○On March 18, 2022, scientists at the Concordia Research Station on the East Antarctic Plateau recorded a remarkable event. They recorded the largest increase in temperature ever measured at any weather center on Earth. According to their instruments, temperatures in the region rose 38.5 degrees Celsius above the seasonal average that day, a world record.
This amazing leap in the coldest place on Earth has left polar researchers struggling to explain it in words. “It's just mind-boggling,” said Professor Michael Meredith, scientific leader at the British Antarctic Survey. “Such a sudden rise is acceptable in sub-zero temperatures, but if the UK were to rise by 40 degrees Celsius now, spring day temperatures would exceed 50 degrees Celsius, which would be fatal for the nation. .”
This surprise was shared by Professor Martin Siegert, a glaciologist at the University of Exeter. “No one in our community expected something like this to happen. It's unusual and really concerning,” he said. observer. “We now have to grapple with something completely unprecedented.”
Scientists say that polar winds, which previously penetrated little into the atmosphere above Antarctica, are now bringing more warm, humid air deep into the continent from lower latitudes, including Australia. It is thought to be responsible for the dramatic polar 'heat wave' that hit Concordia. However, it is still unclear exactly what allows these currents to penetrate so deeply into continental airspace.
Scientists also discovered that this significant temperature increase was not an isolated event. The past two years have seen a surge in reports of disturbing weather anomalies across the continent. Glaciers adjacent to the West Antarctic ice sheet are losing mass to the ocean at an increasing rate, while sea ice levels in the ocean surrounding the continent have declined dramatically and remain stable for more than a century. Ta.
These events meant that Antarctica, once thought to be too cold to experience the early effects of global warming, has become dramatically and rapidly affected by rising levels of greenhouse gases that humans continue to emit into the atmosphere. This raises concerns that it may be in decline.
These risks were highlighted in a paper published last week by a team of scientists led by Will Hobbs from the University of Tasmania. climate journal. The research group investigated recent changes in Antarctica's sea ice extent and found that there was a “sudden and significant change” in the Antarctic region's climate, with implications for both the local Antarctic ecosystem and the global climate system. It was concluded that there is a possibility of giving
“The extreme decline in Antarctic sea ice has led researchers to suggest that a regime shift is underway in the Southern Ocean, with multiple evidence supporting such a shift to new sea ice conditions. We found evidence,” Hobbs said.
Meredith emphasized the dramatic nature of this change. “Antarctic sea ice extent actually increased slightly in the late 20th and early 21st centuries. But it fell off a cliff in the middle of the last decade. This portends a new horizon for the Antarctic climate system. “This could be very troubling for this region and the rest of the world.”
The continent is now catching up with the Arctic, which is experiencing the most intense warming effects ever on Earth, Siegert added. “The Arctic is currently warming four times faster than the rest of the planet. But the Antarctic is also starting to catch up, and is already warming twice as fast as the entire planet.”
The main reason the Arctic and Antarctic are being disproportionately hit by global warming is because the Earth's oceans, warmed by the burning of fossil fuels, are losing extreme sea ice. The dark water that was once beneath the ice has been exposed, and solar radiation is no longer reflected back into space. Instead, it is absorbed into the ocean, further heating it there.
“Essentially, it's a vicious cycle of ocean warming and sea ice melting, but the root cause is humanity and the continued burning of fossil fuels and the production of greenhouse gases,” Meredith said. “All of this business has to be on our doorstep.”
Researchers warn that the effects of this climate change could be devastating. If all of Antarctica's ice melted, sea levels around the world would rise by more than 60 meters. Islands and coastal areas, where much of the world's population currently makes their home, will be flooded.
However, such an apocalypse is unlikely to occur any time soon. The Antarctic ice sheet is 14 meters square kilometers (approximately 5.4 meters square miles), roughly the area of the United States and Mexico combined, and approximately 30 meters square kilometers (7.2 meters cubic miles), containing about 60% of the world's fresh water. Contains ice. This vast cover hides a mountain range almost as tall as the Alps, and scientists say it will take a very long time for it to completely melt.
Nevertheless, as West Antarctica's ice sheets and glaciers continue to shrink, there is a real risk of significant sea level rise in the coming decades. The roots of these structures are being eroded by warming ocean waters and could collapse in a few decades. If they were to disappear completely, sea levels would rise by 5 meters, enough to harm people in coastal areas around the world. It's difficult to assess how quickly that will happen. The Intergovernmental Panel on Climate Change has said sea levels could rise by 0.3 meters to 1.1 meters by the end of this century. Many experts now fear this is a dangerous underestimate. In the past, climate change deniers have accused scientists of exaggerating the threat of global warming. But evidence now emerging from Antarctica and other parts of the world shows that scientists are not exaggerating. In fact, they probably significantly underestimated the threat currently facing humanity.
“The situation is even more confusing in Antarctica, where data availability has historically been problematic,” Meredith added. “This continent is so remote and so hostile that we had no information about its climate or ecosystem compared to the data we get from other parts of the world.” Our record is relatively short, which means that the climate models we create, while highly capable, are based on sparse data. Capturing all of the physics, chemistry, and biology. They can make consistent predictions, but they can't capture the kind of extreme phenomena that we are now beginning to observe.”
But the challenges facing Antarctica are not just of human interest. Professor Kate Hendry, a chemical oceanographer based at the British Antarctic Survey, said: “We are already seeing serious ecological impacts that could spread through the food chain.”
An important example is provided by algae that grow under and around West Antarctic sea ice. This is having a very serious impact and is starting to disappear, Hendry added. Algae are eaten by krill, small marine crustaceans that are among the most abundant animals on Earth and feed on predators such as fish, penguins, seals, and whales. “If krill starts disappearing because of algae, there will be all sorts of disruptions to the food chain,” Hendry said.
But the threat posed by the disappearance of krill is even more serious. They play an important role in limiting global warming. Algae absorb carbon dioxide. Krill eat them and excrete them, and their feces sinks to the ocean floor and stays there. Reduced levels of algae and krill mean carbon from the atmosphere is deposited on the ocean floor, instead staying near the ocean surface and returning to the atmosphere.
“They act like a conveyor belt that can take carbon out of the atmosphere and transport it to the deep ocean floor, where it can be trapped. So if we start tinkering with that system, we can begin to address the effects of global warming. There could be all sorts of other ramifications for our efforts to do so,” Hendry added. “That's a scary scenario. And yet, unfortunately, that's what we're facing now.”
Another victim of the sudden and catastrophic warming that has hit the continent is its most famous resident, the emperor penguin. The penguin, which lives only in Antarctica, suffered a devastating breeding failure last year. That's because the sea ice bedrock in which they are born begins to break down long before the young penguins grow waterproof feathers.
Peter Fretwell, from the British Antarctic Survey, said: “We have never seen emperor penguins fail to breed on such a scale in one season.” “As sea ice in the region decreased during the Antarctic summer, the chances of survival for the evacuated chicks became very low.”
Researchers say the discovery of emperor penguin extinctions suggests that if global warming trends continue at the current dire rate, more than 90% of colonies will be gone by the end of this century. “The chicks can't survive on the sea ice until they leave the nest,” Meredith says. “Then they are able to take care of themselves. But the sea ice has broken up before they get to that stage, and mass drownings are now occurring. Penguin colonies are becoming extinct. And that's a tragedy. This is an iconic species, a species that represents the new vulnerability of Antarctica and its ecosystem.”
The crisis facing the continent has far-reaching implications. More than 40 countries have signed the Antarctic Treaty's Environmental Protocol, which protects Antarctica from a variety of threats, with habitat degradation being one of the most important. The fact that this continent is currently experiencing alarming changes to its ice cover, ecosystems, and climate is a clear sign that this protection is no longer available.
“The causes of this ecological and meteorological change lie outside the continent,” Siegert added. “This problem is caused by the fact that the rest of the world continues to emit huge amounts of carbon dioxide.
“Nevertheless, if countries are deliberately polluting the atmosphere with greenhouse gases and Antarctica is affected as a result, then the Protocol to the Convention is being violated by signatories and their actions are There are good grounds to argue that it can be challenged on legal and legal grounds, as well as on political grounds. There is no doubt that there will be some difficult meetings at the United Nations in the coming years.”
