice floes.
Ice floes drift around with ocean currents, which is a great threat to passing cruise ships and ships. The famous Titanic incident was when the ice floes cut the ship, eventually causing the ship to be destroyed and killed.
Ice floes also directly affect the temperature of seawater. In the depression of the ice sheet, the water will gather together to absorb the light, the land that was originally covered by the ice layer, after the ice melts, will expose the rock, the specific heat capacity of the rock is much lower than the ice layer, and it will heat up rapidly under the influence of light, which will further aggravate the melting of the glacier and enter a vicious circle.
So, is there a way to remedy the bad situation?
"We've been looking at these remotely sensed observations to see how the loss and accumulation of ice cubes change. And we found that the amount of ice discharged into the ocean far exceeds the amount of snow on the surface of the ice sheet. The melting of the glacier has led to a constant loss of the entire ice sheet, and even if the climate remains the same, or even becomes colder, the quality of the ice sheet will still decline. ”
The above is the ohio State University Bird Center for Polar and Climate Research Researcher Michaela King and the Earth Sciences Professor Ian Howat in the paper, to put it simply, Greenland's ice sheet melting is irreversible.
Fortunately, although humans cannot change the reality that the ice sheet continues to melt, it does not mean that the rate of ice sheet melting can be delayed.
Scientific progress is now unstoppable, with Switzerland trying in 2018 to cover the River's glaciers with insulating foam to prevent it from melting, and scientists making bold proposals to build artificial walls on the seabed to keep warm currents out.
Although this method can slow the melting of the ice to some extent, the project is huge and complex, requires a lot of technology, capital and labor, and the working environment on the seabed is very harsh, and it is a difficult task to build an artificial wall on the seabed of the entire Greenland Island.
How to solve the problem of global warming is a "huge wall" in front of everyone. All countries should strengthen cooperation to share resources, technology, experience, burdens, and jointly resist the problem of climate warming.
At the same time, instead of "making up for the dead sheep", it is more important to improve the public's awareness of climate warming and awaken human awareness of the protection of the earth, only if all mankind attaches importance to it, can we delay the speed of climate warming and make qualitative changes in environmental protection.
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[1] Greenland's melting ice sheet;
[2] Based on GRACE/GRACE-FO and Swarm satellites, the spatio-temporal changes of ice sheet mass in Antarctica and Greenland from 2002 to 2020 are studied;
[3] Joint observations by GRACE, Swarm and GRACE-FO satellites determined the spatio-temporal variation of ice sheet mass in Greenland.