Antarctic Sea Ice Hit Another New Low This Year: How Ocean Warming is Driving the Loss

BY CRAIG STEVENS

 APRIL 12, 2024
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Lana Young/AntarcticaNZ/NIWA/K872, CC BY-SA

Craig Stevens, University of Auckland, Waipapa Taumata Rau

At the end of the southern summer, Antarctica’s sea ice hit its annual minimum. By at least one measure, which tracks the area of ocean that contains at least 15% of sea ice, it was a little above the record low of 2023.

Source: NASA’s Scientific Visualization Studio.

At the time, I was aboard the Italian icebreaker Laura Bassi, ironically surrounded by sea ice about 10km off Cape Hallett and unable to make our way to one of the expedition’s sampling sites.

Even just a decade ago, sea ice reliably rebuilt itself each winter. But something has changed in how the Southern Ocean works and the area covered by sea ice has decreased dramatically.

Our aim was to track the changes happening in the ocean around Antarctica and to make targeted measurements of some of the processes we think are responsible for this loss of sea ice. Most likely, this is a consequence of warming oceans and so we focused on identifying the pathways warmer seawater could find to drive more melting.

The southernmost shelf sea

The annual freeze-thaw cycle of Antarctic sea ice is one of the defining properties of our planet.

It affects the reflectivity of a vast area of the globe, oxygenates the deep ocean, provides habitat across the Southern Ocean food web and plays a role in the resilience of ice shelves.

The voyage was led by a team of scientists who coordinate Italy’s longstanding research in the Southern Ocean.

For decades, they have been maintaining instruments in the Ross Sea region and the data they have been collecting are now proving crucial as we seek to understand the implications of sea-ice changes in terms of physics and biogeochemistry.

The research expedition sailed close to the front of the Ross Ice Shelf.
Lana Young/AntNZ/NIWA/K872, CC BY-SA

The expedition sailed a two-month counter-clockwise loop of the continental shelf in the Ross Sea. Continental shelves are shallower and biologically very productive regions that surround all of Earth’s continents.

Continental shelf seas around Antarctica are special because of the presence of sea ice – but this varies in space and time.

The US National Snow and Ice Data Center has developed a visualisation tool to compare sea-ice conditions during different times.

It shows that by the end of summer, the Ross Sea region holds only a few patches of sea ice. And this year, the patches were even fewer than in the past.

The region is the southernmost open water on the planet and acts as a gateway to seawater flowing in and out under the largest (by area) ice shelf on the planet – the Ross Ice Shelf.

The sea ice we encountered came in a variety of thicknesses and snow cover. We could see that in some places, sea ice was present in densities less than a satellite could recognise, but possibly enough to have an influence on how the upper ocean exchanges heat with the atmosphere above.

The state of sea ice

This reinforced our understanding of the importance of the spatial variability of sea ice. Satellites show that most of the sea-ice coverage, at its minimum, was found in a big patch in East Antarctica, due south of Hobart, and the ice-choked Weddell Sea.

The Weddell Sea and its Filchner-Ronne Ice Shelf are the Ross Sea’s opposite. At the late-summer sea-ice minimum, the Ross Sea is largely free of ice, while the Weddell Sea stays filled with ice.

This was the pack-ice nightmare that trapped Shackleton’s Endurance over a century ago.

The minimum extent of Antarctic sea ice in 2024 was the second-lowest recorded by satellites, reflecting a trend of declining coverage.
NASA, CC BY-SA

At a personal level, the sights during our expedition were a privilege. They took me beyond anything imagined from data and models. Giant icebergs became common place. Penguins, seals, skua and whales all passed by the ship at various times.

In the same way we send people into space, there are substantial benefits to having scientists on location developing their perspectives on the science. However, it is clear that Antarctic ocean data collection systems need to expand when and where they collect information.

The future is robotic

One feature of the voyage was the use of robots. We deployed 11 relatively simple Argo floats that will drift around the region for years, surfacing to send back data on temperature, salinity and in some cases oxygen.

We also sent three robotic ocean gliders on their data-collecting missions independent of the ship. This meant we could capture flow data in the long north-south troughs that are a feature of the region, while the ship was elsewhere.

The expedition deployed moorings, gliders and automated floats to gather data.
Lana Young/AntNZ/NIWA/K872, CC BY-SA

We retrieved these robot gliders after several weeks, bringing back unique maps of changing ocean temperature and salinity. The data provide evidence of warmer water lying just beneath the edge of the continental shelf, highlighting the fragility of the system.

There is a growing sense that the Ross Sea sector will become more important in the coming decade. With substantial changes upstream in the Amundsen Sea, where glaciers are retreating at an accelerating rate, and the possibility for warmer water finding its way onto the continental shelf, there is the potential that the largest ice shelf on the planet might start to change.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Craig Stevens is Professor in Ocean Physics at the University of Auckland, Waipapa Taumata Rau.

Survival Without Bombs or Borders

BY ROBERT KOEHLER

 APRIL 12, 2024
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Image by Egor Myznik.

An enormous flash, a mushroom cloud, multi-thousands of human beings dead. We win!

Nuclear weapons won’t go away, the cynics — the souls in despair — tell us. You can’t put the genie back in the bottle. You can’t, as Gen. James E. Cartwright, former head of U.S. Strategic Command, once put it, “un-invent nuclear weapons.” So apparently we’re stuck with them until the “big oops” happens and humanity becomes extinct. Until then: Modernize, modernize, modernize. Threaten, threaten, threaten.

David Barash and Ward Wilson make the case that this is completely false. We’re not “stuck” with nuclear weapons any more than we’re stuck with obsolete and ineffective technology of any sort, bluntly pointing out: “Crappy ideas don’t have to be forgotten in order to be abandoned.

“Useless, dangerous, or outmoded technology needn’t be forced out of existence. Once a thing is no longer useful, it unceremoniously and deservedly gets ignored.”

This is a valid and significant challenge to the cynicism of so many people, which is an easy trap to get caught in. Nuclear weapons will eventually go the way of the penny-farthing (huge front-wheeled) bicycle, according to the authors. Humanity is capable of simply moving beyond this valueless technology — and eventually it will. The genie has no power to stop this. Praise the Lord.

Transcending cynicism is the first step in envisioning change — but envisioning change isn’t the same thing as creating it. The next step in the process is hardly a matter of “better technology” — i.e., a better (less radioactive?) means of killing the enemy. The next step involves a change in humanity’s collective consciousness. As far as I can tell, we’re caught — horrifically caged — in the psychology of a border-drawn, divided planet. Social scientist Charles Tilly once put it with stunning simplicity:

“War made the state and the state made war.”

The human race cuddles with the concept of “state sovereignty.” It’s the basic right of the 193 national entities that have claimed their specific slices of Planet Earth — and I certainly understand the “sovereignty” part. Who doesn’t want to make his or her own life decisions? But the “state” part? It’s full of paradox and contradiction, not to mention a dark permission to behave at one’s worst. The militarism that worships the nuclear genie couldn’t exist without state sovereignty.

To me the question in crucial need of being asked right now is this: What is our alternative to nationalism, which currently claims free rein (and reign) on the planet? And nationalism strides with a lethal swagger — especially nuclear-armed nationalism. For instance, as AP recently reported:

“President Vladimir Putin said Wednesday that Russia is ready to use nuclear weapons if its sovereignty or independence is threatened, issuing another blunt warning to the West just days before an election in which he’s all but certain to secure another six-year term.”

Or here’s the Times of Israel: “Heritage Minister Amichai Eliyahu said Sunday that one of Israel’s options in the war against Hamas could be to drop a nuclear bomb on the Gaza Strip . . .”

Plunk! Finish the job!

And then, of course, there’s the global good guy — USA! USA! — leading the charge to bring peace to the world wherever and however it can: for instance, by claiming “sovereignty” (you might say) over the national interests of South Korea and declaring, as Simone Chun puts it at Truthout, a “new Cold War with China” and implementing a “massive expansion of the provocative U.S.-led military exercises in the Korean Peninsula.”

Wow, a new Cold War! More than 300,000 South Korean troops and 10,000 American troops, in a series of war games known as “Freedom Shield 2024,” have conducted numerous field maneuvers, including bombing runs, at the North Korean border.

Chun writes:

“The combined United States Forces Korea (USFK) and South Korean forces far overshadow those of North Korea, whose entire military budget is $1.47 billion compared to that of South Korea at $43.1 billion, not to mention that of the U.S. at $816.7 billion. . . .

“The U.S. is using North Korea as a pretext for its new Cold War against China,” she goes on, “and, with its control of 40 percent of the world’s nuclear stockpile, is even willing to risk nuclear war to further its geopolitical aims.”

And she quotes Noam Chomsky who, addressing the country’s blatant indifference to this risk, points out that “the United States always plays with fire.”

How do we get it to stop?

We live in a self-declared democracy but we, the people, are not the ones with real authority here. Those who run the show seem essentially blind to the consequences of militarism, war and, for God’s sake, nukes. Having power means having the ability to threaten — and, if necessary, cause — harm . . . beyond their divinely sanctioned borders, of course (not counting the likely consequences that know no borders).

If Tilly is right — if “war made the state and the state made war” — then the state, as currently perceived, at least by those besotted with military power, is the problem. Knowing this is the beginning . . . but of what? Survival means finding an answer.

Robert Koehler is a Chicago award-winning journalist and editor.

How Ecuador Shredded Norms Around Asylum and Refugees

BY ARIEL DORFMAN

 APRIL 12, 2024
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As soon as I heard the news that Ecuadorian police had stormed the Mexican Embassy in Quito, arresting former vice president Jorge Glas, who had just been given diplomatic asylum, I was transported 50 years back in time. I myself had managed to take refuge in the Argentine Embassy in Santiago, Chile, to escape being killed by the Pinochet dictatorship after the coup in September 1973.

Just like Glas now and countless Latin Americans in the past, I was certain an embassy was an inviolable refuge. A country’s embassy is customarily considered a sovereign territory. In Latin America during the bloody 19th century, elites who lost power because of civil wars or coups often sought refuge in foreign legations. This practice was respected by their victorious adversaries, who understood that tomorrow they could be the ones knocking on the doors of an embassy on their way to an uncertain exile.

The 20th century institutionalized refugee protections in a series of agreements and laws, not only at the inter-American level (the Organization of American States in Caracas, Venezuela, in 1954) but also in broader treaties (the 1951 Refugee Convention and the 1961 Vienna Convention). So valuable were those accords that even a regime such as Augusto Pinochet’s, which violated the human rights of Chileans with frightful abandon – disappearing, executing, torturing and harassing supporters of ousted president Salvador Allende – accepted these norms. The military authorities did so even if it meant that their enemies could survive the coup and one day return to the country and lead the resistance.

It was not easy to access an embassy such as the Argentine one I entered in 1973. Dodging the ferociously armed police who patrolled the surrounding area was already a feat. One afternoon, as I was walking through the embassy’s garden, a backpack and a sleeping bag fell at my feet, thrown from the other side of the wall. Those belongings were not, alas, joined by their unfortunate owner. I saw the fingers of both his hands clinging to that wall, but only for an instant; a succession of shots fired by Chilean troops ended that escape attempt. Wounded, dead, hauled off for interrogation? Who knows?

Many times during the endless months I spent in the embassy waiting for safe conduct to leave Chile, I conjured up the possibility that Pinochet’s secret police would try to infiltrate someone among us – to obtain information or, worse, to assassinate the most prominent dissidents. My fears never materialized. A thousand individuals crammed into that embassy and so many more in other diplomatic premises scattered around the city managed to leave Chile thanks to the right of asylum.

The same right has now been abrogated by the inept government of Daniel Noboa in Ecuador. His unprecedented act has already had dramatic consequences. Mexico has broken off relations with Ecuador, and its condemnation has been joined by Latin American nations from both the left (Brazil, Colombia, Chile) and the right (Argentina, Uruguay, Paraguay).

Without the minimum confidence given by certain international agreements to which governments of different political persuasions adhere, it is difficult to resolve the critical tensions and conflicts that inexorably arise in an era as unstable as the one we are living in. And the list of pressing problems we need to tackle together is daunting – drug trafficking, widespread crime, migration and climate change are but a few that spring to mind.

Beyond the practical consequences, what saddens me most is how Noboa’s brazen act undermines the dream of the great Latin American patria–that project of a common homeland proclaimed by Simón Bolívar, José Martí and Allende–as well as by Antonio José de Sucre, the great hero of Ecuador’s struggle for independence. This need for solidarity among dispersed nations – all of them suffering from the plagues of fratricidal violence and frustrated development–lies at the core of Latin American identity. This solidarity was on display, in fact, in the Argentine Embassy in Santiago in 1973. Along with Chileans, citizens from all over the continent who were fleeing their own countries had sought refuge there. During our prolonged cohabitation, we forged a community out of diversity, caring for one another, and surviving together, in the hope that someday our dispersed nations would also learn how to coexist.

It is inevitable, it depresses me to admit, that tomorrow or the day after tomorrow, other men and women will feel the need to flee a regime in power. It is imperative that when they are welcomed into a foreign embassy, they are certain their safety is guaranteed. As a survivor myself, it pains me to think they might suffer the excruciating fate of that stranger who threw his backpack and sleeping bag over the wall of the Argentine Embassy so many decades ago.

It is essential that this deranged action of Noboa not go unpunished. An example must be set so that no other ruler will dare follow his example.

Or are we prepared to let basic international norms that protect the vulnerable be trampled upon so wantonly?

A version of this essay first appeared in the Washington Post.