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Thwaites Glacier won’t collapse like dominoes as feared, study finds, but that doesn’t mean the ‘Doomsday Glacier’ is stable

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theconversation.com – Mathieu Morlighem, Professor of Earth Sciences, Dartmouth College – 2024-08-21 13:00:03

The calving front of Thwaites’ ice shelf. The blue area is light reflecting off ice below the water.
James Yungel/NASA Icebridge

Mathieu Morlighem, Dartmouth College

Antarctica’s Thwaites Glacier got its nickname the “Doomsday Glacier” for its potential to flood coastlines around the world if it collapsed. It is already contributing about 4% of annual sea-level rise as it loses ice, and one theory suggests the glacier could soon begin to collapse into the ocean like a row of dominoes.

But is that kind of rapid collapse really as likely as feared? A new study of Thwaites Glacier’s susceptibility to what’s known as marine ice cliff instability offers some hope. But the findings don’t mean Thwaites is stable.

Polar scientist Mathieu Morlighem, who led the study, explains the results.

Why is the Thwaites Glacier so important?

Thwaites Glacier drains a huge area of Antarctica’s ice sheet – about 74,000 square miles (192,000 square kilometers), an expanse bigger than Florida. If a snowflake falls within that drainage system, it will eventually end up as part of an iceberg in the ocean off Thwaites.

What we are seeing with Thwaites Glacier right now is a disaster in slow motion.

The bedrock under Thwaites Glacier sits below sea level and slopes downward going inland, so the glacier gets deeper toward the interior of the ice sheet. Once the glacier begins losing more ice than it gains from new snowfall and starts to retreat, it’s very hard to slow it down because of this slope. And Thwaites is already retreating at an accelerating rate as the climate warms.

A cross section shows an ice shelf starting to float at the end of a glacier and how the bedrock below slopes inward toward the center of the ice sheet
A cross-section showing an ice shelf and inward-sloping bedrock.
Kelvinsong via Wikimedia, CC BY-SA

Thwaites Glacier holds enough ice to raise global sea level by more than 2 feet (0.65 meters). Once Thwaites starts to destabilize, it also will destabilize neighboring glaciers. So, what happens to Thwaites affects all of the West Antarctic Ice Sheet, and that affects sea-level rise along coastlines everywhere.

What is marine ice cliff instability?

Marine ice cliff instability is a relatively new concept proposed by scientists in the past decade.

Many of the glaciers around Antarctica have huge floating extensions called ice shelves that buttress the glacier and slow its ice flow into the ocean. With the climate warming, we have seen some of these floating extensions collapse, sometimes very rapidly, in the span of a few weeks or months.

An aerial photo of the tall front of Thwaites' ice shelf, where icebergs calve off into the ocean.
The front of Thwaites’ floating ice shelf is over 200 feet (60 meters) tall in places. It becomes higher closer to land.
James Yungel/NASA Icebridge 2012

If Thwaites’ ice shelf were to collapse, it would expose a very tall ice cliff facing the ocean along its 75-mile (120-kilometer) front. There is only so much force that ice can sustain, so if the cliff is too tall, it will collapse into the ocean.

Once that happens, a new ice cliff farther back would be exposed, and the new cliff would be even taller because it is farther inland. The theory of marine ice cliff instability suggests that if the cliffs collapse quickly enough, that could have a domino effect of ever-higher ice cliffs collapsing one after the other.

However, no one has observed marine ice cliff instability in action. We don’t know if it will happen, because a lot depends on how quickly the ice collapses.

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Watching the Larsen B ice shelf collapse over less than six weeks in 2002. Once the ice shelf was gone, glaciers it had buttressed began flowing several times faster into the ocean. AGU.

What did you discover about the risk to Thwaites?

When the theory of marine ice cliff instability was first introduced, it used a rough approximation of how ice cliffs might collapse once the ice shelf was gone.

Studies since then have determined that ice cliffs won’t fail systematically until the ice is about 442 feet (135 meters) high. Even at that point, they would fail more slowly than projected until they became much taller.

We used three high-resolution models to explore what this new physical understanding of ice cliff instability would mean for Thwaites Glacier this century.

Our results show that if Thwaites’ entire ice shelf collapsed today, its ice front would not rapidly retreat inland due to marine ice cliff instability alone. Without the ice shelf, the glacier’s ice would flow much faster toward the ocean, thinning the front of the glacier. As a result, the ice cliffs wouldn’t be as high.

We found that Thwaites would remain fairly stable at least through 2100. We also simulated an ice shelf collapse in 50 years, when the glacier’s grounding line – where its grounded ice meets the ocean – would have retreated deeper inland. Even then, we found that marine ice cliff instability alone would not cause a rapid retreat.

YouTube video
Satellite data shows Antarctica losing ice mass since 2002. The area with the fastest ice loss includes Thwaites Glacier. NASA.

The results call into question some recent estimates of just how fast Thwaites might collapse. That includes a worst-case scenario that the Intergovernmental Panel on Climate Change mentioned in its latest assessment report but labeled as “low likelihood.”

Thwaites is the glacier everyone is worried about. If you model the entire ice sheet, this is where marine ice cliff instability starts and where it propagates far inland. So, if Thwaites isn’t as vulnerable to ice cliff failure as we thought, that’s a good sign for the entire ice sheet.

But marine ice cliff instability is only one mechanism of ice loss. This finding doesn’t mean Thwaites is stable.

What else is causing glaciers to retreat at an accelerating rate?

There are many processes that make the Antarctic ice sheet unstable, some of them very well understood.

Ice-ocean interactions explain most of the recent ice mass loss so far. Antarctica is a very cold place, so atmospheric warming isn’t having a large effect yet. But warm ocean currents are getting under the ice shelves, and they are thinning the ice from below, which weakens the ice shelves. When that happens, the ice streams flow faster because there is less resistance.

Colors show Thwaites Glacier flowing faster as it nears the ocean.
Ocean-bottom water temperatures reach above freezing under parts of the Thwaites ice shelf. Thwaites Glacier is outlined in dashes, with colors showing how fast the ice flows. Ocean areas in gray are too shallow to affect the glacial undersides.
NASA JPL/CalTech

Over the past few decades, the Amundsen Sea sector, where Thwaites and Pine Island glaciers are located, has seen an intrusion of warm water from the Antarctic Circumpolar Current, which has been melting the ice from below.

What does climate change have to do with it?

Antarctica can seem like a faraway place, but human activities that warm the planet – such as burning fossil fuels – are having dramatic effects at the poles. Ice loss contributes to sea-level rise, affecting coastal regions around the world.

People’s choices today will determine how quickly the water rises.The Conversation

Mathieu Morlighem, Professor of Earth Sciences, Dartmouth College

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

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Being alone has its benefits − a psychologist flips the script on the ‘loneliness epidemic’

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theconversation.com – Virginia Thomas, Assistant Professor of Psychology, Middlebury – 2025-04-04 07:18:00

Studies show that choosing ‘me time’ is not a recipe for loneliness but can boost your creativity and emotional well-being.
FotoDuets/iStock via Getty Images Plus

Virginia Thomas, Middlebury

Over the past few years, experts have been sounding the alarm over how much time Americans spend alone.

Statistics show that we’re choosing to be solitary for more of our waking hours than ever before, tucked away at home rather than mingling in public. Increasing numbers of us are dining alone and traveling solo, and rates of living alone have nearly doubled in the past 50 years.

These trends coincided with the surgeon general’s 2023 declaration of a loneliness epidemic, leading to recent claims that the U.S. is living in an “anti-social century.”

Loneliness and isolation are indeed social problems that warrant serious attention, especially since chronic states of loneliness are linked with poor outcomes such as depression and a shortened lifespan.

But there is another side to this story, one that deserves a closer look. For some people, the shift toward aloneness represents a desire for what researchers call “positive solitude,” a state that is associated with well-being, not loneliness.

As a psychologist, I’ve spent the past decade researching why people like to be alone – and spending a fair amount of time there myself – so I’m deeply familiar with the joys of solitude. My findings join a host of others that have documented a long list of benefits gained when we choose to spend time by ourselves, ranging from opportunities to recharge our batteries and experience personal growth to making time to connect with our emotions and our creativity.

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Being alone can help remind people who they are.

So it makes sense to me why people live alone as soon as their financial circumstances allow, and when asked why they prefer to dine solo, people say simply, “I want more me time.”

It’s also why I’m not surprised that a 2024 national survey found that 56% of Americans considered alone time essential for their mental health. Or that Costco is now selling “solitude sheds” where for around US$2,000 you can buy yourself some peace and quiet.

It’s clear there is a desire, and a market, for solitude right now in American culture. But why does this side of the story often get lost amid the warnings about social isolation?

I suspect it has to do with a collective anxiety about being alone.

The stigma of solitude

This anxiety stems in large part from our culture’s deficit view of solitude. In this type of thinking, the desire to be alone is seen as unnatural and unhealthy, something to be pitied or feared rather than valued or encouraged.

This isn’t just my own observation. A study published in February 2025 found that U.S. news headlines are 10 times more likely to frame being alone negatively than positively. This type of bias shapes people’s beliefs, with studies showing that adults and children alike have clear judgments about when it is – and importantly when it is not – acceptable for their peers to be alone.

This makes sense given that American culture holds up extraversion as the ideal – indeed as the basis for what’s normal. The hallmarks of extraversion include being sociable and assertive, as well as expressing more positive emotions and seeking more stimulation than the opposite personality – the more reserved and risk-averse introverts. Even though not all Americans are extraverts, most of us have been conditioned to cultivate that trait, and those who do reap social and professional rewards. In this cultural milieu, preferring to be alone carries stigma.

But the desire for solitude is not pathological, and it’s not just for introverts. Nor does it automatically spell social isolation and a lonely life. In fact, the data doesn’t fully support current fears of a loneliness epidemic, something scholars and journalists have recently acknowledged.

In other words, although Americans are indeed spending more time alone than previous generations did, it’s not clear that we are actually getting lonelier. And despite our fears for the eldest members of our society, research shows that older adults are happier in solitude than the loneliness narrative would lead us to believe.

YouTube video
It’s all a balancing act – along with solitude, you need to socialize.

Social media disrupts our solitude

However, solitude’s benefits don’t automatically appear whenever we take a break from the social world. They arrive when we are truly alone – when we intentionally carve out the time and space to connect with ourselves – not when we are alone on our devices.

My research has found that solitude’s positive effects on well-being are far less likely to materialize if the majority of our alone time is spent staring at our screens, especially when we’re passively scrolling social media.

This is where I believe the collective anxiety is well placed, especially the focus on young adults who are increasingly forgoing face-to-face social interaction in favor of a virtual life – and who may face significant distress as a result.

Social media is by definition social. It’s in the name. We cannot be truly alone when we’re on it. What’s more, it’s not the type of nourishing “me time” I suspect many people are longing for.

True solitude turns attention inward. It’s a time to slow down and reflect. A time to do as we please, not to please anyone else. A time to be emotionally available to ourselves, rather than to others. When we spend our solitude in these ways, the benefits accrue: We feel rested and rejuvenated, we gain clarity and emotional balance, we feel freer and more connected to ourselves.

But if we’re addicted to being busy, it can be hard to slow down. If we’re used to looking at a screen, it can be scary to look inside. And if we don’t have the skills to validate being alone as a normal and healthy human need, then we waste our alone time feeling guilty, weird or selfish.

The importance of reframing solitude

Americans choosing to spend more time alone is indeed a challenge to the cultural script, and the stigmatization of solitude can be difficult to change. Nevertheless, a small but growing body of research indicates that it is possible, and effective, to reframe the way we think about solitude.

For example, viewing solitude as a beneficial experience rather than a lonely one has been shown to help alleviate negative feelings about being alone, even for the participants who were severely lonely. People who perceive their time alone as “full” rather than “empty” are more likely to experience their alone time as meaningful, using it for growth-oriented purposes such as self-reflection or spiritual connection.

Even something as simple as a linguistic shift – replacing “isolation” with “me time” – causes people to view their alone time more positively and likely affects how their friends and family view it as well.

It is true that if we don’t have a community of close relationships to return to after being alone, solitude can lead to social isolation. But it’s also true that too much social interaction is taxing, and such overload negatively affects the quality of our relationships. The country’s recent gravitational pull toward more alone time may partially reflect a desire for more balance in a life that is too busy, too scheduled and, yes, too social.

Just as connection with others is essential for our well-being, so is connection with ourselves.The Conversation

Virginia Thomas, Assistant Professor of Psychology, Middlebury

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Measles can ravage the immune system and brain, causing long-term damage – a virologist explains

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theconversation.com – Peter Kasson, Professor of Chemistry and Biomedical Engineering, Georgia Institute of Technology – 2025-03-31 07:16:00

Measles infections send 1 in 5 people to the hospital.
wildpixel/ iStock via Getty Images Plus

Peter Kasson, Georgia Institute of Technology

The measles outbreak that began in west Texas in late January 2025 continues to grow, with 400 confirmed cases in Texas and more than 50 in New Mexico and Oklahoma as of March 28.

Public health experts believe the numbers are much higher, however, and some worry about a bigger resurgence of the disease in the U.S. In the past two weeks, health officials have identified potential measles exposures in association with planes, trains and automobiles, including at Washington Dulles International Airport and on an Amtrak train from New York City to Washington, D.C. – as well as at health care facilities where the infected people sought medical attention.

Measles infections can be extremely serious. So far in 2025, 14% of the people who got measles had to be hospitalized. Last year, that number was 40%. Measles can damage the lungs and immune system, and also inflict permanent brain damage. Three in 1,000 people who get the disease die. But because measles vaccination programs in the U.S. over the past 60 years have been highly successful, few Americans under 50 have experienced measles directly, making it easy to think of the infection as a mere childhood rash with fever.

As a biologist who studies how viruses infect and kill cells and tissues, I believe it is important for people to understand how dangerous a measles infection can be.

Underappreciated acute effects

Measles is one of the most contagious diseases on the planet. One person who has it will infect nine out of 10 people nearby if those people are unvaccinated. A two-dose regimen of the vaccine, however, is 97% effective at preventing measles.

When the measles virus infects a person, it binds to specific proteins on the surface of cells. It then inserts its genome and replicates, destroying the cells in the process. This first happens in the upper respiratory tract and the lungs, where the virus can damage the person’s ability to breathe well. In both places, the virus also infects immune cells that carry it to the lymph nodes, and from there, throughout the body.

YouTube video
Measles can wipe out immune cells’ ability to recognize pathogens.

What generally lands people with measles in the hospital is the disease’s effects on the lungs. As the virus destroys lung cells, patients can develop viral pneumonia, which is characterized by severe coughing and difficulty breathing. Measles pneumonia afflicts about 1 in 20 children who get measles and is the most common cause of death from measles in young children.

The virus can directly invade the nervous system and also damage it by causing inflammation. Measles can cause acute brain damage in two different ways: a direct infection of the brain that occurs in roughly 1 in 1,000 people, or inflammation of the brain two to 30 days after infection that occurs with the same frequency. Children who survive these events can have permanent brain damage and impairments such as blindness and hearing loss.

Yearslong consequences of infection

An especially alarming but still poorly understood effect of measles infection is that it can reduce the immune system’s ability to recognize pathogens it has previously encountered. Researchers had long suspected that children who get the measles vaccine also tend to have better immunity to other diseases, but they were not sure why. A study published in 2019 found that having a measles infection destroyed between 11% and 75% of their antibodies, leaving them vulnerable to many of the infections to which they previously had immunity. This effect, called immune amnesia, lasts until people are reinfected or revaccinated against each disease their immune system forgot.

Occasionally, the virus can lie undetected in the brain of a person who recovered from measles and reactivate typically seven to 10 years later. This condition, called subacute sclerosing panencephalitis, is a progressive dementia that is almost always fatal. It occurs in about 1 in 25,000 people who get measles but is about five times more common in babies infected with measles before age 1.

Researchers long thought that such infections were caused by a special strain of measles, but more recent research suggests that the measles virus can acquire mutations that enable it to infect the brain during the course of the original infection.

There is still much to learn about the measles virus. For example, researchers are exploring antibody therapies to treat severe measles. However, even if such treatments work, the best way to prevent the serious effects of measles is to avoid infection by getting vaccinated.The Conversation

Peter Kasson, Professor of Chemistry and Biomedical Engineering, Georgia Institute of Technology

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

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Supreme Court considers whether states may prevent people covered by Medicaid from choosing Planned Parenthood as their health care provider

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theconversation.com – Naomi Cahn, Professor of Law, University of Virginia – 2025-04-02 17:04:00

Planned Parenthood clinics, like this one in Los Angeles, are located across the United States.
Patrick T. Fallon/AFP via Getty Images

Naomi Cahn, University of Virginia and Sonia Suter, George Washington University

Having the freedom to choose your own health care provider is something many Americans take for granted. But the Supreme Court is weighing whether people who rely on Medicaid for their health insurance have that right, and if they do – is it enforceable by law?

That’s the key question at the heart of a case, Medina v. Planned Parenthood South Atlantic, that began during President Donald Trump’s first term in office.

“There’s a right, and the right is the right to choose your doctor,” said Justice Elena Kagan on April 2, 2025, during oral arguments on the case. John J. Bursch, the Alliance Defending Freedom lawyer who is representing South Carolina Director of Health and Human Services Eunice Medina, countered that none of the words in the underlying statute had what he called a “rights-creating pedigree.”

As law professors who teach courses about health and poverty law as well as reproductive justice, we think this case could affect access to health care for 72 million Americans, including low-income people and their children and people with disabilities.

Excluding Planned Parenthood

The case started with Julie Edwards, who is enrolled in Medicaid and lives in South Carolina. After she struggled to get contraceptive services, she was able to receive care from a Planned Parenthood South Atlantic clinic in Columbia, South Carolina.

Planned Parenthood, an array of nonprofits with roots that date back more than a century, is among the nation’s top providers of reproductive services. It operates two clinics in South Carolina, where Medicaid patients can get physical exams, cancer screenings, contraception and other services. It also provides same-day appointments and keeps long hours.

In July 2018, however, South Carolina Gov. Henry McMaster issued an executive order that barred health care providers in South Carolina that offer abortions from reimbursement through Medicaid.

That meant Planned Parenthood, a longtime target of conservatives’ ire, would no longer be reimbursed for any type of care for Medicaid patients, preventing Edwards from transferring all her gynecological care to that office as she had hoped to do.

Planned Parenthood and Edwards sued South Carolina, claiming that the state was violating the federal Medicare and Medicaid Act, which Congress passed in 1965, by not letting Edwards obtain care from the provider of her choice.

A ‘free-choice-of-provider’ requirement

Medicaid operates as a partnership between the federal government and the states. Congress passed the law that led to its creation based on its power under the Constitution’s spending clause, which allows Congress to subject federal funds to certain requirements.

Two years later, due to concerns that states were restricting which providers Medicaid recipients could choose, Congress added a “free-choice-of-provider” requirement to the program. It states that people enrolled in Medicaid “may obtain such assistance from any institution, agency, community pharmacy, or person, qualified to perform the service or services required.”

This provision is at the core of this case. At issue is whether a civil rights statute provides a right for Medicaid beneficiaries to sue a state when their federal rights have been violated. Known as Section 1983, it was enacted in 1871.

Bursch, backed by the Trump administration, argued before the court that the absence of words like “right” in the Medicaid provision that requires states to provide a free choice of provider means that neither Edwards nor Planned Parenthood has the authority to file a lawsuit to enforce this aspect of the Medicaid statute.

Nicole A. Saharsky, Planned Parenthood’s lawyer, argued that the creation of a right shouldn’t depend on “some kind of magic words test.” Instead, she said it was clear that the Medicaid statute created “a right to choose their own doctor” because “it’s mandatory” that the state provide this option to everyone with health insurance through Medicaid.

She also emphasized that Congress wanted to protect “an intensely personal right” to be able “to choose your doctor, the person that you see when you’re at your most vulnerable, facing … some of the most significant … challenges to your life and your health.”

Restricting Medicaid funds

Through a federal law known as the Hyde Amendment, Medicaid cannot reimburse health care providers for the cost of abortions, with a few exceptions: when a patient’s life is at risk or her pregnancy is due to rape or incest. Some states do cover abortion when their laws allow it, without using any federal funds.

Therefore, Planned Parenthood only gets federal Medicaid funds for abortions in those limited circumstances.

McMaster explained that he removed “abortion clinics,” including Planned Parenthood, from the South Carolina Medicaid Program because he didn’t want state funds to indirectly subsidize abortions.

South Carolina “decided that Planned Parenthood was unqualified for many reasons, chiefly because they’re the nation’s largest abortion provider,” Bursch told the Supreme Court.

But only 3% of Planned Parenthood’s services nationwide last year were related to abortion. Its most common service is testing for sexually transmitted diseases. Across the nation, Planned Parenthood provides health care to more than 2 million patients per year, most of whom have low incomes.

Man with gray hair in a suit and red tie speaks at a podium.
South Carolina Gov. Henry McMaster speaks to a crowd during an election night party on Nov. 3, 2020, in Columbia.
Photo by Sean Rayford/Getty Images

Section 1983

Because the Medicaid statute itself does not allow an individual to sue, Edwards and Planned Parenthood are relying on Section 1983.

Lower courts have repeatedly upheld that the Medicaid statute provides Edwards with the right to obtain Medicaid-funded health care at her local Planned Parenthood clinic.

And the Supreme Court has long recognized that Section 1983 protects an individual’s ability to sue when their rights under a federal statute have been violated.

In 2023, for example, the court found such a right under the Medicaid Nursing Home Reform Act. The court held that Section 1983 confers the right to sue when a statute’s provisions “unambiguously confer individual federal rights.”

Consequences beyond South Carolina

The court’s decision in the Medina case on whether Medicaid patients can choose their own health care provider could have consequences far beyond South Carolina. Arkansas, Missouri and Texas have already barred Planned Parenthood from getting reimbursed by Medicaid for any kind of health care. More states could follow suit.

In addition, given Planned Parenthood’s role in providing expansive contraceptive care, disqualifying it from Medicaid could harm access to health care and increase the already-high unintended pregnancy rate in America.

The ramifications, likewise, could extend beyond the finances of Planned Parenthood.

If the court rules in South Carolina’s favor, states could also try to exclude providers based on other characteristics, such as whether their employees belong to unions or if they provide their patients with gender-affirming care, further restricting patients’ choices.

Or, as Kagan observed, states could go the opposite direction and exclude providers that don’t provide abortions and so forth. What’s really at stake, she said, is whether a patient is “entitled to see” the provider they choose regardless of what their state happens to “think about contraception or abortion or gender transition treatment.”

If the Supreme Court rules that Edwards does have a right to get health care at a Planned Parenthood clinic, the controversy would not be over. The lower courts would then have to decide whether South Carolina appropriately removed Planned Parenthood from Medicaid as an “unqualified provider.”

And if the Supreme Court rules in favor of South Carolina, then Planned Parenthood could still sue South Carolina over its decision to find them to be unqualified.The Conversation

Naomi Cahn, Professor of Law, University of Virginia and Sonia Suter, Professor of Law, George Washington University

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

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