Monday , March 1 2021

The Arctic is in even worse form than you realize

Over the last three decades of global warming, the oldest and thickest Arctic ice has dropped by a stunning 95 percent, according to the annual Arctic Ocean Report and the Atmospheric Administration.

The intention is that the sea in the upper part of the world has already become a new and very different country, with great consequences not only for creatures like walruses and polar bears, but in the long run maybe the pace of global warming itself.

The oldest ice can be considered a kind of glue that keeps the Arctic together, and through its relative permanence helps keep the Arctic cold even in the long summers.

"The younger the ice, the thinner the ice, the easier it is to disappear," said Don Perovic, a Darthmouth scientist who coordinates the sea ice in the annual report.

If the Arctic begins to experience a full-summer ice, scientists say, the planet will get warmer as the dark ocean water absorbs large amounts of solar heating that has been diverted from the ice cover. The new findings have been published as climate negotiators in Poland are trying to reach a global consensus on how to deal with climate change.

In March, NASA scientists with Operation IceBridge, exploring the polar regions using research aircraft, witnessed a dramatic case of ongoing changes. Flying over the seas to the north of Greenland, in an area that usually contains some of the oldest, thickest ice in the Arctic, they instead see smooth, thin strips that combine thicker, protruding pieces.

"I was just shocked by how different this is," said Nathan Kurtz of NASA, who has flown over the area several times. The floating sea ice had completely disintegrated the previous month – very unusual for that place – and now it was fogging again.

Scientists believe the strange wind event has caused the collapse in this area just a few hundred miles south of the North Pole, so it is unclear whether it is directly related to climate change. Still, disintegration can only be another sign of the growing vulnerability of the oldest ice.

What matters is the volume – not just the ice

The new findings for the Arctic's age reduction point to a less-regarded aspect of the dramatic changes that have occurred there. As for the ice cap at the top of the Arctic Ocean, we mostly talk about its surface – how much the ocean is covered with ice and not with open water. This is easily visible – it can be seen directly from a satellite – and the area is indeed in a clear decline.

But the loss of old and thick ice, as well as the simultaneous reduction of the total volume of ice, is even greater – and perhaps a much bigger deal. Small and thin ice can resume relatively quickly after dark and cold winter darkens. But it may not add much stability or persistence to the Arctic ice system if it spills again next summer.

The total ice volume in September, the lowest ice month, dropped 78 percent between 1979 and 2012, a record low. This is according to the analysis of scientists at the University of Seattle in Washington called PIOMAS or the modeling and assimilation system of the Pan-Arctic Ice Ocean, the main source for tracking the volume of ice.

In fairness, the volume of ice has fallen slightly since 2012. And PIOMAS is just a model, warned Axel Schweiger of the University of Washington, who made the analysis. (The model is based on direct measurements of the thickness of ice taken from submarines, satellites and other sources). However, Schweiger agrees that when you consider the total amount of ice rather than just superficial, you realize that much more was lost.

"We lost about half of the grade, we lost half the thickness, and if you multiply these two things, we lost 75% of the sea ice in September," he said.

Going by PIOMAS numbers, losses account for more than 10 trillion tons of ice. While the Arctic Ocean contains over 15 trillion tonnes of floating ice in 1979 in September, that same month in 2012, it was just under 3.5 trillion tons. This year it reached only 4.66 trillion tons in September.

Trends in sea ice thickness / volume are another important indicator of Arctic climate change. While observations of the thickness of sea ice are rare, we use the ocean and sea ice model, PIOMAS (Zhang and Rothrock, 2003) to visualize the thickness and volume of ice ice in September 1979 to 2018. Updated until September 2018 (Zack Labe))

"The Arctic is an indicator of what is coming to the rest of the globe," says Walter Meyer, an ice expert at the National Snow and Ice Data Center. "In the Arctic ocean, a difference of 2 degrees can be huge, and if you get from the 31 Fahrenheit to 33 Fahrenheit, you go by bathing skating … The Arctic is an early warning system for the climate."

The New Arctic Youth

And the transition is not just a volume of ice – this is the version of the Arctic for the movie "Curious case of Benjamin Button". The ice literally becomes younger.

The Arctic's oldest ice, surviving four or more years and called "perennial ice," is the most fat. She has built her table over time and can be over ten feet thick. It can grow even thicker in places where high ridges hit other shocks of ice or sustained pressure from the rest of the pack.

But this ice either melts due to the warming of air and seas, or thrown south through Fram Protok, between Greenland and Svalbard – and then melts in warmer sub-Arctic waters.

Increasingly, what remains is the ice formed only after peak heat in the summer, usually in September, and which may not survive the following summer. This "first year of ice" is more fragile, it is easier to throw around the winds and waves, making Arctic ice more mobile and more likely to fall apart.

In 1985, NOAA's new report found that 16% of the Arctic is covered by the oldest ice, more than four years, at the height of the winter. But by March this figure has fallen below 1%. This is a drop of 95%.

At the same time, the youngest year of the first year went from 55% of the package in the 80s to 77%, the report said. (The residue is ice that is 2 to 3 years old.)

"A decade ago, there were enormous Arctic regions that had ice that was a few years old," said Alec Peti, a NASA researcher working with Operation IceBridge. "But now, this is a rare phenomenon … if you get rid of this ice, which is 5 or 10 years old, it will obviously take so long to finish it."

"And that does not seem to happen," said Peti.

The deep danger of the dark ocean of the Arctic

This backwarding process, scientists say, is geared towards a key moment – when all the Arctic ice will be thin and one year old or less. When this happens – the day of maximum youth – we will be on the verge of a very dangerous cornerstone – a totally untouched Arctic ocean in the summer.

"Looking down from the North Pole on top, for all intents and purposes, you will see the blue ocean of the Arctic," Meyer said.

It is unclear how soon such an event can arrive. A. a recent report by the Intergovernmental Panel on Climate Change has suggested that this will happen once every 10 years if global warming reaches 2 degrees Celsius but only once every 100 years at 1.5 degrees Celsius. (Warming is 1 degrees Celsius now.)

So, as we pass 1.5 degrees, potentially over the next few decades, if the warming continues, the chances of the first summer summer will begin to rise.

The reason Arctic ice is shrinking so quickly, and why scientists worry that they are going on, is the same.

In the Arctic there is a well-known feedback line caused by the reflection of ice and darkness of the ocean. When the Arctic Ocean is covered by lighter, white ice, it reflects more sunlight back into space. But when there is less ice, more heat is absorbed by the darker ocean – warming the planet further. This warmer ocean then suppresses the growth of future ice, which is why the process is being fed by itself.

The open ocean absorbs about twice as much sunlight as floating ice, "said Verabahrr Ramanaten, a climate expert at the Scripps Institute of Oceanography, who discovered the role of chlorofluorocarbons (or CFCs) not only in destroying the ozone layer but also in boosting global warming .

Therefore, the loss of Arctic ice from the sea has already increased the warming of the planet as a whole. Ramanaten said the impact is equivalent to the warming effect of 250 billion tonnes of carbon dioxide emissions or about six years of global emissions.

Ramanathan fears that the icy summers, if they start appearing regularly, could add half a degree Celsius (.9 degrees Fahrenheit) to warming up on everything else the planet has experienced at the time.

"If that happens, I would think of it as a disastrous disaster," Ramanaten says of the successive ice-free Arctic summers. – She will quickly pump this half-level warming.

This additional warming, he said, could in turn trigger a world with many other cascading effects such as increasing carbon losses from the northern soil or serious damage to the Amazon Rainforest. Additional heat will melt snow cover over the Earth's surface in the Arctic, which will further increase global temperatures as the darker surface of the earth absorbs more incoming radiation.

Some believe that the situation in the Arctic is so worrying that it calls for urgent intervention. A group called Ice911, founded by the inventor and senior lecturer Leslie Fields, proposes a strategic "geoengineering" project that includes the spread of reflective silicon particles in the young sea ice in key areas, weakening sunlight and helping the emerging ice first summer.

"If and when it is decided to intervene in the Arctic or elsewhere, we want to be there with all our field tests, climate modeling and comprehensive testing to say, here's a viable and safe solution for recovering ice, which can mitigate some of these extreme impacts, "said Roman Deka, a strategist in the group.

We are still far from a world in which such a radical move is seriously considered. But the concern of Arctic researchers is hard to ignore.

"I would have thought that the icy ice disappears as a real point from which we were afraid of climate change," Ramanaten said.

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