This article is reproduced from the WeChat public account "Lookout Think Tank" (ID: zhczyj), the original text was first published on September 9, 2021, the original title was "Greenland rained a rainstorm, taking away 7 billion tons of water!" What's wrong with the north and south poles..."
A few days ago, Greenland fell the first heavy rainstorm since human meteorological records have been recorded, and it occurred at an altitude of 3216 meters in Greenland.
According to data from researchers at the University of Colorado, glaciers will melt at an accelerated rate as heavy rainstorms fall from greenland, eventually causing at least 7 billion tons of water to be lost with heavy rains. This is the third large-scale melting event in Greenland in the past 10 years.
Thirty years ago, Greenland's large-scale melting occurred about once every 150 years, and the situation was far less serious than it is now.
In the summer of 2016, meltwater from the surface of the Greenland ice sheet converged into rivers. Rivers rush out of holes (called ice mortars) in the fissures, forming shafts that direct water to the bottom of the ice sheet. The lubricating effect of the running water will cause the ice sheet to slide into the sea more quickly. The orange dot in the figure is a tent for researchers studying this effect.
As for the cause of heavy rain, some researchers said that this is mainly caused by the extreme heat in the northern hemisphere.
In recent years, the phenomenon of high temperatures in the Arctic and Antarctic has become more and more serious, which has led to a sharp decline in flora and fauna, rising sea levels, and frequent global extreme weather.
Antarctica and Arctic, what the hell is going on?
Horrible data
The ancient Antarctic ice is one of the best memory memories on our planet. It records temperatures and carbon dioxide levels over the past 500,000 years, information captured by bubbles buried inside the ice.
Ice cores drilled by the Soviet Union at Vostok Station in Antarctica in the 1980s and 1990s revealed for the first time two facts that are crucial to climate change research: the first is that changes in temperature and carbon dioxide levels always coincide, with both rising and falling in the same direction; the second is that both reached higher values ever recorded.
NASA's satellite photo of Antarctica, which is the coldest, driest and windiest place on Earth. The Antarctic Peninsula is located in the upper left.
So what does climate change mean for Antarctica and the surrounding waters? Some predict that the land surface around the coast will become greener, heralding the arrival of invasive species. In fact, the warming climate in recent decades has quadrupled the amount of moss in many areas of the Antarctic Peninsula where snow and ice have melted.
Adélie penguins who spend their summers on the Antarctic Peninsula are also in dire need of attention, a region most deeply affected by the warming waters and wind currents of the Southern Ocean.
Over the past 30 years, a breeding colony of Adélie penguins on the northern tip of the Antarctic Peninsula has decreased by 80 percent, possibly due to the disappearance of nearby sea ice, which activates the food chains on which penguins depend. For now, this loss is balanced by the growth of the population of Adélie penguins in east Antarctica, where the amount of localized sea ice is actually increasing, but this may not be sustainable.
As the Southern Ocean warms, more light shines through the thinner ice to the ocean floor, and some marine species may flourish. The Ross Sea is a giant bay located just south of New Zealand, where researchers recently found explosive growth in deep-sea sponges, starfish, sea snake tails, and sea cucumbers, but this sharp increase may be misleading.
The researchers found invasions of benth worms and other new species in the Belinskoggen Sea near the Antarctic Peninsula, squeezing out the original species and causing damage to total biodiversity.
Marine biologists believe that about four-fifths of the native invertebrate species living on the seabed around Antarctica are threatened by climate change. According to the UNITED Nations Intergovernmental Panel on Climate Change, about a quarter of the sea ice could disappear in the 21st century, and phytoplankton will also decline. This means that krill will also decrease, and as a chain reaction, all species that feed on krill in the Southern Ocean, from fish, squid, penguins to humpback whales, will decrease. The collapse of krill populations has devastated entire ecosystems.
Papua penguins prey on krill off the coast of their breeding grounds and bring them back to feed their growing young birds. The penguins belong to a colony of more than 100 animals, and their breeding colony is located near Danko Island on the Antarctic Peninsula. As Antarctic sea ice contracted, Papua penguins expanded their diets, partly because Papua penguins don't rely on krill as much as Adélie penguins, and partly because they are larger, so they can dive deeper and catch a wider variety of fish.
In the Arctic, the impact of reduced sea ice on the fate of walruses is particularly pronounced. For walruses, sea ice serves two purposes: sea ice breeds algae, which is the basis of the marine food chain, and sea ice is a platform for walruses to dive into the ocean floor to feed clams and mussels and rest during feeding. But as the Arctic warms, Pacific walruses in the far north are losing these icy platforms and are forced ashore to become fugitives from climate change.
The Chukotka Sea, located between Siberia and Alaska, is a major feeding ground for Pacific walruses, but sea ice is almost non-existent in the summer. Most of the remaining sea ice is farther north, above the deep sea. As a result, walruses migrate south to the headlands off the coast of Siberia, where they can land and rest. The problem is that the sheer number of walruses has overloaded these "rock camps".
Migrating Pacific walruses – Mother walruses and cubs, along with thousands of other individuals, landed on the Siberian coast of Russia's Arctic Circle region. The coast is one of the few areas suitable for migratory walruses to rest in the fall, when sea ice has melted into the heart of the Arctic Ocean after several consecutive extremely warm summers.
On the eastern shore of the Chukotka Sea, the number of walruses increased 10-fold. With more than 100,000 walruses huddled together, one next to the other, this is probably one of the largest colonies of mammals on our planet.
As space runs out, some of the new walruses at the landing sites can only climb cliffs up to 50 meters high to find a rest. There, the pinnipeds are exhausted, hungry, and disoriented by their heights, and they can slip and fall, or they can be frightened by harassment by wild dog herds or humans, and fall to their deaths on rocks below.
At a landing site off the coast of Chukotka, when the "Our Planet" film crew was filming, more than 650 walrus bodies were found on the shore.
Thousands of Pacific walruses gather at a headland on the edge of the Chukotka Sea, the world's largest walrus landing area. In the fall of 2017, more than 100,000 walruses used the rest area, which represents the majority of the Pacific population.
An aura of acceleration
The difference between the Arctic and the Antarctic is not so obvious.
On the surface, they seem to be the same, both covered in endless white ice, but in other respects they are opposite poles. The South Pole is a continent surrounded by oceans, while the North Pole is an ocean surrounded by continents. Antarctica's thick ice has allowed the Antarctic region to maintain low temperatures, while the Arctic has warmed much more severely, resulting in a sharp retreat of Arctic sea ice, which has posed serious challenges for many species.
In March, after months of 24-hour winter polar nights and temperatures below 0 degrees Celsius, the ice sheet stretches across the ocean, connecting Siberia's tundra with North America. Polar bears can thus cross two continents.
In summer, high temperatures and extreme daylight cause most of the sea ice to melt, and the amount of sea ice reaches a minimum in September.
Maximum: In March 2017, after three consecutive years of warm winter, the annual maximum range of floating Arctic sea ice reached a record low. | Minimum: In late summer, in September 2017, the arctic's annual minimum range of polar sea ice reached a record low.
But in recent decades, this seasonal cycle has been disrupted. Fewer and fewer sea ices survive summer melting, and fewer sea ice forms in winter, leaving much thinner ice than in the past. At the same time, in many places sea ice thaws earlier and refreezes later, which means that species such as polar bears spend less time foraging on the ice and more time on shore, and their chances of encountering humans are increasing.
What is happening in the far north of our planet looks like a harbinger of an acceleration in global climate change. The whole planet is warming.
This is due to the accumulation of greenhouse gases in the atmosphere, which capture the sun's heat. Carbon dioxide is an important class of greenhouse gases that is released in large quantities as we burn carbon-based fuels such as coal, oil and natural gas.
In the Arctic, it is warming more than twice as fast as elsewhere on the planet, because the reduction in sea ice accelerates warming. The ice is white, so it can reflect 85 percent of the sun's radiation back into space, which helps keep the Arctic cold. But in recent decades, as the ice has melted, this white surface has been replaced by a darker ocean that reflects only 10 percent of the sun's rays, and the remaining heat is absorbed, heating the surrounding air and water.
The most immediate effect of all this is that more of the ice floating in the Arctic Ocean melts during the summer. The warmer the climate, the more ice melts, which in turn leads to a further increase in temperature. When winter temperatures drop, ice forms again, but the ice that forms again is much thinner because most of the ice that once lasted year after year has disappeared.
Until recently, much of the Arctic was covered by permanent ice sheets that don't melt in the summer, but more than 40 percent of that ice has disappeared. The average thickness of the Arctic ice sheet has decreased by 2/3 since 1975 to 1.2 meters. The effect is spiraling out of control: as the winter ice thins, it melts more easily in the following summers.
Unless the world can limit global warming to 1.5 degrees Celsius (which means the Arctic is warming by about 3 degrees Celsius), scientists believe that by the middle of the 21st century, the remaining permanent sea ice in the Arctic will exist only in small areas of the far north, concentrated between the northwest coast of Greenland and the archipelagos north of Canada's Baffin Island. In summer, almost the entire Arctic Ocean will be completely ice-free.
In late summer, icebergs float in Scottsby Bay, the world's largest fjord system on the east coast of Greenland. The big icebergs here are actually ice floes from the massive Daugaard Jensen Glacier, which crashes into rocks as they float through narrow passages.
The consequences of warming are already significant for Arctic ecosystems and the people who live there, but the potential impacts are even more far-reaching. Without the protection of the "mirror" of the Arctic, the resulting accelerated warming effect will act on all parts of the world.
In 2008, in a tunnel under the mountains of Norway's Svalbard, not far from the North Pole, agricultural researchers operating the World Seed Bank built a "Doomsday Seed Bank."
Its goal is to preserve seed samples from the world's wild and cultivated crops to build a permanent reserve of those seeds from any conceivable global catastrophe, whether it's nuclear war, asteroid impacts, global warming or rising sea levels. Survivors of the future apocalypse will at least find seeds to grow crops to feed themselves.
But in the summer of 2017, temperatures in Svalbard reached unprecedented levels and ice on the mountain began to melt and enter the tunnels. In order to protect the tunnel from future floods, people had to make other preparations. One of the doomsday disasters that seed researchers envisioned seems to have emerged.
Global impact
No one expected Arctic ice melting to happen so early and so quickly. The ablation effect is extending to the continents that surround the Arctic.
Over the past 40 years, snow cover in Canada, Alaska, Siberia and Scandinavia has been cut in half in June. The traditional hunting, fishing and grazing lifestyles of the 40 indigenous groups living in the Arctic have been disrupted by the movement and unpredictability of inshore ice, the loss of grazing land due to new phenomena such as tundra wildfires, and changes in the way marine and terrestrial life migrate.
As the temperature of the soil rises faster than the surface in some places, the permafrost layer is also rapidly disappearing. For thousands of years, the lands of Siberia, northern Canada and Alaska have been frozen, sometimes to depths of up to 700 meters. Today, however, the topsoil is turning from solid ice to mud, leading to road collapse, pipe bursting, building dumping, methane fires, and pothole formation.
Methane is a greenhouse gas with a stronger warming potential than carbon dioxide. If the permafrost continues to melt and this gas enters the atmosphere in large quantities, then, as many scientists predict, warming will accelerate, or even significantly.
A report by the Arctic Council warns that permafrost close to the surface may melt by 20 percent by 2040.
The Siberian permafrost, frozen for more than 2 million years, melts and collapses into river valleys.
The ice-free Arctic, which emerged as the world warmed, is biologically and physically different from what has been the case over the past 2 million years. Nature is adaptable, and some wild animals are relieved and benefit from deep freezing. For example, many Atlantic and Pacific fish are expanding northward, with mackerel being the representative of the victors. But the Arctic has never been an ecological wasteland, and as a result, there will be losers.
Arctic sea ice has always been a refuge for marine life. Take corals, for example: we think corals always form coral reefs around tropical islands, but some of the world's wonderful corals live in the cold deep waters of the Arctic ocean floor, under a near-permanent ice sheet. Like tropical reefs, these cold-water corals also provide habitat for the flourishing of other marine species.
The world's northernmost known distribution of cold-water corals lives on the Carrasque Seamount on the Langsset Ridge in northern Svalbarbar, just 400 km from the North Pole. "It's full of life," German marine biologist Angelo Boetius blogged after releasing a submarine to take photos, "and among the giant sponges that are 1 meter in size and live for hundreds of years live giant white starfish, blue conchs, red crabs, and white and brown clams." "Many cold-water reefs are also economically valuable fish nurseries, such as the flat squid, a deep-sea squid distributed in the northern waters.
As the Arctic is invaded by organisms that thrive in warmer waters, these species adapting to cold waters are likely to decline.
It is clear that floating sea ice is essential for marine mammals such as polar bears, seals and walruses. Ringed seals hunt in the subglacial waters most of the time, but they also play a game of "cat and mouse" with polar bears lurking on the ice. Seals use their fin-footed claws to dig holes in the ice so they can float up to breathe air, while polar bears stand by the holes waiting for food. Seals interfere with polar bear judgment by digging a few more holes to improve their chances of survival. But thinning ice changes the dynamics of this hunting: seals are easier to burrow, but harder to hide.
Not far from Baylot Island, north of Baffin Island in the Canadian Arctic Circle, a young, skinny polar bear stands on top of ice floes. It had just finished eating a seal and was looking for more potential food.
Ringed seals dig their burrows in the snow on the ice, hiding their newborn cubs inside. However, in years with little snowfall, the top of the den collapses prematurely, exposing the cubs. Where the snow is no longer thick enough, the cubs are born on the open ice – and they gradually become unable to survive.
In the short term, bears may have the upper hand, but when the ice melts further, both are losers because they will not have any ice floes available for hunting.
The Arctic is home to 22,000-31,000 polar bears. On the surface, they live quite well. Their number has grown from 6,000 more than 20 years ago to the present day thanks to an international convention to protect them in 1973, which reduced human hunting. In fact, they are one of the few large carnivores on Earth that can still be found in most primitive habitats. But polar bears have evolved to rely on arctic ice for predation, so as the ice disappears, scientists predict that by 2050, 1/3 of the world's polar bears will disappear.
A polar bear stands on a thick ice cap covering Changpu Island, which belongs to the French Josephine Islands within Russia's Arctic Circle. It is surrounded by the largest marine protected area in the Arctic Ocean.
Animal disasters
Other marine mammals face similar challenges.
The horned whale is one of the 3 species of cetaceans that cruise throughout the year in arctic waters, the other 2 being bowhead whales and beluga whales. Their lives are closely linked to the annual expansion and retreat of Arctic sea ice.
Whales from Canada and West Greenland spend most of their winter foraging in the deep waters of Baffin Bay in western Greenland. They congregate in areas with thick ice floes and dive deep in search of their main food, the Greenland halibut, which also feeds on Arctic cod under the ice. The fading of ice reduces their predation zones, and in open water bodies, their risk of hunting increases – as the ice disappears, killer whales migrate to the Arctic.
In summer, the whale feeds not far from Baffin Island in the Canadian Arctic.
The hotspots with the greatest abundance of Arctic wildlife are semi-permanent open water bodies in the middle of sea ice, which are usually formed by upwelling and are called interglacial lakes.
A large number of algae blooms form in the interglacial lake, and wild animals gather in it. Interglacial lakes are vital to the world's largest population of animals such as short-winged puffins, polar bears, horned whales and another species of cetacean that depends on Arctic ice, the bowhead whale. UNESCO has designated some interglacial lakes as World Heritage Sites, but the disappearance of ice poses a serious threat to interglacial lakes.
In addition, the fate of algae is also a big question for the future of marine life. Over the past 20 years, warmer water temperatures have increased algae production by 20 percent, resulting in more blooms, which provide significant food for microcrustaceans (zooplankton) on the ice edge, which in turn feed on fish, birds and marine mammals.
Scientists have noticed changes in the composition of algae species that affect the associated marine food web. Blooms caused by explosive algal blooms are important for marine life, as the life cycles of many species are synchronized with the timing of blooms. But the timing of spring blooms has changed dramatically, as early as 50 days in some places, posing a threat. If blooms don't appear on time, some of the Arctic's most important species will suffer.
On one of the islands of Svalbard in norway's Arctic region, small short-winged puffins collectively return to their nests on rocky shores. They feed on copepods at sea, and warming water bodies will cause planktonic copepods to migrate, which will have a huge impact on the reproduction of short-winged puffins.
This will affect migratory bird species, for example, which will breed and feed during the boom of marine life endowed by Arctic algae. Every spring and autumn, about 12 million seabirds depart from the Pacific Ocean and fly into the Arctic Ocean. On the way, they nest, feed and breed in the narrow Bering Strait. It contains small Arctic terns that travel between the Antarctic and the Arctic each year. If the "ice season" changes, they may arrive without food.
Already in trouble are the Brownick's puffins living in northern Canada, also known as thick-billed puffy crows. Thick-billed sea crows feed their young on Arctic cod, while Arctic cod feed on algal blooms on the ice edge. But now the ice melts two weeks earlier than in the past, before the time when the young hatch. When there is less food, more young birds will die.
Arctic cod juveniles between the ice of the Arctic Ocean. Arctic cod juveniles live around the ice until they are two years old and feed on small crustaceans such as copepods. The antifreeze components in the blood allow them to live below 0 degrees Celsius. When they grow large enough, they travel to open waters and become an important food source for marine mammals and seabirds.
Conservationists aren't sure if thick-billed puffy crows can quickly change their feeding habits in favor of woolly scales, which enter the area after retreating from icy Arctic waters. If not, the thick-billed crow will be in trouble. Also in trouble are ivory gulls, whose populations in the Canadian Arctic have been reduced by 70 per cent.
As the composition of species in the Arctic changes, new food chains may form, but they will have unpredictable effects on humans and nature. Mackerel was not seen in the waters around Greenland until more than 10 years ago, but now they are quite abundant, and together with halibut and shrimp, they are the main exports of Greenland. Their arrival, along with other fish that until recently appeared more in the far south, will prompt more new species to come to the Arctic — especially when humans decide to exploit arctic resources.
Humans have fished for fish in areas further south of the Arctic, such as salmon and white-eyed cod in the Bering Sea, and Arctic cod and haddock in the Barents Sea in northern Scandinavia.
As the Arctic warms, some of these populations decline, such as the white-eyed cod, which feeds mainly along the ice edge, and its number decreases as the ice decreases. Some other species of cod, as well as scaly fish and halibut, may be luckier. One study estimates that the value of Arctic fish stocks will increase by 50 percent by 2050 to about $30 billion.
Disappearing ice caps
A peculiar irony in the polar regions is that humans' influence on Earth's temperature regulation system is strongest in this sparsely populated place. So what can we do, and what have we done to protect them?
In 1959, 12 countries with bases in Antarctica signed the Antarctic Treaty, which prohibited military and commercial mining activities there, effectively guaranteeing that the continent was used only for scientific purposes. Another convention on marine resources, signed at the same time, restricted the fishing of krill and fish in the Southern Ocean.
The establishment of the world's first high-seas marine protected area, the South Orkney Islands South Continental Shelf Marine Reserve, and the world's largest protected marine area, the Ross Sea Marine Reserve in Antarctica's most species-rich bay, suggests that polar protection is escalating.
Conservationists also call for more marine protected areas around the Antarctic continent, giving water bodies the same level of protection as current land. These proposals include the inclusion of another large bay, the Weddell Sea, and the Antarctic Peninsula.
At the same time, the threats facing the Arctic are more diverse and urgent. Unlike the Antarctic, the Arctic is barely officially protected. But in late 2017, countries reached an international agreement to set a 16-year commercial fishing ban on an area in the central Arctic Ocean that is larger than the Mediterranean Sea.
That's good news, but biologists want to go further by formally protecting biodiversity hotspots such as submarine volcanoes (fish breeding grounds), cold-water coral reefs and interglacial lakes. Another proposal is to bring the areas of northern Greenland and parts of the north-eastern Canadian Arctic Archipelago fully under formal protection. Known as the "Last Ice Zone," this area is estimated to last the longest amount of sea ice and will become a key refuge for many Arctic species, including polar bears, in the future.
But the truth is that in the Arctic, establishing formal protection needs to go hand in hand with limiting global warming to 1.5 degrees Celsius and protecting sea ice from further melting.
Off the northern coast of Alaska, a bowhead whale and its juvenile whale surface among the ice of the Arctic Ocean. Bowhead whales live among ice floes and feed on zooplankton such as copepods. The extremely thick skull allows them to break through 18 centimeters of ice when they need to make breathing holes.
The Arctic has been altered by rising temperatures, melting waters of sea ice and thawed soil, and it will retaliate.
Melting sea ice has no direct effect on sea level because it is already floating in the ocean itself (if it melts does not add extra volume). But when land ice melts and water pours into the ocean, sea levels rise worldwide and coastal areas are submerged.
There is a lot of ice on land – most of which belong to the 3 huge ice sheets that cover Greenland and Antarctica. Greenland is about six times the size of Germany and has an ice sheet up to 3 km thick. This ice sheet is melting, which is causing global sea levels to rise by 1 millimeter per year. If it all melts (it will take at least a few centuries, but may become unstoppable), it will eventually raise sea levels by 7.3 meters.
The largest ice domain on the planet is the Southeast Antarctic Ice Sheet. It appears to be stable, both because of its enormous size and because of its location on solid land. This is good news, because if it melts completely, it will raise sea levels by as much as 53 meters. But its smaller relative, the Southwest Antarctic Ice Sheet, is a different story.
The Southwest Antarctic Ice Sheet is not on a solid continent, but is anchored to a series of underwater mountains. Scientists warn that when warm ocean currents form a circulation under the ice, it can cause the ice to break off and drift away, and the ice will continue to melt as it drifts away.
The disappearance of the south-west polar ice sheet will cause sea levels to rise by 5 meters. NASA calls this "the single biggest threat to rapid sea level rise." Its demise will be a global catastrophe, with many of the world's large cities and some of the best agricultural land being submerged, along with coastal ecosystems.
The disappearance of ice may have been slow at first, contributing little to sea-level rise over two centuries. But if we don't stop global warming during this time, sea level rise will quickly accelerate.
More than 600 million people worldwide live in areas no more than 10 meters above sea level. We observed sea levels rising by more than 3 mm per year. This rate is increasing, reaching 60 centimeters by 2100.
The lesson, it seems, is that our immediate priority is not just to stop gradual warming, but also to prevent the far North and South Poles from crossing the tipping point, or our world will eventually become a swamp.
Source: Lookout Oriental Weekly