Category: The Conversation – USA

Source: The Conversation – USA (2) – By Neal H. Hutchens, University Research Professor of Education, University of Kentucky

American colleges and universities are increasingly firing or punishing professors and other employees for what they say, whether it’s on social media or in the classroom.

After the Sept. 10, 2025, killing of conservative activist Charlie Kirk, several universities, including Iowa State University, Clemson University, Ball State University and others, fired or suspended employees for making negative online comments about Kirk.

Some of these dismissed professors compared Kirk to a Nazi, described his views as hateful, or said there was no reason to be sorry about his death.

Some professors are now suing their employers for taking disciplinary action against them, claiming they are violating their First Amendment rights.

In one case, the University of South Dakota fired Phillip Michael Cook, a tenured art professor, after he posted on Facebook in September that Kirk was a “hate spreading Nazi.” Cook, who took down his post within a few hours and apologized for it, then sued the school, saying it was violating his First Amendment rights.

A federal judge stated in a Sept. 23 preliminary order that the First Amendment likely protected what Cook posted. The judge ordered the University of South Dakota to reinstate Cook, and the university announced on Oct. 4 that it would reverse Cook’s firing.

Cook’s lawsuit, as well as other lawsuits filed by dismissed professors, is testing how much legal authority colleges have over their employees’ speech – both when they are on the job and when they are not.

For decades, American colleges and universities have traditionally encouraged free speech and open debate as a core part of their academic mission.

As scholars who study college free speech and academic freedom, we recognize that these events raise an important question: When, if ever, can a college legally discipline an employee for what they say?

Limits of public employees’ speech rights

The First Amendment limits the government’s power to censor people’s free speech. People in the United States can, for instance, join protests, criticize the government and say things that others find offensive.

But the First Amendment only applies to the government – which includes public colleges and universities – and not private institutions or companies, including private colleges and universities.

This means private colleges typically have wide authority to discipline employees for their speech.

In contrast, public colleges are considered part of the government. The First Amendment limits the legal authority they have over their employees’ speech. This is especially true when an employee is speaking as a private citizen – such as participating in a political rally outside of work hours, for example.

The Supreme Court ruled in a landmark 1968 case that public employees’ speech rights as private citizens can extend to criticizing their employer, like if they write a letter critical of their employer to a newspaper.

The Supreme Court also ruled in 2006 that
the First Amendment does not protect public employees from being disciplined by their employers when they say or write something as part of their official job duties.

Even when a public college employee is speaking outside of their job duties as a private citizen, they might not be guaranteed First Amendment protection. To reach this legal threshold, what they say must be about something of importance to the public, or what courts call a “matter of public concern.”

Talking or writing about news, politics or social matters – Kirk’s murder – often meets the legal test for when speech is about a matter of public concern.

In contrast, courts have ruled that personal workplace complaints or gossip typically does not guarantee freedom of speech protection.

And in some cases, even when a public employee speaks as a private citizen on a topic that a court considers a matter of public concern, their speech may still be unprotected.

A public employer can still convince a court that its reasons for prohibiting an employee’s speech – like preventing conflict among co-workers – are important enough to deny this employee First Amendment protection.

Lawsuits brought by the employees of public colleges and universities who have been fired for their comments about Kirk may likely be decided based on whether what they said or wrote amounts to a matter of public concern. Another important factor is whether a court is convinced that an employee’s speech about Kirk was serious enough to disrupt a college’s operations, thus justifying the employee’s firing.

Academic freedom and professors’ speech

There are also questions over whether professors at public universities, in particular, can cite other legal rights to protect their speech.

Academic freedom refers to a faculty member’s rights connected to their teaching and research expertise.

At both private and public colleges, professors’ work contracts – like the ones typically signed after receiving tenure – potentially provide legal protections for faculty speech connected to academic freedom, such as in the classroom.

However, the First Amendment does not apply to how a private college regulates its professors’ speech or academic freedom.

Professors at public colleges have at least the same First Amendment free speech rights as their fellow employees, like when speaking in a private citizen capacity.

Additionally, the First Amendment might protect a public college professor’s work-related speech when academic freedom concerns arise, like in their teaching and research.

In 2006, the Supreme Court left open the question of whether the First Amendment covers academic freedom, in a case where it found the First Amendment did not cover what public employees say when carrying out their official work.

Since then, the Supreme Court has not dealt with this complicated issue. And lower federal courts have reached conflicting decisions about First Amendment protection for public college professors’ speech in their teaching and research.

Future of free speech for university employees

Some colleges, especially public ones, are testing the legal limits of their authority over their employees’ speech.

These incidents demonstrate a culture of extreme political polarization in higher education.

Beyond legal questions, colleges are also grappling with how to define their commitments to free speech and academic freedom.

In particular, we believe campus leaders should consider the purpose of higher education. Even if legally permitted, restricting employees’ speech could run counter to colleges’ traditional role as places for the open exchange of ideas.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Does the First Amendment protect professors being fired over what they say? It depends – https://theconversation.com/does-the-first-amendment-protect-professors-being-fired-over-what-they-say-it-depends-266128

Source: The Conversation – USA (2) – By Aradhna Krishna, Dwight F. Benton Professor of Marketing, University of Michigan

Surveillance pricing has dominated headlines recently. Delta Air Lines’ announcement that it will use artificial intelligence to set individualized ticket prices has led to widespread concerns about companies using personal data to charge different prices for identical products. As The New York Times reported, this practice involves companies tracking everything from your hotel bookings to your browsing history to determine what you’re willing to pay.

The reaction has been swift. Democratic lawmakers have responded with outrage, with Texas Rep. Greg Casar introducing legislation to ban the practice. Meanwhile, President Donald Trump’s new chair of the Federal Trade Commission has shut down public comment on the issue, signaling that the regulatory pendulum may swing away from oversight entirely.

What’s missing in this political back-and-forth is a deeper look at the economics. As a business school professor who researches pricing strategy, I think the debate misses important nuances. Opponents of surveillance pricing overlook some potential benefits that could make markets both more efficient and, counterintuitively, more equitable.

What surveillance pricing actually is

Surveillance pricing differs from traditional dynamic pricing, where prices rise for everyone at times of peak demand. Instead, it uses personal data – browsing history, location, purchase patterns, even device type – to charge a unique price based on what algorithms predict you’re willing to pay.

The goal is to discover each customer’s “reservation price” – the most they’ll pay before walking away. Until recently, this was extremely difficult to do, but modern data collection has made it increasingly feasible.

An FTC investigation found that companies track highly personal consumer behaviors to set individualized prices. For example, a new parent searching for “baby thermometers” might find pricier products on the first page of their results than a nonparent would. It’s not surprising that many people think this is unfair.

The unintended progressive tax

But consider this: Surveillance pricing also means that wealthy customers pay more for identical goods, while lower-income customers pay less. That means it could achieve redistribution goals typically pursued through government policy. Pharmaceutical companies already do this globally, charging wealthier countries more for identical drugs to make medications accessible in poorer nations. Surveillance pricing could function as a private-sector progressive tax system.

Economists call it “price discrimination,” but it often helps poorer consumers access goods they might otherwise be unable to afford. And unlike government programs, this type of redistribution requires no taxpayer funding. When Amazon’s algorithm charges me more than a college student for the same laptop, it’s effectively running a means-tested subsidy program – funded by consumers.

The two-tier economy problem

In my view, the most legitimate concern about surveillance pricing isn’t that it exists, but how it’s implemented. Online retailers can seamlessly adjust prices in real time, while physical stores remain largely stuck with uniform pricing. Imagine the customer fury if Target’s checkout prices varied by person based on their smartphone data: There could be chaos in the stores. This digital-physical divide could also create unfair advantages for tech-savvy companies while leaving traditional retailers behind. That would raise fairness considerations for consumers as well as retailers.

This is related to another force that could limit how far surveillance pricing can go: arbitrage, or the practice of buying something where it is cheaper and selling it where it is more expensive.

If a system consistently charges wealthy customers $500 for items that cost poor customers $200, it creates opportunities for entrepreneurial intermediaries to exploit these price gaps. Personal shopping services, buying cooperatives or even friends and family networks could arbitrage these differences, providing wealthy customers access to the lower prices while splitting the savings. This means surveillance pricing can’t discriminate too aggressively – market forces will erode excessive price gaps.

That’s why I believe the solution isn’t to ban surveillance pricing entirely, but to monitor how it is put in practice.

The regulatory sweet spot

The current political moment offers a strange opportunity. With Republicans focused on AI innovation and Democrats fixated on bans, there’s space for a more sophisticated position that embraces market-based redistribution while demanding strong consumer protections.

In my view, smart regulation would require companies to disclose when personal data influences pricing, and would prohibit discrimination based on protected characteristics such as race, color or religion – and this list needs to be created extremely carefully. This would preserve the efficiency benefits while preventing abuse.

Surveillance pricing based on desperation or need also raises unique ethical questions. Charging a wealthier customer more for a taxi ride is one thing; charging someone extra solely because their battery is low and they risk being stranded is another.

As I see it, the distinction between ability to pay and urgency of need must become the cornerstone of regulation. While distinguishing the two may seem challenging, it’s far from impossible. It would help if customers were empowered to report exploitative practices, using mechanisms similar to existing price-gouging protections.

A solid regulatory framework must also clarify the difference between dynamic pricing and surveillance-based exploitation. Dynamic pricing has long been standard practice: Airlines charge all last-minute travelers higher fares, regardless of their circumstances. But consider two passengers buying tickets on the same day – one rushing to a funeral, another planning a spontaneous vacation. Right now, airlines can use technology to identify and exploit the funeral attendee’s desperate circumstances.

The policy challenge is precise: Can we design regulations that prevent airlines from exploiting the bereaved while still allowing retailers to offer discounts on laptops to lower-income families? The answer will determine whether surveillance pricing becomes a tool for equity or exploitation.

Aradhna Krishna does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. In defense of ‘surveillance pricing’: Why personalized prices could be an unexpected force for equity – https://theconversation.com/in-defense-of-surveillance-pricing-why-personalized-prices-could-be-an-unexpected-force-for-equity-266293

Source: The Conversation – USA (2) – By Rodney Coates, Professor of Critical Race and Ethnic Studies, Miami University

As millions of student loan borrowers settle into the school year, many are stressed about how they’ll pay for their degrees. These students may find that the One Big Beautiful Bill Act, the big tax and spending bill that President Donald Trump signed into law over the summer, could limit how much they can borrow.

Until recently, graduate students could take out two types of federal loans: Direct Unsubsidized Loans, which had a lifetime limit of US$138,500, and Grad PLUS loans, which allowed students to borrow up to the full cost of attendance, minus financial aid.

But Grad PLUS loans will be eliminated next summer, with a three-year transitional period for current borrowers. That will leave only the capped loans for new borrowers, and those loans have new lifetime borrowing limits: $200,000 for students pursuing certain professional degrees, and $100,000 for nonprofessional graduate programs.

If you add both undergraduate and graduate loans, there’s a new lifetime limit of $257,500 per person.

That seems modest to me. Consider that the annual average costs for an undergraduate degree range from $24,920 for in-state public universities to $58,000 for private universities. That means we’re looking at up to $224,000 for a bachelor’s degree. If we add three years of law school, we’re looking at an additional $132,000 to $168,000, respectively. Alternatively, completing four years of medical school will set you back another $268,000 to $363,000. It’s not easy to make those numbers add up to less than $257,500.

As I reflect on these numbers and my journey to becoming a college professor, specializing in race and ethnic studies, one thing becomes clear: I would never have been able to earn my bachelor’s degree, two master’s degrees, and Ph.D. under these new rules.

Adjusting for inflation, I took out nearly $300,000 in student loans, and I paid them all off within a decade of starting my college teaching career. For me, the system worked. I wonder how today’s aspiring professionals, especially those from less prosperous backgrounds, will manage.

The future of professionals

Professional students already graduate with a lot of debt – often far more than the new loan caps will allow. In 2020, more than a quarter of graduating medical students and nearly 60% of graduating dental students had borrowed more than the new limits would allow, author Mark Kantrowitz, who is an expert on student loans, has found. In 2024, nearly a quarter of medical school graduates left school with more than $300,000 in debt.

The new borrowing limits will likely hit minority students especially hard. While about 61% of all graduate students take out student loans, the share is much higher for Black students compared with white students, 48% to 17%.

While some might be able to supplement their federal loans with private ones – which tend to have much worse terms for borrowers – I fear that many others will be forced to end their educations prematurely.

That, in turn, would worsen the already severe shortage of doctors serving the Black community. As pointed out in a 2023 report of the Journal of the American Medical Association, the shortage of Black primary care physicians is directly related to overall lower population health and ultimately higher mortality rates within the Black community. As of 2023, fewer than 6% of U.S. doctors were Black, versus 14.4% of the population.

Research has suggested that student loan relief would help diversify the medical workforce. Adding new restrictions would likely have the opposite effect, making the profession more homogeneous and significantly undermining Black public health.

Or consider attorneys. Law school costs have risen more than 600% over the past two decades. The average 2020 law school graduate left with $165,000 in student debt.

Black law students face unique challenges, graduating with approximately 8% more debt on average than white students and facing significant wage disparities once they enter the legal workforce. Making it harder for Black students to afford law school could reduce the number of Black attorneys, which has held steady at about 5% of active lawyers over the past 10 years.

Reducing access to federal student loans risks disproportionately affecting women, since they hold roughly two-thirds of all student debt.

What comes next

Supporters of the change say that capping graduate student borrowing will encourage universities to rein in tuition hikes. They also say private student loan providers will step in to help students. I am skeptical, but the true test will come next year.

In the meantime, professional students might want to familiarize themselves with the many scholarship opportunities available. Many organizations offer a range of medical school scholarships, including those targeting women and minorities. The same is true for students interested in law school. A helpful starting point is this list of scholarships with approaching deadlines and these opportunities for women and people of color.

Rodney Coates does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. New student loan limits could change who gets to become a professor, doctor or lawyer – https://theconversation.com/new-student-loan-limits-could-change-who-gets-to-become-a-professor-doctor-or-lawyer-262008

Source: The Conversation – USA (2) – By Vivek Astvansh, Associate Professor of Quantitative Marketing and Analytics, McGill University

When Starbucks announced that it would phase out its mobile-order pickup-only locations beginning in 2026, it raised a question: Why abandon a format seemingly built for speed and efficiency?

As Starbucks CEO Brian Niccol explained the decision in an earnings call, the pickup-only stores had a “transactional” feel, lacking “the warmth and human connection that defines our brand.”

While Niccol also touted the mobile-order options at its traditional coffee shops, I see Starbucks’ move as an attempt to return to its roots as a “third place” – a destination between home and work where people can gather and connect.

But this sort of pivot comes with trade-offs – and it creates interesting market opportunities for competitors. As a marketing professor and a coffee connoisseur, I’m offering this analysis to go with your morning cup of joe.

The two types of coffee shop patrons

In general, coffee shops attract two distinct customer segments. The first are what I call “stay-and-savor” customers – people who mostly use the site as a place to meet others or work. Their primary interest is in the space, not the mocha or muffins.

The second are “grab-and-go” customers – people who want a consistent product, delivered efficiently. They don’t linger at the store, so the place is less important to them than convenience, speed and product quality. Think of the morning rush at your local coffee joint.

Starbucks’ pickup-only stores, branded as Starbucks PICK UP, cater to grab-and-go customers. If you don’t live in a busy area, you might never have heard of the brand: There are fewer than 100 Starbucks PICK UPs, many in densely packed cities.

In contrast, there are about 17,000 sit-in Starbucks stores across the United States. That means its plan will affect just 0.5% of its locations. That’s not very much.

So why does this change have me a little, well, steamed up?

Back to the third place, whether you like it or not

As I said before, I see this move as part of an effort to emphasize “stay-and-savor” customers over their “grab-and-go” counterparts. Indeed, Niccol’s recent earnings call presentation claimed that Starbucks is “prioritizing warmth, connection and community.” Starbucks also publishes a document stating its “principles for upholding the third place,” and its commitment seems to be more than just rhetorical.

The problem is that coffee shops aren’t like regular restaurants in terms of menu prices and customer spending. “Stay-and-savor” customers are costly to serve for coffee shops, and may generate insufficient revenue, making them less profitable. That could be bad for the bottom line.

The change could also have unintended consequences for workers and customers. For example, pickup-only stores allow employees to focus on food and beverage preparation, with less pressure to engage in small talk in the hopes of generating warmth and tips. Indeed, much academic research has shown that restaurant workers who serve customers report more emotional labor and stress and worse morale and well-being than those who don’t.

In contrast, Starbucks’ rivals, such as Dunkin’ and the Chinese new entrant Luckin Coffee, have embraced the grab-and-go customers. These rivals provide space for seating space, but they don’t elevate their positioning as if their baristas are serving warmth, connection and community.

Starbucks CEO Niccol has described the plan as a “sunsetting.” I’d watch out for Dunkin’ and Luckin Coffee, and of course, Starbucks’ financials in 2026, to determine whether the Starbucks sun sets or rises.

Vivek Astvansh does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Starbucks wants you to stay awhile – but shuttering its mobile-only pickup locations could be a risky move – https://theconversation.com/starbucks-wants-you-to-stay-awhile-but-shuttering-its-mobile-only-pickup-locations-could-be-a-risky-move-262591

Source: The Conversation – USA – By Sam D. Hayes, Assistant professor of politics and policy, Simmons University

On Oct. 15, 2025, the Supreme Court will hear oral arguments in one of the most anticipated cases of the 2025-2026 term, Louisiana v. Callais, with major implications for the Voting Rights Act, racial representation and Democratic Party power in congress.

The central question in the case is to what extent race can, or must, be used when congressional districts are redrawn. Plaintiffs are challenging whether the longstanding interpretation of Section 2 of the Voting Rights Act, which requires protection of minority voting power in redistricting, violates the Equal Protection Clause of the U.S. Constitution, which guarantees that individuals should be treated the same by the law.

In short, the plaintiffs argue that the state of Louisiana’s use of race to make a second Black-majority district is forbidden by the U.S. Constitution.

This is the second time that the court will hear oral arguments in Louisiana v. Callais after no decision was reached last term. From my perspective as a scholar of U.S. federal courts and electoral systems, this case represents the collision of decades of Supreme Court decisions on race, redistricting and the Voting Rights Act.

Long legal battle

To understand the stakes of the current case, it’s important to know what the Voting Rights Act does. Initially passed in 1965, the act helped end decades of racially discriminatory voting laws by providing federal enforcement of voting rights.

Section 2 of the Voting Rights Act forbids discrimination by states in relation to voting rights and has been used for decades to challenge redistricting plans.

The current case has its roots in the redistricting of Louisiana’s congressional districts following the 2020 Census. States are required to redraw districts each decade based on new population data. Louisiana lawmakers redrew the state’s six congressional districts without major changes in 2022.

Soon after the state redistricted, a group of Black voters challenged the map in federal court as a violation of the Voting Rights Act. The plaintiffs argued that the new map was discriminatory because the voting power of Black citizens in the state was being illegally diluted. The state’s population was 31% Black, but only one of the six districts featured a majority-Black population.

The federal courts in 2022 sided with the plaintiffs’ claim that the plan did violate the Voting Rights Act and ordered the state legislature to redraw the congressional plan with a second Black-majority district.

The judges relied on an interpretation of Section 2 of the Voting Rights Act from a 1986 Supreme Court decision in the case known as Thornburg v. Gingles. Under this interpretation, Section 2’s nondiscrimination requirement means that congressional districts must be drawn in a way that allows large, politically cohesive and compact racial minorities to be able to elect representatives of their choice.

In 2023, the Supreme Court upheld a lower court’s interpretation of Section 2 of the Voting Rights Act in a similar racial gerrymandering case in Alabama.

Louisiana lawmakers redraw districts

Following the court order, the Louisiana state legislature passed Senate Bill 8 in January 2024, redrawing the congressional map and creating two districts where Black voters composed a substantial portion of the electorate in compliance with the Gingles ruling. This map was used in the 2024 congressional election and both Black-majority districts elected Democrats, while the other four districts elected Republicans.

These new congressional districts from Senate Bill 8 were challenged by a group of white voters in 2024 in a set of cases that became Louisiana v. Callais.

The plaintiffs argued that the Louisiana legislature’s drawing of districts based on race in Senate Bill 8 was in violation of the 14th Amendment’s Equal Protection Clause, which requires equal treatment of individuals by the government, and the 15th Amendment, which forbids denying the right to vote based on race.

Essentially, the plaintiffs claimed that the courts’ interpretation of Section 2 of the Voting Rights Act was unconstitutional and that the use of race to create a majority-minority district is itself discriminatory. Similar arguments about the 14th Amendment’s Equal Protection Clause were also the basis of the Supreme Court’s recent decisions striking down race-based affirmative action in college admissions.

In 2024, a three-judge district court sided with the white plaintiffs in Louisiana v. Callais, with a 2-1 decision. The Black plaintiffs from the original case, and the state of Louisiana, appealed the case to the Supreme Court. The court originally heard the case at the end of the 2024-2025 term before ordering the case re-argued for 2025-2026.

High stakes and significant precedent

If the Supreme Court ultimately upholds the lower court decision in Louisiana v. Callais, deciding that Louisiana’s congressional districts are unconstitutional racial gerrymanders, it will have substantial impacts on minority representation. The decision would upend decades of precedent for Section 2 of the Voting Rights Act.

For 39 years, Section 2 of the Voting Rights Act has required redistricting institutions to consider racial and ethnic minority representation when devising congressional districts. Majority-minority districting is required when a state has large, compact and cohesive minority communities. Historically, some states have redistricted minority communities in ways that dilute their voting power, such as “cracking” a community into multiple districts where they compose a small percentage of the electorate.

Section 2 also provides voters and residents with a legal tool that has been used to challenge districts as discriminatory. Many voters and groups have used Section 2 successfully to challenge redistricting plans.

Section 2 has been the main legal tool for challenging racial discrimination in redistricting for the past decade. In 2013, the Supreme Court effectively ended the other major component of the Voting Rights Act, the preclearance provision, which required certain states to have changes to their elections laws approved by the federal government, including redistricting.

If the court overrules the current interpretation of Section 2, it would limit the legality of using race in redistricting, end requirements for majority-minority districts and eliminate the most common way to challenge discriminatory districting.

Additionally, because of the strong relationship between many minority communities and the Democratic party, the court’s decision has major implications for partisan control of the House of Representatives.

If Section 2 no longer required majority-minority districts, then Republicans could use the ruling to redraw congressional districts across the country to benefit their party. Politico reported that Democrats could lose as many as 19 House seats if the Supreme Court sides with the lower court.

Recent Supreme Court precedent gives conflicting signals as to how it will decide this case.

In 2023, the court rejected a challenge to Section 2 of the Voting Rights Act related to Alabama’s congressional districts. In 2024, the court overruled a lower court’s finding of racial vote dilution in South Carolina.

Sam D. Hayes does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Supreme Court redistricting ruling could upend decades of voting rights law – and tilt the balance of power in Washington – https://theconversation.com/supreme-court-redistricting-ruling-could-upend-decades-of-voting-rights-law-and-tilt-the-balance-of-power-in-washington-267269

Source: The Conversation – USA – By Mojtaba Akhavan-Tafti, Associate Research Scientist, University of Michigan

Weather forecasting is a powerful tool. During hurricane season, for instance, meteorologists create computer simulations to forecast how these destructive storms form and where they might travel, which helps prevent damage to coastal communities. When you’re trying to forecast space weather, rather than storms on Earth, creating these simulations gets a little more complex. To simulate space weather, you would need to fit the Sun, the planets and the vast empty space between them in a virtual environment, also known as a simulation box, where all the calculations would take place.

Space weather is very different from the storms you see on Earth. These events come from the Sun, which ejects eruptions of charged particles and magnetic fields from its surface. The most powerful of these events are called interplanetary coronal mass ejections, or CMEs, which travel at speeds approaching 1,800 miles per second (2,897 kilometers per second).

To put that in perspective, a single CME could move a mass of material equivalent to all the Great Lakes from New York City to Los Angeles in just under two seconds – almost faster than it takes to say “space weather.”

When these CMEs hit Earth, they can cause geomagnetic storms, which manifest in the sky as beautiful auroras. These storms can also damage key technological infrastructure, such as by interfering with the flow of electricity in the power grid and causing transformers to overheat and fail.

To better understand how these storms can wreak so much havoc, our research team created simulations to show how storms interact with Earth’s natural magnetic shield and trigger the dangerous geomagnetic activity that can shut down electric grids.

In a study published in October 2025 in the Astrophysical Journal, we modeled one of the sources of these geomagnetic storms: small, tornado-like vortices spun off of an ejection from the Sun. These vortices are called flux ropes, and satellites had previously observed small flux ropes – but our work helped uncover how they are generated.

The challenge

Our team started this research in summer 2023, when one of us, a space weather expert, spotted inconsistencies in space weather observations. This work had found geomagnetic storms occurring during periods when no solar eruptions were predicted to hit Earth.

Bewildered, the space weather expert wanted to know if there could be space weather events that were smaller than coronal mass ejections and did not originate directly from solar eruptions. He predicted that such events might form in the space between the Sun and Earth, instead of in the Sun’s atmosphere.

One example of such smaller space weather events is a magnetic flux rope – bundles of magnetic fields wrapped around each other like a rope. Its detection in computer simulations of solar eruptions would hint to where these space weather events may be forming. Unlike satellite observations, in simulations you can turn back the clock or track an event upstream to see where they originate.

So he asked the other author, a leading simulation expert. It turned out that finding smaller space weather events was not as simple as simulating a big solar eruption and letting the computer model run long enough for the eruption to reach Earth. Current computer simulations are not meant to resolve these smaller events. Instead, they are designed to focus on the large solar eruptions because these have the most effects on infrastructure on Earth.

This shortfall was quite disappointing. It was like trying to forecast a hurricane with a simulation that only shows you global weather patterns. Because you can’t see a hurricane at that scale, you would completely miss it.

These larger-scale simulations are known as global simulations. They study how solar eruptions form on the Sun’s surface and travel through space. These simulations treat streams of charged particles and magnetic fields floating through space as fluids to reduce the computational cost, compared with modeling every charged particle independently. It’s like measuring the overall temperature of water in a bottle, instead of tracking every single water molecule individually.

Because these simulations are computational phenomena that happen across such a vast space, they can’t resolve every detail. To affordably resolve the vast space between the Sun and the planets, researchers divide the space into large cubes – analogous to two-dimensional pixels in a camera. In the simulation, these cubes each represent an area 1 million miles (1.6 million kilometers) wide, tall and across. That distance is equivalent to about 1% of the distance from Earth to the Sun.

The search begins

Our search began with what felt like hunting for a needle in a haystack. We were looking into old global simulations, searching for a tiny, transient blob – which would signify a flux rope – within an area of space hundreds of times wider than the Sun itself. Our initial search did not yield anything.

We then shifted our focus to the simulations of the May 2024 solar eruption event. This time, we specifically looked at the region where the solar eruption collided into a quiet flow of charged particles and magnetic fields, called the solar wind, ahead of it.

There it was: a distinct system of magnetic flux ropes.

However, our excitement was short-lived. We could not tell where these flux ropes came from. The modeled flux ropes were also too small to survive, eventually fizzling out because they became too small to resolve with our simulation grid.

But that was the type of clue we needed – the presence of flux ropes at the location where the solar eruption collided with the solar wind.

To settle the issue, we decided to bridge this gap and create a computer model with a finer grid size than those previous global simulations used. Since increasing the resolution across the entire simulation space would have been prohibitively expensive, we decided to only increase the simulation resolution along the trajectory of the flux ropes.

The new simulations could now resolve features that spanned distances six times Earth’s 8,000-mile (or 128,000-kilometer) diameter down to tens of thousands of miles – nearly 100 times better than previous simulations.

Making the discovery

Once we designed and tested the simulation grid, it was time to simulate that same solar eruption that led to the formation of those flux ropes in the less fine-grained model. We wanted to study the formation of those flux ropes and how they grew, changed shape and possibly terminated in the narrow wedge encompassing the space between the Sun and Earth. The results were astonishing.

The high-resolution view revealed that the flux ropes formed when the solar eruption slammed into the slower solar wind ahead of it. The new structures possessed incredible complexity and strength that persisted far longer than we expected. In meteorological terms, it was like watching a hurricane spawn a cluster of tornadoes.

We found that the magnetic fields in these vortices were strong enough to trigger a significant geomagnetic storm and cause some real trouble here on Earth. But most importantly, the simulations confirmed that there are indeed space weather events that form locally in the space between the Sun and Earth. Our next step is to simulate how such tornado-like features in the solar wind may impact our planet and infrastructure.

Watching these flux ropes in the simulation form so quickly and move toward Earth was exciting, but concerning. It was exciting because this discovery could help us better plan for future extreme space weather events. It was at the same time concerning because these flux ropes would only appear as a small blip in today’s space weather monitors.

We would need multiple satellites to directly see these flux ropes in greater detail so that scientists can more reliably predict whether, when and in what orientation they may affect our planet and what the outcome may be. The good news is that scientists and engineers are developing the next-generation space missions that could address this.

Mojtaba Akhavan-Tafti is the Principal Investigator of Space Weather Investigation Frontier (SWIFT). He receives funding from NASA.

W. Manchester is a Co-Investigator of Space Weather Investigation Frontier (SWIFT). He receives funding from NASA and the National Science Foundation (NSF).

– ref. ‘Space tornadoes’ could cause geomagnetic storms – but these phenomena, spun off ejections from the Sun, aren’t easy to study – https://theconversation.com/space-tornadoes-could-cause-geomagnetic-storms-but-these-phenomena-spun-off-ejections-from-the-sun-arent-easy-to-study-266567

Source: The Conversation – USA – By Kelling Donald, Professor of Chemistry, University of Richmond

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

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“What is radium and why is it dangerous?” – Aurora, 10, Laredo, Texas

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The element radium can be found in extremely tiny amounts in the Earth’s crust and oceans, and in its pure form it is a soft silvery metal. To an untrained eye, a small piece of radium may look like a chip off a regular gray rock. But radium can invisibly emit radiation – energy and small fragments of itself – that you can’t feel, see or smell. And that invisible radiation can hurt you, without you even noticing right away.

What’s going on with this silent threat that can stealthily damage your body in ways that can take years to reveal themselves?

As a chemist, I’m interested in what makes different elements safe to handle or hazardous. This dangerous release of radiation is called radioactivity, and even though its source may look unassuming, it can burn you or even give you diseases that don’t manifest for years.

Atoms and isotopes

Everything you see around you – your skin, rocks, the pages of books – is all made up of different combinations of extremely small particles called atoms.

An atom has a small, dense center called the nucleus. Negatively charged particles called electrons move around the nucleus. Inside the nucleus, there are two types of particles: positively charged protons and neutral neutrons.

All atoms with the same number of protons in their nuclei are the same element. Besides radium, some elements you may have heard of are carbon and oxygen. All carbon atoms have six protons and all oxygen atoms have eight protons. Radium atoms are much heavier – all radium atoms have 88 protons.

Interestingly, it is possible for atoms of the same element to have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. For instance, two carbon atoms would each have six protons, but one might have six neutrons while another could have seven or eight.

The number of protons and neutrons packed together in the nucleus determines whether the nucleus of an isotope is stable or not. If the nucleus is not stable, problems can arise.

Radioactive decay

The nucleus of each atom wants to be stable, but only certain arrangements of protons and neutrons make that possible. The number of protons and neutrons do not have to be equal, but some combinations make for a happy, or stable, coexistence in the nucleus while others don’t.

A nucleus with an unhappy mix of protons and neutrons might break down or deteriorate in some way. That process is called radioactivity or radioactive decay.

That radioactive decay process releases some form of radiation from the nucleus. This radiation can take the form of tiny particles moving rapidly or high-energy electromagnetic waves emerging from the nucleus. It is that radiation – the high-energy particles and waves shooting out from the nucleus of unstable atomic nuclei – that can make you sick.

There are different types of radioactive decay. In one case, an atom decays by kicking out a small fragment of itself that is made up of two protons and two neutrons. Since the number of protons determines what element we have, decay that changes the number of protons in an atom turns it into a different element.

Radioactive decay can be quite slow, though. It can take thousands of years for one element to decay into a different one.

The case of radium

All radium atoms are unstable and radioactive. Many of these isotopes decay very quickly, but Ra-226, which has 138 neutrons and 88 protons and is the most common, decays the slowest. It takes 1,600 years for half a sample of Ra-226 to decay.

As Ra-226 decays, it loses two protons and two neutrons, which turns it into an isotope of radon. Then the radon decays, and the atom eventually reaches a stable form as the element lead. Each step in that decay series releases more nuclear radiation.

Some other elements in nature with no stable isotope are technetium, polonium, actinium and uranium.

Effects on the human body

The nuclear radiation emitted when radium and other elements decay can damage the cells in the human body. It can lead to cancers or other health problems.

Whether you’re exposed to a lot of radiation quickly, like making the mistake of walking around for a few hours with radioactive material in your pocket, or you’re exposed to just a little over a long time, the high-energy particles and electromagnetic waves from nuclear radiation can lead to serious health problems, including burns and cancers.

Remarkably, even though radioactivity is a threat to life, scientists can control and use it to diagnose and treat diseases – including cancers. If the radiation is delivered precisely to where cancer cells are, the radiation can destroy those rogue cells wreaking havoc in the body.

People who work professionally with radioactive materials need to follow strict guidelines and procedures to protect themselves. They use special shields and radiation detectors, and they minimize the amount of time they’re exposed to any radioactivity.

Pierre and Marie Curie, who discovered radium in 1898, suffered some of the negative effects of radioactivity. Pierre experienced radioactive burns, and Marie died from a blood disease likely caused by chronic radiation exposure. Over 100 years later, her notebooks are still radioactive.

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Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

Kelling Donald does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Why are elements like radium dangerous? A chemist explains radioactivity and its health effects – https://theconversation.com/why-are-elements-like-radium-dangerous-a-chemist-explains-radioactivity-and-its-health-effects-262923

Source: The Conversation – USA – By James T. Stroud, Assistant Professor of Ecology and Evolution, Georgia Institute of Technology

We are lizard biologists, and to do our work we need to catch lizards – never an easy task with such fast, agile creatures.

Years ago, one of us was in the Bahamas chasing a typically uncooperative lizard across dense and narrow branches, frustrated that its nimble agility was thwarting efforts to catch it. Only when finally captured did we discover this wily brown anole was missing its entire left hind leg. This astonishing observation set our research down an unexpected path.

That chance encounter led us to collaborate with over 60 colleagues worldwide to document what we suspected might be a broader phenomenon. Our research uncovered 122 cases of limb loss across 58 lizard species and revealed that these “three-legged pirates” – the rare survivors of traumatic injuries – can run just as fast, maintain healthy body weight, reproduce successfully and live surprisingly long lives.

To be clear, most lizards probably do not survive such devastating injuries. What we’re documenting are the exceptional cases that defy our expectations about how natural selection works.

This discovery is startling because lizard limbs represent one of biology’s most studied examples of evolutionary adaptation. For decades, scientists have demonstrated that even tiny differences in leg length between individual lizards can mean the difference between life and death – affecting their ability to escape predators, catch prey and find mates.

Since subtle variations matter so much, biologists have long assumed that losing an entire limb should be catastrophic.

Yet our global survey tells a different story about these remarkable survivors. Working with colleagues across six continents, we found limb-damaged lizards across nearly all major lizard families, from tiny geckos to massive iguanas.

These animals had clearly healed from whatever trauma caused their injuries – likely accidents or the failed attempts of a predator to eat them. Perhaps most remarkably, we documented surviving limb loss even in chameleons, tree-climbing specialists whose movements seem to require perfect limb coordination.

Thriving, not just surviving

The body condition of these lizards was most surprising. Rather than appearing malnourished, many limb-damaged lizards were actually heavier than expected for their size, suggesting they were successfully finding food despite their handicap. Some were actively reproducing, with females found carrying eggs and males observed successfully mating.

These findings force us to reconsider some basic assumptions about how evolution might work in wild populations. Charles Darwin envisioned natural selection as an omnipresent force, “daily and hourly scrutinizing” every feature.

But perhaps selection is more episodic than constant. Maybe sometimes limb length matters tremendously, while during other times – such as when food is abundant and predators are scarce – limb length matters less and three-legged lizards can flourish.

These lizard survivors showcase the incredible solutions that millions of years of evolution have built into their biology. Rather than being passive victims of their injuries, these lizards may survive by actively choosing safer habitats or hunting strategies, using smart behavior to avoid situations where their disability would be a disadvantage.

Biological engineering in action

Our research combines old-fashioned natural history observations with cutting-edge, biomechanical analysis.

We use high-speed cameras and computer software that can track movement frame by frame to analyze running mechanics invisible to the naked eye. This combination of field biology and laboratory precision allows us to understand not just that these lizards survive, but how they accomplish this remarkable feat.

When we tested the three-legged lizards’ athletic performance, the results defied expectations. Some animals were clearly impaired in their sprinting capabilities, but others actually ran faster than fully-limbed individuals of the same size across a 2-meter dash during our “Lizard Olympics.”

High-speed video analysis revealed their secret: The speedy survivors compensate through creative biomechanical solutions. One brown anole missing half its hind limb dramatically increased its body undulation during sprinting, using exaggerated snakelike movements to compensate for the missing leg.

By documenting the unexpected – the seemingly impossible survivors – we’re reminded that nature still holds surprises that can fundamentally change how we think about life itself.

Jonathan Losos receives funding from the National Science Foundation.

James T. Stroud does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. 3-legged lizards can thrive against all odds, challenging assumptions about how evolution works in the wild – https://theconversation.com/3-legged-lizards-can-thrive-against-all-odds-challenging-assumptions-about-how-evolution-works-in-the-wild-262467

Source: The Conversation – USA – By Ryan Kennedy, Timashev Chair of Data Analytics and Professor of Political Science, The Ohio State University

A series of recent events has sparked alarm about rising levels of political violence in the U.S. These episodes include the assassination of political activist Charlie Kirk on Sept. 10, 2025; the murder of a Democratic Minnesota state legislator and her husband in June 2025; and two attempts to kill Donald Trump during the 2024 presidential campaign.

Some surveys have reported that a large number of Americans are willing to support the use of force for political ends, or they believe that political violence may sometimes be justified.

My research is in political science and data analytics. I have conducted surveys for almost 25 years. For the past three years, I have studied new techniques that leverage artificial intelligence to conduct and analyze interviews.

My own recent surveys, which use AI to ask people about why they give their answers, show that the surprisingly high level of support in response to these questions is likely the result of confusion about what these questions are asking, not actual support for political violence.

A failure to communicate

Why would multiple surveys get the answers to this important question wrong? I believe the cause is an issue called response error. It means that respondents don’t interpret a question in the way the researcher thinks they will.

As a result, the answers people provide don’t really reflect what the researcher thinks the answers show.

For example, asking whether someone would support the use of force to achieve a political goal raises the question of what the respondent thinks “use of force” means in this context. It could be interpreted as violence, but it could also be interpreted as using legal means to “force” someone to do something.

Such response errors have been a concern for pollsters ever since survey research began. They can affect even seemingly straightforward questions.

What did you mean by that?

To avoid this problem, I used an AI interviewing system developed by CloudResearch, a well-known survey research company, to ask respondents some of the same questions about political violence from previous surveys. Then I used it to ask what they were thinking when they answered those questions. This process is called cognitive interviewing.

I then used AI to go through these interviews and categorize them. Two short reports that summarize this process as applied to both polls are available online. These analyses have not been peer-reviewed, and the results should be considered very preliminary.

Nonetheless, the results clearly demonstrate that respondents interpret these questions in very different ways.

Nuance matters

For example, in my survey, about 33% of Democrats agreed with the statement that “use of force is justified to remove President Trump from office.” However, when asked why they agreed, more than 57% gave responses like this: “I was not thinking physically but more in the sense that he – the president – might need to be ‘fired’ or forced out of office due to rules or laws.” Still others were envisioning future scenarios where a president illegally seizes power in a coup.

Once you account for these different interpretations of the question, the AI only coded about 8% of Democrats as supporting use of force in violent terms under current conditions.

Even here, there was substantial ambiguity – for example, this type of response was not unusual: “The language ‘use of force’ was a bit too broad for me. I could not justify killing Trump, for example, but less extreme uses of force were valid in my eyes.”

Similarly, 29% of Republicans agreed that “use of the military is justified to stop protests against President Trump’s agenda.” However, almost all of the respondents who agreed with this statement envisioned the National Guard interceding nonviolently to stop violent protests and riots. Only about 2.6% of Republicans gave comments supporting use of the military against nonviolent protests.

Almost all those who agreed that use of the military was justified expressed thoughts like this: “I see the military coming and acting as a police force to stop or prevent the demonstrations that become violent. Peaceful protesters must be allowed to exercise their right to free speech.”

When is political violence justified?

Even questions that explicitly ask about political violence are open to wide interpretation. Take, for example, this question: “Do you think it is ever justified for citizens to resort to violence in order to achieve political goals?”

The lack of a specific scenario or location in this question invites respondents to engage in all kinds of philosophical and historical speculation.

In my survey, almost 15% of respondents said violence could sometimes be justified. When asked about the examples they were thinking of, respondents cited the American Revolution, the anti-Nazi French Resistance and many other incidents as a reason for their responses. Only about 3% of respondents said they were thinking about actions in the U.S. at the current time.

Moreover, almost all respondents stated that violence should be a last resort when all other peaceful and legal methods fail.

One respondent illustrated both problems with one sentence: “The (American) colonists tried petitions and negotiations first, but, when those efforts failed, they resorted to armed conflict to gain independence.”

A call for understanding

Even these numbers likely overestimate Americans’ support for political violence. I read the interviews, checking the AI system’s labeling, and concluded that, if anything, it was overestimating support for violence.

Other factors may also be distorting reports of public support for political violence. Many surveys are conducted primarily online. One study estimated that anywhere from 4% to 7% of respondents in online surveys are “bogus respondents” who are selecting arbitrary responses. Another study reported that such respondents dramatically increase positive responses on questions about political violence.

Respondents may also be willing to espouse attitudes anonymously online that they would never say or do in real life. Studies have suggested that “online disinhibition effects” or “survey trolling” can impact survey results.

In sum, my preliminary research suggests that response error is a substantial problem in surveys about political violence.

Americans almost universally condemn the recent political violence they have witnessed. The recent poll results showing otherwise more likely stem from confusion about what the questions are asking than actual support for political violence.

Ryan Kennedy does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Far fewer Americans support political violence than recent polls suggest – https://theconversation.com/far-fewer-americans-support-political-violence-than-recent-polls-suggest-266113

Source: The Conversation – USA (2) – By Alexandra A Phillips, Assistant Teaching Professor in Environmental Communication, University of California, Santa Barbara

As the planet warms, it risks crossing catastrophic tipping points: thresholds where Earth systems, such as ice sheets and rain forests, change irreversibly over human lifetimes.

Scientists have long warned that if global temperatures warmed more than 1.5 degrees Celsius (2.7 Fahrenheit) compared with before the Industrial Revolution, and stayed high, they would increase the risk of passing multiple tipping points. For each of these elements, like the Amazon rain forest or the Greenland ice sheet, hotter temperatures lead to melting ice or drier forests that leave the system more vulnerable to further changes.

Worse, these systems can interact. Freshwater melting from the Greenland ice sheet can weaken ocean currents in the North Atlantic, disrupting air and ocean temperature patterns and marine food chains.

With these warnings in mind, 194 countries a decade ago set 1.5 C as a goal they would try not to cross. Yet in 2024, the planet temporarily breached that threshold.

The term “tipping point” is often used to illustrate these problems, but apocalyptic messages can leave people feeling helpless, wondering if it’s pointless to slam the brakes. As a geoscientist who has studied the ocean and climate for over a decade and recently spent a year on Capitol Hill working on bipartisan climate policy, I still see room for optimism.

It helps to understand what a tipping point is – and what’s known about when each might be reached.

Tipping points are not precise

A tipping point is a metaphor for runaway change. Small changes can push a system out of balance. Once past a threshold, the changes reinforce themselves, amplifying until the system transforms into something new.

Almost as soon as “tipping points” entered the climate science lexicon — following Malcolm Gladwell’s 2000 book, “The Tipping Point: How Little Things Can Make a Big Difference” — scientists warned the public not to confuse global warming policy benchmarks with precise thresholds.

The scientific reality of tipping points is more complicated than crossing a temperature line. Instead, different elements in the climate system have risks of tipping that increase with each fraction of a degree of warming.

For example, the beginning of a slow collapse of the Greenland ice sheet, which could raise global sea level by about 24 feet (7.4 meters), is one of the most likely tipping elements in a world more than 1.5 C warmer than preindustrial times. Some models place the critical threshold at 1.6 C (2.9 F). More recent simulations estimate runaway conditions at 2.7 C (4.9 F) of warming. Both simulations consider when summer melt will outpace winter snow, but predicting the future is not an exact science.

Forecasts like these are generated using powerful climate models that simulate how air, oceans, land and ice interact. These virtual laboratories allow scientists to run experiments, increasing the temperature bit by bit to see when each element might tip.

Climate scientist Timothy Lenton first identified climate tipping points in 2008. In 2022, he and his team revisited temperature collapse ranges, integrating over a decade of additional data and more sophisticated computer models.

Their nine core tipping elements include large-scale components of Earth’s climate, such as ice sheets, rain forests and ocean currents. They also simulated thresholds for smaller tipping elements that pack a large punch, including die-offs of coral reefs and widespread thawing of permafrost.

Some tipping elements, such as the East Antarctic ice sheet, aren’t in immediate danger. The ice sheet’s stability is due to its massive size – nearly six times that of the Greenland ice sheet – making it much harder to push out of equilibrium. Model results vary, but they generally place its tipping threshold between 5 C (9 F) and 10 C (18 F) of warming.

Other elements, however, are closer to the edge.

Alarm bells sounding in forests and oceans

In the Amazon, self-perpetuating feedback loops threaten the stability of the Earth’s largest rain forest, an ecosystem that influences global climate. As temperatures rise, drought and wildfire activity increase, killing trees and releasing more carbon into the atmosphere, which in turn makes the forest hotter and drier still.

By 2050, scientists warn, nearly half of the Amazon rain forest could face multiple stressors. That pressure may trigger a tipping point with mass tree die-offs. The once-damp rainforest canopy could shift to a dry savanna for at least several centuries.

Rising temperatures also threaten biodiversity underwater.

The second Global Tipping Points Report, released Oct. 12, 2025, by a team of 160 scientists including Lenton, suggests tropical reefs may have passed a tipping point that will wipe out all but isolated patches.

Corals rely on algae called zooxanthellae to thrive. Under heat stress, the algae leave their coral homes, draining reefs of nutrition and color. These mass bleaching events can kill corals, stripping the ecosystem of vital biodiversity that millions of people rely on for food and tourism.

Low-latitude reefs have the highest risk of tipping, with the upper threshold at just 1.5 C, the report found. Above this amount of warming, there is a 99% chance that these coral reefs tip past their breaking point.

Similar alarms are ringing for ocean currents, where freshwater ice melt is slowing down a major marine highway that circulates heat, known as the Atlantic Meridional Overturning Circulation, or AMOC.

The AMOC carries warm water northward from the tropics. In the North Atlantic, as sea ice forms, the surface gets colder and saltier, and this dense water sinks. The sinking action drives the return flow of cold, salty water southward, completing the circulation’s loop. But melting land ice from Greenland threatens the density-driven motor of this ocean conveyor belt by dilution: Fresher water doesn’t sink as easily.

A weaker current could create a feedback loop, slowing the circulation further and leading to a shutdown within a century once it begins, according to one estimate. Like a domino, the climate changes that would accompany an AMOC collapse could worsen drought in the Amazon and accelerate ice loss in the Antarctic.

There is still room for hope

Not all scientists agree that an AMOC collapse is close. For the Amazon rain forest and the North Atlantic, some cite a lack of evidence to declare the forest is collapsing or currents are weakening.

In the Amazon, researchers have questioned whether modeled vegetation data that underpins tipping point concerns is accurate. In the North Atlantic, there are similar concerns about data showing a long-term trend.

Climate models that predict collapses are also less accurate when forecasting interactions between multiple tipping points. Some interactions can push systems out of balance, while others pull an ecosystem closer to equilibrium.

Other changes driven by rising global temperatures, like melting permafrost, likely don’t meet the criteria for tipping points because they aren’t self-sustaining. Permafrost could refreeze if temperatures drop again.

Risks are too high to ignore

Despite the uncertainty, tipping points are too risky to ignore. Rising temperatures put people and economies around the world at greater risk of dangerous conditions.

But there is still room for preventive actions – every fraction of a degree in warming that humans prevent reduces the risk of runaway climate conditions. For example, a full reversal of coral bleaching may no longer be possible, but reducing emissions and pollution can allow reefs that still support life to survive.

Tipping points highlight the stakes, but they also underscore the climate choices humanity can still make to stop the damage.

Alexandra A Phillips does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Climate tipping points sound scary, especially for ice sheets and oceans – here’s why there’s still room for optimism – https://theconversation.com/climate-tipping-points-sound-scary-especially-for-ice-sheets-and-oceans-heres-why-theres-still-room-for-optimism-265183