Nature Climate Change, Published online: 19 August 2026; doi:10.1038/s41558-026-02727-5

Extreme heat events are increasing, and urban adaptation is urgently needed for humans and non-humans to function safely under heat. Here we present a thermal justice framework and highlight how its use facilitates equitable adaptation and minimizes heat-risk displacement.

Nature Climate Change, Published online: 19 August 2026; doi:10.1038/s41558-026-02728-4

Informal adaptation can augment or replace formal adaptation with flexible and responsive actions, yet it can also reproduce and intensify existing injustices. We propose justice-oriented co-creation between informal and formal actions as a pathway for effective heat adaptation.

Nature Climate Change, Published online: 19 August 2026; doi:10.1038/s41558-026-02717-7

Adaptation to climate risks requires integrating knowledge across IPCC working groups. This study presents a climate impact taxonomy that connects climatic impact-drivers from Working Group I to representative key risks from Working Group II and provides more direct guidance for risk assessment and adaptation strategies.

A federal appeals court just made it harder for online services, big and small, to get lawsuits over user speech dismissed early. In California v. Meta, a Ninth Circuit three-judge panel held that the lower court’s denial of Section 230 immunity to Meta is not immediately appealable. The misguided ruling has the potential to have widespread impact and to threaten the free speech of all internet users.

The ruling is bigger than a loss for Meta, which has the resources to defend itself against these lawsuits. The court’s ruling signals that all online services (and internet users) that host others’ speech—including those without Meta’s deep pockets—must bear the burden and expense of fighting lawsuits that Section 230 ultimately precludes. This will have real consequences, incentivizing online services to take down users’ speech in response to spurious legal threats, filter speech preemptively, or simply stop offering a place for people to speak online. So even though some may think that Meta is not a sympathetic company, the ruling should raise concerns for anyone who cares about an open and free internet.

Immunities from Suit Advance Important Public Interests

A little procedural background is necessary to understand the implications of the Ninth Circuit’s ruling.

Meta had moved to dismiss a group of social media addiction cases brought by state attorneys general, school districts, and local governments. Meta argued that Section 230(c)(1) immunity applies because the plaintiffs’ claims, framed as seeking to hold Meta liable for allegedly harmful platform features, really seek to hold the company liable for publishing decisions related to third-party content. Section 230 is one of the most important laws supporting online free speech, because its protections for online services enable them to distribute users’ speech at an unprecedented scale.

The district court ruled that Section 230 does not apply to certain features (and does apply to others) and so denied the motion to dismiss on the claims related to those features. Meta immediately appealed invoking appellate jurisdiction under 28 U.S.C. § 1291, but the question before the Ninth Circuit was whether the appeal was legally appropriate.

Under Section 1291, U.S. circuit courts generally only have jurisdiction to hear appeals of “final decisions” from the district courts. Final decisions are trial court orders ending a case, or come after a trial on the merits. Section 230 appellate cases often arise from a district court’s grant of a defendant platform’s motion to dismiss the plaintiff’s case based on Section 230. Typically, a district court’s denial of a defendant’s motion to dismiss is not a final order—it simply means that the case may continue to discovery and summary judgment or trial, after which time an appeal would be appropriate.

However, federal law allows for “interlocutory appeals,” which are appeals of orders that do not end a case but nonetheless are allowed because they involve important legal issues. For example, there is an exception to Section 1291 called the “collateral order doctrine”—at issue in this case—allowing for immediate appeal if, as the Ninth Circuit explained here, “holding a trial would imperil a substantial public interest.”

Inherent in the collateral order doctrine is the consideration of whether an immunity like Section 230 provides mere “immunity from liability” or a more robust “immunity from suit.”

An immunity from liability does not require an immediate appeal and so demands that Section 1291’s final order rule be followed. That’s because waiting until the end of a case before an appellate court can consider the trial court’s denial of immunity does not prejudice the defendant. The appellate court may overturn the trial court and grant the immunity, and thus the defendant’s right to be immune from liability would be vindicated on appeal.

Immunity from suit is different. It means that the public interest demands that a defendant be able to get out of a case as early as possible and avoid having to litigate the case to the end. The U.S. Supreme Court has held, for example, that qualified immunity is such an immunity, and that a district court’s denial of qualified immunity for a government official is immediately appealable under Section 1291, notwithstanding the lack of a final order. The idea is that the public interest is served when government officials are free to act without fear of consequences when established rights are not implicated, and so determining as soon as possible whether their acts are immune serves that public interest.

Here, the Ninth Circuit held that the district court’s denial of Section 230 immunity for Meta was not immediately appealable under Section 1291’s collateral order doctrine because the immunity is not from suit, but rather from ultimate liability. The panel’s absurd result contravenes the text of Section 230, the statute’s policy goals, and the court’s own prior rulings.

Treating Section 230 as an Immunity from Suit Protects Online Free Speech

Meta rightly argued that Section 230(e)(3) plainly states, “No cause of action may be brought and no liability may be imposed under any State or local law that is inconsistent with this section.” The panel dismissed this argument, stating that this language likely amounts to “redundancy” reflecting only immunity from liability. The court failed to side with the more reasonable position that statutory language should generally not be interpreted as superfluous.

Meta also reminded the panel that the Ninth Circuit has many times over the past two decades framed Section 230 as both an immunity from liability and an immunity from suit. The panel also dismissed this argument, stating, “It is true that we have used the phrase ‘immunity’ somewhat loosely in our section 230 jurisprudence.”

But “loosely” is a gross mischaracterization—the panel did not discuss a seminal prior ruling, Fair Housing Council of San Fernando Valley v. Roommates.com (2008), in which the entire Ninth Circuit, not just a three-judge panel, explicitly ruled that Section 230 is also an immunity from suit. That court rightly explained that Section 230 “must be interpreted to protect websites not merely from ultimate liability, but from having to fight costly and protracted legal battles.”

Why is it important that social media platforms and other internet intermediaries (and their users) have immunity from suit for engaging in publishing activities related to third-party content—and thus a right to immediately appeal when Section 230 immunity is denied?

The Ninth Circuit panel here, using their own words, failed to “evaluate the interests that would be lost through rigorous application of a final judgment requirement” and failed to consider the “substantial public interest” served by treating Section 230 as an immunity from suit.

Section 230 immunity, contrary to what some argue, is not a gift to Big Tech—it applies to all internet intermediaries, big and small, from the large social media companies to smaller entities like community message boards and local ISPs. It even protects internet users who forward others’ emails or host comments on their blogs. In turn, the law supports the free speech of all internet users.

While it is helpful when an internet intermediary can ultimately benefit from Section 230 immunity, if a trial court’s early denial is not immediately appealable, that means the intermediary must bear the extended logistical and financial burdens of defending itself. Under the Ninth Circuit’s logic, anyone hosting others’ speech online would have to endure the pain and expense of discovery, summary judgment, or trial, before they ultimately can be protected by Section 230.

Congress crafted Section 230 to give internet intermediaries legal breathing room, so that they will be incentivized to facilitate online communication and commerce, allowing the rest of us to go online with minimal barriers to entry, without needing to have loads of money or to know how to code. Congress acknowledged in Section 230 itself, “Increasingly Americans are relying on interactive media for a variety of political, educational, cultural, and entertainment services.”

Yet if platforms, especially smaller platforms, know that they will have to defend themselves for years in court before they can ultimately benefit from Section 230 immunity, this alone will create a perverse incentive, as we have explained, to censor user speech, in order to reduce the platforms’ legal exposure. And this incentive is only exacerbated at scale, where the sheer volume of user-generated content hosted by modern platforms makes legal risk astronomical.

Unfortunately, this opinion seems to be part of larger trend reflecting the Ninth Circuit’s increasing disdain for Section 230, and apparently for free speech rights more broadly. The court similarly held last year in Gopher Media v. Melone (2025)—overruling itself—that a trial court’s denial of a defendant’s anti-SLAPP motion also is not immediately appealable under the collateral order doctrine. This is despite the fact that, similar to Section 230, California’s anti-SLAPP law is intended to allow defendants to get harassing lawsuits meant to silence them dismissed early, lest they be chilled from engaging in lawful speech on public issues due to the risk of being mired in litigation, even if they ultimately win a delayed appeal.

Age verification (laws and regulations requiring platforms and websites to assure or estimate that a user seeking to use an online service is of a certain age) is everywhere. At the time of writing, about half the states in the US have some internet age verification law in place, and dangerous proposals, from the KIDS Act to the Kids Online Safety Act (KOSA), have been advancing at the federal level. European Union member states are moving toward having age verification in a centralized app by the end of this year. Australia famously now has one extremely broad restriction in place.

Most age verification laws tend to fail at their primary goal of barring kids from being online or from entering only specially designated zones, not to mention they pose a significant threat to everyone’s privacy. Some proponents of these age-based internet restrictions think they've found the silver bullet: Zero-Knowledge Proofs (ZKPs). We wrote about ZKP’s when they were first rolled out in the age verification context last year. However, more recent examples show our concerns weren’t just conjecture; ZKP-focused AV schemes are gameable, hackable, and not the cure-all some may claim.

ZKPs in Age Verification Would Only Centralize Power and Create More Harms

Before we jump into how these systems work, it must be said: creating a single point of failure for internet access contradicts the very idea of a free and open internet. 

The mechanisms underlying ZKPs pose an existential threat to everyone’s digital rights, not just kids. The idea behind ZKPs is that you are issued a “token” that vouches for your age every time you log in, creating a constant link back to the entity that verified you. The issuer of the tokens these AV schemes rely on could track every time that credential is used, creating a dangerous trail of metadata on any user they wanted to target. The issuer itself could be pressured by authoritarian governments to remove a user's access to a service, essentially removing that person’s access to the internet entirely. Without oversight of who has authority to implement and operate these systems, this approach centralizes critical internet infrastructure in the hands of very few actors. 

How ZKPs Work

ZKPs are mathematically impressive cryptographic tools–but they weren’t developed with age verification in mind. Essentially, they let a computer quickly attest to the validity of a given question asked by another computer without divulging any underlying private data. 

Computer A (such as the device operated by a person trying to access a website) is able to prove to Computer B (such as the server for the website that person is trying to access) that something is true without actually sharing the contents of that information itself. Computer A locks in a "commitment" to the information it needs to convey. Computer B, which wants to verify that information, generates mathematical "challenges" that can be answered correctly only if the information is true. Traditionally, this happens over many different “challenges" until there is no room for doubt that Computer A’s "commitment" is true.

Since that kind of lengthy back-and-forth process would drastically slow things down over the internet, there's a shortened version of this exchange that's "non-interactive.” In that case, the ZKP is verified instantly. The answer itself is hashed (mathematically converted into a fixed, shorter string of characters), and the resulting hash is theoretically unpredictable and tamper-resistant. This shortened version of the ZKP exchange is called "zk-SNARK," which is the current preferred method for age verification.

In the ideal scenario, this means that ZKP’s are able to attest to a person’s status as an adult or a child without actually giving away any other private information about that person. In other words, only one entity would collect that private information, typically on the user’s device, instead of every website or app that needs the user’s age attested to. Unfortunately, recent real-world testing of these systems prove that ZKP’s aren’t the silver bullet that proponents of AV laws were hoping for.

EU’s AV Rollout Reveals How Broken It Is

By the end of 2026, the 27 states within the European Union are expected to have infrastructure in place to do age verification within a "mini-wallet" app that will live inside the EUDI (European Digital Identity) Wallet. This is being met with plenty of warranted criticism from digital rights experts. The "mini-wallet" version is already being rolled out, with promises that the ZKPs are in working order. But recent insights show that the ZKP features aren't yet turned on except for the closed demo/prototype build (not the version of the app people are using “out of the box”), which the vast majority of everyday users can’t access. 

Worse still, a security researcher found they could bypass the app's system using a quickly built Chrome extension that tricked the app into repeatedly accepting the same "over-18" token. It did so without ever asking for fresh verification. 

Over 400 security researchers signed an open letter stating that age assurance checkpoints, even if implemented with privacy in mind, would cause more harm than good. A primary focus of their concern, which we share, is the fact that a centralized identity verification system creates a single point of failure that is extremely vulnerable to both cyberattack and authoritarian overreach.

Once the "mini-wallet" version of this is fully integrated into the EUDI Wallet, it will replicate these same failures, perhaps more, but at a much larger scale. At that point, the failures will involve many more pieces of sensitive information that the EUDI Wallet contains: passports, driver's licenses, travel information, financial information, to name a few.

ZKP’s Aren’t The Magic Bullet

As we’ve said time and time again, no method of online age verification is privacy-protective, fully accurate, and capable of guaranteeing universal coverage without introducing severe security risks. 

Lawmakers concerned about the privacy failures of age verification mandates must understand that ZKPs are not a magic bullet. They do not solve the age verification paradox; they simply push the burden of trust down the road, relying on technical ignorance and magical thinking about how the internet actually functions.  

Mandatory online age verification of any kind is a dangerously flawed idea. Tell your lawmakers we said so.

When an artificial intelligence image generator produces a portrait, whose work went into it? The question sits at the center of lawsuits, licensing deals, and proposed regulations worldwide. Artists want credit. Companies want clarity. Policymakers want a way to assign responsibility.

New work from a team of researchers at MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) suggests that for models trained on large datasets, the question may often have no answer. It's not that the tools for finding it are inadequate. The connection itself has disappeared.

The scientists identified a phenomenon they call attribution decay, where the more data a generative model is trained on, the less any individual training example matters to any particular output. It feels counterintuitive, but at sufficiently large scales, they find, you can often remove any single image from the training data, or every image by a given artist, or every photograph of a given person, and the generated sample doesn't change.

And if removing something changes nothing, the researchers argue, it can't be said to be responsible for anything. 

"If you take away a piece of data and the output of the model doesn't change, then that piece of data didn't affect the output," says Zheng Dai SM ’21, PhD ’24, former MIT CSAIL researcher and lead author on the work. "So it doesn't make much sense to attribute the output to that piece of data. And if you then do this one at a time for every other piece of data and find that the output doesn’t change for any of them either, then it doesn't make much sense to attribute the output to any one of them."

"All previous methods were approximate," says MIT Professor David Gifford, who is an MIT CSAIL principal investigator. "They really could not absolutely show that deleting individual things did not change the output. This paper introduces the first method that is absolute. You're actually deleting the inputs and deleting all influences of the inputs. This is the first exact method for doing large-scale deletion efficiently and showing that the results don't change."

Dai and Gifford's project is described in an open-access paper published today in Nature Communications.

The retraining problem

Testing this idea directly meant answering a what-if question. What would this model have produced if it had never seen this particular image? Answering it honestly means retraining the model from scratch without that image, then doing it again for the next image, and the next. With millions of training examples, the math quickly becomes prohibitive, which is why prior work in the attribution field has relied on approximations that estimate a training example's influence, rather than actually removing it.

Their workaround is an architecture they built themselves, called a "diffusion ensemble." Instead of one monolithic model, it's made up of many smaller components, each trained on a different slice of the data. Want to know what the model would do without a particular image? Just switch off the parts that saw it. No retraining, no approximation. What's left is a true counterfactual model, not an estimate of one.

Of course, a clever architecture only matters if it still works as a generator. So the team put the ensembles head to head with 24 conventional diffusion models trained on the exact same data. The images came out looking about as good by standard measures. 

One nice surprise in the numbers: The more training data, the better the ensembles held up against their single-model counterparts, a hint that they may actually be more data-efficient.

"When you have low amounts of data, they do very poorly," says Dai. "But if you have more data, it actually scales better compared to the vanilla diffusion model." 

Exploring a counterfactual universe

With ablation working, the researchers could finally ask their question at scale. Take one generated image, then imagine every alternate version of it, each produced by removing a different piece of the training data. The team calls this the image's counterfactual universe. The distance between the original and its most different alternate, the counterfactual radius, captures the most that any single piece of training data could have mattered.

They trained 24 ensembles on datasets from 256 images to more than 160,000, pulled from seven public collections including CIFAR-10, CelebA, MetFaces, and ArtBench. The pattern was consistent: The bigger the training set, the smaller the radius, shrinking along an inverse power law. It held whether differences were measured pixel by pixel or by semantic meaning, with statistical significance both ways.

The team also stress-tested their own result. Maybe ablation itself was the culprit? They redid it the brute-force way at small scale, training 1,282 separate models, and the decay showed up anyway. Maybe bigger datasets just make each removal proportionally smaller? They pinned the removed fraction in place, and it persisted. Fixed epochs, text-prompted models, class-conditioned models, four similarity metrics — the finding survived everything.

The privacy paradox

The implications run in a direction that surprised the researchers themselves.

Gifford sees the finding as bearing directly on the legal question of whether model outputs are derivative works. 

"One way to think about this is that these models are creative. They are not simply copying what they are fed, but creating brand new outputs. If those outputs have nothing to do with any individual piece of training data, that raises questions about fair use, about whether the outputs are themselves copyrightable as novel works, and about how authors get compensated when what comes out of a model isn't attributable to anything on the internet." 

Gifford also notes that the work shows how to produce outputs that are guaranteed to be unattributable, a capability he frames as an obligation for the industry, rather than a loophole. 

"In order for these companies to claim their outputs aren't derivative of the internet in a copyright-infringing way, they need to revise their models to take advantage of the advances in this work, so they can show they're not creating derivatives of individual people or items."

The work looks at diffusion models, now dominant in generating audiovisual media and prevalent in scientific applications including protein structure modeling and therapeutic discovery. Whether the same decay holds for the large language models at the center of the highest-profile copyright litigation is still an open question.

"If attribution worked, it would reliably tell us whether similarities between a model's output and a copyright-protected work are due to copying or coincidence," says James Grimmelmann, a law professor at Cornell Law School and Cornell Tech. "But this paper provides reason to think that attribution will fail for interesting models. Instead, technologists and courts will need to resort to other methods for assessing copying."

Dai and Gifford's work was supported by Schmidt Futures. 

MIT Principal Research Scientist and Haystack Observatory Assistant Director Emerita Anthea J. Coster was awarded the prestigious Appleton Prize at the International Union of Radio Science (URSI) General Assembly and Science Symposium in Krakow, Poland, on Aug. 16. 

The Appleton Prize recognizes career achievements and outstanding contributions to studies in ionospheric physics. Appleton awardees are regarded as pillars of the URSI atmospheric science community; the citation for Coster, an URSI Fellow, is for “pioneering research in GNSS [Global Navigation Satellite System] science, developing techniques to provide global-scale view of storm responses in the ionosphere, operationalizing novel algorithms, and providing novel ionospheric products to the community.” 

The Appleton Prize honors Sir Edward Victor Appleton, a Nobel Prize–winning physicist and former president of URSI (1934–52) who proved the existence of the ionosphere.

Coster joined MIT in 1984, originally at MIT Lincoln Laboratory, where she worked on satellite tracking applications within the Space Surveillance Complex situated at MIT Haystack Observatory. While at Lincoln, she was introduced to the Global Positioning System (GPS), the first GNSS; her GPS research at Lincoln eventually led to an appointment in Haystack’s geospace and atmospheric science research group. She continued and expanded her Lincoln-based GNSS research, focusing on ionospheric and atmospheric applications. At Haystack, Coster started as a research scientist, becoming an MIT principal research scientist in 2012; she also served as assistant director for the observatory from 2015 until 2024. 

Her career research focus spans the physics of the ionosphere, magnetosphere, and thermosphere, covering space weather and storm-time effects and coupling of these atmospheric regions, with particular expertise on GNSS positioning and measurement accuracy. Coster’s breakthrough contributions in GNSS applications to frontier geospace research span many areas, including ionosphere-magnetosphere coupling and mid-latitude ionospheric dynamics. A selected number of her accomplishments include the first real-time GNSS ionospheric monitoring system, as well as pioneering work in monitoring tropospheric water vapor with GNSS signals. She also was responsible for the first GNSS observations of storm-enhanced density, a bright and important feature that can span the heavily populated continental United States, with significant impacts to the Federal Aviation Administration Wide Area Augmentation System, which supplements traditional GPS navigation systems.

MIT Haystack Observatory director Phil Erickson says, "Dr. Coster's award from the International Radio Science Union is most well-deserved, and reflects her substantial international impact on the field of geospace remote sensing. Coster's pioneering application of GNSS signals to global and precise maps of total ionospheric electron density has produced a rich and insightful scientific output that anchors and greatly complements the multi-messenger, sensor fusion techniques at the forefront of the research field in near-Earth space weather dynamics. These areas are of critical importance to our increasingly spacefaring civilization."

Coster’s career also encompasses a lifetime of professional service contributions to the U.S. and international geophysical sciences community, including many leadership positions with the U.S. chapter of the Union of Radio Science, the Institute of Navigation, and the American Geophysical Union. She has served as co-chair of NASA's Living with a Star Program Analysis Group and is a current member of the U.S. National Academies of Science, Medicine, and Engineering Space Weather Roundtable. 

She is an author or co-author on more than 200 peer-reviewed publications, and is the principal investigator of numerous federal scientific grants from NASA, the National Science Foundation, the Office of Naval Research, and the Air Force Office of Scientific Research. Prominent results of Coster’s work are heavily used, including scientifically rich GNSS total electron content (TEC) and scintillation data products available to the research community through NSF's CEDAR Madrigal database and the Millstone Hill Geospace Facility. 

Coster has also made a number of notable contributions to science outreach, such as deploying radio instrumentation with MIT graduate students in Brazil and Peru, presenting outreach talks to high school and middle school students in Rwanda and Zambia, and installing GNSS receivers in Inuit villages and along the remote Steese Highway in Alaska. For many years, she has taught U.N.-sponsored GNSS workshops aimed at workforce education and career advancement in disadvantaged countries.

Originally from Texas, Coster attended the University of Texas at Austin as an undergraduate and earned her master's and doctorate degrees at Rice University in Houston, where she was involved with ionospheric experiments at the Arecibo Observatory in Puerto Rico. She moved to Massachusetts in 1984 to join MIT Lincoln Laboratory. 

"Anthea Coster has made seminal contributions to the state of the profession, enabling the international science community to conduct ionospheric research at spatio-temporal scales that were previously unachievable," says Larisa Goncharenko, assistant director and head of the atmospheric and geospace group at Haystack. "Her pioneering work on introducing and relating GPS measurements to fundamental research has led the community to employ GNSS as an information-rich sensor for ionospheric remote sensing and space weather monitoring. Her effort enabled countless discoveries in the near-Earth space environment that has become increasingly important for human activities in space. I am truly in awe of Anthea's pioneering accomplishments, and incredibly proud of her receiving the Appleton Prize."

With this award, MIT Haystack Observatory is now home to three URSI prize recipients. Former director and research scientist John Evans received the Appleton Prize in 1975 with a citation for "ionospheric physics, including application of the incoherent scatter technique," and research scientist Alan Rogers received the 2008 John Howard Dellinger Gold Medal for outstanding contributions to radio astronomy. 

I have been thinking a lot about AI and integrity. Part of that is contextual integrity. I recently found two papers on the topic.

“CIMemories: A Compositional Benchmark for Contextual Integrity of Persistent Memory in LLMs“:

Abstract: Large Language Models (LLMs) increasingly use persistent memory from past interactions to enhance personalization and task performance. However, this memory introduces critical risks when sensitive information is revealed in inappropriate contexts. We present CIMemories, a benchmark for evaluating whether LLMs appropriately control information flow from memory based on task context. CIMemories uses synthetic user profiles with over 100 attributes per user, paired with diverse task contexts in which each attribute may be essential for some tasks but inappropriate for others. Our evaluation reveals that frontier models exhibit up to 69% attribute-level violations (leaking information inappropriately), with lower violation rates often coming at the cost of task utility. Violations accumulate across both tasks and runs: as usage increases from 1 to 40 tasks, GPT-5’s violations rise from 0.1% to 9.6%, reaching 25.1% when the same prompt is executed 5 times, revealing arbitrary and unstable behavior in which models leak different attributes for identical prompts. Privacy-conscious prompting does not solve this—models overgeneralize, sharing everything or nothing rather than making nuanced, context-dependent decisions. These findings reveal fundamental limitations that require contextually aware reasoning capabilities, not just better prompting or scaling...

The president’s favorite indicator of economic health will have to reckon with the woes of a warming planet.

A bipartisan push to stymie partisan discrimination in disaster assistance could be complicated by election-year politicking.

The progressive megadonor is back to talking about climate policy after an unsuccessful run for governor.

Staff must deal with patients too sweaty to receive IV drips, medication at risk of degrading in high temperatures and colleagues collapsing with heat fatigue.

The summertime ideal — lazy days, warm nights and escape from classes or parents or work or rules — seems dead this year.

The EU and regional authorities are helping cheese producers as dairy herds suffer in heat waves that are becoming the norm.

Tornadoes, heavy rains and flash flooding brought serious damage to communities from Illinois to western Pennsylvania in recent days.

The passing storm's strong winds took down trees, utility poles and transmission towers. The Big Island's power transmission system suffered "extensive damage," the Hawaiian Electric utility said.

You’ve heard of gig workers, freelancers, and temporary employees. But do you know about marginal workers? 

Accounting for about one in six U.S. jobs, it’s a huge category of people, who are going nowhere fast in the workplace — and don’t really have much say about that. 

“Marginal workers are employees who have no career prospects at their organizations,” says MIT Professor Emeritus Paul Osterman, author of a new book on the subject. “They are employees of the organization for whom they work, but the organization does not intend to keep them, and these workers are much less attached to any career ladder.” 

As such, marginal workers are part of a larger trend in U.S. employment. According to Osterman’s analysis, 35 percent of U.S. workers are either marginal employees, freelancers, contractors, or gig employees finding work on online platforms like ridesharing services. 

“That’s a big number,” says Osterman, who is the Nanyang Technological University Professor Emeritus at the MIT Sloan School of Management, where he is also a professor emeritus of work and organization studies. “That’s over 55 million people in the American work force.”

Osterman scrutinizes this employment landscape in his new book, “Disposable Workers: The Transformation of Employment,” published this month by Harvard University Press. In it, he examines the different categories of “disposable” workers in the U.S., while making the case that they are all part of a still-growing movement by firms to control labor costs, leaving many workers in precarious positions. 

“I wanted to present a unified way of thinking about these trends,” Osterman says.

Cutting costs

Osterman is a longtime labor economist and author of several previous books, whose work has often focused on job quality and labor-market fairness. 

He was motivated to write “Disposable Workers,” he says, because of how significantly marginal workers have been overlooked. Indeed, the category and term “marginal workers” comes from Osterman. 

In researching the book, Osterman conducted an original survey of over 6,000 workers, which helped shed light on the concept of marginal workers. They can fit a range of professions: staff attorneys at a law firm, adjunct faculty, and many kinds of part-time employees with few opportunities for advancement.

Overall, Osterman finds that about 17 percent of U.S. employees are marginal workers. Roughly 12 percent are contract workers, who are often employed by staffing agencies but then assigned to work at varying locations. Another 5 percent are organizational freelancers, working for firms without being part of the permanent staff. This includes gig workers, who account for a little more than 1 percent of the workforce and draw work from online platforms such as rideshare services. (Beyond this, there are also freelancers who work individually for multiple clients.) 

The common denominator among these categories is that each has evolved as a result of firms trying to cut back on labor expenses while trying to gain flexibility and more managerial discretion. The result is fewer workers with promotion prospects, health benefits, and employment stability.

“I’m putting the discussion of freelancing, contracting, and marginal workers into a coherent story that shows they’re all of a piece, they’re all part of the same thing, in terms of how employers are thinking about it,” Osterman says. 

Long term versus short term

How employers think about it, to be clear, revolves primarily around employee costs. By deploying employees in a variety of marginal, freelance, and contract roles, and making some of those positions part-time, businesses have constructed a system in which fewer employees have rising wages or additional benefits, and the portion of firm revenues plowed back into paying for workers can shrink. 

“This is not a book that argues that there’s dishonesty or that anyone’s evil, but at the end of the day, firms only care about one thing, which is to maximize profits, period, end of story,” Osterman says. 

He adds: “I’m very careful to say it’s a good thing that firms create jobs and develop new products — all good.” Still, he notes, for people who prioritize the plight of workers, the expansion of a disposable work force is a significant issue. 

To be sure, many scholars have found that short-term labor cost reductions can be counterproductive. Many firms have appeared to benefit from having a more stable, committed, motivated work force, which seems to result in greater productivity. What Osterman finds is that firms are likely aware of this tradeoff, and still willing to have a less-committed, less-expensive staff.

“The firms are obviously making a decision that the costs outweigh the value of commitment,” Osterman says. He also notes that the evidence on the matter is not entirely clear-cut. 

“There’s a debate on both sides of that question,” Osterman says. “I can’t prove that firms are being smart or stupid. But I can just tell you what they’re doing. And what they’re doing is making the decision that they benefit from having a large fraction of their workforce be disposable.”

Making the issue matter

“Disposable Workers” has drawn praise from other scholars. David Weil, a professor in the Heller School for Social Policy and Management and the Department of Economics at Brandeis University, has called it “a carefully researched and engaging book documenting the degradation of employment in recent decades.” 

Indeed, as “Disposable Workers” makes clear, the workplace has been challenging for many employees for a while now. Add artificial intelligence into this setting, and the outlook would seem to get even tougher for employees. Indeed, Osterman thinks AI could increase the use of disposable workers, if only for indirect reasons.

“I think this trend is going to be exacerbated by AI, because AI introduces a lot of uncertainty to firms about what their staffing needs are, and if firms are uncertain, they’re going to want disposable workers,” Osterman says. However, he emphasizes, “Disposable Workers” is not a book about AI. 

In any case, if jobs in the U.S. have become more precarious, what can be done to reverse that trend? One answer might be more expansive worker protections stemming from union negotiations. But these days, Osterman notes, only about 6 percent of U.S. employees are in a union, so that will only go so far.

Still, Osterman points out that nonunion organizations can help the situations of workers, such as the advocacy groups that lobbied for a $15/hour minimum wage in many places several years ago. 

Then too, he observes, sometimes customer pressure gets firms, even large multinationals, to improve working conditions, either for the firm’s own workers, or along its supply chain. 

“There is no magic solution,” Osterman says. “There is a set of tools.”

A key reason he wrote “Disposable Workers” is to bring attention to the topic in the first place, and the full extent to which the U.S. now has a workforce without much security or prospects of upward mobility. Without recognition of that point, no effort to change things will unfold, Osterman believes.

“The bigger policy point is: This issue has to become salient,” Osterman says. “If it does, then public and political pressure will come to bear on firms. If it doesn’t, then it won’t.” 

Shannon Knight attributes her interest in neuroscience to an experience she had in high school. She and her sister attended a medical day for students at the nearby University of Illinois Chicago. As they were on their way out of the event, they walked past a room with a person holding a brain.

“We stopped and backpedaled into the room, and I was so fascinated,” says Knight. “I was able to hold the brain of a patient who had passed away of Alzheimer’s. The brain holds so much emotion, decision-making — everything. I realized that this man’s entire memory was in my hands, and something clicked for me. I decided that I really wanted to learn much more about this organ.”

Now in her sixth year of doctoral studies at MIT’s McGovern Institute for Brain Research, Knight is working on developing a novel gene therapy for childhood-onset epilepsy, specifically SYNGAP1 haploinsufficiency. This rare genetic disorder is caused by a mutation in the SYNGAP1 gene, rendering one of the two copies of the gene nonfunctional. 

SYNGAP1 is important for brain development and neuronal communication, and the disorder leads to seizures in children starting as young as 4 months old. Other symptoms include intellectual disabilities, challenges with eating and sleeping, and difficulties with movement.

While there are currently methods to address the symptoms of the disorder, such as anti-seizure medications and dietary restrictions, as the child ages, the seizures often become resistant to medications. Knight is working to develop a therapeutic using CRISPR, a biotechnology tool used to edit genes. This therapeutic aims to address the root cause of this medication resistance by focusing on the gene itself.

“The idea of leading science with empathy is something that I feel very deeply,” she says. “I hope my efforts in the lab work toward the benefit of the people affected, rather than just for the benefit of my own science.”

Researching gene therapies

Knight’s interest in the brain flourished as a neuroscience major at Bowdoin College, working with Professor Hadley Horch. While she had originally planned to be pre-med, Knight ultimately decided that it wasn’t the best fit. She enjoyed the research she did as part of her honors thesis, exploring the regeneration of neurons in the auditory system of crickets, and decided that she wanted to pursue more research in molecular neuroscience, as well as genetics.

After graduating, Knight worked at the Perrimon Lab at Harvard University, where she first learned about CRISPR, applying it in a fruit fly model. She worked for two years in the lab, co-authoring a few papers and applying to graduate schools. 

She ultimately landed in the lab of MIT Professor Guoping Feng, studying the potential of utilizing CRISPR to develop a gene therapy treatment for Phelan-McDermid Syndrome, a rare genetic disorder caused by a deletion or mutation on the 22nd chromosome.

“Many of our graduate students are passionate about making a positive impact to society through cutting-edge research, and Shannon is a perfect example,” says Feng, the James W. and Patricia T. Poitras Professor and associate director at the McGovern Institute. “She is developing gene therapy technologies that have the potential to help many kids with devastating neurodevelopmental disorders.”

Building off of the gene therapy research around Phelan-McDermid syndrome, which is now in clinical trials in patients, Knight is now in the early phases of testing gene therapy for SYNGAP1 disorder. The goal is to go through the same process for the SYNGAP1 gene therapy as for the Phelan-McDermid gene therapy — eventually obtaining U.S. Food and Drug Administration approval and beginning clinical trials. 

The testing of the gene therapy on mice with a version of SYNGAP1 disorder has shown promising preliminary results in alleviating seizures and all of the behavioral phenotypes. This work is being accelerated by the Rare Brain Disorders Nexus, an MIT initiative that launched in the fall of 2025.

“Something I think about a lot is the idea of who ‘deserves’ the attention of a gene therapy. I feel that, regardless of how rare a genetic disorder might be, it still deserves care,” says Knight. “SYNGAP1 disorder is extremely rare, only impacting one to four out of every 10,000 children. I am very fortunate to be at an institution like MIT that has so many labs and brilliant researchers working on diseases that impact large portions of society, and it was really important to me to spend my PhD years helping a small, often unseen population. Although I don’t actually have a relationship with someone who has SYNGAP1 disorder, I know so many people who feel invisible in systems, and it is really important to me to be able to focus on people who feel unseen and give them hope.”

Inspiring others in the lab

In addition to her passion for neuroscience and genetic research, Knight has also developed a love of teaching. She has been a teaching assistant for 9.12 (Experimental Molecular Neurobiology), leading the lab portion of the course. She has enjoyed working closely with small classes of students, introducing them to the fundamentals of neuroscience lab research.

“We walked through the process of looking at a specific protein in neurons, and talked about how you can go from cell culture all the way up to a mouse brain — and all the steps in between. It was so important to me to be able to teach the students and help them to consider all of the different types of experiments they could do,” she says. “I’ve talked to many of the students since then, and many said it was one of their favorite classes.”

Knight received the Goodwin Medal in 2025 in recognition of her commitment to excellent teaching.

“Shannon has a rare combination of scientific excellence, teaching talent, and compassion,” says Laura Frawley, senior lecturer and teaching and curriculum development specialist in the Department of Brain and Cognitive Sciences. “Students trust her because she is approachable and invested in their success, and they learn from her because she has an exceptional ability to make complex ideas accessible and engaging. Her influence extends far beyond the laboratory skills she teaches.”

Knight has also invited high school and other college students into the lab and worked with them during the summers.

“It’s so exciting to bring in kids with no previous experience in a wet lab, and watch them be so amazed by all of the things that you can do,” she says. “Experiments that might seem so routine and relatively simple to me, at this point, are so exciting for them.”

Following the completion of her PhD program, Knight plans to do postdoctoral research and would ultimately like to be a faculty member at a small liberal arts college.

“It’s amazing to see students gain confidence over time, and then seeing them progress in their careers as scientists,” she says. “That’s very rewarding for me.”

Nature Climate Change, Published online: 18 August 2026; doi:10.1038/s41558-026-02676-z

Leading European cities race to reach net-zero emissions, but residual emissions are tied to easier-to-abate sectors and temporary, land-intensive carbon removal for compensation. To keep climate neutrality credible and fair, policy must tighten expectations on cutting emissions and set clear rules for carbon removal and credits.

A functional nervous system depends on the cooperation of many kinds of cells. So as developing organisms build their nervous systems, their neurons must take on different forms and functions to fulfill their designated roles. That carefully orchestrated process gives rise to thousands of different cell types in the human brain.

In the tiny worm known as C. elegans, the nervous system is far simpler, comprising a mere 118 classes of neurons.

At MIT, scientists in H. Robert Horvitz’s lab are studying the worms to learn about how nervous systems develop. Horvitz is the David H. Koch Professor of Biology at MIT, an investigator at the McGovern Institute for Brain Research at MIT, and an investigator at the Howard Hughes Medical Institute. His team has just discovered that a protein complex called cohesin, which helps shape the three-dimensional structure of the genome in both worms and humans, is critical for establishing some neurons’ identities as development unfolds.

The open-access findings, reported July 31 in the journal Science Advances, could help scientists find a way to treat a rare developmental disorder called Cornelia de Lange syndrome, which is caused by mutations that interrupt the cohesin complex.

Model organism

MIT postdoc Dongyeop Lee explains that C. elegans is a powerful model for studying neurodevelopment not just because its nervous system has been comprehensively mapped, but also because of the ease and speed with which scientists can study the function of its genes.

Because many of the worm’s genes have been retained through evolution, findings from studies of C. elegans often reveal important aspects of human biology. The current study began with worms that, because of a genetic mutation, make too many neurons of a certain type.

Adrenergic neurons, named for the kind of neurotransmitter they use to communicate with other neurons, are vital for enabling worms to respond to both their environment and their own internal state. Normally, C. elegans has just two pairs of adrenergic neurons: two RIM neurons and two RIC neurons. But the worms Lee studied had extras of both.

Takashi Hirose, a former member of the Horvitz lab, first observed this change in 2007.

Lee later continued the study and discovered that worms carrying a mutation in a gene called coh-1 have extra adrenergic neurons. The coh-1 gene encodes one part of the cohesin complex.

When Lee tested other mutations that disrupt cohesin, he found the same effect: Worms without fully functional cohesin had too many RIM neurons and too many RIC neurons.

Molecular switch

With a series of experiments designed to tease apart how cohesin impacts neurons’ identities, Lee discovered that cohesin cooperates with a gene-regulating protein called EOR-1 (known in humans as PLZF) to direct some neurons to develop into neurons that communicate with the inhibitory neurotransmitter GABA.

By reorganizing the structure of the genome, cohesin can change the way gene regulators like EOR-1 interact with DNA. Lee’s experiments showed that when either cohesin or EOR-1 couldn’t do its job, cells that should have become GABA-producing neurons become adrenergic neurons instead.

“What we found is that there are two alternative possible fates of certain neurons, and cohesin acts as a molecular switch that decides one of the possible neuronal fates,” Lee explains. “This means the structure of genomic DNA in the nucleus is important for neuronal fate determination.”

Disease connection

Lee adds that extra adrenergic neurons were not the only abnormality he observed in worms with cohesin mutations. Cohesin is important for shaping cells and tissues throughout the body. “The mutants have severe developmental defects,” Lee says. “They grow slowly. They don’t move well, and they also have defects in reproduction.”

Notably, the problems Lee saw in the worms echo aspects of Cornelia de Lange syndrome, a rare genetic disorder that impacts physical, cognitive, and behavioral development. Cornelia de Lange syndrome can be caused by mutations in cohesin genes, and Lee says that the discovery of how cohesin mutations affect worm development and behavior opens new opportunities to study the disease and search for potential therapeutic targets in C. elegans.

The Horvitz lab already has some promising leads. Taking advantage of the quick genetic screens that are possible in worms, Lee has found additional mutations that can counteract impaired cohesin, improving the health of worms with cohesin mutations. The team is now working to identify the genes where these suppressor mutations occur, so they can investigate whether they might make good therapeutic targets in humans.

Meanwhile, the team is also exploring a potential role for cohesin in shaping the fates of other neuron types, as well as searching broadly for additional molecules that work with cohesin to guide development. “We expect we have opened up a new biology,” Lee says. “This paper is just the beginning.”