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Earth’s ice is rightly in the news more and more often. As the planet and its oceans warm, our call cryosphere is melting rapidly.
There are two factors that cause sea level to rise: the expansion of water as it warms and the added water from melting ice sheets and glaciers.
Melting ice could lead to catastrophic sea level rise
NASA Ice Viewer/Business Insider
While it is easier to plan for a steady rise in sea level, Scientists are very concerned about what would happen if huge chunks of ice collapsed and will abruptly change the level of the oceans.
According to Alex Brisbourne, a glaciologist at the British Antarctic Survey, and Theodore Scambos, an Antarctic researcher at the University of Colorado, These are the places around the world that scientists are watching closely and why they matter.
Glaciers
The glaciers will be the first to disappear.
According to the Intergovernmental Panel on Climate Change (IPCC), Glaciers outside Greenland and Antarctica have been primarily responsible for rising sea levels over the past century.
Catastrophic collapse – Columbia Glacier in Alaska (America)
Glaciers took centuries to freeze over, but they can disappear within a few years. When they begin to break up, a negative feedback loop is triggered: meltwater warms the glacier, which creates more meltwater.
The Columbia Glacier in Alaska is one of the most recognizable examples of rapid glacial sinking. This glacier has almost completely disappeared today.
“It’s an example of how this will affect many coastal glaciers,” Scambos told Business Insider in an email.
Albedo – Presena Glacier in the Alps (Europe)
Glaciers are not only important because they store water far from the oceans. Because they are light-colored, they reflect a lot of light back into space. This effect, called ice albedois crucial because it prevents sunlight from heating the Earth.
Miguel Medina/AFP/Getty Images
Scientists studying the albedo of glaciers have discovered a peculiar effect of thawing.
Colourful glacial and snow algae have grown in the meltwater of glaciers, creating spectacular pink and purple colours and effects on the ice, as is the case on the Presena glacier in the Alps. The problem is that this reduces the albedo of the glacier, which again promotes warming and melting.
Freshwater – Himalayan Glaciers of the Hindu Kush (Central Asia)
Glaciers are also a vital source of fresh water. More than 1 billion people living in Central Asian countries depend on the glaciers of the Hindu Kush Himalayas for drinking water.and scientists have recently discovered that these glaciers are rapidly shrinking, which is a cause for concern.
Pool /Samir Hussein/WireImage / Getty
“Around 2050 it will peak. Beyond that point, there will be less fusion,” AB said.
Geopolitical experts are concerned that This increasingly scarce resource could cause tensions in neighbouring countries.
Greenland and Antarctica
The Greenland and Antarctic ice sheets are huge glaciers that cover the poles. Besides, They contain most of the fresh water of the earth’s surface.
The Antarctic ice sheet is much larger than that of Greenland. If they were to melt completely, the Greenland ice sheet would contribute about 7 metres to sea level, while the Antarctic ice sheet contains enough ice to raise sea level by 17 metres. Of course, this is not expected to happen for centuries.
The other big difference is that the Greenland ice sheet rests on solid land above sea level, while Much of the Antarctic ice sheet lies below sea level, making it more vulnerable to warming ocean temperatures..
Greenland
According to the IPCC, Greenland is melting twice as fast as the Antarctic ice sheet.
According to Brisbourne, as the atmosphere around the North Pole warms, All ice below an altitude of 2,000 metres is at risk of collapse.
“The problem is that as the ice melts, it becomes thinner, and that means there is more ice below 2,000 metres,” he added.
This is happening all over the Greenland ice sheet, as seen in this terrifying animated video from NASA.
Ilulissat Glacier, also known as Jakobshavn, is a glacier that scientists are closely monitoring on the west coast of Greenland, where the ice sheet is melting most rapidly.
Ilulissant Glacier, also known as Jakobshavn
Ice flows down ice sheets like very slow rivers. Carried by its own weight, the ice falls from the top of the glacier to the lowest point. In perfect equilibrium, enough snow falls to replenish the ice sheet, but This balance is broken when the ice melts too quickly, there is not enough snowfall, or it rains instead of snows.
When this happens, the ice sheet begins to thin and the glaciers at the edge of the sheet retreat, as seen below.
Antarctica
The Antarctic ice sheet, located at the South Pole, is about 8 times larger than that of Greenland.
Because much of this ice sheet lies below sea level, it is much more affected by warming ocean temperatures.
Scientists divide this ice sheet into three parts: the peninsula, West Antarctica and East Antarctica.
Antarctic Peninsula – Larsen-A and -B
The peninsula is much more affected by atmospheric temperature than other areas of Antarctica.explains Brisbourne.
In 2002, scientists watched helplessly as an ice shelf called Larsen-B sank into the ocean within weeks.
Between January 31 and April 13, 2002, some 500 billion tons of ice and snow disintegrated into the ocean.
This happened less than a decade after another ice shelf in the area, Larsen-A, also disintegrated.
Ice shelves do not contribute to sea level rise when they melt. Since they float, they occupy the same volume in the sea, whether frozen or melted, just as an ice cube does not raise the water level in a glass when it melts.
However, ice shelves stabilize the glaciers and ice sheets that lie behind them.Without their ice shelves, Larsen-A and -B glaciers began to melt much more rapidly, releasing three times more ice into the ocean than before.
According to Brisbourne, the collapse of Larsen-B was likely due to melt ponds, also known as melt pools.
Melt ponds appear when the warming atmosphere causes meltwater to pool on the surface of the ice. As they grow, their weight cracks the ice and can cause the ice shelf to collapse, a process called hydrofracturing.
NASA Earth Observatory/Courtesy of the MABEL team
Since there was not much ice on the Antarctic Peninsula to begin with, the loss of these ice shelves did not greatly change global sea level.
But these losses are seen as “the canary in the coal mine” for Antarctica, Brisbourne said.
West Antarctica – Thwaites Glacier and Pine Island
Scientists are much more concerned about West Antarctica. Its ice cap rests on a bedrock below sea level, meaning that is much more vulnerable to ocean warming.
Ice from West Antarctica flows through several glaciers, including Pine Island Glacier, Dodson Glacier, and Thwaites Glacier. These act as buffers between the ice sheet and warming oceans.
Scientists are very concerned that Thwaites is holding on “by its fingernails,” which has earned it its nickname: the “doomsday glacier.” The ice cap in front of Thwaites is creaking and It is believed that the glacier could collapse within this decade.
“We think that if we lose the Thwaites zone, the entire West Antarctic Ice Sheet could follow,” Brisbourne said.
That could raise global sea levels by up to 3 metres.
But there is still hope.
Pine Island was collapsing more rapidly than Thwaites, but it slowed down, Brisbourne said. What scientists didn’t expect was that The ice sheet has become stuck to a small island off the coast of Antarctica, slowing the rate of its collapse.
East Antarctica – Conger Ice Shelf
It is believed that The eastern part of Antarctica is quite stable.
“East Antarctica is a bit more like Greenland in that it’s above sea level. So it hasn’t been greatly affected by ocean warming and the atmosphere hasn’t warmed as much,” Brisbourne said.
East Antarctica It has enough ice to raise sea level by a total of 52 meters.so if it were to collapse, it would be pretty catastrophic. But Brisbourne says scientists don’t expect that to happen for a long time.
Even so, Scientists were stunned to see an ice shelf called Conger collapse on the east side of Antarctica earlier this yearConger was not under the radar of most scientists. In fact, Brisbourne says that most of his colleagues had never heard of him.
“It’s a very small ice shelf and it’s fed by a glacier that drains a very small area. So in terms of contribution to sea level rise, it’s actually going to be very small,” he said.
“But again, it’s one of these warning signs that in this area we’re starting to see processes that we know have affected other parts of the continent and led to some pretty dramatic ice loss,” Brisbourne said.
Other effects of thawing
There are further indirect effects of melting ice on sea level rise.
Arctic sea ice
Every winter, the water in the Arctic Ocean freezes, covering our planet in white during the winter and receding during the summer.
But The extent of this white layer in winter has been decreasing every year.