Glaciers are shrinking, permafrost grounds are thawing, the Arctic could soon be temporarily ice-free: Can we still save Earth’s ice?
The Polar Ice
The Arctic – rapid melting at the North Pole
What is ice shelf?
2 meter high ice sheets of large dimensions floating on the sea, which are fed by inland ice, glaciers or ice streams
Climate change is already strongly noticeable in the Arctic. The melting process of the sea ice and ice shelf at the North Pole is progressing rapidly. In the summer of 2020, the Arctic ice melted to its second lowest extent since satellite recordings began more than 40 years ago. According to current studies, the Arctic Ocean could even be ice-free by the summer of 2050.
“It’s been a crazy year up north, with sea ice at a near-record low, 100-degree (Fahrenheit) heat waves in Siberia, and massive forest fires,” said Mark Serreze, director of NSIDC. “The year 2020 will stand as an exclamation point on the downward trend in Arctic sea ice extent. We are headed towards a seasonally ice-free Arctic Ocean, and this year is another nail in the coffin.”
The rapid melting shows how dramatically climate change is advancing and threatening our planet.
Scientists warn that Earth’s ecosystem could tilt faster than previously assumed. If critical tipping points are exceeded, these changes will have consequences for the global balance. The first domino effects can already be observed. If the seas in the North Atlantic heat up even more, ocean currents will also change. This has an impact on other regions of the world, leading to drought and trees dying in the Amazon region, the decline of coral reefs or rapidly accelerating the extinction of species.
Despite what some might think, the melting of sea ice has no effect on the sea level. Since the melting ice displaces seawater by the same amount as its frozen volume — it is therefore an almost* zero-sum game. (*Almost, because the melting sea ice is not salty and its density and volume do not exactly match the salty seawater.)
The melting ice of Greenland’s mainland, on the other hand, has enormous consequences for the sea level.
Greenland’s ice is mainly located on its mainland. It is estimated at 21.6 million gigatons. According to the latest research findings, Greenland lost almost 5,000 gigatons of ice between 1972 and 2018, raising the global sea level by 13.7 millimeters. If all of Greenland’s ice were to melt, the total sea level would rise by about 7 meters (almost 23 feet). Due to the rather moderate climate at the North Pole, in contrast to Antarctica, even a few degrees of warming already have an extreme effect. In 2019, one million tons of ice already melted every minute in Greenland. New, not entirely undisputed, research results say that Greenland has reached the so-called tipping point — the ice will melt in the coming centuries, no matter how much the global emissions are reduced.
Antarctica — Mysterious growth of sea ice at the South Pole
While the melting process in the Arctic ice sheet at the North Pole has accelerated dramatically, the sea ice of the Antarctic is growing. For a long time, it was assumed that the extremely low temperatures around the South Pole would protect the ice masses from melting.
But now experts are blaming winds, ocean currents and a reduction in salinity for this phenomenon. Nevertheless, the global warming does not sit well with the Antarctic, the largest ice sheet on Earth. Because the Antarctic land ice shows a completely different picture: The many kilometers thick ice shield is increasingly losing mass.
The Mountain Glaciers
The volume of the world’s 200,000 mountain glaciers and ice caps will decrease by about a quarter by 2100, leading to a sea-level rise of about 16 centimeters (just over 6 inches).
Particularly worrying here is that the pace of melting is accelerating. This phenomenon can be explained by the difference between sitting in the sun with a white or black T-shirt: What percentage of sunlight is reflected (thrown back) or absorbed (taken in) in a white T-shirt on a hot summer day, we sweat less than in a black one, which heats up.
White snow surfaces reflect about 90 percent of the sunlight. The underlying layer of ice is protected and the surrounding air is hardly heated at all.
In contrast, water and ground without an ice surface absorb a large part of the sunlight, which means they absorb between 80 and 90 percent of the sunlight. As a result, their own temperature and that of their immediate surroundings increase. These higher temperatures lead to even more meltwater: ice melts faster and faster because the solar energy is swallowed by the ice-exposed dark ocean. Before that, it was reflected back by the white ice sheet. This self-reinforcing cycle is called positive feedback.
In India, Bolivia, Peru or the European Alps, the melting of glaciers is already having far-reaching effects. All over the world, glaciers serve as freshwater reservoirs for the watering of agricultural land and for the production of drinking water and energy. The danger of natural disasters, such as landslides, mudslides or avalanches, is increasing because the frozen ice gives stability to mountain slopes. The consequences for tourism are also dramatic, as snow guarantees the economic survival of many regions.
Desperate attempts by the winter sports resort of Garmisch-Partenkirchen to save the Schneeferner Glacier on the Zugspitze, Germany's highest mountain, from melting have failed. For 20 years almost 6000 square meters of glacier were covered with snow and white tarpaulins. So in another 20 years the Schneeferner Glacier will probably have disappeared completely.
The Permafrost Areas — Frozen Time Bombs
If you want to find out how the eternal ice is doing, you will have to look beyond the classic ice regions. It is not the search for polar bears at the North Pole that provides the answer, but also the ground beneath your feet: permafrost regions. These can be found in Alaska, Canada, as well as in the east and north of Siberia — from the Arctic Ocean to the Urals and in the south to Kazakhstan.
A threatening effect of global warming can be observed there, to which, according to experts, too little attention has been paid for a long time.
What is a permafrost ground? A soil that has been permanently below freezing point for at least two to three years. Only a superficial layer can thaw temporarily, but the ground below remains frozen. The permafrost soil is a relic of the ice age. Everywhere where no ice shield protected the earth from the icy temperatures 20,000 years ago, the ground froze through, in Siberia up to 1,500 meters deep. A quarter of the land area in the northern hemisphere belongs to the permafrost region. According to scientists, half of the land area in Russia is frozen.
The permafrost ground traps huge amounts of greenhouse gases — more than the entire atmosphere. Because of climate change, it is thawing faster and faster — and releasing more and more gases. A vicious circle. About 1500 gigatons of carbon dioxide are trapped in the permafrost soils of the world.
Like giant freezers, permafrost ground stores immense quantities of the remains of plants and animals that have not yet been decomposed by microbes.
These only become active when temperatures rise and the soil softens. If the ground thaws, microorganisms begin to decompose the organic material and convert the carbon into methane gas.
Methane gas is considered by scientists to have a much greater effect on the climate than CO2. This, in turn, contributes to the atmosphere heating up further and melting more permafrost, which releases further greenhouse gases — a dangerous positive feedback loop is created. For more information:
Methane is about 34 times as climate-effective as CO2 over a period of 100 years and about 86 times as greenhouse gas-effective over a period of 20 years
The fact that the permafrost is thawing is undisputed — only how fast this process is accelerating and how much greenhouse gas could be released is a matter of disagreement among scientists.
From 2007 to 2016, experts examined the temperature of the soil and found a significant increase in temperature at well over half of their measuring points. At five of these 123 stations, the ground even thawed completely.