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    3Q: How MIT is working to reduce carbon emissions on our campus

    Fast Forward: MIT’s Climate Action Plan for the Decade, launched in May 2021, charges MIT to eliminate its direct carbon emissions by 2050. Setting an interim goal of net zero emissions by 2026 is an important step to getting there. Joe Higgins, vice president for campus services and stewardship, speaks here about the coordinated, multi-team effort underway to address the Institute’s carbon-reduction goals, the challenges and opportunities in getting there, and creating a blueprint for a carbon-free campus in 2050.

    Q: The Fast Forward plan laid out specific goals for MIT to address its own carbon footprint. What has been the strategy to tackle these priorities?

    A: The launch of the Fast Forward Climate Action Plan empowered teams at MIT to expand the scope of our carbon reduction tasks beyond the work we’ve been doing to date. The on-campus activities called for in the plan range from substantially expanding our electric vehicle infrastructure on campus, to increasing our rooftop solar installations, to setting impact goals for food, water, and waste systems. Another strategy utilizes artificial intelligence to further reduce energy consumption and emissions from our buildings. When fully implemented, these systems will adjust a building’s temperature setpoints throughout the day while maintaining occupant comfort, and will use occupancy data, weather forecasts, and carbon intensity projections from the grid to make more efficient use of energy. 

    We have tremendous momentum right now thanks to the progress made over the past decade by our teams — which include planners, designers, engineers, construction managers, and sustainability and operations experts. Since 2014, our efforts to advance energy efficiency and incorporate renewable energy have reduced net emissions on campus by 20% (from a 2014 baseline) despite significant campus growth. One of our current goals is to further reduce energy use in high-intensity research buildings — 20 of our campus buildings consume more than 50% of our energy. To reduce energy usage in these buildings we have major energy retrofit projects in design or in planning for buildings 32, 46, 68, 76, E14, and E25, and we expect this work will reduce overall MIT emissions by an additional 10 to 15%.

    Q: The Fast Forward plan acknowledges the challenges we face in our efforts to reach our campus emission reduction goals, in part due to the current state of New England’s electrical grid. How does MIT’s district energy system factor into our approach? 

    A: MIT’s district energy system is a network of underground pipes and power lines that moves energy from the Central Utilities Plant (CUP) around to the vast majority of Institute buildings to provide electricity, heating, and air conditioning. Using a closed-loop, central-source system like this enables MIT to operate more efficiently by using less energy to heat and cool its buildings and labs, and by maintaining better load control to accommodate seasonal variations in peak demand.

    When the new MIT campus was built in Cambridge in 1916, it included a centralized state-of-the-art steam and electrical power plant that would service the campus buildings. This central district energy approach allowed MIT to avoid having individual furnaces in each building and to easily incorporate progressively cleaner fuel sources campus-wide over the years. After starting with coal as a primary energy source, MIT transitioned to fuel oil, then to natural gas, and then to cogeneration in 1995 — and each step has made the campus more energy efficient. Our continuous investment in a centralized infrastructure has facilitated our ability to improve energy efficiency while adding capacity; as new technologies become available, we can implement them across the entire campus. Our district energy system is very adaptable to seasonal variations in demand for cooling, heating and electricity, and builds upon decades of centralized investments in energy-efficient infrastructure.

    This past year, MIT completed a major upgrade of the district energy system whereby the majority of buildings on campus now benefit from the most advanced cogeneration technology for combined heating, cooling, and power delivery. This system generates electrical power that produces 15 to 25% less carbon than the current New England grid. We also have the ability to export power during times when the grid is most stressed, which contributes to the resiliency of local energy systems. On the flip side, any time the grid is a cleaner option, MIT is able to import a higher amount of electricity from the utility by distributing this energy through our centralized system. In fact, it’s important to note that we have the ability to import 100% of our electrical energy from the grid as it becomes cleaner. We anticipate that this will happen as the next major wave of technology innovation unfolds and the abundance of offshore wind and other renewable resources increases as anticipated by the end of this decade. As the grid gets greener, our adaptable district energy system will bring us closer to meeting our decarbonization goals.

    MIT’s ability to adapt its system and use new technologies is crucial right now as we work in collaboration with faculty, students, industry experts, peer institutions, and the cities of Cambridge and Boston to evaluate various strategies, opportunities, and constraints. In terms of evolving into a next-generation district energy system, we are reviewing options such as electric steam boilers and industrial-scale heat pumps, thermal batteries, geothermal exchange, micro-reactors, bio-based fuels, and green hydrogen produced from renewable energy. We are preparing to incorporate the most beneficial technologies into a blueprint that will get us to our 2050 goal.

    Q: What is MIT doing in the near term to reach the carbon-reduction goals of the climate action plan?

    A: In the near term, we are exploring several options, including enabling large-scale renewable energy projects and investing in verified carbon offset projects that reduce, avoid, or sequester carbon. In 2016, MIT joined a power purchase agreement (PPA) partnership that enabled the construction of a 650-acre solar farm in North Carolina and resulted in the early retirement of a nearby coal plant. We’ve documented a huge emissions savings from this, and we’re exploring how to do something similar on a much larger scale with a broader group of partners. As we seek out collaborative opportunities that enable the development of new renewable energy sources, we hope to provide a model for other institutions and organizations, as the original PPA did. Because PPAs accelerate the de-carbonization of regional electricity grids, they can have an enormous and far-reaching impact. We see these partnerships as an important component of achieving net zero emissions on campus as well as accelerating the de-carbonization of regional power grids — a transformation that must take place to reach zero emissions by 2050.

    Other near-term initiatives include enabling community solar power projects in Massachusetts to support the state’s renewable energy goals and provide opportunities for more property owners (municipalities, businesses, homeowners, etc.) to purchase affordable renewable energy. MIT is engaged with three of these projects; one of them is in operation today in Middleton, and the two others are scheduled to be built soon on Cape Cod.

    We’re joining the commonwealth and its cities, its organizations and utility providers on an unprecedented journey — the global transition to a clean energy system. Along the way, everything is going to change as technologies and the grid continue to evolve. Our focus is on both the near term and the future, as we plan a path into the next energy era. More

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    MIT accelerates efforts on path to carbon reduction goals

    Under its “Fast Forward” climate action plan, which was announced in May 2021, MIT has set a goal of eliminating direct emissions from its campus by 2050. An important near-term milestone will be achieving net-zero emissions by 2026. Many other colleges and universities have set similar targets. What does it take to achieve such a dramatic reduction?

    Since 2014, when MIT launched a five-year plan for action on climate change, net campus emissions have been cut by 20 percent. To meet the 2026 target, and ultimately achieve zero direct emissions by 2050, the Institute is making its campus buildings dramatically more energy efficient, transitioning to electric vehicles (EVs), and enabling large-scale renewable energy projects, among other strategies.

    “This is an ‘all-in’ moment for MIT, and we’re taking comprehensive steps to address our carbon footprint,” says Glen Shor, executive vice president and treasurer. “Reducing our emissions to zero will be challenging, but it’s the right aspiration.”

    “As an energy-intensive campus in an urban setting, our ability to achieve this goal will, in part, depend on the capacity of the local power grid to support the electrification of buildings and transportation, and how ‘green’ that grid electricity will become over time,” says Joe Higgins, MIT’s vice president for campus services and stewardship. “It will also require breakthrough technology improvements and new public policies to drive their adoption. Many of those tech breakthroughs are being developed by our own faculty, and our teams are planning scenarios in anticipation of their arrival.”

    Working toward an energy-efficient campus

    The on-campus reductions have come primarily from a major upgrade to MIT’s Central Utilities Plant, which provides electricity, heating, and cooling for about 80 percent of all Institute buildings. The upgraded plant, which uses advanced cogeneration technology, became fully operational at the end of 2021 and is meeting campus energy needs at greater efficiency and lower carbon intensity (on average 15 to 25 percent cleaner) compared to the regional electricity grid. Carbon reductions from the increased efficiency provided by the enhanced plant are projected to counter the added greenhouse gas emissions caused by recently completed and planned construction and operation of new buildings on campus, especially energy-intensive laboratory buildings.

    Energy from the plant is delivered to campus buildings through MIT’s district energy system, a network of underground pipes and power lines providing electricity, heating, and air conditioning. With this adaptable system, MIT can introduce new technologies as they become available to increase the system’s energy efficiency. The system enables MIT to export power when the regional grid is under stress and to import electricity from the power grid as it becomes cleaner, likely over the next decade as the availability of offshore wind and renewable resources increases. “At the same time, we are reviewing additional technology options such as industrial-scale heat pumps, thermal batteries, geothermal exchange, microreactors, bio-based fuels, and green hydrogen produced from renewable energy,” Higgins says.

    Along with upgrades to the plant, MIT is gradually converting existing steam-based heating systems into more efficient hot-water systems. This long-term project to lower campus emissions requires replacing the vast network of existing steam pipes and infrastructure, and will be phased in as systems need to be replaced. Currently MIT has four buildings that are on a hot-water system, with five more buildings transitioning to hot water by the fall of 2022.  

    Minimizing emissions by implementing meaningful building efficiency standards has been an ongoing strategy in MIT’s climate mitigation efforts. In 2016, MIT made a commitment that all new campus construction and major renovation projects must earn at least Leadership in Energy and Environmental Design (LEED) Gold certification. To date, 24 spaces and buildings at MIT have earned a LEED designation, a performance-based rating system of a building’s environmental attributes associated with its design, construction, operations, and management.

    Current efficiency efforts focus on reducing energy in the 20 buildings that account for more than 50 percent of MIT’s energy usage. One such project under construction aims to improve energy efficiency in Building 46, which houses the Department of Brain and Cognitive Sciences and the Picower Institute for Learning and Memory and is the biggest energy user on the campus because of its large size and high concentration of lab spaces. Interventions include optimizing ventilation systems that will significantly reduce energy use while improving occupant comfort, and working with labs to implement programs such as fume hood hibernation and equipment adjustments. For example, raising ultralow freezer set points by 10 degrees can reduce their energy consumption by as much as 40 percent. Together, these measures are projected to yield a 35 percent reduction in emissions for Building 46, which would contribute to reducing campus-level emissions by 2 percent.

    Over the past decade, in addition to whole building intervention programs, the campus has taken targeted measures in over 100 campus buildings to add building insulation, replace old, inefficient windows, transition to energy-efficient lighting and mechanical systems, optimize lab ventilation systems, and install solar panels on solar-ready rooftops on campus — and will increase the capacity of renewable energy installations on campus by a minimum of 400 percent by 2026. These smaller scale contributions to overall emissions reductions are essential steps in a comprehensive campus effort.

    Electrification of buildings and vehicles

    With an eye to designing for “the next energy era,” says Higgins, MIT is looking to large-scale electrification of its buildings and district energy systems to reduce building use-associated emissions. Currently under renovation, the Metropolitan Storage Warehouse — which will house the MIT School of Architecture and Planning (SA+P) and the newly established MIT Morningside Academy for Design — will be the first building on campus to undergo this transformation by using electric heat pumps as its main heating and supplemental cooling source. The project team, consisting of campus engineering and construction teams as well as the designers, is working with SA+P faculty to design this innovative electrification project. The solution will move excess heat from the district energy infrastructure and nearby facilities to supply the heat pump system, creating a solution that uses less energy — resulting in fewer carbon emissions. 

    Next to building energy use, emissions from on-campus vehicles are a key target for reduction; one of the goals in the “Fast Forward” plan is the electrification of on-campus vehicles. This includes the expansion of electric vehicle charging stations, and work has begun on the promised 200 percent expansion of the number of stations on campus, from 120 to 360. Sites are being evaluated to make sure that all members of the MIT community have easy access to these facilities.

    The electrification also includes working toward replacing existing MIT-owned vehicles, from shuttle buses and vans to pickup trucks and passenger cars, as well as grounds maintenance equipment. Shu Yang Zhang, a junior in the Department of Materials Science and Engineering, is part of an Office of Sustainability student research team that carried out an evaluation of the options available for each type of vehicle and compared both their lifecycle costs and emissions.

    Zhang says the team examined “the specifics of the vehicles that we own, looking at key measures such as fuel economy and cargo capacity,” and determined what alternatives exist in each category. The team carried out a study of the costs for replacing existing vehicles with EVs on the market now, versus buying new gas vehicles or leaving the existing ones in place. They produced a set of specific recommendations about fleet vehicle replacement and charging infrastructure installation on campus that supports both commuters and an MIT EV fleet in the future. According to their estimates, Zhang says, “the costs should be not drastically different” in the long run for the new electric vehicles.

    Strength in numbers

    While a panoply of measures has contributed to the successful offsetting of emissions so far, the biggest single contributor was MIT’s creation of an innovative, collaborative power purchase agreement (PPA) that enabled the construction of a large solar farm in North Carolina, which in turn contributed to the early retirement of a large coal-fired power plant in that region. MIT is committed to buying 73 percent of the power generated by the new facility, which is equivalent to approximately 40 percent of the Institute’s electricity use.

    That PPA, which was a collaboration between three institutions, provided a template that has already been emulated by other institutions, in many cases enabling smaller organizations to take part in such a plan and achieve greater offsets of their carbon emissions than might have been possible acting on their own. Now, MIT is actively pursuing new, larger variations on that plan, which may include a wider variety of organizational participants, perhaps including local governments as well as institutions and nonprofits. The hope is that, as was the case with the original PPA, such collaborations could provide a model that other institutions and organizations may adopt as well.

    Strategic portfolio agreements like the PPA will help achieve net zero emissions on campus while accelerating the decarbonization of regional electricity grids — a transformation critical to achieving net zero emissions, alongside all the work that continues to reduce the direct emissions from the campus itself.

    “PPAs play an important role in MIT’s net zero strategy and have an immediate and significant impact in decarbonization of regional power grids by enabling renewable energy projects,” says Paul L. Joskow, the Elizabeth and James Killian Professor of Economics. “Many well-known U.S. companies and organizations that are seeking to enable and purchase CO2-free electricity have turned to long-term PPAs selected through a competitive procurement process to help to meet their voluntary internal decarbonization commitments. While there are still challenges regarding organizational procurements — including proper carbon emissions mitigation accounting, optimal contract design, and efficient integration into wholesale electricity markets — we are optimistic that MIT’s efforts and partnerships will contribute to resolving some of these issues.”

    Addressing indirect sources of emissions

    MIT’s examination of emissions is not limited to the campus itself but also the indirect sources associated with the Institute’s operations, research, and education. Of these indirect emissions, the three major ones are business travel, purchased goods and services, and construction of buildings, which are collectively larger than the total direct emissions from campus.

    The strategic sourcing team in the Office of the Vice President for Finance has been working to develop opportunities and guidelines for making it easier to purchase sustainable products, for everything from office paper to electronics to lab equipment. Jeremy Gregory, executive director of MIT’s Climate and Sustainability Consortium, notes that MIT’s characteristic independent spirit resists placing limits on what products researchers can buy, but, he says, “we have opportunities to centralize some of our efforts and empower our community to choose low-impact alternatives when making procurement decisions.”

    The path forward

    The process of identifying and implementing MIT’s carbon reductions will be supported, in part, by the Carbon Footprint Working Group, which was launched by the Climate Nucleus, a new body MIT created to manage the implementation of the “Fast Forward” climate plan. The nucleus includes a broad representation from MIT’s departments, labs, and centers that are working on climate change issues. “We’ve created this internal structure in an effort to integrate operational expertise with faculty and student research innovations,” says Director of Sustainability Julie Newman.

    Whatever measures end up being adopted to reduce energy and associated emissions, their results will be made available continuously to members of the MIT community in real-time, through a campus data gateway, Newman says — a degree of transparency that is exceptional in higher education. “If you’re interested in supporting all these efforts and following this,” she says, “you can track the progress via Energize MIT,” a set of online visualizations that display various measures of MIT’s energy usage and greenhouse gas emissions over time. More

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    From bridges to DNA: civil engineering across disciplines

    How is DNA like a bridge? This question is not a riddle or logic game, it is a concern of Johannes Kalliauer’s doctoral thesis.

    As a student at TU Wien in Austria, Kalliauer was faced with a monumental task: combining approaches from civil engineering and theoretical physics to better understand the forces that act on DNA.

    Kalliauer, now a postdoc at the MIT Concrete Sustainability Hub, says he modeled DNA as though it were a beam, using molecular dynamics principles to understand its structural properties.

    “The mechanics of very small objects, like DNA helices, and large ones, like bridges, are quite similar. Each may be understood in terms of Newtonian mechanics. Forces and moments act on each system, subjecting each to deformations like twisting, stretching, and warping,” says Kalliauer.

    As a 2020 article from TU Wien noted, Kalliauer observed a counterintuitive behavior when examining DNA at an atomic level. Unlike a typical spring which becomes less coiled as it is stretched, DNA was observed to become more wound as its length was increased. 

    In situations like these where conventional logic appears to break down, Kalliauer relies on the intuition he has gained as an engineer.

    “To understand this strange behavior in DNA, I turned to a fundamental approach: I examined what was the same about DNA and macroscopic structures and what was different. Civil engineers use methods and calculations which have been developed over centuries and which are very similar to the ones I employed for my thesis,” Kalliauer explains. 

    As Kalliauer continues, “Structural engineering is an incredibly versatile discipline. If you understand it, you can understand atomistic objects like DNA strands and very large ones like galaxies. As a researcher, I rely on it to help me bring new viewpoints to fields like biology. Other civil engineers can and should do the same.”

    Kalliauer, who grew up in a small town in Austria, has spent his life applying unconventional approaches like this across disciplines. “I grew up in a math family. While none of us were engineers, my parents instilled an appreciation for the discipline in me and my two older sisters.”

    After middle school, Kalliauer attended a technical school for civil engineering, where he discovered a fascination for mechanics. He also worked on a construction site to gain practical experience and see engineering applied in a real-world context.

    Kalliauer studied out of interest intensely, working upwards of 100 hours per week to better understand coursework in university. “I asked teachers and professors many questions, often challenging their ideas. Above everything else, I needed to understand things for myself. Doing well on exams was a secondary concern.”

    In university, he studied topics ranging from car crash testing to concrete hinges to biology. As a new member of the CSHub, he is studying how floods may be modeled with the statistical physics-based model provided by lattice density functional theory.

    In doing this, he builds on the work of past and present CSHub researchers like Elli Vartziotis and Katerina Boukin. 

    “It’s important to me that this research has a real impact in the world. I hope my approach to engineering can help researchers and stakeholders understand how floods propagate in urban contexts, so that we may make cities more resilient,” he says. More

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    Stranded assets could exact steep costs on fossil energy producers and investors

    A 2021 study in the journal Nature found that in order to avert the worst impacts of climate change, most of the world’s known fossil fuel reserves must remain untapped. According to the study, 90 percent of coal and nearly 60 percent of oil and natural gas must be kept in the ground in order to maintain a 50 percent chance that global warming will not exceed 1.5 degrees Celsius above preindustrial levels.

    As the world transitions away from greenhouse-gas-emitting activities to keep global warming well below 2 C (and ideally 1.5 C) in alignment with the Paris Agreement on climate change, fossil fuel companies and their investors face growing financial risks (known as transition risks), including the prospect of ending up with massive stranded assets. This ongoing transition is likely to significantly scale back fossil fuel extraction and coal-fired power plant operations, exacting steep costs — most notably asset value losses — on fossil-energy producers and shareholders.

    Now, a new study in the journal Climate Change Economics led by researchers at the MIT Joint Program on the Science and Policy of Global Change estimates the current global asset value of untapped fossil fuels through 2050 under four increasingly ambitious climate-policy scenarios. The least-ambitious scenario (“Paris Forever”) assumes that initial Paris Agreement greenhouse gas emissions-reduction pledges are upheld in perpetuity; the most stringent scenario (“Net Zero 2050”) adds coordinated international policy instruments aimed at achieving global net-zero emissions by 2050.

    Powered by the MIT Joint Program’s model of the world economy with detailed representation of the energy sector and energy industry assets over time, the study finds that the global net present value of untapped fossil fuel output through 2050 relative to a reference “No Policy” scenario ranges from $21.5 trillion (Paris Forever) to $30.6 trillion (Net Zero 2050). The estimated global net present value of stranded assets in coal power generation through 2050 ranges from $1.3 to $2.3 trillion.

    “The more stringent the climate policy, the greater the volume of untapped fossil fuels, and hence the higher the potential asset value loss for fossil-fuel owners and investors,” says Henry Chen, a research scientist at the MIT Joint Program and the study’s lead author.

    The global economy-wide analysis presented in the study provides a more fine-grained assessment of stranded assets than those performed in previous studies. Firms and financial institutions may combine the MIT analysis with details on their own investment portfolios to assess their exposure to climate-related transition risk. More

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    Power, laws, and planning

    Think about almost any locale where people live: Why does it have its current built form? Why do people reside where they do? No doubt there are quirks of geography or history involved. But places are also shaped by money, politics, and the law — in short, by power.

    Studying those issues is the work of Justin Steil, an associate professor in MIT’s Department of Urban Studies and Planning. Steil’s research largely focuses on cities, drawing out the ways that politics and the law sustain social divisions on the ground.

    Or, as Steil says, “The biggest theme that runs through my work is: How is power exercised through control of space, and access to particular places? What are the spatial and social and legal processes of inclusion and exclusion that generate or can address inequality, generally?”

    Those mechanisms can be found all around. Wealthy suburbs with large minimum lot sizes restrict growth and access to high-ranking school districts; gated communities take that process of separation even more literally; and many U.S. metro areas have island-like jurisdictions that have seceded from larger surrounding cities. City residential geography often displays the legacies of redlining (discrimination laws) and even century-old mob violence incidents used to curb integration.

    “I really like to try to get down to pinpoint what are the precise laws, ordinances, and policies, and specific social processes, which continue to generate inequality,” says Steil. “And ask: How can we change that to generate greater access to resources and opportunities?”

    While investigating questions that range widely across the theme of power and space, Steil has published many research articles and book chapters while helping edit volumes on the subject. For his research and teaching, Steil was awarded tenure at MIT earlier this year.

    Combining law and urban planning

    Steil grew up in New York City, where his surroundings helped him realize how much urban policy and laws matters. He attended Harvard University as an undergraduate, majored in African American Studies, and spent a summer as a student in South Africa in 1998, just as the country was launching its new democracy.

    “That had a big impact,” Steil says. “Both seeing the power of grassroots organizing and social movements, to overthrow this white supremacist government, but also to understand how the apartheid system had worked, the role of law and of space — how the landscape and built environment had been consciously designed to keep people separate and unequal.”

    Between graduating from college and finishing his PhD, Steil embarked on an odyssey of jobs in the nonprofit sector and graduate work on multiple academic disciplines, touching on pressing social topics. Steil worked at the City School in Boston, a youth leadership program; the Food Project, a Massachusetts agricultural program; two nonprofits in Juarez, Mexico, focused on preventing domestic violence and on environmental justice; and the New Economy Project in New York, studying predatory lending. In the midst of this, Steil took time to earn a master’s in city design and social science from the London School of Economics.

    “I learned so much from studying city design, and really enjoyed it,” Steil says of that program. “But I also realized that my personal strengths are not in design. … I was more interested and more capable in the social science realm.”

    With that in mind, Steil was accepted into a joint PhD and JD program at Columbia University, combining a law degree with doctoral studies in urban planning.

    “So much of urban planning is determined by law, by property law and constitutional law,” Steil says. “I felt that if I wanted to research and teach these things, I needed to understand the law.”

    After finishing his law school and doctoral courses, Steil’s dissertation, written under the guidance of the late Peter Marcuse, examined the policy responses of two sets of paired towns — two in Nebraska, two in Pennsylvania — to immigration. In each of the states, one town was far more receptive to immigrants than the other. Steil concluded that the immigration-receptive towns had more local organizations and civic connections that reached across economic classes; instead of being more atomized, they were more cohesive socially, and willing to create more economic opportunities for those willing to work for them.

    Without such ties, Steil notes, people can end up “seeing things as a zero-sum game, instead of seeing the possibilities for new residents to enliven and enrich and contribute to a community.”

    By contrast, he adds, “sustained collaboration across what people might have seen as differences toward a shared goal created opportunities for a dialogue about immigration, its challenges and benefits, to imagine a future that could include these new neighbors. There was an emphasis in some of those towns on being communities where people were proud of working hard, and respected other people who did that.”

    From PhD to EMT

    Steil joined the MIT faculty after completing his PhD in 2015, and has continued to produce work on an array of issues about policy, law, and inclusion. Some of that work bears directly on contemporary housing policy. With Nicholas Kelly PhD ’21, Lawrence Vale, the Ford Professor of Urban Design and Planning at MIT, and Maia Woluchem MCP ’19, he co-edited the volume “Furthering Fair Housing” (Temple University Press, 2021), which analyzes recent political clashes over federal fair-housing policy.

    Some of Steil’s other work is more historically oriented. He has published multiple papers on race and housing in the early 20th century, when both violence against Blacks and race-based laws kept many cities segregated. As Steil notes, U.S. laws have been rewritten so as to be no longer explicitly race-based. However, he notes, “That legacy, entrenched into the built environment, is very durable.”

    There are also significant effects stemming from the local, property-tax-based system of funding education in the U.S., another policy approach that effectively leaves many Americans living in very different realms of metro areas.

    “By fragmenting [funding] at the local level and then having resources redistributed within these small jurisdictions, it creates powerful incentives for wealthy households and individuals to use land-use law and other law to exclude people,” Steil says. “That’s partly why we have this tremendous crisis of housing affordability today, as well as deep inequalities in educational opportunities.”

    Since arriving at MIT, Steil has also taught on these topics extensively. The undergraduate classes he teaches include an introduction to housing and community development, a course on land use and civil rights law, another course on land use and environmental law, and one on environmental justice.

    “What an amazing privilege it is to be here at MIT, and learn every day, from our students, our undergraduate and graduate students, and from my colleagues,” Steil says. “It makes it fun to be here.”

    As if Steil didn’t have enough on his plate, he takes part in still another MIT-based activity: For the last few years, he has worked as an Emergency Medical Technician (EMT) for MIT’s volunteer corps, having received his training from MIT’s EMT students since arriving on campus.

    As Steil describes it, his volunteer work has been a process of “starting out at the bottom of the totem pole as a beginning EMT and being trained by other students and progressing with my classmates.”

    It is “amazing,” he adds, to work with students and see “their dedication to this service and to MIT and to Cambridge and Boston, how hard they work and how capable they are, and what a strong community gets formed through that.” More

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    Silk offers an alternative to some microplastics

    Microplastics, tiny particles of plastic that are now found worldwide in the air, water, and soil, are increasingly recognized as a serious pollution threat, and have been found in the bloodstream of animals and people around the world.

    Some of these microplastics are intentionally added to a variety of products, including agricultural chemicals, paints, cosmetics, and detergents — amounting to an estimated 50,000 tons a year in the European Union alone, according to the European Chemicals Agency. The EU has already declared that these added, nonbiodegradable microplastics must be eliminated by 2025, so the search is on for suitable replacements, which do not currently exist.

    Now, a team of scientists at MIT and elsewhere has developed a system based on silk that could provide an inexpensive and easily manufactured substitute. The new process is described in a paper in the journal Small, written by MIT postdoc Muchun Liu, MIT professor of civil and environmental engineering Benedetto Marelli, and five others at the chemical company BASF in Germany and the U.S.

    The microplastics widely used in industrial products generally protect some specific active ingredient (or ingredients) from being degraded by exposure to air or moisture, until the time they are needed. They provide a slow release of the active ingredient for a targeted period of time and minimize adverse effects to its surroundings. For example, vitamins are often delivered in the form of microcapsules packed into a pill or capsule, and pesticides and herbicides are similarly enveloped. But the materials used today for such microencapsulation are plastics that persist in the environment for a long time. Until now, there has been no practical, economical substitute available that would biodegrade naturally.

    Much of the burden of environmental microplastics comes from other sources, such as the degradation over time of larger plastic objects such as bottles and packaging, and from the wear of car tires. Each of these sources may require its own kind of solutions for reducing its spread, Marelli says. The European Chemical Agency has estimated that the intentionally added microplastics represent approximately 10-15 percent of the total amount in the environment, but this source may be relatively easy to address using this nature-based biodegradable replacement, he says.

    “We cannot solve the whole microplastics problem with one solution that fits them all,” he says. “Ten percent of a big number is still a big number. … We’ll solve climate change and pollution of the world one percent at a time.”

    Unlike the high-quality silk threads used for fine fabrics, the silk protein used in the new alternative material is widely available and less expensive, Liu says. While silkworm cocoons must be painstakingly unwound to produce the fine threads needed for fabric, for this use, non-textile-quality cocoons can be used, and the silk fibers can simply be dissolved using a scalable water-based process. The processing is so simple and tunable that the resulting material can be adapted to work on existing manufacturing equipment, potentially providing a simple “drop in” solution using existing factories.

    Silk is recognized as safe for food or medical use, as it is nontoxic and degrades naturally in the body. In lab tests, the researchers demonstrated that the silk-based coating material could be used in existing, standard spray-based manufacturing equipment to make a standard water-soluble microencapsulated herbicide product, which was then tested in a greenhouse on a corn crop. The test showed it worked even better than an existing commercial product, inflicting less damage to the plants, Liu says.

    While other groups have proposed degradable encapsulation materials that may work at a small laboratory scale, Marelli says, “there is a strong need to achieve encapsulation of high-content actives to open the door to commercial use. The only way to have an impact is where we can not only replace a synthetic polymer with a biodegradable counterpart, but also achieve performance that is the same, if not better.”

    The secret to making the material compatible with existing equipment, Liu explains, is in the tunability of the silk material. By precisely adjusting the polymer chain arrangements of silk materials and addition of a surfactant, it is possible to fine-tune the properties of the resulting coatings once they dry out and harden. The material can be hydrophobic (water-repelling) even though it is made and processed in a water solution, or it can be hydrophilic (water-attracting), or anywhere in between, and for a given application it can be made to match the characteristics of the material it is being used to replace.

    In order to arrive at a practical solution, Liu had to develop a way of freezing the forming droplets of encapsulated materials as they were forming, to study the formation process in detail. She did this using a special spray-freezing system, and was able to observe exactly how the encapsulation works in order to control it better. Some of the encapsulated “payload” materials, whether they be pesticides or nutrients or enzymes, are water-soluble and some are not, and they interact in different ways with the coating material.

    “To encapsulate different materials, we have to study how the polymer chains interact and whether they are compatible with different active materials in suspension,” she says. The payload material and the coating material are mixed together in a solution and then sprayed. As droplets form, the payload tends to be embedded in a shell of the coating material, whether that’s the original synthetic plastic or the new silk material.

    The new method can make use of low-grade silk that is unusable for fabrics, and large quantities of which are currently discarded because they have no significant uses, Liu says. It can also use used, discarded silk fabric, diverting that material from being disposed of in landfills.

    Currently, 90 percent of the world’s silk production takes place in China, Marelli says, but that’s largely because China has perfected the production of the high-quality silk threads needed for fabrics. But because this process uses bulk silk and has no need for that level of quality, production could easily be ramped up in other parts of the world to meet local demand if this process becomes widely used, he says.

    “This elegant and clever study describes a sustainable and biodegradable silk-based replacement for microplastic encapsulants, which are a pressing environmental challenge,” says Alon Gorodetsky, an associate professor of chemical and biomolecular engineering at the University of California at Irvine, who was not associated with this research. “The modularity of the described materials and the scalability of the manufacturing processes are key advantages that portend well for translation to real-world applications.”

    This process “represents a potentially highly significant advance in active ingredient delivery for a range of industries, particularly agriculture,” says Jason White, director of the Connecticut Agricultural Experiment Station, who also was not associated with this work. “Given the current and future challenges related to food insecurity, agricultural production, and a changing climate, novel strategies such as this are greatly needed.”

    The research team also included Pierre-Eric Millard, Ophelie Zeyons, Henning Urch, Douglas Findley and Rupert Konradi from the BASF corporation, in Germany and in the U.S. The work was supported by BASF through the Northeast Research Alliance (NORA). More

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    Getting the carbon out of India’s heavy industries

    The world’s third largest carbon emitter after China and the United States, India ranks seventh in a major climate risk index. Unless India, along with the nearly 200 other signatory nations of the Paris Agreement, takes aggressive action to keep global warming well below 2 degrees Celsius relative to preindustrial levels, physical and financial losses from floods, droughts, and cyclones could become more severe than they are today. So, too, could health impacts associated with the hazardous air pollution levels now affecting more than 90 percent of its population.  

    To address both climate and air pollution risks and meet its population’s escalating demand for energy, India will need to dramatically decarbonize its energy system in the coming decades. To that end, its initial Paris Agreement climate policy pledge calls for a reduction in carbon dioxide intensity of GDP by 33-35 percent by 2030 from 2005 levels, and an increase in non-fossil-fuel-based power to about 40 percent of cumulative installed capacity in 2030. At the COP26 international climate change conference, India announced more aggressive targets, including the goal of achieving net-zero emissions by 2070.

    Meeting its climate targets will require emissions reductions in every economic sector, including those where emissions are particularly difficult to abate. In such sectors, which involve energy-intensive industrial processes (production of iron and steel; nonferrous metals such as copper, aluminum, and zinc; cement; and chemicals), decarbonization options are limited and more expensive than in other sectors. Whereas replacing coal and natural gas with solar and wind could lower carbon dioxide emissions in electric power generation and transportation, no easy substitutes can be deployed in many heavy industrial processes that release CO2 into the air as a byproduct.

    However, other methods could be used to lower the emissions associated with these processes, which draw upon roughly 50 percent of India’s natural gas, 25 percent of its coal, and 20 percent of its oil. Evaluating the potential effectiveness of such methods in the next 30 years, a new study in the journal Energy Economics led by researchers at the MIT Joint Program on the Science and Policy of Global Change is the first to explicitly explore emissions-reduction pathways for India’s hard-to-abate sectors.

    Using an enhanced version of the MIT Economic Projection and Policy Analysis (EPPA) model, the study assesses existing emissions levels in these sectors and projects how much they can be reduced by 2030 and 2050 under different policy scenarios. Aimed at decarbonizing industrial processes, the scenarios include the use of subsidies to increase electricity use, incentives to replace coal with natural gas, measures to improve industrial resource efficiency, policies to put a price on carbon, carbon capture and storage (CCS) technology, and hydrogen in steel production.

    The researchers find that India’s 2030 Paris Agreement pledge may still drive up fossil fuel use and associated greenhouse gas emissions, with projected carbon dioxide emissions from hard-to-abate sectors rising by about 2.6 times from 2020 to 2050. But scenarios that also promote electrification, natural gas support, and resource efficiency in hard-to-abate sectors can lower their CO2 emissions by 15-20 percent.

    While appearing to move the needle in the right direction, those reductions are ultimately canceled out by increased demand for the products that emerge from these sectors. So what’s the best path forward?

    The researchers conclude that only the incentive of carbon pricing or the advance of disruptive technology can move hard-to-abate sector emissions below their current levels. To achieve significant emissions reductions, they maintain, the price of carbon must be high enough to make CCS economically viable. In that case, reductions of 80 percent below current levels could be achieved by 2050.

    “Absent major support from the government, India will be unable to reduce carbon emissions in its hard-to-abate sectors in alignment with its climate targets,” says MIT Joint Program deputy director Sergey Paltsev, the study’s lead author. “A comprehensive government policy could provide robust incentives for the private sector in India and generate favorable conditions for foreign investments and technology advances. We encourage decision-makers to use our findings to design efficient pathways to reduce emissions in those sectors, and thereby help lower India’s climate and air pollution-related health risks.” More

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    Better living through multicellular life cycles

    Cooperation is a core part of life for many organisms, ranging from microbes to complex multicellular life. It emerges when individuals share resources or partition a task in such a way that each derives a greater benefit when acting together than they could on their own. For example, birds and fish flock to evade predators, slime mold swarms to hunt for food and reproduce, and bacteria form biofilms to resist stress.

    Individuals must live in the same “neighborhood” to cooperate. For bacteria, this neighborhood can be as small as tens of microns. But in environments like the ocean, it’s rare for cells with the same genetic makeup to co-occur in the same neighborhood on their own. And this necessity poses a puzzle to scientists: In environments where survival hinges on cooperation, how do bacteria build their neighborhood?

    To study this problem, MIT professor Otto X. Cordero and colleagues took inspiration from nature: They developed a model system around a common coastal seawater bacterium that requires cooperation to eat sugars from brown algae. In the system, single cells were initially suspended in seawater too far away from other cells to cooperate. To share resources and grow, the cells had to find a mechanism of creating a neighborhood. “Surprisingly, each cell was able to divide and create its own neighborhood of clones by forming tightly packed clusters,” says Cordero, associate professor in the Department of Civil and Environmental Engineering.

    A new paper, published today in Current Biology, demonstrates how an algae-eating bacterium solves the engineering challenge of creating local cell density starting from a single-celled state.

    “A key discovery was the importance of phenotypic heterogeneity in supporting this surprising mechanism of clonal cooperation,” says Cordero, lead author of the new paper.

    Using a combination of microscopy, transcriptomics, and labeling experiments to profile a cellular metabolic state, the researchers found that cells phenotypically differentiate into a sticky “shell” population and a motile, carbon-storing “core.” The researchers propose that shell cells create the cellular neighborhood needed to sustain cooperation while core cells accumulate stores of carbon that support further clonal reproduction when the multicellular structure ruptures.

    This work addresses a key piece in the bigger challenge of understanding the bacterial processes that shape our earth, such as the cycling of carbon from dead organic matter back into food webs and the atmosphere. “Bacteria are fundamentally single cells, but often what they accomplish in nature is done through cooperation. We have much to uncover about what bacteria can accomplish together and how that differs from their capacity as individuals,” adds Cordero.

    Co-authors include Julia Schwartzman and Ali Ebrahimi, former postdocs in the Cordero Lab. Other co-authors are Gray Chadwick, a former graduate student at Caltech; Yuya Sato, a senior researcher at Japan’s National Institute of Advanced Industrial Science and Technology; Benjamin Roller, a current postdoc at the University of Vienna; and Victoria Orphan of Caltech.

    Funding was provided by the Simons Foundation. Individual authors received support from the Swiss National Science Foundation, Japan Society for the Promotion of Science, the U.S. National Science Foundation, the Kavli Institute of Theoretical Physics, and the National Institutes of Health. More