Antarctica Will Teach Us A Hard Lesson About Non-Linear Change

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Antarctica is experiencing astonishing, astounding, mind-boggling climate alterations. On March 18, 2022, scientists at the Concordia research station on the east Antarctic plateau recorded the largest jump in temperature ever measured at a meteorological facility anywhere on Earth. According to their instruments, the temperature outside that day was 38.5º C (69.3º F) above its seasonal average — a world record. Those findings are included in a paper that was published last week in the Journal of Climate by a team of scientists led by Will Hobbs of the University of Tasmania. Here is the abstract of that paper:

In recent years, the Southern Ocean has experienced extremely low sea ice cover in multiple summers. These low events were preceded by a multi-decadal positive trend that culminated in record high ice coverage in 2014. This abrupt transition has led some authors to suggest that Antarctic sea ice has undergone a regime shift. In this study we analyze the satellite sea ice record and atmospheric reanalyses to assess the evidence for such a shift.

We find that the standard deviation of the summer sea ice record has doubled from 0.31 million km2 in 1979–2006 to 0.76 million km2 for 2007–22. This increased variance is accompanied by a longer season-to-season sea ice memory. The atmosphere is the primary driver of Antarctic sea ice variability, but using a linear predictive model we show that sea ice changes cannot be explained by the atmosphere alone.

Identifying whether a regime shift has occurred is difficult without a complete understanding of the physical mechanism of change. However, the statistical changes that we demonstrate (i.e., increased variance and autocorrelation, and a changed response to atmospheric forcing), as well as the increased spatial coherence noted by previous research, are indicators based on dynamical systems theory of an abrupt critical transition. Thus, our analysis is further evidence in support of a changed Antarctic sea ice system.

Linear Versus Non-Linear Change In Antarctica

I have a friend who talks frequently about the difference between linear and non-linear change. As humans, we are reasonably good at managing linear change. Clocks are linear. We are generally aware of how long a minute or an hour is, but twice a year we set our clocks ahead or back an hour and it takes our bodies days to adjust. That’s a small example of non-linear change. Those who travel long distances by airplane are familiar with what we call jet lag. It can take our bodies up to a week to adjust when we leave Sydney, Australia, after breakfast and arrive in Los Angeles in time for lunch the same day. That’s an example of moderate non-linear change.

On August 6, 1945, the citizens of Hiroshima, Japan, experienced major, dramatic non-linear change when the first atomic bomb exploded over their city. Humanity still has not adjusted to that change in the tools of war. It is not an exaggeration to suggest what is happening in Antarctica is as much a non-linear change as what happened over Hiroshima that morning and may affect all humanity in ways that are as yet not fully understood.

There is a secondary connection between the atomic bomb and what is happening in Antarctica. Matthew England, an oceanographer and climate scientist at the University of New South Wales, describes the connection quite vividly. He and his colleagues have determined that between 1971 and 2018, the ocean gained 396 zettajoules of heat — equivalent to the energy of more than 25 billion Hiroshima atomic bombs. And of course we have added much more heat to the ecosystem since 2018, and are making plans to add lots more.

England says that simple physics means the ocean “has this huge ability to absorb heat and then hold on to it.” To raise the temperature of a cubic meter of air by 1º C requires about 2,000 joules, but to raise the temperature of a cubic meter of seawater requires about 4,200,000 joules. “By absorbing all this heat, the ocean lulls people into a false sense of security that climate change is progressing slowly. But there is a huge payback. It’s overwhelming when you start to go through all the negative impacts of a warming ocean.”

“There’s sea level rise, coastal inundation, increased floods and drought cycles, bleached corals, intensification of cyclones, ecological impacts, melting of ice at higher latitudes in the coastal margins — that gives us a double whammy on sea level rise. The oceans have stored the problem but it’s coming back to bite us.” Coming back to bite us means an imminent shift from linear changes in the ocean to non-linear changes on the horizon.

Mind-Boggling Change In Antarctica

What happened in Antarctica in March of 2022 was “simply mind-boggling,” Michael Meredith, science leader at the British Antarctic Survey, told The Guardian. “In sub-zero temperatures such a massive leap is tolerable but if we had a 40º C rise in the UK now, that would take temperatures for a spring day to over 50º C (122º F) — and that would be deadly for the population.” Glaciologist Martin Siegert of the University of Exeter said, “No one in our community thought that anything like this could ever happen. It is extraordinary and a real concern. We are now having to wrestle with something that is completely unprecedented.” Non-linear, in other words.

Winds blowing toward the South Pole, which previously made few inroads into the atmosphere above Antarctica, are now carrying more and more warm, moist air from lower latitudes, including Australia, deep into Antarctica and are the primary reason for the polar heatwave that hit Concordia two years ago. Exactly why these currents are now able to plunge so deep into the air over the continent is not yet fully understood, but such huge temperature anomalies are becoming more frequent.

For the past two years, there has been a dramatic increase in reports of disturbing meteorological events on the continent. Glaciers bordering the west Antarctic ice sheet are losing mass to the ocean at an increasing rate, while levels of sea ice, which floats on the oceans around the continent, have plunged dramatically after remained stable for more than a century. These events have raised fears that Antarctica, once thought to be too cold to experience the early impacts of global warming, is now succumbing dramatically and rapidly to the swelling levels of greenhouse gases that humans continue to pump into the atmosphere. Can you say “non-linear change,” boys and girls?

After examining recent changes in sea ice coverage in Antarctica, the scientists concluded there had been an “abrupt critical transition” in the continent’s climate that could have repercussions for both local Antarctic ecosystems and the global climate system. “The extreme lows in Antarctic sea ice have led researchers to suggest that a regime shift is under way in the Southern Ocean, and we found multiple lines of evidence that support such a shift to a new sea ice state,” said Will Hobbs.

The dramatic nature of this transformation was emphasized by Michael Meredith. “Antarctic sea ice coverage actually increased slightly in the late 20th and early 21st century. However, in the middle of the last decade it fell off a cliff. It is a harbinger of the new ground with the Antarctic climate system, and that could be very troubling for the region and for the rest of the planet. “The continent is now catching up with the Arctic, where the impacts of global warming have, until now, been the most intense experienced across the planet,” added Siegert. “The Arctic is currently warming at four times the rate experienced by the rest of the planet. But the Antarctic has started to catch up, so that it is already warming twice as quickly as the planet overall.”

Antarctica & Human Activity

A key reason for the Arctic and Antarctic to be taking disproportionate hits from global warming is because the Earth’s oceans —  warmed by burning fossil fuels — are losing their sea ice at their polar extremities. The dark waters that used to lie below the ice are being exposed and solar radiation is no longer reflected back into space. Instead, it is being absorbed by the sea, further heating the oceans there. “Essentially, it is a vicious circle of warming oceans and melting of sea ice, though the root cause is humanity and its continuing burning of fossil fuels and its production of greenhouse gases,” said Meredith. “This whole business has to be laid at our door.”

The consequences of this non-linear change in temperatures at the South Pose could be devastating, researchers warn. If all the ice on Antarctica were to melt, this would raise sea levels around the globe by more than 60 meters (197 feet). Islands and coastal zones where much of the world’s population now have homes would find themselves at the bottom of the ocean.

That’s not going to happen anytime soon. Antarctica’s ice sheet covers 14 million square kilometers (about 5.4 million square miles), which is roughly the area of the United States and Mexico combined. It contains about 30 million cubic kilometers (7.2 million cubic miles) of ice — which represents about 60% of the world’s fresh water. This vast covering hides a mountain range that is nearly as high as the Alps, so it will take a very long time for that to melt completely, say scientists.

Nevertheless, there is now a real danger that some significant sea level rises will occur in the next few decades as the ice sheets and glaciers of west Antarctica continue to shrink. These are being eroded at their bases by warming ocean water and could disintegrate in a few decades. If they disappear entirely, that would raise sea levels by 5 meters (17 feet) which would be enough to cause significant damage to coastal populations around the world.

IPCC May Be Too Conservative

How quickly that will happen is difficult to determine. The Intergovernmental Panel on Climate Change has said that sea levels are likely to rise between 0.3 to 1.5 meters by the end of this century. Many experts now fear this is a dangerous underestimate. In the past, climate change deniers accused scientists of exaggerating the threat of global warming. However, the evidence that is now emerging from Antarctica and other parts of the world makes it very clear that, rather then exaggerating, scientists have probably underestimated the threat to humanity from rising sea levels by a significant degree.

“The picture is further confused in Antarctica because, historically, we have had problems getting data,” added Meredith. “We have never had the information about weather and ecosystem, compared with the data we get from the rest of the world, because the continent is so remote and so hostile. Our records are comparatively short and that means that the climate models we have created, although very capable, are based on sparse data. They cannot capture all of the physics, chemistry and biology. They can make predictions that are coherent but they cannot capture the sort of extremes that we’re now beginning to observe.”

More than 40 nations are signatories of the Antarctic Treaty’s environmental protocol, which is supposed to shield it from a host of different threats, with habitat degradation being one of the most important. The fact that the continent is now undergoing alarming shifts in its ice covering, eco-systems, and climate is a clear sign that this protection is no longer being provided. “The cause of this ecological and meteorological change lies outside the continent,” added Siegert. “It is being caused because the rest of the world is continuing to emit vast amounts carbon dioxide.

“Nevertheless, there is a good case for arguing that if countries are knowingly polluting the atmosphere with greenhouse gases, and Antarctica is being affected as a consequence, then the treaty protocol is being breached by its signatories and their behavior could be challenged on legal and political grounds. It should certainly make for some challenging meetings at the UN in the coming years,” he said.

The Takeaway

We humans are poorly equipped to deal with non-linear change. Our “fight or flight” response programmed into the limbic part of our brains may allow us to react instantaneously to the attack of a sabertooth tiger, but there is no corresponding part of our brain that reacts instinctively to long term threats. We simply ignore them most of the time. That characteristic allows cigarette and fossil fuel companies to whisper sweet nothings into our ears to distract us from threats that are less than immediate so they can continue socking away hundreds of billions in profits. The fact they overlook is that non-linear climate change is coming for them, too, and there will be no way all their piles of money will protect them.

We are poorly prepared to manage non-linear changes in our environment, which suggests they will overwhelm us just as the seas will overwhelm our cities. There are three kinds of people in the world — those who make change happen, those who notice change happening, and those who wonder what happened. Our mission at CleanTechnica is to move as many readers as possible out of the third category and into the middle category, where perhaps a few will then transition into the first category. In the words of Winston Churchill, “So much to do and so little time.”