Researchers from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) interdisciplinary research group of the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, in collaboration with Temasek Life Sciences Laboratory (TLL) and MIT, have developed a groundbreaking near-infrared (NIR) fluorescent nanosensor capable of simultaneously detecting and differentiating between iron forms — Fe(II) and Fe(III) — in living plants. 

Iron is crucial for plant health, supporting photosynthesis, respiration, and enzyme function. It primarily exists in two forms: Fe(II), which is readily available for plants to absorb and use, and Fe(III), which must first be converted into Fe(II) before plants can utilize it effectively. Traditional methods only measure total iron, missing the distinction between these forms — a key factor in plant nutrition. Distinguishing between Fe(II) and Fe(III) provides insights into iron uptake efficiency, helps diagnose deficiencies or toxicities, and enables precise fertilization strategies in agriculture, reducing waste and environmental impact while improving crop productivity.

The first-of-its-kind nanosensor developed by SMART researchers enables real-time, nondestructive monitoring of iron uptake, transport, and changes between its different forms — providing precise and detailed observations of iron dynamics. Its high spatial resolution allows precise localization of iron in plant tissues or subcellular compartments, enabling the measurement of even minute changes in iron levels within plants — changes that can inform how a plant handles stress and uses nutrients. 

Traditional detection methods are destructive, or limited to a single form of iron. This new technology enables the diagnosis of deficiencies and optimization of fertilization strategies. By identifying insufficient or excessive iron intake, adjustments can be made to enhance plant health, reduce waste, and support more sustainable agriculture. While the nanosensor was tested on spinach and bok choy, it is species-agnostic, allowing it to be applied across a diverse range of plant species without genetic modification. This capability enhances our understanding of iron dynamics in various ecological settings, providing comprehensive insights into plant health and nutrient management. As a result, it serves as a valuable tool for both fundamental plant research and agricultural applications, supporting precision nutrient management, reducing fertilizer waste, and improving crop health.

“Iron is essential for plant growth and development, but monitoring its levels in plants has been a challenge. This breakthrough sensor is the first of its kind to detect both Fe(II) and Fe(III) in living plants with real-time, high-resolution imaging. With this technology, we can ensure plants receive the right amount of iron, improving crop health and agricultural sustainability,” says Duc Thinh Khong, DiSTAP research scientist and co-lead author of the paper.

“In enabling non-destructive real-time tracking of iron speciation in plants, this sensor opens new avenues for understanding plant iron metabolism and the implications of different iron variations for plants. Such knowledge will help guide the development of tailored management approaches to improve crop yield and more cost-effective soil fertilization strategies,” says Grace Tan, TLL research scientist and co-lead author of the paper.

The research, recently published in Nano Letters and titled, “Nanosensor for Fe(II) and Fe(III) Allowing Spatiotemporal Sensing in Planta,” builds upon SMART DiSTAP’s established expertise in plant nanobionics, leveraging the Corona Phase Molecular Recognition (CoPhMoRe) platform pioneered by the Strano Lab at SMART DiSTAP and MIT. The new nanosensor features single-walled carbon nanotubes (SWNTs) wrapped in a negatively charged fluorescent polymer, forming a helical corona phase structure that interacts differently with Fe(II) and Fe(III). Upon introduction into plant tissues and interaction with iron, the sensor emits distinct NIR fluorescence signals based on the iron type, enabling real-time tracking of iron movement and chemical changes.

The CoPhMoRe technique was used to develop highly selective fluorescent responses, allowing precise detection of iron oxidation states. The NIR fluorescence of SWNTs offers superior sensitivity, selectivity, and tissue transparency while minimizing interference, making it more effective than conventional fluorescent sensors. This capability allows researchers to track iron movement and chemical changes in real time using NIR imaging. 

“This sensor provides a powerful tool to study plant metabolism, nutrient transport, and stress responses. It supports optimized fertilizer use, reduces costs and environmental impact, and contributes to more nutritious crops, better food security, and sustainable farming practices,” says Professor Daisuke Urano, TLL senior principal investigator, DiSTAP principal investigator, National University of Singapore adjunct assistant professor, and co-corresponding author of the paper.

“This set of sensors gives us access to an important type of signalling in plants, and a critical nutrient necessary for plants to make chlorophyll. This new tool will not just help farmers to detect nutrient deficiency, but also give access to certain messages within the plant. It expands our ability to understand the plant response to its growth environment,” says Professor Michael Strano, DiSTAP co-lead principal investigator, Carbon P. Dubbs Professor of Chemical Engineering at MIT, and co-corresponding author of the paper.

Beyond agriculture, this nanosensor holds promise for environmental monitoring, food safety, and health sciences, particularly in studying iron metabolism, iron deficiency, and iron-related diseases in humans and animals. Future research will focus on leveraging this nanosensor to advance fundamental plant studies on iron homeostasis, nutrient signaling, and redox dynamics. Efforts are also underway to integrate the nanosensor into automated nutrient management systems for hydroponic and soil-based farming and expand its functionality to detect other essential micronutrients. These advancements aim to enhance sustainability, precision, and efficiency in agriculture.

The research is carried out by SMART, and supported by the National Research Foundation under its Campus for Research Excellence And Technological Enterprise program.

For over 30 years, science photographer Felice Frankel has helped MIT professors, researchers, and students communicate their work visually. Throughout that time, she has seen the development of various tools to support the creation of compelling images: some helpful, and some antithetical to the effort of producing a trustworthy and complete representation of the research. In a recent opinion piece published in Nature magazine, Frankel discusses the burgeoning use of generative artificial intelligence (GenAI) in images and the challenges and implications it has for communicating research. On a more personal note, she questions whether there will still be a place for a science photographer in the research community.

Q: You’ve mentioned that as soon as a photo is taken, the image can be considered “manipulated.” There are ways you’ve manipulated your own images to create a visual that more successfully communicates the desired message. Where is the line between acceptable and unacceptable manipulation?

A: In the broadest sense, the decisions made on how to frame and structure the content of an image, along with which tools used to create the image, are already a manipulation of reality. We need to remember the image is merely a representation of the thing, and not the thing itself. Decisions have to be made when creating the image. The critical issue is not to manipulate the data, and in the case of most images, the data is the structure. For example, for an image I made some time ago, I digitally deleted the petri dish in which a yeast colony was growing, to bring attention to the stunning morphology of the colony. The data in the image is the morphology of the colony. I did not manipulate that data. However, I always indicate in the text if I have done something to an image. I discuss the idea of image enhancement in my handbook, “The Visual Elements, Photography.”

Q: What can researchers do to make sure their research is communicated correctly and ethically?

A: With the advent of AI, I see three main issues concerning visual representation: the difference between illustration and documentation, the ethics around digital manipulation, and a continuing need for researchers to be trained in visual communication. For years, I have been trying to develop a visual literacy program for the present and upcoming classes of science and engineering researchers. MIT has a communication requirement which mostly addresses writing, but what about the visual, which is no longer tangential to a journal submission? I will bet that most readers of scientific articles go right to the figures, after they read the abstract. 

We need to require students to learn how to critically look at a published graph or image and decide if there is something weird going on with it. We need to discuss the ethics of “nudging” an image to look a certain predetermined way. I describe in the article an incident when a student altered one of my images (without asking me) to match what the student wanted to visually communicate. I didn’t permit it, of course, and was disappointed that the ethics of such an alteration were not considered. We need to develop, at the very least, conversations on campus and, even better, create a visual literacy requirement along with the writing requirement.

Q: Generative AI is not going away. What do you see as the future for communicating science visually?

A: For the Nature article, I decided that a powerful way to question the use of AI in generating images was by example. I used one of the diffusion models to create an image using the following prompt:

“Create a photo of Moungi Bawendi’s nano crystals in vials against a black background, fluorescing at different wavelengths, depending on their size, when excited with UV light.”

The results of my AI experimentation were often cartoon-like images that could hardly pass as reality — let alone documentation — but there will be a time when they will be. In conversations with colleagues in research and computer-science communities, all agree that we should have clear standards on what is and is not allowed. And most importantly, a GenAI visual should never be allowed as documentation.

But AI-generated visuals will, in fact, be useful for illustration purposes. If an AI-generated visual is to be submitted to a journal (or, for that matter, be shown in a presentation), I believe the researcher MUST

• clearly label if an image was created by an AI model;
• indicate what model was used;
• include what prompt was used; and
• include the image, if there is one, that was used to help the prompt.

Senior Kevin Guo, a computer science major, and junior Erin Hovendon, studying mechanical engineering, are on widely divergent paths at MIT. But their lives do intersect in one dimension: They share an understanding that their political science and public policy minors provide crucial perspectives on their research and future careers.

For Guo, the connection between computer science and policy emerged through his work at MIT's Election Data and Science Lab. “When I started, I was just looking for a place to learn how to code and do data science,” he reflects. “But what I found was this fascinating intersection where technical skills could directly shape democratic processes.”

Hovendon is focused on sustainable methods for addressing climate change. She is currently participating in a multisemester research project at MIT's Environmental Dynamics Lab (ENDLab) developing monitoring technology for marine carbon dioxide removal (mCDR).

She believes the success of her research today and in the future depends on understanding its impact on society. Her academic track in policy provides that grounding. “When you’re developing a new technology, you need to focus as well on how it will be applied,” she says. “This means learning about the policies required to scale it up, and about the best ways to convey the value of what you’re working on to the public.”

Bridging STEM and policy

For both Hovendon and Guo, interdisciplinary study is proving to be a valuable platform for tangibly addressing real-world challenges.

Guo came to MIT from Andover, Massachusetts, the son of parents who specialize in semiconductors and computer science. While math and computer science were a natural track for him, Guo was also keenly interested in geopolitics. He enrolled in class 17.40 (American Foreign Policy). “It was my first engagement with MIT political science and I liked it a lot, because it dealt with historical episodes I wanted to learn more about, like World War II, the Korean War, and Vietnam,” says Guo.

He followed up with a class on American Military History and on the Rise of Asia, where he found himself enrolled with graduate students and active duty U.S. military officers. “I liked attending a course with people who had unusual insights,” Guo remarks. “I also liked that these humanities classes were small seminars, and focused a lot on individual students.”

From coding to elections

It was in class 17.835 (Machine Learning and Data Science in Politics) that Guo first realized he could directly connect his computer science and math expertise to the humanities. “They gave us big political science datasets to analyze, which was a pretty cool application of the skills I learned in my major,” he says.

Guo springboarded from this class to a three-year, undergraduate research project in the Election Data and Science Lab. “The hardest part is data collection, which I worked on for an election audit project that looked at whether there were significant differences between original vote counts and audit counts in all the states, at the precinct level,” says Guo. “We had to scrape data, raw PDFs, and create a unified dataset, standardized to our format, that we could publish.”

The data analysis skills he acquired in the lab have come in handy in the professional sphere in which he has begun training: investment finance.

“The workflow is very similar: clean the data to see what you want, analyze it to see if I can find an edge, and then write some code to implement it,” he says. “The biggest difference between finance and the lab research is that the development cycle is a lot faster, where you want to act on a dataset in a few days, rather than weeks or months.”

Engineering environmental solutions

Hovendon, a native of North Carolina with a deep love for the outdoors, arrived at MIT committed “to doing something related to sustainability and having a direct application in the world around me,” she says.

Initially, she headed toward environmental engineering, “but then I realized that pretty much every major can take a different approach to that topic,” she says. “So I ended up switching to mechanical engineering because I really enjoy the hands-on aspects of the field.”

In parallel to her design and manufacturing, and mechanics and materials courses, Hovendon also immersed herself in energy and environmental policy classes. One memorable anthropology class, 21A.404 (Living through Climate Change), asked students to consider whether technological or policy solutions could be fully effective on their own for combating climate change. “It was useful to apply holistic ways of exploring human relations to the environment,” says Hovendon.

Hovendon brings this well-rounded perspective to her research at ENDLab in marine carbon capture and fluid dynamics. She is helping to develop verification methods for mCDR at a pilot treatment plant in California. The facility aims to remove 100 tons of carbon dioxide directly from the ocean by enhancing natural processes. Hovendon hopes to design cost-efficient monitoring systems to demonstrate the efficacy of this new technology. If scaled up, mCDR could enable oceans to store significantly more atmospheric carbon, helping cool the planet.

But Hovendon is well aware that innovation with a major impact cannot emerge on the basis of technical efficacy alone.

“You're going to have people who think that you shouldn't be trying to replicate or interfere with a natural system, and if you're putting one of these facilities somewhere in water, then you're using public spaces and resources,” she says. “It's impossible to come up with any kind of technology, but especially any kind of climate-related technology, without first getting the public to buy into it.”

She recalls class 17.30J (Making Public Policy), which emphasized the importance of both economic and social analysis to the successful passage of highly impactful legislation, such as the Affordable Care Act.

“I think that breakthroughs in science and engineering should be evaluated not just through their technological prowess, but through the success of their implementation for general societal benefit,” she says. “Understanding the policy aspects is vital for improving accessibility for scientific advancements.”

Beyond the dome

Guo will soon set out for a career as a quantitative financial trader, and he views his political science background as essential to his success. While his expertise in data cleaning and analysis will come into play, he believes other skills will as well: “Understanding foreign policy, considering how U.S. policy impacts other places, that's actually very important in finance,” he explains. “Macroeconomic changes and politics affect trading volatility and markets in general, so it's very important to understand what's going on.”

With one year to go, Hovendon is contemplating graduate school in mechanical engineering, perhaps designing renewable energy technologies. “I just really hope that I'm working on something I'm genuinely passionate about, something that has a broader purpose,” she says. “In terms of politics and technology, I also hope that at least some government research and development will still go to climate work, because I'm sure there will be an urgent need for it.”

Interesting article—with photos!—of the US/UK “Combined Cipher Machine” from WWII.

A northern Colorado group that works to reduce wildfires in two conservative counties wonders if the Trump administration will ever pay out federal awards.

Should the state improve air quality and preserve land? Or should it pay for projects that will protect utility customers from rate hikes?

The president's withdrawal of the White House's power to write National Environmental Policy Act rules has created uncertainty for project developers.

Aaron Szabo's carefully worded message for senators was clear: Climate change is real, but his job would not be fighting it.

Jay Bhattacharya said at his confirmation hearing that President Donald Trump's executive orders don't target health initiatives for minorities.

The Labour government has promised to lead the world on climate change, but its renewed focus on defense has thrown those plans into uncertainty.

The city's lord mayor said modeling showed that up to 20,000 homes in his city of more than 3 million people could experience some level of flooding.

Only 1 percent of Vietnam's coral reefs are still healthy, and in those cases it's because of their remoteness, according to the World Resources Institute.

Nature Climate Change, Published online: 06 March 2025; doi:10.1038/s41558-025-02255-8

How discussions around key climate change topics evolve over time and which organizations drive such change are important questions. We found that business non-governmental organizations affiliated with fossil fuels focus on hosting renewable energy events but remain absent from anti-fossil-fuel discussions, led instead by a tightly connected network of environmental non-governmental organizations.

We recently learned that users of the Albion Online gaming forum have received direct messages purporting to be from us. That message, which leverages the fear of an account ban, is a phishing attempt.

If you’re an Albion Online forum user and receive a message that claims to be from “the EFF team,” don’t click the link, and be sure to use the in-forum reporting tool to report the message and the user who sent it to the moderators.

A screenshot of the message shared by a user of the forums.

The message itself has some of the usual hallmarks of a phishing attempt, including tactics like creating a sense of fear that your account may be suspended, leveraging the name of a reputable group, and further raising your heart rate with claims that the message needs a quick response. The goal appears to be to get users to download a PDF file designed to deliver malware. That PDF even uses our branding and typefaces (mostly) correctly.

A full walk through of this malware and what it does was discovered by the Hunt team. The PDF is a trojan, or malware disguised as a non malicious file or program, that has an embedded script that calls out to an attacker server. The attacker server then sends a “stage 2” payload that installs itself onto the user’s device. The attack structure used was discovered to be the Pyramid C2 framework. In this case, it is a Windows operating system intended malware. There’s a variety of actions it takes, like writing and modifying files to the victim’s physical drive. But the most worrisome discovery is that it appears to connect the user’s device to a malicious botnet and has potential access to the “VaultSvc” service. This service securely stores user credentials, such as usernames and passwords

File-based IoCs:
act-7wbq8j3peso0qc1.pages[.]dev/819768.pdf
Hash: 4674dec0a36530544d79aa9815f2ce6545781466ac21ae3563e77755307e0020

This incident is a good reminder that often, the best ways to avoid malware and phishing attempts are the same: avoid clicking strange links in unsolicited emails, keep your computer’s software updated, and always scrutinize messages claiming to come from computer support or fraud detection. If a message seems suspect, try to verify its authenticity through other channels—in this case, poking around on the forum and asking other users before clicking on anything. If you ever absolutely must open a file, do so in an online document reader, like Google Drive, or try sending the link through a tool like VirusTotal, but try to avoid opening suspicious files whenever possible.

For more information to help protect yourself, check out our guides for protecting yourself from malware and avoiding phishing attacks.

We've opposed the Take It Down Act because it could be easily manipulated to take down lawful content that powerful people simply don't like. Last night, President Trump demonstrated he has a similar view on the bill. He wants to sign the bill into law, then use it to remove content about — him. And he won't be the only powerful person to do so. 

Here’s what Trump said to a joint session of Congress:    

The Senate just passed the Take It Down Act…. Once it passes the House, I look forward to signing that bill into law. And I’m going to use that bill for myself too if you don’t mind, because nobody gets treated worse than I do online, nobody. 

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Video courtesy C-SPAN.

The Take It Down Act is an overbroad, poorly drafted bill that would create a powerful system to pressure removal of internet posts, with essentially no safeguards. While the bill is meant to address a serious problem—the distribution of non-consensual intimate imagery (NCII)—the notice-and-takedown system it creates is an open invitation for powerful people to pressure websites into removing content they dislike. There are no penalties for applying very broad, or even farcical definitions of what constitutes NCII, and then demanding that it be removed.  

take action

TELL CONGRESS: "Take It Down" Has No real Safeguards  

This Bill Will Punish Critics, and The President Wants It Passed Right Now 

Congress should believe Trump when he says he would use the Take It Down Act simply because he's "treated badly," despite the fact that this is not the intention of the bill. There is nothing in the law, as written, to stop anyone—especially those with significant resources—from misusing the notice-and-takedown system to remove speech that criticizes them or that they disagree with.  

Trump has frequently targeted platforms carrying content and speakers of entirely legal speech that is critical of him, both as an elected official and as a private citizen.  He has filed frivolous lawsuits against media defendants which threaten to silence critics and draw scarce resources away from important reporting work.   

Now that Trump issued a call to action for the bill in his remarks, there is a possibility that House Republicans will fast track the bill into a spending package as soon as next week. Non-consensual intimate imagery is a serious problem that deserves serious consideration, not a hastily drafted, overbroad bill that sweeps in legal, protected speech. 

How The Take It Down Act Could Silence People 

A few weeks ago, a "deepfake" video of President Trump and Elon Musk was displayed across various monitors in the Housing and Urban Development office. The video was subsequently shared on various platforms. While most people wouldn't consider this video, which displayed faked footage of Trump kissing Elon Musk's feet, "nonconsensual intimate imagery," the takedown provision of the bill applies to an “identifiable individual” engaged in “sexually explicit conduct.” This definition leaves much room for interpretation, and nudity or graphic displays are not necessarily required.  

Moreover, there are no penalties whatsoever to dissuade a requester from simply insisting that content is NCII. Apps and websites only have 48 hours to remove content once they receive a request, which means they won’t be able to verify claims. Especially if the requester is an elected official with the power to start an investigation or prosecution, what website would stand up to such a request?  

The House Must Not Pass This Dangerous Bill 

Congress should focus on enforcing and improving the many existing civil and criminal laws that address NCII, rather than opting for a broad takedown regime that is bound to be abused. Take It Down would likely lead to the use of often-inaccurate automated filters that are infamous for flagging legal content, from fair-use commentary to news reporting. It will threaten encrypted services, which may respond by abandoning encryption entirely in order to be able to monitor content—turning private conversations into surveilled spaces.   

Protecting victims of NCII is a legitimate goal. But good intentions alone are not enough to make good policy. Tell your Member of Congress to oppose censorship and to oppose H.R.633. 

take action

Tell the house to stop "Take it down" 

Treating severe or chronic injury to soft tissues such as skin and muscle is a challenge in health care. Current treatment methods can be costly and ineffective, and the frequency of chronic wounds in general from conditions such as diabetes and vascular disease, as well as an increasingly aging population, is only expected to rise.

One promising treatment method involves implanting biocompatible materials seeded with living cells (i.e., microtissue) into the wound. The materials provide a scaffolding for stem cells, or other precursor cells, to grow into the wounded tissue and aid in repair. However, current techniques to construct these scaffolding materials suffer a recurring setback. Human tissue moves and flexes in a unique way that traditional soft materials struggle to replicate, and if the scaffolds stretch, they can also stretch the embedded cells, often causing those cells to die. The dead cells hinder the healing process and can also trigger an inadvertent immune response in the body.

"The human body has this hierarchical structure that actually un-crimps or unfolds, rather than stretches," says Steve Gillmer, a researcher in MIT Lincoln Laboratory's Mechanical Engineering Group. "That's why if you stretch your own skin or muscles, your cells aren't dying. What's actually happening is your tissues are uncrimping a little bit before they stretch."

Gillmer is part of a multidisciplinary research team that is searching for a solution to this stretching setback. He is working with Professor Ming Guo from MIT's Department of Mechanical Engineering and the laboratory's Defense Fabric Discovery Center (DFDC) to knit new kinds of fabrics that can uncrimp and move just as human tissue does.

The idea for the collaboration came while Gillmer and Guo were teaching a course at MIT. Guo had been researching how to grow stem cells on new forms of materials that could mimic the uncrimping of natural tissue. He chose electrospun nanofibers, which worked well, but were difficult to fabricate at long lengths, preventing him from integrating the fibers into larger knit structures for larger-scale tissue repair.

"Steve mentioned that Lincoln Laboratory had access to industrial knitting machines," Guo says. These machines allowed him to switch focus to designing larger knits, rather than individual yarns. "We immediately started to test new ideas through internal support from the laboratory."

Gillmer and Guo worked with the DFDC to discover which knit patterns could move similarly to different types of soft tissue. They started with three basic knit constructions called interlock, rib, and jersey.

"For jersey, think of your T-shirt. When you stretch your shirt, the yarn loops are doing the stretching," says Emily Holtzman, a textile specialist at the DFDC. "The longer the loop length, the more stretch your fabric can accommodate. For ribbed, think of the cuff on your sweater. This fabric construction has a global stretch that allows the fabric to unfold like an accordion."

Interlock is similar to ribbed but is knitted in a denser pattern and contains twice as much yarn per inch of fabric. By having more yarn, there is more surface area on which to embed the cells. "Knit fabrics can also be designed to have specific porosities, or hydraulic permeability, created by the loops of the fabric and yarn sizes," says Erin Doran, another textile specialist on the team. "These pores can help with the healing process as well."

So far, the team has conducted a number of tests embedding mouse embryonic fibroblast cells and mesenchymal stem cells within the different knit patterns and seeing how they behave when the patterns are stretched. Each pattern had variations that affected how much the fabric could uncrimp, in addition to how stiff it became after it started stretching. All showed a high rate of cell survival, and in 2024 the team received an R&D 100 award for their knit designs.

Gillmer explains that although the project began with treating skin and muscle injuries in mind, their fabrics have the potential to mimic many different types of human soft tissue, such as cartilage or fat. The team recently filed a provisional patent that outlines how to create these patterns and identifies the appropriate materials that should be used to make the yarn. This information can be used as a toolbox to tune different knitted structures to match the mechanical properties of the injured tissue to which they are applied.

"This project has definitely been a learning experience for me," Gillmer says. "Each branch of this team has a unique expertise, and I think the project would be impossible without them all working together. Our collaboration as a whole enables us to expand the scope of the work to solve these larger, more complex problems."

A new MIT-led study confirms that the Antarctic ozone layer is healing, as a direct result of global efforts to reduce ozone-depleting substances.

Scientists including the MIT team have observed signs of ozone recovery in the past. But the new study is the first to show, with high statistical confidence, that this recovery is due primarily to the reduction of ozone-depleting substances, versus other influences such as natural weather variability or increased greenhouse gas emissions to the stratosphere.

“There’s been a lot of qualitative evidence showing that the Antarctic ozone hole is getting better. This is really the first study that has quantified confidence in the recovery of the ozone hole,” says study author Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies and Chemistry. “The conclusion is, with 95 percent confidence, it is recovering. Which is awesome. And it shows we can actually solve environmental problems.”

The new study appears today in the journal Nature. Graduate student Peidong Wang from the Solomon group in the Department of Earth, Atmospheric and Planetary Sciences (EAPS) is the lead author. His co-authors include Solomon and EAPS Research Scientist Kane Stone, along with collaborators from multiple other institutions.

Roots of ozone recovery

Within the Earth’s stratosphere, ozone is a naturally occurring gas that acts as a sort of sunscreen, protecting the planet from the sun’s harmful ultraviolet radiation. In 1985, scientists discovered a “hole” in the ozone layer over Antarctica that opened up during the austral spring, between September and December. This seasonal ozone depletion was suddenly allowing UV rays to filter down to the surface, leading to skin cancer and other adverse health effects.

In 1986, Solomon, who was then working at the National Oceanic and Atmospheric Administration (NOAA), led expeditions to the Antarctic, where she and her colleagues gathered evidence that quickly confirmed the ozone hole’s cause: chlorofluorocarbons, or CFCs — chemicals that were then used in refrigeration, air conditioning, insulation, and aerosol propellants. When CFCs drift up into the stratosphere, they can break down ozone under certain seasonal conditions.

The following year, those relevations led to the drafting of the Montreal Protocol — an international treaty that aimed to phase out the production of CFCs and other ozone-depleting substances, in hopes of healing the ozone hole.

In 2016, Solomon led a study reporting key signs of ozone recovery. The ozone hole seemed to be shrinking with each year, especially in September, the time of year when it opens up. Still, these observations were qualitative. The study showed large uncertainties regarding how much of this recovery was due to concerted efforts to reduce ozone-depleting substances, or if the shrinking ozone hole was a result of other “forcings,” such as year-to-year weather variability from El Niño, La Niña, and the polar vortex.

“While detecting a statistically significant increase in ozone is relatively straightforward, attributing these changes to specific forcings is more challenging,” says Wang.

Anthropogenic healing

In their new study, the MIT team took a quantitative approach to identify the cause of Antarctic ozone recovery. The researchers borrowed a method from the climate change community, known as “fingerprinting,” which was pioneered by Klaus Hasselmann, who was awarded the Nobel Prize in Physics in 2021 for the technique. In the context of climate, fingerprinting refers to a method that isolates the influence of specific climate factors, apart from natural, meteorological noise. Hasselmann applied fingerprinting to identify, confirm, and quantify the anthropogenic fingerprint of climate change.

Solomon and Wang looked to apply the fingerprinting method to identify another anthropogenic signal: the effect of human reductions in ozone-depleting substances on the recovery of the ozone hole.

“The atmosphere has really chaotic variability within it,” Solomon says. “What we’re trying to detect is the emerging signal of ozone recovery against that kind of variability, which also occurs in the stratosphere.”

The researchers started with simulations of the Earth’s atmosphere and generated multiple “parallel worlds,” or simulations of the same global atmosphere, under different starting conditions. For instance, they ran simulations under conditions that assumed no increase in greenhouse gases or ozone-depleting substances. Under these conditions, any changes in ozone should be the result of natural weather variability. They also ran simulations with only increasing greenhouse gases, as well as only decreasing ozone-depleting substances.

They compared these simulations to observe how ozone in the Antarctic stratosphere changed, both with season, and across different altitudes, in response to different starting conditions. From these simulations, they mapped out the times and altitudes where ozone recovered from month to month, over several decades, and identified a key “fingerprint,” or pattern, of ozone recovery that was specifically due to conditions of declining ozone-depleting substances.

The team then looked for this fingerprint in actual satellite observations of the Antarctic ozone hole from 2005 to the present day. They found that, over time, the fingerprint that they identified in simulations became clearer and clearer in observations. In 2018, the fingerprint was at its strongest, and the team could say with 95 percent confidence that ozone recovery was due mainly to reductions in ozone-depleting substances.

“After 15 years of observational records, we see this signal to noise with 95 percent confidence, suggesting there’s only a very small chance that the observed pattern similarity can be explained by variability noise,” Wang says. “This gives us confidence in the fingerprint. It also gives us confidence that we can solve environmental problems. What we can learn from ozone studies is how different countries can swiftly follow these treaties to decrease emissions.”

If the trend continues, and the fingerprint of ozone recovery grows stronger, Solomon anticipates that soon there will be a year, here and there, when the ozone layer stays entirely intact. And eventually, the ozone hole should stay shut for good.

“By something like 2035, we might see a year when there’s no ozone hole depletion at all in the Antarctic. And that will be very exciting for me,” she says. “And some of you will see the ozone hole go away completely in your lifetimes. And people did that.”

This research was supported, in part, by the National Science Foundation and NASA.

Of the five, one is a Windows vulnerability, another is a Cisco vulnerability. We don’t have any details about who is exploiting them, or how.

News article. Slashdot thread.

Energy Secretary Chris Wright’s keynote speech on energy poverty will come on the heels of the gutting of Power Africa’s USAID programs.

The demise of the Chevron doctrine could weaken the Trump administration's effort to undo the scientific underpinning for climate rules.