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    3 Questions: What the laws of physics tell us about CO2 removal

    Human activities continue to pump billions of tons of carbon dioxide into the atmosphere each year, raising global temperatures and driving extreme weather events. As countries grapple with climate impacts and ways to significantly reduce carbon emissions, there have been various efforts to advance carbon dioxide removal (CDR) technologies that directly remove carbon dioxide from the air and sequester it for long periods of time.Unlike carbon capture and storage technologies, which are designed to remove carbon dioxide at point sources such as fossil-fuel plants, CDR aims to remove carbon dioxide molecules that are already circulating in the atmosphere.A new report by the American Physical Society and led by an MIT physicist provides an overview of the major experimental CDR approaches and determines their fundamental physical limits. The report focuses on methods that have the biggest potential for removing carbon dioxide, at the scale of gigatons per year, which is the magnitude that would be required to have a climate-stabilizing impact.The new report was commissioned by the American Physical Society’s Panel on Public Affairs, and appeared last week in the journal PRX. The report was chaired by MIT professor of physics Washington Taylor, who spoke with MIT News about CDR’s physical limitations and why it’s worth pursuing in tandem with global efforts to reduce carbon emissions.Q: What motivated you to look at carbon dioxide removal systems from a physical science perspective?A: The number one thing driving climate change is the fact that we’re taking carbon that has been stuck in the ground for 100 million years, and putting it in the atmosphere, and that’s causing warming. In the last few years there’s been a lot of interest both by the government and private entities in finding technologies to directly remove the CO2 from the air.How to manage atmospheric carbon is the critical question in dealing with our impact on Earth’s climate. So, it’s very important for us to understand whether we can affect the carbon levels not just by changing our emissions profile but also by directly taking carbon out of the atmosphere. Physics has a lot to say about this because the possibilities are very strongly constrained by thermodynamics, mass issues, and things like that.Q: What carbon dioxide removal methods did you evaluate?A: They’re all at an early stage. It’s kind of the Wild West out there in terms of the different ways in which companies are proposing to remove carbon from the atmosphere. In this report, we break down CDR processes into two classes: cyclic and once-through.Imagine we are in a boat that has a hole in the hull and is rapidly taking on water. Of course, we want to plug the hole as quickly as we can. But even once we have fixed the hole, we need to get the water out so we aren’t in danger of sinking or getting swamped. And this is particularly urgent if we haven’t completely fixed the hole so we still have a slow leak. Now, imagine we have a couple of options for how to get the water out so we don’t sink.The first is a sponge that we can use to absorb water, that we can then squeeze out and reuse. That’s a cyclic process in the sense that we have some material that we’re using over and over. There are cyclic CDR processes like chemical “direct air capture” (DAC), which acts basically like a sponge. You set up a big system with fans that blow air past some material that captures carbon dioxide. When the material is saturated, you close off the system and then use energy to essentially squeeze out the carbon and store it in a deep repository. Then you can reuse the material, in a cyclic process.The second class of approaches is what we call “once-through.” In the boat analogy, it would be as if you try to fix the leak using cartons of paper towels. You let them saturate and then throw them overboard, and you use each roll once.There are once-through CDR approaches, like enhanced rock weathering, that are designed to accelerate a natural process, by which certain rocks, when exposed to air, will absorb carbon from the atmosphere. Worldwide, this natural rock weathering is estimated to remove about 1 gigaton of carbon each year. “Enhanced rock weathering” is a CDR approach where you would dig up a lot of this rock, grind it up really small, to less than the width of a human hair, to get the process to happen much faster. The idea is, you dig up something, spread it out, and absorb CO2 in one go.The key difference between these two processes is that the cyclic process is subject to the second law of thermodynamics and there’s an energy constraint. You can set an actual limit from physics, saying any cyclic process is going to take a certain amount of energy, and that cannot be avoided. For example, we find that for cyclic direct-air-capture (DAC) plants, based on second law limits, the absolute minimum amount of energy you would need to capture a gigaton of carbon is comparable to the total yearly electric energy consumption of the state of Virginia. Systems currently under development use at least three to 10 times this much energy on a per ton basis (and capture tens of thousands, not billions, of tons). Such systems also need to move a lot of air; the air that would need to pass through a DAC system to capture a gigaton of CO2 is comparable to the amount of air that passes through all the air cooling systems on the planet.On the other hand, if you have a once-through process, you could in some respects avoid the energy constraint, but now you’ve got a materials constraint due to the central laws of chemistry. For once-through processes like enhanced rock weathering, that means that if you want to capture a gigaton of CO2, roughly speaking, you’re going to need a billion tons of rock.So, to capture gigatons of carbon through engineered methods requires tremendous amounts of physical material, air movement, and energy. On the other hand, everything we’re doing to put that CO2 in the atmosphere is extensive too, so large-scale emissions reductions face comparable challenges.Q: What does the report conclude, in terms of whether and how to remove carbon dioxide from the atmosphere?A: Our initial prejudice was, CDR is just going to take so much energy, and there’s no way around that because of the second law of thermodynamics, regardless of the method.But as we discussed, there is this nuance about cyclic versus once-through systems. And there are two points of view that we ended up threading a needle between. One is the view that CDR is a silver bullet, and we’ll just do CDR and not worry about emissions — we’ll just suck it all out of the atmosphere. And that’s not the case. It will be really expensive, and will take a lot of energy and materials to do large-scale CDR. But there’s another view, where people say, don’t even think about CDR. Even thinking about CDR will compromise our efforts toward emissions reductions. The report comes down somewhere in the middle, saying that CDR is not a magic bullet, but also not a no-go.If we are serious about managing climate change, we will likely want substantial CDR in addition to aggressive emissions reductions. The report concludes that research and development on CDR methods should be selectively and prudently pursued despite the expected cost and energy and material requirements.At a policy level, the main message is that we need an economic and policy framework that incentivizes emissions reductions and CDR in a common framework; this would naturally allow the market to optimize climate solutions. Since in many cases it is much easier and cheaper to cut emissions than it will likely ever be to remove atmospheric carbon, clearly understanding the challenges of CDR should help motivate rapid emissions reductions.For me, I’m optimistic in the sense that scientifically we understand what it will take to reduce emissions and to use CDR to bring CO2 levels down to a slightly lower level. Now, it’s really a societal and economic problem. I think humanity has the potential to solve these problems. I hope that we can find common ground so that we can take actions as a society that will benefit both humanity and the broader ecosystems on the planet, before we end up having bigger problems than we already have.  More

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    Seeking climate connections among the oceans’ smallest organisms

    Andrew Babbin tries to pack light for work trips. Along with the travel essentials, though, he also brings a roll each of electrical tape, duct tape, lab tape, a pack of cable ties, and some bungee cords.“It’s my MacGyver kit: You never know when you have to rig something on the fly in the field or fix a broken bag,” Babbin says.The trips Babbin takes are far out to sea, on month-long cruises, where he works to sample waters off the Pacific coast and out in the open ocean. In remote locations, repair essentials often come in handy, as when Babbin had to zip-tie a wrench to a sampling device to help it sink through an icy Antarctic lake.Babbin is an oceanographer and marine biogeochemist who studies marine microbes and the ways in which they control the cycling of nitrogen between the ocean and the atmosphere. This exchange helps maintain healthy ocean ecosystems and supports the ocean’s capacity to store carbon.By combining measurements that he takes in the ocean with experiments in his MIT lab, Babbin is working to understand the connections between microbes and ocean nitrogen, which could in turn help scientists identify ways to maintain the ocean’s health and productivity. His work has taken him to many coastal and open-ocean regions around the globe.“You really become an oceanographer and an Earth scientist to see the world,” says Babbin, who recently earned tenure as the Cecil and Ida Green Career Development Professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “We embrace the diversity of places and cultures on this planet. To see just a small fraction of that is special.”A powerful cycleThe ocean has been a constant presence for Babbin since childhood. His family is from Monmouth County, New Jersey, where he and his twin sister grew up playing along the Jersey shore. When they were teenagers, their parents took the kids on family cruise vacations.“I always loved being on the water,” he says. “My favorite parts of any of those cruises were the days at sea, where you were just in the middle of some ocean basin with water all around you.”In school, Babbin gravitated to the sciences, and chemistry in particular. After high school, he attended Columbia University, where a visit to the school’s Earth and environmental engineering department catalyzed a realization.“For me, it was always this excitement about the water and about chemistry, and it was this pop of, ‘Oh wow, it doesn’t have to be one or the other,’” Babbin says.He chose to major in Earth and environmental engineering, with a concentration in water resources and climate risks. After graduating in 2008, Babbin returned to his home state, where he attended Princeton University and set a course for a PhD in geosciences, with a focus on chemical oceanography and environmental microbiology. His advisor, oceanographer Bess Ward, took Babbin on as a member of her research group and invited him on several month-long cruises to various parts of the eastern tropical Pacific.“I still remember that first trip,” Babbin recalls. “It was a whirlwind. Everyone else had been to sea a gazillion times and was loading the boat and strapping things down, and I had no idea of anything. And within a few hours, I was doing an experiment as the ship rocked back and forth!”Babbin learned to deploy sampling cannisters overboard, then haul them back up and analyze the seawater inside for signs of nitrogen — an essential nutrient for all living things on Earth.As it turns out, the plants and animals that depend on nitrogen to survive are unable to take it up from the atmosphere themselves. They require a sort of go-between, in the form of microbes that “fix” nitrogen, converting it from nitrogen gas to more digestible forms. In the ocean, this nitrogen fixation is done by highly specialized microbial species, which work to make nitrogen available to phytoplankton — microscopic plant-like organisms that are the foundation of the marine food chain. Phytoplankton are also a main route by which the ocean absorbs carbon dioxide from the atmosphere.Microorganisms may also use these biologically available forms of nitrogen for energy under certain conditions, returning nitrogen to the atmosphere. These microbes can also release a byproduct of nitrous oxide, which is a potent greenhouse gas that also can catalyze ozone loss in the stratosphere.Through his graduate work, at sea and in the lab, Babbin became fascinated with the cycling of nitrogen and the role that nitrogen-fixing microbes play in supporting the ocean’s ecosystems and the climate overall. A balance of nitrogen inputs and outputs sustains phytoplankton and maintains the ocean’s ability to soak up carbon dioxide.“Some of the really pressing questions in ocean biogeochemistry pertain to this cycling of nitrogen,” Babbin says. “Understanding the ways in which this one element cycles through the ocean, and how it is central to ecosystem health and the planet’s climate, has been really powerful.”In the lab and out to seaAfter completing his PhD in 2014, Babbin arrived at MIT as a postdoc in the Department of Civil and Environmental Engineering.“My first feeling when I came here was, wow, this really is a nerd’s playground,” Babbin says. “I embraced being part of a culture where we seek to understand the world better, while also doing the things we really want to do.”In 2017, he accepted a faculty position in MIT’s Department of Earth, Atmospheric and Planetary Sciences. He set up his laboratory space, painted in his favorite brilliant orange, on the top floor of the Green Building.His group uses 3D printers to fabricate microfluidic devices in which they reproduce the conditions of the ocean environment and study microbe metabolism and its effects on marine chemistry. In the field, Babbin has led research expeditions to the Galapagos Islands and parts of the eastern Pacific, where he has collected and analyzed samples of air and water for signs of nitrogen transformations and microbial activity. His new measuring station in the Galapagos is able to infer marine emissions of nitrous oxide across a large swath of the eastern tropical Pacific Ocean. His group has also sailed to southern Cuba, where the researchers studied interactions of microbes in coral reefs.Most recently, Babbin traveled to Antarctica, where he set up camp next to frozen lakes and plumbed for samples of pristine ice water that he will analyze for genetic remnants of ancient microbes. Such preserved bacterial DNA could help scientists understand how microbes evolved and influenced the Earth’s climate over billions of years.“Microbes are the terraformers,” Babbin notes. “They have been, since life evolved more than 3 billion years ago. We have to think about how they shape the natural world and how they will respond to the Anthropocene as humans monkey with the planet ourselves.”Collective actionBabbin is now charting new research directions. In addition to his work at sea and in the lab, he is venturing into engineering, with a new project to design denitrifying capsules. While nitrogen is an essential nutrient for maintaining a marine ecosystem, too much nitrogen, such as from fertilizer that runs off into lakes and streams, can generate blooms of toxic algae. Babbin is looking to design eco-friendly capsules that scrub excess anthropogenic nitrogen from local waterways. He’s also beginning the process of designing a new sensor to measure low-oxygen concentrations in the ocean. As the planet warms, the oceans are losing oxygen, creating “dead zones” where fish cannot survive. While others including Babbin have tried to map these oxygen minimum zones, or OMZs, they have done so sporadically, by dropping sensors into the ocean over limited range, depth, and times. Babbin’s sensors could potentially provide a more complete map of OMZs, as they would be deployed on wide-ranging, deep-diving, and naturally propulsive vehicles: sharks.“We want to measure oxygen. Sharks need oxygen. And if you look at where the sharks don’t go, you might have a sense of where the oxygen is not,” says Babbin, who is working with marine biologists on ways to tag sharks with oxygen sensors. “A number of these large pelagic fish move up and down the water column frequently, so you can map the depth to which they dive to, and infer something about the behavior. And my suggestion is, you might also infer something about the ocean’s chemistry.”When he reflects on what stimulates new ideas and research directions, Babbin credits working with others, in his own group and across MIT.“My best thoughts come from this collective action,” Babbin says. “Particularly because we all have different upbringings and approach things from a different perspective.”He’s bringing this collaborative spirit to his new role, as a mission director for MIT’s Climate Project. Along with Jesse Kroll, who is a professor of civil and environmental engineering and of chemical engineering, Babbin co-leads one of the project’s six missions: Restoring the Atmosphere, Protecting the Land and Oceans. Babbin and Kroll are planning a number of workshops across campus that they hope will generate new connections, and spark new ideas, particularly around ways to evaluate the effectiveness of different climate mitigation strategies and better assess the impacts of climate on society.“One area we want to promote is thinking of climate science and climate interventions as two sides of the same coin,” Babbin says. “There’s so much action that’s trying to be catalyzed. But we want it to be the best action. Because we really have one shot at doing this. Time is of the essence.” More

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    MIT spinout Gradiant reduces companies’ water use and waste by billions of gallons each day

    When it comes to water use, most of us think of the water we drink. But industrial uses for things like manufacturing account for billions of gallons of water each day. For instance, making a single iPhone, by one estimate, requires more than 3,000 gallons.Gradiant is working to reduce the world’s industrial water footprint. Founded by a team from MIT, Gradiant offers water recycling, treatment, and purification solutions to some of the largest companies on Earth, including Coca Cola, Tesla, and the Taiwan Semiconductor Manufacturing Company. By serving as an end-to-end water company, Gradiant says it helps companies reuse 2 billion gallons of water each day and saves another 2 billion gallons of fresh water from being withdrawn.The company’s mission is to preserve water for generations to come in the face of rising global demand.“We work on both ends of the water spectrum,” Gradiant co-founder and CEO Anurag Bajpayee SM ’08, PhD ’12 says. “We work with ultracontaminated water, and we can also provide ultrapure water for use in areas like chip fabrication. Our specialty is in the extreme water challenges that can’t be solved with traditional technologies.”For each customer, Gradiant builds tailored water treatment solutions that combine chemical treatments with membrane filtration and biological process technologies, leveraging a portfolio of patents to drastically cut water usage and waste.“Before Gradiant, 40 million liters of water would be used in the chip-making process. It would all be contaminated and treated, and maybe 30 percent would be reused,” explains Gradiant co-founder and COO Prakash Govindan PhD ’12. “We have the technology to recycle, in some cases, 99 percent of the water. Now, instead of consuming 40 million liters, chipmakers only need to consume 400,000 liters, which is a huge shift in the water footprint of that industry. And this is not just with semiconductors. We’ve done this in food and beverage, we’ve done this in renewable energy, we’ve done this in pharmaceutical drug production, and several other areas.”Learning the value of waterGovindan grew up in a part of India that experienced a years-long drought beginning when he was 10. Without tap water, one of Govindan’s chores was to haul water up the stairs of his apartment complex each time a truck delivered it.“However much water my brother and I could carry was how much we had for the week,” Govindan recalls. “I learned the value of water the hard way.”Govindan attended the Indian Institute of Technology as an undergraduate, and when he came to MIT for his PhD, he sought out the groups working on water challenges. He began working on a water treatment method called carrier gas extraction for his PhD under Gradiant co-founder and MIT Professor John Lienhard.Bajpayee also worked on water treatment methods at MIT, and after brief stints as postdocs at MIT, he and Govindan licensed their work and founded Gradiant.Carrier gas extraction became Gradiant’s first proprietary technology when the company launched in 2013. The founders began by treating wastewater created by oil and gas wells, landing their first partner in a Texas company. But Gradiant gradually expanded to solving water challenges in power generation, mining, textiles, and refineries. Then the founders noticed opportunities in industries like electronics, semiconductors, food and beverage, and pharmaceuticals. Today, oil and gas wastewater treatment makes up a small percentage of Gradiant’s work.As the company expanded, it added technologies to its portfolio, patenting new water treatment methods around reverse osmosis, selective contaminant extraction, and free radical oxidation. Gradiant has also created a digital system that uses AI to measure, predict, and control water treatment facilities.“The advantage Gradiant has over every other water company is that R&D is in our DNA,” Govindan says, noting Gradiant has a world-class research lab at its headquarters in Boston. “At MIT, we learned how to do cutting-edge technology development, and we never let go of that.”The founders compare their suite of technologies to LEGO bricks they can mix and match depending on a customer’s water needs. Gradiant has built more than 2,500 of these end-to-end systems for customers around the world.“Our customers aren’t water companies; they are industrial clients like semiconductor manufacturers, drug companies, and food and beverage companies,” Bajpayee says. “They aren’t about to start operating a water treatment plant. They look at us as their water partner who can take care of the whole water problem.”Continuing innovationThe founders say Gradiant has been roughly doubling its revenue each year over the last five years, and it’s continuing to add technologies to its platform. For instance, Gradiant recently developed a critical minerals recovery solution to extract materials like lithium and nickel from customers’ wastewater, which could expand access to critical materials essential to the production of batteries and other products.“If we can extract lithium from brine water in an environmentally and economically feasible way, the U.S. can meet all of its lithium needs from within the U.S.,” Bajpayee says. “What’s preventing large-scale extraction of lithium from brine is technology, and we believe what we have now deployed will open the floodgates for direct lithium extraction and completely revolutionized the industry.”The company has also validated a method for eliminating PFAS — so-called toxic “forever chemicals” — in a pilot project with a leading U.S. semiconductor manufacturer. In the near future, it hopes to bring that solution to municipal water treatment plants to protect cities.At the heart of Gradiant’s innovation is the founders’ belief that industrial activity doesn’t have to deplete one of the world’s most vital resources.“Ever since the industrial revolution, we’ve been taking from nature,” Bajpayee says. “By treating and recycling water, by reducing water consumption and making industry highly water efficient, we have this unique opportunity to turn the clock back and give nature water back. If that’s your driver, you can’t choose not to innovate.” More

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    Toward sustainable decarbonization of aviation in Latin America

    According to the International Energy Agency, aviation accounts for about 2 percent of global carbon dioxide emissions, and aviation emissions are expected to double by mid-century as demand for domestic and international air travel rises. To sharply reduce emissions in alignment with the Paris Agreement’s long-term goal to keep global warming below 1.5 degrees Celsius, the International Air Transport Association (IATA) has set a goal to achieve net-zero carbon emissions by 2050. Which raises the question: Are there technologically feasible and economically viable strategies to reach that goal within the next 25 years?To begin to address that question, a team of researchers at the MIT Center for Sustainability Science and Strategy (CS3) and the MIT Laboratory for Aviation and the Environment has spent the past year analyzing aviation decarbonization options in Latin America, where air travel is expected to more than triple by 2050 and thereby double today’s aviation-related emissions in the region.Chief among those options is the development and deployment of sustainable aviation fuel. Currently produced from low- and zero-carbon sources (feedstock) including municipal waste and non-food crops, and requiring practically no alteration of aircraft systems or refueling infrastructure, sustainable aviation fuel (SAF) has the potential to perform just as well as petroleum-based jet fuel with as low as 20 percent of its carbon footprint.Focused on Brazil, Chile, Colombia, Ecuador, Mexico and Peru, the researchers assessed SAF feedstock availability, the costs of corresponding SAF pathways, and how SAF deployment would likely impact fuel use, prices, emissions, and aviation demand in each country. They also explored how efficiency improvements and market-based mechanisms could help the region to reach decarbonization targets. The team’s findings appear in a CS3 Special Report.SAF emissions, costs, and sourcesUnder an ambitious emissions mitigation scenario designed to cap global warming at 1.5 C and raise the rate of SAF use in Latin America to 65 percent by 2050, the researchers projected aviation emissions to be reduced by about 60 percent in 2050 compared to a scenario in which existing climate policies are not strengthened. To achieve net-zero emissions by 2050, other measures would be required, such as improvements in operational and air traffic efficiencies, airplane fleet renewal, alternative forms of propulsion, and carbon offsets and removals.As of 2024, jet fuel prices in Latin America are around $0.70 per liter. Based on the current availability of feedstocks, the researchers projected SAF costs within the six countries studied to range from $1.11 to $2.86 per liter. They cautioned that increased fuel prices could affect operating costs of the aviation sector and overall aviation demand unless strategies to manage price increases are implemented.Under the 1.5 C scenario, the total cumulative capital investments required to build new SAF producing plants between 2025 and 2050 were estimated at $204 billion for the six countries (ranging from $5 billion in Ecuador to $84 billion in Brazil). The researchers identified sugarcane- and corn-based ethanol-to-jet fuel, palm oil- and soybean-based hydro-processed esters and fatty acids as the most promising feedstock sources in the near term for SAF production in Latin America.“Our findings show that SAF offers a significant decarbonization pathway, which must be combined with an economy-wide emissions mitigation policy that uses market-based mechanisms to offset the remaining emissions,” says Sergey Paltsev, lead author of the report, MIT CS3 deputy director, and senior research scientist at the MIT Energy Initiative.RecommendationsThe researchers concluded the report with recommendations for national policymakers and aviation industry leaders in Latin America.They stressed that government policy and regulatory mechanisms will be needed to create sufficient conditions to attract SAF investments in the region and make SAF commercially viable as the aviation industry decarbonizes operations. Without appropriate policy frameworks, SAF requirements will affect the cost of air travel. For fuel producers, stable, long-term-oriented policies and regulations will be needed to create robust supply chains, build demand for establishing economies of scale, and develop innovative pathways for producing SAF.Finally, the research team recommended a region-wide collaboration in designing SAF policies. A unified decarbonization strategy among all countries in the region will help ensure competitiveness, economies of scale, and achievement of long-term carbon emissions-reduction goals.“Regional feedstock availability and costs make Latin America a potential major player in SAF production,” says Angelo Gurgel, a principal research scientist at MIT CS3 and co-author of the study. “SAF requirements, combined with government support mechanisms, will ensure sustainable decarbonization while enhancing the region’s connectivity and the ability of disadvantaged communities to access air transport.”Financial support for this study was provided by LATAM Airlines and Airbus. More

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    For clean ammonia, MIT engineers propose going underground

    Ammonia is the most widely produced chemical in the world today, used primarily as a source for nitrogen fertilizer. Its production is also a major source of greenhouse gas emissions — the highest in the whole chemical industry.Now, a team of researchers at MIT has developed an innovative way of making ammonia without the usual fossil-fuel-powered chemical plants that require high heat and pressure. Instead, they have found a way to use the Earth itself as a geochemical reactor, producing ammonia underground. The processes uses Earth’s naturally occurring heat and pressure, provided free of charge and free of emissions, as well as the reactivity of minerals already present in the ground.The trick the team devised is to inject water underground, into an area of iron-rich subsurface rock. The water carries with it a source of nitrogen and particles of a metal catalyst, allowing the water to react with the iron to generate clean hydrogen, which in turn reacts with the nitrogen to make ammonia. A second well is then used to pump that ammonia up to the surface.The process, which has been demonstrated in the lab but not yet in a natural setting, is described today in the journal Joule. The paper’s co-authors are MIT professors of materials science and engineering Iwnetim Abate and Ju Li, graduate student Yifan Gao, and five others at MIT.“When I first produced ammonia from rock in the lab, I was so excited,” Gao recalls. “I realized this represented an entirely new and never-reported approach to ammonia synthesis.’”The standard method for making ammonia is called the Haber-Bosch process, which was developed in Germany in the early 20th century to replace natural sources of nitrogen fertilizer such as mined deposits of bat guano, which were becoming depleted. But the Haber-Bosch process is very energy intensive: It requires temperatures of 400 degrees Celsius and pressures of 200 atmospheres, and this means it needs huge installations in order to be efficient. Some areas of the world, such as sub-Saharan Africa and Southeast Asia, have few or no such plants in operation.  As a result, the shortage or extremely high cost of fertilizer in these regions has limited their agricultural production.The Haber-Bosch process “is good. It works,” Abate says. “Without it, we wouldn’t have been able to feed 2 out of the total 8 billion people in the world right now, he says, referring to the portion of the world’s population whose food is grown with ammonia-based fertilizers. But because of the emissions and energy demands, a better process is needed, he says.Burning fuel to generate heat is responsible for about 20 percent of the greenhouse gases emitted from plants using the Haber-Bosch process. Making hydrogen accounts for the remaining 80 percent.  But ammonia, the molecule NH3, is made up only of nitrogen and hydrogen. There’s no carbon in the formula, so where do the carbon emissions come from? The standard way of producing the needed hydrogen is by processing methane gas with steam, breaking down the gas into pure hydrogen, which gets used, and carbon dioxide gas that gets released into the air.Other processes exist for making low- or no-emissions hydrogen, such as by using solar or wind-generated electricity to split water into oxygen and hydrogen, but that process can be expensive. That’s why Abate and his team worked on developing a system to produce what they call geological hydrogen. Some places in the world, including some in Africa, have been found to naturally generate hydrogen underground through chemical reactions between water and iron-rich rocks. These pockets of naturally occurring hydrogen can be mined, just like natural methane reservoirs, but the extent and locations of such deposits are still relatively unexplored.Abate realized this process could be created or enhanced by pumping water, laced with copper and nickel catalyst particles to speed up the process, into the ground in places where such iron-rich rocks were already present. “We can use the Earth as a factory to produce clean flows of hydrogen,” he says.He recalls thinking about the problem of the emissions from hydrogen production for ammonia: “The ‘aha!’ moment for me was thinking, how about we link this process of geological hydrogen production with the process of making Haber-Bosch ammonia?”That would solve the biggest problem of the underground hydrogen production process, which is how to capture and store the gas once it’s produced. Hydrogen is a very tiny molecule — the smallest of them all — and hard to contain. But by implementing the entire Haber-Bosch process underground, the only material that would need to be sent to the surface would be the ammonia itself, which is easy to capture, store, and transport.The only extra ingredient needed to complete the process was the addition of a source of nitrogen, such as nitrate or nitrogen gas, into the water-catalyst mixture being injected into the ground. Then, as the hydrogen gets released from water molecules after interacting with the iron-rich rocks, it can immediately bond with the nitrogen atoms also carried in the water, with the deep underground environment providing the high temperatures and pressures required by the Haber-Bosch process. A second well near the injection well then pumps the ammonia out and into tanks on the surface.“We call this geological ammonia,” Abate says, “because we are using subsurface temperature, pressure, chemistry, and geologically existing rocks to produce ammonia directly.”Whereas transporting hydrogen requires expensive equipment to cool and liquefy it, and virtually no pipelines exist for its transport (except near oil refinery sites), transporting ammonia is easier and cheaper. It’s about one-sixth the cost of transporting hydrogen, and there are already more than 5,000 miles of ammonia pipelines and 10,000 terminals in place in the U.S. alone. What’s more, Abate explains, ammonia, unlike hydrogen, already has a substantial commercial market in place, with production volume projected to grow by two to three times by 2050, as it is used not only for fertilizer but also as feedstock for a wide variety of chemical processes.For example, ammonia can be burned directly in gas turbines, engines, and industrial furnaces, providing a carbon-free alternative to fossil fuels. It is being explored for maritime shipping and aviation as an alternative fuel, and as a possible space propellant.Another upside to geological ammonia is that untreated wastewater, including agricultural runoff, which tends to be rich in nitrogen already, could serve as the water source and be treated in the process. “We can tackle the problem of treating wastewater, while also making something of value out of this waste,” Abate says.Gao adds that this process “involves no direct carbon emissions, presenting a potential pathway to reduce global CO2 emissions by up to 1 percent.” To arrive at this point, he says, the team “overcame numerous challenges and learned from many failed attempts. For example, we tested a wide range of conditions and catalysts before identifying the most effective one.”The project was seed-funded under a flagship project of MIT’s Climate Grand Challenges program, the Center for the Electrification and Decarbonization of Industry. Professor Yet-Ming Chiang, co-director of the center, says “I don’t think there’s been any previous example of deliberately using the Earth as a chemical reactor. That’s one of the key novel points of this approach.”  Chiang emphasizes that even though it is a geological process, it happens very fast, not on geological timescales. “The reaction is fundamentally over in a matter of hours,” he says. “The reaction is so fast that this answers one of the key questions: Do you have to wait for geological times? And the answer is absolutely no.”Professor Elsa Olivetti, a mission director of the newly established Climate Project at MIT, says, “The creative thinking by this team is invaluable to MIT’s ability to have impact at scale. Coupling these exciting results with, for example, advanced understanding of the geology surrounding hydrogen accumulations represent the whole-of-Institute efforts the Climate Project aims to support.”“This is a significant breakthrough for the future of sustainable development,” says Geoffrey Ellis, a geologist at the U.S. Geological Survey, who was not associated with this work. He adds, “While there is clearly more work that needs to be done to validate this at the pilot stage and to get this to the commercial scale, the concept that has been demonstrated is truly transformative.  The approach of engineering a system to optimize the natural process of nitrate reduction by Fe2+ is ingenious and will likely lead to further innovations along these lines.”The initial work on the process has been done in the laboratory, so the next step will be to prove the process using a real underground site. “We think that kind of experiment can be done within the next one to two years,” Abate says. This could open doors to using a similar approach for other chemical production processes, he adds.The team has applied for a patent and aims to work towards bringing the process to market.“Moving forward,” Gao says, “our focus will be on optimizing the process conditions and scaling up tests, with the goal of enabling practical applications for geological ammonia in the near future.”The research team also included Ming Lei, Bachu Sravan Kumar, Hugh Smith, Seok Hee Han, and Lokesh Sangabattula, all at MIT. Additional funding was provided by the National Science Foundation and was carried out, in part, through the use of MIT.nano facilities. More

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    Explained: Generative AI’s environmental impact

    In a two-part series, MIT News explores the environmental implications of generative AI. In this article, we look at why this technology is so resource-intensive. A second piece will investigate what experts are doing to reduce genAI’s carbon footprint and other impacts.The excitement surrounding potential benefits of generative AI, from improving worker productivity to advancing scientific research, is hard to ignore. While the explosive growth of this new technology has enabled rapid deployment of powerful models in many industries, the environmental consequences of this generative AI “gold rush” remain difficult to pin down, let alone mitigate.The computational power required to train generative AI models that often have billions of parameters, such as OpenAI’s GPT-4, can demand a staggering amount of electricity, which leads to increased carbon dioxide emissions and pressures on the electric grid.Furthermore, deploying these models in real-world applications, enabling millions to use generative AI in their daily lives, and then fine-tuning the models to improve their performance draws large amounts of energy long after a model has been developed.Beyond electricity demands, a great deal of water is needed to cool the hardware used for training, deploying, and fine-tuning generative AI models, which can strain municipal water supplies and disrupt local ecosystems. The increasing number of generative AI applications has also spurred demand for high-performance computing hardware, adding indirect environmental impacts from its manufacture and transport.“When we think about the environmental impact of generative AI, it is not just the electricity you consume when you plug the computer in. There are much broader consequences that go out to a system level and persist based on actions that we take,” says Elsa A. Olivetti, professor in the Department of Materials Science and Engineering and the lead of the Decarbonization Mission of MIT’s new Climate Project.Olivetti is senior author of a 2024 paper, “The Climate and Sustainability Implications of Generative AI,” co-authored by MIT colleagues in response to an Institute-wide call for papers that explore the transformative potential of generative AI, in both positive and negative directions for society.Demanding data centersThe electricity demands of data centers are one major factor contributing to the environmental impacts of generative AI, since data centers are used to train and run the deep learning models behind popular tools like ChatGPT and DALL-E.A data center is a temperature-controlled building that houses computing infrastructure, such as servers, data storage drives, and network equipment. For instance, Amazon has more than 100 data centers worldwide, each of which has about 50,000 servers that the company uses to support cloud computing services.While data centers have been around since the 1940s (the first was built at the University of Pennsylvania in 1945 to support the first general-purpose digital computer, the ENIAC), the rise of generative AI has dramatically increased the pace of data center construction.“What is different about generative AI is the power density it requires. Fundamentally, it is just computing, but a generative AI training cluster might consume seven or eight times more energy than a typical computing workload,” says Noman Bashir, lead author of the impact paper, who is a Computing and Climate Impact Fellow at MIT Climate and Sustainability Consortium (MCSC) and a postdoc in the Computer Science and Artificial Intelligence Laboratory (CSAIL).Scientists have estimated that the power requirements of data centers in North America increased from 2,688 megawatts at the end of 2022 to 5,341 megawatts at the end of 2023, partly driven by the demands of generative AI. Globally, the electricity consumption of data centers rose to 460 terawatts in 2022. This would have made data centers the 11th largest electricity consumer in the world, between the nations of Saudi Arabia (371 terawatts) and France (463 terawatts), according to the Organization for Economic Co-operation and Development.By 2026, the electricity consumption of data centers is expected to approach 1,050 terawatts (which would bump data centers up to fifth place on the global list, between Japan and Russia).While not all data center computation involves generative AI, the technology has been a major driver of increasing energy demands.“The demand for new data centers cannot be met in a sustainable way. The pace at which companies are building new data centers means the bulk of the electricity to power them must come from fossil fuel-based power plants,” says Bashir.The power needed to train and deploy a model like OpenAI’s GPT-3 is difficult to ascertain. In a 2021 research paper, scientists from Google and the University of California at Berkeley estimated the training process alone consumed 1,287 megawatt hours of electricity (enough to power about 120 average U.S. homes for a year), generating about 552 tons of carbon dioxide.While all machine-learning models must be trained, one issue unique to generative AI is the rapid fluctuations in energy use that occur over different phases of the training process, Bashir explains.Power grid operators must have a way to absorb those fluctuations to protect the grid, and they usually employ diesel-based generators for that task.Increasing impacts from inferenceOnce a generative AI model is trained, the energy demands don’t disappear.Each time a model is used, perhaps by an individual asking ChatGPT to summarize an email, the computing hardware that performs those operations consumes energy. Researchers have estimated that a ChatGPT query consumes about five times more electricity than a simple web search.“But an everyday user doesn’t think too much about that,” says Bashir. “The ease-of-use of generative AI interfaces and the lack of information about the environmental impacts of my actions means that, as a user, I don’t have much incentive to cut back on my use of generative AI.”With traditional AI, the energy usage is split fairly evenly between data processing, model training, and inference, which is the process of using a trained model to make predictions on new data. However, Bashir expects the electricity demands of generative AI inference to eventually dominate since these models are becoming ubiquitous in so many applications, and the electricity needed for inference will increase as future versions of the models become larger and more complex.Plus, generative AI models have an especially short shelf-life, driven by rising demand for new AI applications. Companies release new models every few weeks, so the energy used to train prior versions goes to waste, Bashir adds. New models often consume more energy for training, since they usually have more parameters than their predecessors.While electricity demands of data centers may be getting the most attention in research literature, the amount of water consumed by these facilities has environmental impacts, as well.Chilled water is used to cool a data center by absorbing heat from computing equipment. It has been estimated that, for each kilowatt hour of energy a data center consumes, it would need two liters of water for cooling, says Bashir.“Just because this is called ‘cloud computing’ doesn’t mean the hardware lives in the cloud. Data centers are present in our physical world, and because of their water usage they have direct and indirect implications for biodiversity,” he says.The computing hardware inside data centers brings its own, less direct environmental impacts.While it is difficult to estimate how much power is needed to manufacture a GPU, a type of powerful processor that can handle intensive generative AI workloads, it would be more than what is needed to produce a simpler CPU because the fabrication process is more complex. A GPU’s carbon footprint is compounded by the emissions related to material and product transport.There are also environmental implications of obtaining the raw materials used to fabricate GPUs, which can involve dirty mining procedures and the use of toxic chemicals for processing.Market research firm TechInsights estimates that the three major producers (NVIDIA, AMD, and Intel) shipped 3.85 million GPUs to data centers in 2023, up from about 2.67 million in 2022. That number is expected to have increased by an even greater percentage in 2024.The industry is on an unsustainable path, but there are ways to encourage responsible development of generative AI that supports environmental objectives, Bashir says.He, Olivetti, and their MIT colleagues argue that this will require a comprehensive consideration of all the environmental and societal costs of generative AI, as well as a detailed assessment of the value in its perceived benefits.“We need a more contextual way of systematically and comprehensively understanding the implications of new developments in this space. Due to the speed at which there have been improvements, we haven’t had a chance to catch up with our abilities to measure and understand the tradeoffs,” Olivetti says. More

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    An abundant phytoplankton feeds a global network of marine microbes

    One of the hardest-working organisms in the ocean is the tiny, emerald-tinged Prochlorococcus marinus. These single-celled “picoplankton,” which are smaller than a human red blood cell, can be found in staggering numbers throughout the ocean’s surface waters, making Prochlorococcus the most abundant photosynthesizing organism on the planet. (Collectively, Prochlorococcus fix as much carbon as all the crops on land.) Scientists continue to find new ways that the little green microbe is involved in the ocean’s cycling and storage of carbon.Now, MIT scientists have discovered a new ocean-regulating ability in the small but mighty microbes: cross-feeding of DNA building blocks. In a study appearing today in Science Advances, the team reports that Prochlorococcus shed these extra compounds into their surroundings, where they are then “cross-fed,” or taken up by other ocean organisms, either as nutrients, energy, or for regulating metabolism. Prochlorococcus’ rejects, then, are other microbes’ resources.What’s more, this cross-feeding occurs on a regular cycle: Prochlorococcus tend to shed their molecular baggage at night, when enterprising microbes quickly consume the cast-offs. For a microbe called SAR11, the most abundant bacteria in the ocean, the researchers found that the nighttime snack acts as a relaxant of sorts, forcing the bacteria to slow down their metabolism and effectively recharge for the next day.Through this cross-feeding interaction, Prochlorococcus could be helping many microbial communities to grow sustainably, simply by giving away what it doesn’t need. And they’re doing so in a way that could set the daily rhythms of microbes around the world.“The relationship between the two most abundant groups of microbes in ocean ecosystems has intrigued oceanographers for years,” says co-author and MIT Institute Professor Sallie “Penny” Chisholm, who played a role in the discovery of Prochlorococcus in 1986. “Now we have a glimpse of the finely tuned choreography that contributes to their growth and stability across vast regions of the oceans.”Given that Prochlorococcus and SAR11 suffuse the surface oceans, the team suspects that the exchange of molecules from one to the other could amount to one of the major cross-feeding relationships in the ocean, making it an important regulator of the ocean carbon cycle.“By looking at the details and diversity of cross-feeding processes, we can start to unearth important forces that are shaping the carbon cycle,” says the study’s lead author, Rogier Braakman, a research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS).Other MIT co-authors include Brandon Satinsky, Tyler O’Keefe, Shane Hogle, Jamie Becker, Robert Li, Keven Dooley, and Aldo Arellano, along with Krista Longnecker, Melissa Soule, and Elizabeth Kujawinski of Woods Hole Oceanographic Institution (WHOI).Spotting castawaysCross-feeding occurs throughout the microbial world, though the process has mainly been studied in close-knit communities. In the human gut, for instance, microbes are in close proximity and can easily exchange and benefit from shared resources.By comparison, Prochlorococcus are free-floating microbes that are regularly tossed and mixed through the ocean’s surface layers. While scientists assume that the plankton are involved in some amount of cross-feeding, exactly how this occurs, and who would benefit, have historically been challenging to probe; any stuff that Prochlorococcus cast away would have vanishingly low concentrations,and be exceedingly difficult to measure.But in work published in 2023, Braakman teamed up with scientists at WHOI, who pioneered ways to measure small organic compounds in seawater. In the lab, they grew various strains of Prochlorococcus under different conditions and characterized what the microbes released. They found that among the major “exudants,” or released molecules, were purines and pyridines, which are molecular building blocks of DNA. The molecules also happen to be nitrogen-rich — a fact that puzzled the team. Prochlorococcus are mainly found in ocean regions that are low in nitrogen, so it was assumed they’d want to retain any and all nitrogen-containing compounds they can. Why, then, were they instead throwing such compounds away?Global symphonyIn their new study, the researchers took a deep dive into the details of Prochlorococcus’ cross-feeding and how it influences various types of ocean microbes.They set out to study how Prochlorococcus use purine and pyridine in the first place, before expelling the compounds into their surroundings. They compared published genomes of the microbes, looking for genes that encode purine and pyridine metabolism. Tracing the genes forward through the genomes, the team found that once the compounds are produced, they are used to make DNA and replicate the microbes’ genome. Any leftover purine and pyridine is recycled and used again, though a fraction of the stuff is ultimately released into the environment. Prochlorococcus appear to make the most of the compounds, then cast off what they can’t.The team also looked to gene expression data and found that genes involved in recycling purine and pyrimidine peak several hours after the recognized peak in genome replication that occurs at dusk. The question then was: What could be benefiting from this nightly shedding?For this, the team looked at the genomes of more than 300 heterotrophic microbes — organisms that consume organic carbon rather than making it themselves through photosynthesis. They suspected that such carbon-feeders could be likely consumers of Prochlorococcus’ organic rejects. They found most of the heterotrophs contained genes that take up either purine or pyridine, or in some cases, both, suggesting microbes have evolved along different paths in terms of how they cross-feed.The group zeroed in on one purine-preferring microbe, SAR11, as it is the most abundant heterotrophic microbe in the ocean. When they then compared the genes across different strains of SAR11, they found that various types use purines for different purposes, from simply taking them up and using them intact to breaking them down for their energy, carbon, or nitrogen. What could explain the diversity in how the microbes were using Prochlorococcus’ cast-offs?It turns out the local environment plays a big role. Braakman and his collaborators performed a metagenome analysis in which they compared the collectively sequenced genomes of all microbes in over 600 seawater samples from around the world, focusing on SAR11 bacteria. Metagenome sequences were collected alongside measurements of various environmental conditions and geographic locations in which they are found. This analysis showed that the bacteria gobble up purine for its nitrogen when the nitrogen in seawater is low, and for its carbon or energy when nitrogen is in surplus — revealing the selective pressures shaping these communities in different ocean regimes.“The work here suggests that microbes in the ocean have developed relationships that advance their growth potential in ways we don’t expect,” says co-author Kujawinski.Finally, the team carried out a simple experiment in the lab, to see if they could directly observe a mechanism by which purine acts on SAR11. They grew the bacteria in cultures, exposed them to various concentrations of purine, and unexpectedly found it causes them to slow down their normal metabolic activities and even growth. However, when the researchers put these same cells under environmentally stressful conditions, they continued growing strong and healthy cells, as if the metabolic pausing by purines helped prime them for growth, thereby avoiding the effects of the stress.“When you think about the ocean, where you see this daily pulse of purines being released by Prochlorococcus, this provides a daily inhibition signal that could be causing a pause in SAR11 metabolism, so that the next day when the sun comes out, they are primed and ready,” Braakman says. “So we think Prochlorococcus is acting as a conductor in the daily symphony of ocean metabolism, and cross-feeding is creating a global synchronization among all these microbial cells.”This work was supported, in part, by the Simons Foundation and the National Science Foundation. More

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    In a unique research collaboration, students make the case for less e-waste

    Brought together as part of the Social and Ethical Responsibilities of Computing (SERC) initiative within the MIT Schwarzman College of Computing, a community of students known as SERC Scholars is collaborating to examine the most urgent problems humans face in the digital landscape.Each semester, students from all levels from across MIT are invited to join a different topical working group led by a SERC postdoctoral associate. Each group delves into a specific issue — such as surveillance or data ownership — culminating in a final project presented at the end of the term.Typically, students complete the program with hands-on experience conducting research in a new cross-disciplinary field. However, one group of undergraduate and graduate students recently had the unique opportunity to enhance their resume by becoming published authors of a case study about the environmental and climate justice implications of the electronics hardware life cycle.Although it’s not uncommon for graduate students to co-author case studies, it’s unusual for undergraduates to earn this opportunity — and for their audience to be other undergraduates around the world.“Our team was insanely interdisciplinary,” says Anastasia Dunca, a junior studying computer science and one of the co-authors. “I joined the SERC Scholars Program because I liked the idea of being part of a cohort from across MIT working on a project that utilized all of our skillsets. It also helps [undergraduates] learn the ins and outs of computing ethics research.”Case study co-author Jasmin Liu, an MBA student in the MIT Sloan School of Management, sees the program as a platform to learn about the intersection of technology, society, and ethics: “I met team members spanning computer science, urban planning, to art/culture/technology. I was excited to work with a diverse team because I know complex problems must be approached with many different perspectives. Combining my background in humanities and business with the expertise of others allowed us to be more innovative and comprehensive.”Christopher Rabe, a former SERC postdoc who facilitated the group, says, “I let the students take the lead on identifying the topic and conducting the research.” His goal for the group was to challenge students across disciplines to develop a working definition of climate justice.From mining to e-wasteThe SERC Scholars’ case study, “From Mining to E-waste: The Environmental and Climate Justice Implications of the Electronics Hardware Life Cycle,” was published by the MIT Case Studies in Social and Ethical Responsibilities of Computing.The ongoing case studies series, which releases new issues twice a year on an open-source platform, is enabling undergraduate instructors worldwide to incorporate research-based education materials on computing ethics into their existing class syllabi.This particular case study broke down the electronics life cycle from mining to manufacturing, usage, and disposal. It offered an in-depth look at how this cycle promotes inequity in the Global South. Mining for the average of 60 minerals that power everyday devices lead to illegal deforestation, compromising air quality in the Amazon, and triggering armed conflict in Congo. Manufacturing leads to proven health risks for both formal and informal workers, some of whom are child laborers.Life cycle assessment and circular economy are proposed as mechanisms for analyzing environmental and climate justice issues in the electronics life cycle. Rather than posing solutions, the case study offers readers entry points for further discussion and for assessing their own individual responsibility as producers of e-waste.Crufting and crafting a case studyDunca joined Rabe’s working group, intrigued by the invitation to conduct a rigorous literature review examining issues like data center resource and energy use, manufacturing waste, ethical issues with AI, and climate change. Rabe quickly realized that a common thread among all participants was an interest in understanding and reducing e-waste and its impact on the environment.“I came in with the idea of us co-authoring a case study,” Rabe said. However, the writing-intensive process was initially daunting to those students who were used to conducting applied research. Once Rabe created sub-groups with discrete tasks, the steps for researching, writing, and iterating a case study became more approachable.For Ellie Bultena, an undergraduate student studying linguistics and philosophy and a contributor to the study, that meant conducting field research on the loading dock of MIT’s Stata Center, where students and faculty go “crufting” through piles of clunky printers, broken computers, and used lab equipment discarded by the Institute’s labs, departments, and individual users.Although not a formally sanctioned activity on-campus, “crufting” is the act of gleaning usable parts from these junk piles to be repurposed into new equipment or art. Bultena’s respondents, who opted to be anonymous, said that MIT could do better when it comes to the amount of e-waste generated and suggested that formal strategies could be implemented to encourage community members to repair equipment more easily or recycle more formally.Rabe, now an education program director at the MIT Environmental Solutions Initiative, is hopeful that through the Zero-Carbon Campus Initiative, which commits MIT to eliminating all direct emissions by 2050, MIT will ultimately become a model for other higher education institutions.Although the group lacked the time and resources to travel to communities in the Global South that they profiled in their case study, members leaned into exhaustive secondary research, collecting data on how some countries are irresponsibly dumping e-waste. In contrast, others have developed alternative solutions that can be duplicated elsewhere and scaled.“We source materials, manufacture them, and then throw them away,” Lelia Hampton says. A PhD candidate in electrical engineering and computer science and another co-author, Hampton jumped at the opportunity to serve in a writing role, bringing together the sub-groups research findings. “I’d never written a case study, and it was exciting. Now I want to write 10 more.”The content directly informed Hampton’s dissertation research, which “looks at applying machine learning to climate justice issues such as urban heat islands.” She said that writing a case study that is accessible to general audiences upskilled her for the non-profit organization she’s determined to start. “It’s going to provide communities with free resources and data needed to understand how they are impacted by climate change and begin to advocate against injustice,” Hampton explains.Dunca, Liu, Rabe, Bultena, and Hampton are joined on the case study by fellow authors Mrinalini Singha, a graduate student in the Art, Culture, and Technology program; Sungmoon Lim, a graduate student in urban studies and planning and EECS; Lauren Higgins, an undergraduate majoring in political science; and Madeline Schlegal, a Northeastern University co-op student.Taking the case study to classrooms around the worldAlthough PhD candidates have contributed to previous case studies in the series, this publication is the first to be co-authored with MIT undergraduates. Like any other peer-reviewed journal, before publication, the SERC Scholars’ case study was anonymously reviewed by senior scholars drawn from various fields.The series editor, David Kaiser, also served as one of SERC’s inaugural associate deans and helped shape the program. “The case studies, by design, are short, easy to read, and don’t take up lots of time,” Kaiser explained. “They are gateways for students to explore, and instructors can cover a topic that has likely already been on their mind.” This semester, Kaiser, the Germeshausen Professor of the History of Science and a professor of physics, is teaching STS.004 (Intersections: Science, Technology, and the World), an undergraduate introduction to the field of science, technology, and society. The last month of the semester has been dedicated wholly to SERC case studies, one of which is: “From Mining to E-Waste.”Hampton was visibly moved to hear that the case study is being used at MIT but also by some of the 250,000 visitors to the SERC platform, many of whom are based in the Global South and directly impacted by the issues she and her cohort researched. “Many students are focused on climate, whether through computer science, data science, or mechanical engineering. I hope that this case study educates them on environmental and climate aspects of e-waste and computing.” More