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      in Environment

      MIT campus goals in food, water, waste support decarbonization efforts

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      With the launch of Fast Forward: MIT’s Climate Action Plan for the Decade, the Institute committed to decarbonize campus operations by 2050 — an effort that touches on every corner of MIT, from building energy use to procurement and waste. At the operational level, the plan called for establishing a set of quantitative climate impact goals in the areas of food, water, and waste to inform the campus decarbonization roadmap. After an 18-month process that engaged staff, faculty, and researchers, the goals — as well as high-level strategies to reach them — were finalized in spring 2023.

      The goal development process was managed by a team representing the areas of campus food, water, and waste, respectively, and includes Director of Campus Dining Mark Hayes and Senior Sustainability Project Manager Susy Jones (food), Director of Utilities Janine Helwig (water), Assistant Director of Campus Services Marty O’Brien, and Assistant Director of Sustainability Brain Goldberg (waste) to co-lead the efforts. The group worked together to set goals that leverage ongoing campus sustainability efforts. “It was important for us to collaborate in order to identify the strategies and goals,” explains Goldberg. “It allowed us to set goals that not only align, but build off of one another, enabling us to work more strategically.”

      In setting the goals, each team relied on data, community insight, and best practices. The co-leads are sharing their process to help others at the Institute understand the roles they can play in supporting these objectives.  

      Sustainable food systems

      The primary food impact goal aims for a 25 percent overall reduction in the greenhouse gas footprint of food purchases starting with academic year 2021-22 as a baseline, acknowledging that beef purchases make up a significant share of those emissions. Additionally, the co-leads established a goal to recover all edible food waste in dining hall and retail operations where feasible, as that reduces MIT’s waste impact and acknowledges that redistributing surplus food to feed people is critically important.

      The work to develop the food goal was uniquely challenging, as MIT works with nine different vendors — including main vendor Bon Appetit — to provide food on campus, with many vendors having their own sustainability targets. The goal-setting process began by understanding vendor strategies and leveraging their climate commitments. “A lot of this work is not about reinventing the wheel, but about gathering data,” says Hayes. “We are trying to connect the dots of what is currently happening on campus and to better understand food consumption and waste, ensuring that we area reaching these targets.”

      In identifying ways to reach and exceed these targets, Jones conducted listening sessions around campus, balancing input with industry trends, best-available science, and institutional insight from Hayes. “Before we set these goals and possible strategies, we wanted to get a grounding from the community and understand what would work on our campus,” says Jones, who recently began a joint role that bridges the Office of Sustainability and MIT Dining in part to support the goal work.

      By establishing the 25 percent reduction in the greenhouse gas footprint of food purchases across MIT residential dining menus, Jones and Hayes saw goal-setting as an opportunity to add more sustainable, local, and culturally diverse foods to the menu. “If beef is the most carbon-intensive food on the menu, this enables us to explore and expand so many recipes and menus from around the globe that incorporate alternatives,” Jones says.

      Strategies to reach the climate food goals focus on local suppliers, more plant-forward meals, food recovery, and food security. In 2019, MIT was a co-recipient of the New England Food Vision Prize provided by the Kendall Foundation to increase the amount of local food served on campus in partnership with CommonWealth Kitchen in Dorchester. While implementation of that program was put on pause due to the pandemic, work resumed this year. Currently, the prize is funding a collaborative effort to introduce falafel-like, locally manufactured fritters made from Maine-grown yellow field peas to dining halls at MIT and other university campuses, exemplifying the efforts to meet the climate impact goal, serve as a model for others, and provide demonstrable ways of strengthening the regional food system.

      “This sort of innovation is where we’re a leader,” says Hayes. “In addition to the Kendall Prize, we are looking to focus on food justice, growing our BIPOC [Black, Indigenous, and people of color] vendors, and exploring ideas such as local hydroponic and container vegetable growing companies, and how to scale these types of products into institutional settings.”

      Reduce and reuse for campus water

      The 2030 water impact goal aims to achieve a 10 percent reduction in water use compared to the 2019 baseline and to update the water reduction goal to align with the new metering program and proposed campus decarbonization plans as they evolve.

      When people think of campus water use, they may think of sprinklers, lab sinks, or personal use like drinking water and showers. And while those uses make up around 60 percent of campus water use, the Central Utilities Plant (CUP) accounts for the remaining 40 percent. “The CUP generates electricity and delivers heating and cooling to the campus through steam and chilled water — all using what amounts to a large percentage of water use on campus,” says Helwig. As such, the water goal focuses as much on reuse as reduction, with one approach being to expand water capture from campus cooling towers for reuse in CUP operations. “People often think of water use and energy separately, but they often go hand-in-hand,” Helwig explains.

      Data also play a central part in the water impact goal — that’s why a new metering program is called for in the implementation strategy. “We have access to a lot of data at MIT, but in reviewing the water data to inform the goal, we learned that it wasn’t quite where we needed it,” explains Helwig. “By ensuring we have the right meter and submeters set up, we can better set boundaries to understand where there is the potential to reduce water use.” Irrigation on campus is one such target with plans to soon release new campuswide landscaping standards that minimize water use.

      Reducing campus waste

      The waste impact goal aims to reduce campus trash by 30 percent compared to 2019 baseline totals. Additionally, the goal outlines efforts to improve the accuracy of indicators tracking campus waste; reduce the percentage of food scraps in trash and percent of recycling in trash in select locations; reduce the percentage of trash and recycling comprised of single use items; and increase the percentage of residence halls and other campus spaces where food is consumed at scale, implementing an MIT food scrap collection program.

      In setting the waste goals, Goldberg and O’Brien studied available campus waste data from past waste audits, pilot programs, and MIT’s waste haulers. They factored in state and city policies that regulate things like the type and amount of waste large institutions can transport. “Looking at all the data it became clear that a 30 percent trash reduction goal will make a tremendous impact on campus and help us drive toward the goal of completely designing out waste from campus,” Goldberg says. The strategies to reach the goals include reducing the amount of materials that come into campus, increasing recycling rates, and expanding food waste collection on campus.

      While reducing the waste created from material sources is outlined in the goals, food waste is a special focus on campus because it comprises approximately 40 percent of campus trash, it can be easily collected separately from trash and recycled locally, and decomposing food waste is one of the largest sources of greenhouse gas emissions found in landfills. “There is a lot of greenhouse gas emissions that result from production, distribution, transportation, packaging, processing, and disposal of food,” explains Goldberg. “When food travels to campus, is removed from campus as waste, and then breaks down in a landfill, there are emissions every step of the way.”

      To reduce food waste, Goldberg and O’Brien outlined strategies that include working with campus suppliers to identify ordering volumes and practices to limit waste. Once materials are on campus, another strategy kicks in, with a new third stream of waste collection that joins recycling and trash — food waste. By collecting the food waste separately — in bins that are currently rolling out across campus — the waste can be reprocessed into fertilizer, compost, and/or energy without the off-product of greenhouse gases. The waste impact goal also relies on behavioral changes to reduce waste, with education materials part of the process to reduce waste and decontaminate reprocessing streams.

      Tracking progress

      As work toward the goals advances, community members can monitor progress in the Sustainability DataPool Material Matters and Campus Water Use dashboards, or explore the Impact Goals in depth.

      “From food to water to waste, everyone on campus interacts with these systems and can grapple with their impact either from a material they need to dispose of, to water they’re using in a lab, or leftover food from an event,” says Goldberg. “By setting these goals we as an institution can lead the way and help our campus community understand how they can play a role, plug in, and make an impact.” More

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      in Environment

      MIT students win Beth Israel Deaconess Medical Center sustainability award

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      MIT senior Anna Kwon and sophomore Nicole Doering have been recognized by Beth Israel Deaconess Medical Center (BIDMC) for their work as interns last summer. Both students received Jane Matlaw Environmental Champion Awards, which honor leaders and innovators who have catalyzed changes that align with BIDMC’s sustainability goals and foster a healthier future for staff and patients.

      The awards, which were established 25 years ago, had previously only been given to individuals and teams within BIDMC. “This year, given the significant leadership and alignment with our public commitments that Nicole and Anna had over the summer, our Sustainability Award Review Committee determined that we would include a student category of our awards for both a high school student and undergraduates as well,” says Avery Palardy, the climate and sustainability director at BIDMC.

      Kwon and Doering worked at BIDMC through the Social Impact Internship Program, one of many experiential learning opportunities offered by MIT’s Priscilla King Gray Center for Public Service. The program provides funded internships to students interested in working with government agencies, nonprofits, and social ventures.

      Both students conducted work that will help BIDMC meet two commitments to the Department of Health and Human Services Health Sector Climate Pledge: to develop a climate resilience plan for continuous operations by the end of 2023, and to conduct an inventory of its supply chain emissions by the end of 2024.

      “It was fun — a new challenge for me,” says Kwon, who is majoring in electrical engineering and computer science. “I have never done research in sustainability before. I was able to dive into the field of health care from a new angle, deepening my understanding of the complexities of environmental issues within health care.” Her internship involved performing data analysis related to carbon emissions. In addition, she developed actionable recommendations for conducting a comprehensive supply chain inventory.

      “Anna demonstrated unwavering diligence and attention to detail throughout her work to conduct a greenhouse gas inventory of our supply chain,” says Palardy. “She showcased exceptional skills in market research as she investigated best practices and emerging technologies to ensure that we stay at the forefront of sustainable practices. Her keen insights and forward-thinking approach have equipped us with valuable information for shaping our path forward on our sustainability goals.”

      Doering, a chemical engineering major, guided several departments in an internal assessment of best practices, vulnerabilities, and future directions to integrate climate resilience into the medical center’s operations. She has continued to work this fall to help finalize the climate resilience plan, and she has also been analyzing food procurement data to identify ways to reduce BIDMC’s Scope 3 emissions.

      Climate resilience isn’t an area of sustainability that Doering had considered before, but the internship experience has inspired her to continue pursuing other sustainability roles in the future. “I’m so thankful for all I’ve learned from BIDMC, so I’m really glad that my work was helpful to them. It is an honor that they trusted me to work with them on something that will have such a wonderful impact on our community,” she says.

      “The impact of Nicole’s contributions cannot be overstated,” notes Palardy. “From planning and organizing crucial focus groups to crafting our climate resilience plan, she played a pivotal role in shaping our climate resilience strategies for the better. I’m so grateful for the collaborative spirit, passion, and leadership that she brought to our team. She helped to drive innovation in health-care climate resilience that is necessary for us to ensure this continues to be a priority.” More

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      in Energy

      Accelerated climate action needed to sharply reduce current risks to life and life-support systems

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      Hottest day on record. Hottest month on record. Extreme marine heatwaves. Record-low Antarctic sea-ice.

      While El Niño is a short-term factor in this year’s record-breaking heat, human-caused climate change is the long-term driver. And as global warming edges closer to 1.5 degrees Celsius — the aspirational upper limit set in the Paris Agreement in 2015 — ushering in more intense and frequent heatwaves, floods, wildfires, and other climate extremes much sooner than many expected, current greenhouse gas emissions-reduction policies are far too weak to keep the planet from exceeding that threshold. In fact, on roughly one-third of days in 2023, the average global temperature was at least 1.5 C higher than pre-industrial levels. Faster and bolder action will be needed — from the in-progress United Nations Climate Change Conference (COP28) and beyond — to stabilize the climate and minimize risks to human (and nonhuman) lives and the life-support systems (e.g., food, water, shelter, and more) upon which they depend.

      Quantifying the risks posed by simply maintaining existing climate policies — and the benefits (i.e., avoided damages and costs) of accelerated climate action aligned with the 1.5 C goal — is the central task of the 2023 Global Change Outlook, recently released by the MIT Joint Program on the Science and Policy of Global Change.

      Based on a rigorous, integrated analysis of population and economic growth, technological change, Paris Agreement emissions-reduction pledges (Nationally Determined Contributions, or NDCs), geopolitical tensions, and other factors, the report presents the MIT Joint Program’s latest projections for the future of the earth’s energy, food, water, and climate systems, as well as prospects for achieving the Paris Agreement’s short- and long-term climate goals.

      The 2023 Global Change Outlook performs its risk-benefit analysis by focusing on two scenarios. The first, Current Trends, assumes that Paris Agreement NDCs are implemented through the year 2030, and maintained thereafter. While this scenario represents an unprecedented global commitment to limit greenhouse gas emissions, it neither stabilizes climate nor limits climate change. The second scenario, Accelerated Actions, extends from the Paris Agreement’s initial NDCs and aligns with its long-term goals. This scenario aims to limit and stabilize human-induced global climate warming to 1.5 C by the end of this century with at least a 50 percent probability. Uncertainty is quantified using 400-member ensembles of projections for each scenario.

      This year’s report also includes a visualization tool that enables a higher-resolution exploration of both scenarios.

      Energy

      Between 2020 and 2050, population and economic growth are projected to drive continued increases in energy needs and electrification. Successful achievement of current Paris Agreement pledges will reinforce a shift away from fossil fuels, but additional actions will be required to accelerate the energy transition needed to cap global warming at 1.5 C by 2100.

      During this 30-year period under the Current Trends scenario, the share of fossil fuels in the global energy mix drops from 80 percent to 70 percent. Variable renewable energy (wind and solar) is the fastest growing energy source with more than an 8.6-fold increase. In the Accelerated Actions scenario, the share of low-carbon energy sources grows from 20 percent to slightly more than 60 percent, a much faster growth rate than in the Current Trends scenario; wind and solar energy undergo more than a 13.3-fold increase.

      While the electric power sector is expected to successfully scale up (with electricity production increasing by 73 percent under Current Trends, and 87 percent under Accelerated Actions) to accommodate increased demand (particularly for variable renewables), other sectors face stiffer challenges in their efforts to decarbonize.

      “Due to a sizeable need for hydrocarbons in the form of liquid and gaseous fuels for sectors such as heavy-duty long-distance transport, high-temperature industrial heat, agriculture, and chemical production, hydrogen-based fuels and renewable natural gas remain attractive options, but the challenges related to their scaling opportunities and costs must be resolved,” says MIT Joint Program Deputy Director Sergey Paltsev, a lead author of the 2023 Global Change Outlook.

      Water, food, and land

      With a global population projected to reach 9.9 billion by 2050, the Current Trends scenario indicates that more than half of the world’s population will experience pressures to its water supply, and that three of every 10 people will live in water basins where compounding societal and environmental pressures on water resources will be experienced. Population projections under combined water stress in all scenarios reveal that the Accelerated Actions scenario can reduce approximately 40 million of the additional 570 million people living in water-stressed basins at mid-century.

      Under the Current Trends scenario, agriculture and food production will keep growing. This will increase pressure for land-use change, water use, and use of energy-intensive inputs, which will also lead to higher greenhouse gas emissions. Under the Accelerated Actions scenario, less agricultural and food output is observed by 2050 compared to the Current Trends scenario, since this scenario affects economic growth and increases production costs. Livestock production is more greenhouse gas emissions-intensive than crop and food production, which, under carbon-pricing policies, drives demand downward and increases costs and prices. Such impacts are transmitted to the food sector and imply lower consumption of livestock-based products.

      Land-use changes in the Accelerated Actions scenario are similar to those in the Current Trends scenario by 2050, except for land dedicated to bioenergy production. At the world level, the Accelerated Actions scenario requires cropland area to increase by 1 percent and pastureland to decrease by 4.2 percent, but land use for bioenergy must increase by 44 percent.

      Climate trends

      Under the Current Trends scenario, the world is likely (more than 50 percent probability) to exceed 2 C global climate warming by 2060, 2.8 C by 2100, and 3.8 C by 2150. Our latest climate-model information indicates that maximum temperatures will likely outpace mean temperature trends over much of North and South America, Europe, northern and southeast Asia, and southern parts of Africa and Australasia. So as human-forced climate warming intensifies, these regions are expected to experience more pronounced record-breaking extreme heat events.

      Under the Accelerated Actions scenario, global temperature will continue to rise through the next two decades. But by 2050, global temperature will stabilize, and then slightly decline through the latter half of the century.

      “By 2100, the Accelerated Actions scenario indicates that the world can be virtually assured of remaining below 2 C of global warming,” says MIT Joint Program Deputy Director C. Adam Schlosser, a lead author of the report. “Nevertheless, additional policy mechanisms must be designed with more comprehensive targets that also support a cleaner environment, sustainable resources, as well as improved and equitable human health.”

      The Accelerated Actions scenario not only stabilizes global precipitation increase (by 2060), but substantially reduces the magnitude and potential range of increases to almost one-third of Current Trends global precipitation changes. Any global increase in precipitation heightens flood risk worldwide, so policies aligned with the Accelerated Actions scenario would considerably reduce that risk.

      Prospects for meeting Paris Agreement climate goals

      Numerous countries and regions are progressing in fulfilling their Paris Agreement pledges. Many have declared more ambitious greenhouse gas emissions-mitigation goals, while financing to assist the least-developed countries in sustainable development is not forthcoming at the levels needed. In this year’s Global Stocktake Synthesis Report, the U.N. Framework Convention on Climate Change evaluated emissions reductions communicated by the parties of the Paris Agreement and concluded that global emissions are not on track to fulfill the most ambitious long-term global temperature goals of the Paris Agreement (to keep warming well below 2 C — and, ideally, 1.5 C — above pre-industrial levels), and there is a rapidly narrowing window to raise ambition and implement existing commitments in order to achieve those targets. The Current Trends scenario arrives at the same conclusion.

      The 2023 Global Change Outlook finds that both global temperature targets remain achievable, but require much deeper near-term emissions reductions than those embodied in current NDCs.

      Reducing climate risk

      This report explores two well-known sets of risks posed by climate change. Research highlighted indicates that elevated climate-related physical risks will continue to evolve by mid-century, along with heightened transition risks that arise from shifts in the political, technological, social, and economic landscapes that are likely to occur during the transition to a low-carbon economy.

      “Our Outlook shows that without aggressive actions the world will surpass critical greenhouse gas concentration thresholds and climate targets in the coming decades,” says MIT Joint Program Director Ronald Prinn. “While the costs of inaction are getting higher, the costs of action are more manageable.” More

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      in Environment

      Unlocking the secrets of natural materials

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      Growing up in Milan, Benedetto Marelli liked figuring out how things worked. He repaired broken devices simply to have the opportunity to take them apart and put them together again. Also, from a young age, he had a strong desire to make a positive impact on the world. Enrolling at the Polytechnic University of Milan, he chose to study engineering.

      “Engineering seemed like the right fit to fulfill my passions at the intersection of discovering how the world works, together with understanding the rules of nature and harnessing this knowledge to create something new that could positively impact our society,” says Marelli, MIT’s Paul M. Cook Career Development Associate Professor of Civil and Environmental Engineering.

      Marelli decided to focus on biomedical engineering, which at the time was the closest thing available to biological engineering. “I liked the idea of pursuing studies that provided me a background to engineer life,” in order to improve human health and agriculture, he says.

      Marelli went on to earn a PhD in materials science and engineering at McGill University and then worked in Tufts University’s biomaterials Silklab as a postdoc. After his postdoc, Marelli was drawn to MIT’s Department of Civil and Environmental in large part because of the work of Markus Buehler, MIT’s McAfee Professor of Engineering, who studies how to design new materials by understanding the architecture of natural ones.

      “This resonated with my training and idea of using nature’s building blocks to build a more sustainable society,” Marelli says. “It was a big leap forward for me to go from biomedical engineering to civil and environmental engineering. It meant completely changing my community, understanding what I could teach and how to mentor students in a new engineering branch. As Markus is working with silk to study how to engineer better materials, this made me see a clear connection with what I was doing and what I could be doing. I consider him one of my mentors here at MIT and was fortunate to end up collaborating with him.”

      Marelli’s research is aimed at mitigating several pressing global problems, he says.

      “Boosting food production to provide food security to an ever-increasing population, soil restoration, decreasing the environmental impact of fertilizers, and addressing stressors coming from climate change are societal challenges that need the development of rapidly scalable and deployable technologies,” he says.

      Marelli and his fellow researchers have developed coatings derived from natural silk that extend the shelf life of food, deliver biofertilizers to seeds planted in salty, unproductive soils, and allow seeds to establish healthier plants and increase crop yield in drought-stricken lands. The technologies have performed well in field tests being conducted in Morocco in collaboration with the Mohammed VI Polytechnic University in Ben Guerir, according to Marelli, and offer much potential.

      “I believe that with this technology, together with the common efforts shared by the MIT PIs participating in the Climate Grand Challenge on Revolutionizing Agriculture, we have a  real opportunity to positively impact planetary health and find new solutions that work in both rural settings and highly modernized agricultural fields,” says Marelli, who recently earned tenure.

      As a researcher and entrepreneur with about 20 patents to his name and awards including a National Science Foundation CAREER award, the Presidential Early Career Award for Scientists and Engineers award, and the Ole Madsen Mentoring Award, Marelli says that in general his insights into structural proteins — and how to use that understanding to manufacture advanced materials at multiple scales — are among his proudest achievements.

      More specifically, Marelli cites one of his breakthroughs involving a strawberry. Having dipped the berry in an odorless, tasteless edible silk suspension as part of a cooking contest held in his postdoctoral lab, he accidentally left it on his bench, only to find a week or so later that it had been well-preserved.

      “The coating of the strawberry to increase its shelf life is difficult to beat when it comes to inspiring people that natural polymers can serve as technical materials that can positively impact our society” by lessening food waste and the need for energy-intensive refrigerated shipping, Marelli says.

      When Marelli won the BioInnovation Institute and Science Prize for Innovation in 2022, he told the journal Science that he thinks students should be encouraged to choose an entrepreneurial path. He acknowledged the steepness of the learning curve of being an entrepreneur but also pointed out how the impact of research can be exponentially increased.

      He expanded on this idea more recently.

      “I believe an increasing number of academics and graduate students should try to get their hands ‘dirty’ with entrepreneurial efforts. We live in a time where academics are called to have a tangible impact on our society, and translating what we study in our labs is clearly a good way to employ our students and enhance the global effort to develop new technology that can make our society more sustainable and equitable,” Marelli says.

      Referring to a spinoff company, Mori, that grew out of the coated strawberry discovery and that develops silk-based products to preserve a wide range of perishable foods, Marelli says he finds it very satisfying to know that Mori has a product on the market that came out of his research efforts — and that 80 people are working to translate the discovery from “lab to fork.”

      “Knowing that the technology can move the needle in crises such as food waste and food-related environmental impact is the highest reward of all,” he says.

      Marelli says he tells students who are seeking solutions to extremely complicated problems to come up with one solution, “however crazy it might be,” and then do an extensive literature review to see what other researchers have done and whether “there is any hint that points toward developing their solution.”

      “Once we understand the feasibility, I typically work with them to simplify it as much as we can, and then to break down the problem in small parts that are addressable in series and/or in parallel,” Marelli says.

      That process of discovery is ongoing. Asked which of his technologies will have the greatest impact on the world, Marelli says, “I’d like to think it’s the ones that still need to be discovered.” More

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      in Environment

      A mineral produced by plate tectonics has a global cooling effect, study finds

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      MIT geologists have found that a clay mineral on the seafloor, called smectite, has a surprisingly powerful ability to sequester carbon over millions of years.

      Under a microscope, a single grain of the clay resembles the folds of an accordion. These folds are known to be effective traps for organic carbon.

      Now, the MIT team has shown that the carbon-trapping clays are a product of plate tectonics: When oceanic crust crushes against a continental plate, it can bring rocks to the surface that, over time, can weather into minerals including smectite. Eventually, the clay sediment settles back in the ocean, where the minerals trap bits of dead organisms in their microscopic folds. This keeps the organic carbon from being consumed by microbes and expelled back into the atmosphere as carbon dioxide.

      Over millions of years, smectite can have a global effect, helping to cool the entire planet. Through a series of analyses, the researchers showed that smectite was likely produced after several major tectonic events over the last 500 million years. During each tectonic event, the clays trapped enough carbon to cool the Earth and induce the subsequent ice age.

      The findings are the first to show that plate tectonics can trigger ice ages through the production of carbon-trapping smectite.

      These clays can be found in certain tectonically active regions today, and the scientists believe that smectite continues to sequester carbon, providing a natural, albeit slow-acting, buffer against humans’ climate-warming activities.

      “The influence of these unassuming clay minerals has wide-ranging implications for the habitability of planets,” says Joshua Murray, a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences. “There may even be a modern application for these clays in offsetting some of the carbon that humanity has placed into the atmosphere.”

      Murray and Oliver Jagoutz, professor of geology at MIT, have published their findings today in Nature Geoscience.

      A clear and present clay

      The new study follows up on the team’s previous work, which showed that each of the Earth’s major ice ages was likely triggered by a tectonic event in the tropics. The researchers found that each of these tectonic events exposed ocean rocks called ophiolites to the atmosphere. They put forth the idea that, when a tectonic collision occurs in a tropical region, ophiolites can undergo certain weathering effects, such as exposure to wind, rain, and chemical interactions, that transform the rocks into various minerals, including clays.

      “Those clay minerals, depending on the kinds you create, influence the climate in different ways,” Murray explains.

      At the time, it was unclear which minerals could come out of this weathering effect, and whether and how these minerals could directly contribute to cooling the planet. So, while it appeared there was a link between plate tectonics and ice ages, the exact mechanism by which one could trigger the other was still in question.

      With the new study, the team looked to see whether their proposed tectonic tropical weathering process would produce carbon-trapping minerals, and in quantities that would be sufficient to trigger a global ice age.

      The team first looked through the geologic literature and compiled data on the ways in which major magmatic minerals weather over time, and on the types of clay minerals this weathering can produce. They then worked these measurements into a weathering simulation of different rock types that are known to be exposed in tectonic collisions.

      “Then we look at what happens to these rock types when they break down due to weathering and the influence of a tropical environment, and what minerals form as a result,” Jagoutz says.

      Next, they plugged each weathered, “end-product” mineral into a simulation of the Earth’s carbon cycle to see what effect a given mineral might have, either in interacting with organic carbon, such as bits of dead organisms, or with inorganic, in the form of carbon dioxide in the atmosphere.

      From these analyses, one mineral had a clear presence and effect: smectite. Not only was the clay a naturally weathered product of tropical tectonics, it was also highly effective at trapping organic carbon. In theory, smectite seemed like a solid connection between tectonics and ice ages.

      But were enough of the clays actually present to trigger the previous four ice ages? Ideally, researchers should confirm this by finding smectite in ancient rock layers dating back to each global cooling period.

      “Unfortunately, as clays are buried by other sediments, they get cooked a bit, so we can’t measure them directly,” Murray says. “But we can look for their fingerprints.”

      A slow build

      The team reasoned that, as smectites are a product of ophiolites, these ocean rocks also bear characteristic elements such as nickel and chromium, which would be preserved in ancient sediments. If smectites were present in the past, nickel and chromium should be as well.

      To test this idea, the team looked through a database containing thousands of oceanic sedimentary rocks that were deposited over the last 500 million years. Over this time period, the Earth experienced four separate ice ages. Looking at rocks around each of these periods, the researchers observed large spikes of nickel and chromium, and inferred from this that smectite must also have been present.

      By their estimates, the clay mineral could have increased the preservation of organic carbon by less than one-tenth of a percent. In absolute terms, this is a miniscule amount. But over millions of years, they calculated that the clay’s accumulated, sequestered carbon was enough to trigger each of the four major ice ages.

      “We found that you really don’t need much of this material to have a huge effect on the climate,” Jagoutz says.

      “These clays also have probably contributed some of the Earth’s cooling in the last 3 to 5 million years, before humans got involved,” Murray adds. “In the absence of humans, these clays are probably making a difference to the climate. It’s just such a slow process.”

      “Jagoutz and Murray’s work is a nice demonstration of how important it is to consider all biotic and physical components of the global carbon cycle,” says Lee Kump, a professor of geosciences at Penn State University, who was not involved with the study. “Feedbacks among all these components control atmospheric greenhouse gas concentrations on all time scales, from the annual rise and fall of atmospheric carbon dioxide levels to the swings from icehouse to greenhouse over millions of years.”

      Could smectites be harnessed intentionally to further bring down the world’s carbon emissions? Murray sees some potential, for instance to shore up carbon reservoirs such as regions of permafrost. Warming temperatures are predicted to melt permafrost and expose long-buried organic carbon. If smectites could be applied to these regions, the clays could prevent this exposed carbon from escaping into and further warming the atmosphere.

      “If you want to understand how nature works, you have to understand it on the mineral and grain scale,” Jagoutz says. “And this is also the way forward for us to find solutions for this climatic catastrophe. If you study these natural processes, there’s a good chance you will stumble on something that will be actually useful.”

      This research was funded, in part, by the National Science Foundation. More

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      in Energy

      A green hydrogen innovation for clean energy

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      Renewable energy today — mainly derived from the sun or wind — depends on batteries for storage. While costs have dropped in recent years, the pursuit of more efficient means of storing renewable power continues.

      “All of these technologies, unfortunately, have a long way to go,” said Sossina Haile SB ’86, PhD ’92, the Walter P. Murphy Professor of Materials Science and Engineering at Northwestern University, at recent talk at MIT. She was the speaker of the fall 2023 Wulff Lecture, an event hosted by the Department of Materials Science and Engineering (DMSE) to ignite enthusiasm for the discipline.

      To add to the renewable energy mix — and help quicken the pace to a sustainable future — Haile is working on an approach based on hydrogen in fuel cells, particularly for eco-friendly fuel in cars. Fuel cells, like batteries, produce electricity from chemical reactions but don’t lose their charge so long as fuel is supplied.

      To generate power, the hydrogen must be pure — not attached to another molecule. Most methods of producing hydrogen today require burning fossil fuel, which generates planet-heating carbon emissions. Haile proposes a “green” process using renewable electricity to extract the hydrogen from steam.

      When hydrogen is used in a fuel cell, “you have water as the product, and that’s the beautiful zero emissions,” Haile said, referring to the renewable energy production cycle that is set in motion.

      Ammonia fuels hydrogen’s potential

      Hydrogen is not yet widely used as a fuel because it’s difficult to transport. For one, it has low energy density, meaning a large volume of hydrogen gas is needed to store a large amount of energy. And storing it is challenging because hydrogen’s tiny molecules can infiltrate metal tanks or pipes, causing cracks and gas leakage.

      Haile’s solution for transporting hydrogen is using ammonia to “carry” it. Ammonia is three parts hydrogen and one part nitrogen, so the hydrogen needs to be separated from the nitrogen before it can be used in the kind of fuel cells that can power cars.

      Ammonia has some advantages, including using existing pipelines and a high transmission capacity, Haile said — so more power can be transmitted at any given time.

      To extract the hydrogen from ammonia, Haile has built devices that look a lot like fuel cells, with cesium dihydrogen phosphate as an electrolyte. The “superprotonic” material displays high proton conductivity — it allows protons, or positively charged particles, to move through it. This is important for hydrogen, which has just a proton and an electron. By letting only protons through the electrolyte, the device strips hydrogen from the ammonia, leaving behind the nitrogen.

      The material has other benefits, too, Haile said: “It’s inexpensive, nontoxic, earth-abundant — all these good things that you want to have when you think about a sustainable energy technology.”

      Play video

      2023 Fall Wulff LectureVideo: Department of Materials Science and Engineering

      Sparking interest — and hope

      Haile’s talk piqued interest in the audience, which nearly filled the 6-120 auditorium at MIT, which seats about 150 people.

      Materials science and engineering major Nikhita Law heard hope in Haile’s talk for a more sustainable future.

      “A major problem in making our energy system sustainable is finding ways to store energy from renewables,” Law says. Even if hydrogen-powered cars are not as wide-scale as lithium-battery-powered electric cars, “a permanent energy storage station where we convert electricity into hydrogen and convert it back seems like it makes more sense than mining more lithium.”

      Another DMSE student, senior Daniel Tong, learned about the challenges involved in transporting hydrogen at another seminar and was curious to learn more. “This was something I hadn’t thought of: Can you carry hydrogen more effectively in a different form? That’s really cool.”

      He adds that talks like the Wulff Lecture are helpful in keeping people up to date in a wide-ranging, interdisciplinary field such as materials science and engineering, which spans chemistry, physics, engineering, and other disciplines. “This is a really good way to get exposed to different parts of materials science. There are so many more facets than you know of.”

      In her talk, Haile encouraged audience members to get involved in sustainability research.

      “There’s lots of room for further insight and materials discovery,” she said.

      Haile concluded by underscoring the challenges faced by developing countries in dealing with climate change impacts, particularly those near the equator where there isn’t adequate infrastructure to deal with big swings in precipitation and temperature. For the people who aren’t driven to solve problems that affect people on the other side of the world, Haile offered some extra motivation.

      “I’m sure many of you enjoy coffee. This is going to put the coffee crops in jeopardy as well,” she said. More

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      in Environment

      Merging science and systems thinking to make materials more sustainable

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      For Professor Elsa Olivetti, tackling a problem as large and complex as climate change requires not only lab research but also understanding the systems of production that power the global economy.

      Her career path reflects a quest to investigate materials at scales ranging from the microscopic to the mass-manufactured.

      “I’ve always known what questions I wanted to ask, and then set out to build the tools to help me ask those questions,” says Olivetti, the Jerry McAfee Professor in Engineering.

      Olivetti, who earned tenure in 2022 and was recently appointed associate dean of engineering, has sought to equip students with similar skills, whether in the classroom, in her lab group, or through the interdisciplinary programs she leads at MIT. Those efforts have earned her accolades including the Bose Award for Excellence in Teaching, a MacVicar Faculty Fellowship in 2021, and the McDonald Award for Excellence in Mentoring and Advising in 2023.

      “I think to make real progress in sustainability, materials scientists need to think in interdisciplinary, systems-level ways, but at a deep technical level,” Olivetti says. “Supporting my students so that’s something that a lot more people can do is very rewarding for me.”

      Her mission to make materials more sustainable also makes Olivetti grateful [EAO1] she’s at MIT, which has a long tradition of both interdisciplinary collaboration and technical know-how.

      “MIT’s core competencies are well-positioned for bold achievements in climate and sustainability — the deep expertise on the economics side, the frontier knowledge in science, the computational creativity,” Olivetti says. “It’s a really exciting time and place where the key ingredients for progress are simmering in transformative ways.”

      Answering the call

      The moment that set Olivetti on her life’s journey began when she was 8, with a knock at her door. Her parents were in the other room, so Olivetti opened the door and met an organizer for Greenpeace, a nonprofit that works to raise awareness of environmental issues.

      “I had a chat with that guy and got hooked on environmental concerns,” Olivetti says. “I still remember that conversation.”

      The interaction changed the way Olivetti thought about her place in the world, and her new perspective manifested itself in some unique ways. Her elementary school science fair projects became elaborate pursuits of environmental solutions involving burying various items in the backyard to test for biodegradability. There was also an awkward attempt at natural pesticide development, which lead to a worm hatching in her bedroom.

      As an undergraduate at the University of Virginia, Olivetti gravitated toward classes in environmentalism and materials science.

      “There was a link between materials science and a broader, systems way of framing design for environment, and that just clicked for me in terms of the way I wanted to think about environmental problems — from the atom to the system,” Olivetti recalls.

      That interest led Olivetti to MIT for a PhD in 2001, where she studied the feasibility of new materials for lithium-ion batteries.

      “I really wanted to be thinking of things at a systems level, but I wanted to ground that in lab-based research,” Olivetti says. “I wanted an experiential experience in grad school, and that’s why I chose MIT’s program.”

      Whether it was her undergraduate studies, her PhD, or her ensuing postdoc work at MIT, Olivetti sought to learn new skills to continue bridging the gap between materials science and environmental systems thinking.

      “I think of it as, ‘Here’s how I can build up the ways I ask questions,’” Olivetti explains. “How do we design these materials while thinking about their implications as early as possible?”

      Since joining MIT’s faculty in 2014, Olivetti has developed computational models to measure the cost and environmental impact of new materials, explored ways to adopt more sustainable and circular supply chains, and evaluated potential materials limitations as lithium-ion battery production is scaled. That work helps companies increase their use of greener, recyclable materials and more sustainably dispose of waste.

      Olivetti believes the wide scope of her research gives the students in her lab a more holistic understanding of the life cycle of materials.

      “When the group started, each student was working on a different aspect of the problem — like on the natural language processing pipeline, or on recycling technology assessment, or beneficial use of waste — and now each student can link each of those pieces in their research,” Olivetti explains.

      Beyond her research, Olivetti also co-directs the MIT Climate and Sustainability Consortium, which has established a set of eight areas of sustainability that it organizes coalitions around. Each coalition involves technical leaders at companies and researchers at MIT that work together to accelerate the impact of MIT’s research by helping companies adopt innovative and more sustainable technologies.

      “Climate change mitigation and resilience is such a complex problem, and at MIT we have practice in working together across disciplines on many challenges,” Olivetti says. “It’s been exciting to lean on that culture and unlock ways to move forward more effectively.”

      Bridging divides

      Today, Olivetti tries to maximize the impact of her and her students’ research in materials industrial ecology by maintaining close ties to applications. In her research, this means working directly with aluminum companies to design alloys that could incorporate more scrap material or with nongovernmental organizations to incorporate agricultural residues in building products. In the classroom, that means bringing in people from companies to explain how they think about concepts like heat exchange or fluid flow in their products.

      “I enjoy trying to ground what students are learning in the classroom with what’s happening in the world,” Olivetti explains.

      Exposing students to industry is also a great way to help them think about their own careers. In her research lab, she’s started using the last 30 minutes of meetings to host talks from people working in national labs, startups, and larger companies to show students what they can do after their PhDs. The talks are similar to the Industry Seminar series Olivetti started that pairs undergraduate students with people working in areas like 3D printing, environmental consulting, and manufacturing.

      “It’s about helping students learn what they’re excited about,” Olivetti says.

      Whether in the classroom, lab, or at events held by organizations like MCSC, Olivetti believes collaboration is humanity’s most potent tool to combat climate change.

      “I just really enjoy building links between people,” Olivetti says. “Learning about people and meeting them where they are is a way that one can create effective links. It’s about creating the right playgrounds for people to think and learn.” More

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      in Energy

      A civil discourse on climate change

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      A new MIT initiative designed to encourage open dialogue on campus kicked off with a conversation focused on how to address challenges related to climate change.

      “Climate Change: Existential Threat or Bump in the Road” featured Steve Koonin, theoretical physicist and former U.S. undersecretary for science during the Obama administration, and Kerry Emanuel, professor emeritus of atmospheric science at MIT. A crowd of roughly 130 students, staff, and faculty gathered in an MIT lecture hall for the discussion on Tuesday, Oct. 24. 

      “The bump is strongly favored,” Koonin said when the talk began, referring to his contention that climate change was a “bump in the road” rather than an existential threat. After proposing a future in which we could potentially expect continued growth in America’s gross domestic product despite transportation and infrastructure challenges related to climate change, he concluded that investments in nuclear energy and capacity increases related to storing wind- and solar-generated energy could help mitigate climate-related phenomena. 

      Emanuel, while mostly agreeing with Koonin’s assessment of climate challenges and potential solutions, cautioned against underselling the threat of human-aided climate change.

      “Humanity’s adaptation to climate stability hasn’t prepared us to effectively manage massive increases in temperature and associated effects,” he argued. “We’re poorly adapted to less-frequent events like those we’re observing now.”

      Decarbonization, Emanuel noted, can help mitigate global conflicts related to fossil fuel usage. “Carbonization kills between 8 and 9 million people annually,” he said.

      The conversation on climate change is one of several planned on campus this academic year. The speaker series is one part of “Civil Discourse in the Classroom and Beyond,” an initiative being led by MIT philosophers Alex Byrne and Brad Skow. The two-year project is meant to encourage the open exchange of ideas inside and outside college and university classrooms. 

      The speaker series pairs external thought leaders with MIT faculty to encourage the interrogation and debate of all kinds of ideas.

      Finding common ground

      At the talk on climate change, both Koonin and Emanuel recommended a slow and steady approach to mitigation efforts, reminding attendees that, for example, developing nations can’t afford to take a developed world approach to climate change. 

      “These people have immediate needs to meet,” Koonin reminded the audience, “which can include fossil fuel use.”

      Both Koonin and Emanuel recommended a series of steps to assist with both climate change mitigation and effective messaging:

      Sustain and improve climate science — continue to investigate and report findings.
      Improve climate communications for non-experts — tell an easy-to-understand and cohesive story.
      Focus on reliability and affordability before mitigation — don’t undertake massive efforts that may disrupt existing energy transmission infrastructure.
      Adopt a “graceful” approach to decarbonization — consider impacts as broadly as possible.
      Don’t constrain energy supply in the developing world.
      Increase focus on developing and delivering alternative responses  — consider the potential ability to scale power generation, and delivery methods like nuclear energy.
      Mitigating climate risk requires political will, careful consideration, and an improved technical approach to energy policy, both concluded.

      “We have to learn to deal rationally with climate risk in a polarized society,” Koonin offered.

      The audience asked both speakers questions about impacts on nonhuman species (“We don’t know but we should,” both shared); nuclear fusion (“There isn’t enough tritium to effectively scale the widespread development of fusion-based energy; perhaps in 30 to 40 years,” Koonin suggested); and the planetary boundaries framework (“There’s good science underway in this space and I’m curious to see where it’s headed,” said Emanuel.) 

      “The event was a great success,” said Byrne, afterward. “The audience was engaged, and there was a good mix of faculty and students.”

      “One surprising thing,” Skow added, “was both Koonin and Emanuel were down on wind and solar power, [especially since] the idea that we need to transition to both is certainly in the air.”

      More conversations

      A second speaker series event, held earlier this month, was “Has Feminism Made Progress?” with Mary Harrington, author of “Feminism Against Progress,” and Anne McCants, MIT professor of history. An additional discussion planned for spring 2024 will cover the public health response to Covid-19.

      Discussions from the speaker series will appear as special episodes on “The Good Fight,” a podcast hosted by Johns Hopkins University political scientist Yascha Mounk.

      The Civil Discourse project is made possible due, in part, to funding from the Arthur Vining Davis Foundations and a collaboration between the MIT History Section and Concourse, a program featuring an integrated, cross-disciplinary approach to investigating some of humanity’s most interesting questions.

      The Civil Discourse initiative includes two components: the speaker series open to the MIT community, and seminars where students can discuss freedom of expression and develop skills for successfully engaging in civil discourse. More