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      in Environment

      Study: Global deforestation leads to more mercury pollution

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      About 10 percent of human-made mercury emissions into the atmosphere each year are the result of global deforestation, according to a new MIT study.

      The world’s vegetation, from the Amazon rainforest to the savannahs of sub-Saharan Africa, acts as a sink that removes the toxic pollutant from the air. However, if the current rate of deforestation remains unchanged or accelerates, the researchers estimate that net mercury emissions will keep increasing.

      “We’ve been overlooking a significant source of mercury, especially in tropical regions,” says Ari Feinberg, a former postdoc in the Institute for Data, Systems, and Society (IDSS) and lead author of the study.

      The researchers’ model shows that the Amazon rainforest plays a particularly important role as a mercury sink, contributing about 30 percent of the global land sink. Curbing Amazon deforestation could thus have a substantial impact on reducing mercury pollution.

      The team also estimates that global reforestation efforts could increase annual mercury uptake by about 5 percent. While this is significant, the researchers emphasize that reforestation alone should not be a substitute for worldwide pollution control efforts.

      “Countries have put a lot of effort into reducing mercury emissions, especially northern industrialized countries, and for very good reason. But 10 percent of the global anthropogenic source is substantial, and there is a potential for that to be even greater in the future. [Addressing these deforestation-related emissions] needs to be part of the solution,” says senior author Noelle Selin, a professor in IDSS and MIT’s Department of Earth, Atmospheric and Planetary Sciences.

      Feinberg and Selin are joined on the paper by co-authors Martin Jiskra, a former Swiss National Science Foundation Ambizione Fellow at the University of Basel; Pasquale Borrelli, a professor at Roma Tre University in Italy; and Jagannath Biswakarma, a postdoc at the Swiss Federal Institute of Aquatic Science and Technology. The paper appears today in Environmental Science and Technology.

      Modeling mercury

      Over the past few decades, scientists have generally focused on studying deforestation as a source of global carbon dioxide emissions. Mercury, a trace element, hasn’t received the same attention, partly because the terrestrial biosphere’s role in the global mercury cycle has only recently been better quantified.

      Plant leaves take up mercury from the atmosphere, in a similar way as they take up carbon dioxide. But unlike carbon dioxide, mercury doesn’t play an essential biological function for plants. Mercury largely stays within a leaf until it falls to the forest floor, where the mercury is absorbed by the soil.

      Mercury becomes a serious concern for humans if it ends up in water bodies, where it can become methylated by microorganisms. Methylmercury, a potent neurotoxin, can be taken up by fish and bioaccumulated through the food chain. This can lead to risky levels of methylmercury in the fish humans eat.

      “In soils, mercury is much more tightly bound than it would be if it were deposited in the ocean. The forests are doing a sort of ecosystem service, in that they are sequestering mercury for longer timescales,” says Feinberg, who is now a postdoc in the Blas Cabrera Institute of Physical Chemistry in Spain.

      In this way, forests reduce the amount of toxic methylmercury in oceans.

      Many studies of mercury focus on industrial sources, like burning fossil fuels, small-scale gold mining, and metal smelting. A global treaty, the 2013 Minamata Convention, calls on nations to reduce human-made emissions. However, it doesn’t directly consider impacts of deforestation.

      The researchers launched their study to fill in that missing piece.

      In past work, they had built a model to probe the role vegetation plays in mercury uptake. Using a series of land use change scenarios, they adjusted the model to quantify the role of deforestation.

      Evaluating emissions

      This chemical transport model tracks mercury from its emissions sources to where it is chemically transformed in the atmosphere and then ultimately to where it is deposited, mainly through rainfall or uptake into forest ecosystems.

      They divided the Earth into eight regions and performed simulations to calculate deforestation emissions factors for each, considering elements like type and density of vegetation, mercury content in soils, and historical land use.

      However, good data for some regions were hard to come by.

      They lacked measurements from tropical Africa or Southeast Asia — two areas that experience heavy deforestation. To get around this gap, they used simpler, offline models to simulate hundreds of scenarios, which helped them improve their estimations of potential uncertainties.

      They also developed a new formulation for mercury emissions from soil. This formulation captures the fact that deforestation reduces leaf area, which increases the amount of sunlight that hits the ground and accelerates the outgassing of mercury from soils.

      The model divides the world into grid squares, each of which is a few hundred square kilometers. By changing land surface and vegetation parameters in certain squares to represent deforestation and reforestation scenarios, the researchers can capture impacts on the mercury cycle.

      Overall, they found that about 200 tons of mercury are emitted to the atmosphere as the result of deforestation, or about 10 percent of total human-made emissions. But in tropical and sub-tropical countries, deforestation emissions represent a higher percentage of total emissions. For example, in Brazil deforestation emissions are 40 percent of total human-made emissions.

      In addition, people often light fires to prepare tropical forested areas for agricultural activities, which causes more emissions by releasing mercury stored by vegetation.

      “If deforestation was a country, it would be the second highest emitting country, after China, which emits around 500 tons of mercury a year,” Feinberg adds.

      And since the Minamata Convention is now addressing primary mercury emissions, scientists can expect deforestation to become a larger fraction of human-made emissions in the future.

      “Policies to protect forests or cut them down have unintended effects beyond their target. It is important to consider the fact that these are systems, and they involve human activities, and we need to understand them better in order to actually solve the problems that we know are out there,” Selin says.

      By providing this first estimate, the team hopes to inspire more research in this area.

      In the future, they want to incorporate more dynamic Earth system models into their analysis, which would enable them to interactively track mercury uptake and better model the timescale of vegetation regrowth.

      “This paper represents an important advance in our understanding of global mercury cycling by quantifying a pathway that has long been suggested but not yet quantified. Much of our research to date has focused on primary anthropogenic emissions — those directly resulting from human activity via coal combustion or mercury-gold amalgam burning in artisanal and small-scale gold mining,” says Jackie Gerson, an assistant professor in the Department of Earth and Environmental Sciences at Michigan State University, who was not involved with this research. “This research shows that deforestation can also result in substantial mercury emissions and needs to be considered both in terms of global mercury models and land management policies. It therefore has the potential to advance our field scientifically as well as to promote policies that reduce mercury emissions via deforestation.

      This work was funded, in part, by the U.S. National Science Foundation, the Swiss National Science Foundation, and Swiss Federal Institute of Aquatic Science and Technology. More

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      in Energy

      MIT researchers map the energy transition’s effects on jobs

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      A new analysis by MIT researchers shows the places in the U.S. where jobs are most linked to fossil fuels. The research could help policymakers better identify and support areas affected over time by a switch to renewable energy.

      While many of the places most potentially affected have intensive drilling and mining operations, the study also measures how areas reliant on other industries, such as heavy manufacturing, could experience changes. The research examines the entire U.S. on a county-by-county level.

      “Our result is that you see a higher carbon footprint for jobs in places that drill for oil, mine for coal, and drill for natural gas, which is evident in our maps,” says Christopher Knittel, an economist at the MIT Sloan School of Management and co-author of a new paper detailing the findings. “But you also see high carbon footprints in areas where we do a lot of manufacturing, which is more likely to be missed by policymakers when examining how the transition to a zero-carbon economy will affect jobs.”

      So, while certain U.S. areas known for fossil-fuel production would certainly be affected — including west Texas, the Powder River Basin of Montana and Wyoming, parts of Appalachia, and more — a variety of industrial areas in the Great Plains and Midwest could see employment evolve as well.

      The paper, “Assessing the distribution of employment vulnerability to the energy transition using employment carbon footprints,” is published this week in Proceedings of the National Academy of Sciences. The authors are Kailin Graham, a master’s student in MIT’s Technology and Policy Program and graduate research assistant at MIT’s Center for Energy and Environmental Policy Research; and Knittel, who is the George P. Shultz Professor at MIT Sloan.

      “Our results are unique in that we cover close to the entire U.S. economy and consider the impacts on places that produce fossil fuels but also on places that consume a lot of coal, oil, or natural gas for energy,” says Graham. “This approach gives us a much more complete picture of where communities might be affected and how support should be targeted.”

      Adjusting the targets

      The current study stems from prior research Knittel has conducted, measuring carbon footprints at the household level across the U.S. The new project takes a conceptually related approach, but for jobs in a given county. To conduct the study, the researchers used several data sources measuring energy consumption by businesses, as well as detailed employment data from the U.S. Census Bureau.

      The study takes advantage of changes in energy supply and demand over time to estimate how strongly a full range of jobs, not just those in energy production, are linked to use of fossil fuels. The sectors accounted for in the study comprise 86 percent of U.S. employment, and 94 percent of U.S. emissions apart from the transportation sector.

      The Inflation Reduction Act, passed by Congress and signed into law by President Joe Biden in August 2022, is the first federal legislation seeking to provide an economic buffer for places affected by the transition away from fossil fuels. The act provides expanded tax credits for economic projects located in “energy community” areas — defined largely as places with high fossil-fuel industry employment or tax revenue and with high unemployment. Areas with recently closed or downsized coal mines or power plants also qualify.

      Graham and Knittel measured the “employment carbon footprint” (ECF) of each county in the U.S., producing new results. Out of more than 3,000 counties in the U.S., the researchers found that 124 are at the 90th percentile or above in ECF terms, while not qualifying for Inflation Reduction Act assistance. Another 79 counties are eligible for Inflation Reduction Act assistance, while being in the bottom 20 percent nationally in ECF terms.

      Those may not seem like colossal differences, but the findings identify real communities potentially being left out of federal policy, and highlight the need for new targeting of such programs. The research by Graham and Knittel offers a precise way to assess the industrial composition of U.S. counties, potentially helping to target economic assistance programs.

      “The impact on jobs of the energy transition is not just going to be where oil and natural gas are drilled, it’s going to be all the way up and down the value chain of things we make in the U.S.,” Knittel says. “That’s a more extensive, but still focused, problem.”

      Graham adds: “It’s important that policymakers understand these economy-wide employment impacts. Our aim in providing these data is to help policymakers incorporate these considerations into future policies like the Inflation Reduction Act.”

      Adapting policy

      Graham and Knittel are still evaluating what the best policy measures might be to help places in the U.S. adapt to a move away from fossil fuels.

      “What we haven’t necessarily closed the loop on is the right way to build a policy that takes account of these factors,” Knittel says. “The Inflation Reduction Act is the first policy to think about a [fair] energy transition because it has these subsidies for energy-dependent counties.” But given enough political backing, there may be room for additional policy measures in this area.

      One thing clearly showing through in the study’s data is that many U.S. counties are in a variety of situations, so there may be no one-size-fits-all approach to encouraging economic growth while making a switch to clean energy. What suits west Texas or Wyoming best may not work for more manufacturing-based local economies. And even among primary energy-production areas, there may be distinctions, among those drilling for oil or natural gas and those producing coal, based on the particular economics of those fuels. The study includes in-depth data about each county, characterizing its industrial portfolio, which may help tailor approaches to a range of economic situations.

      “The next step is using this data more specifically to design policies to protect these communities,” Knittel says. More

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      in Energy

      Faculty, staff, students to evaluate ways to decarbonize MIT’s campus

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      With a goal to decarbonize the MIT campus by 2050, the Institute must look at “new ideas, transformed into practical solutions, in record time,” as stated in “Fast Forward: MIT’s Climate Action Plan for the Decade.” This charge calls on the MIT community to explore game-changing and evolving technologies with the potential to move campuses like MIT away from carbon emissions-based energy systems.

      To help meet this tremendous challenge, the Decarbonization Working Group — a new subset of the Climate Nucleus — recently launched. Comprised of appointed MIT faculty, researchers, and students, the working group is leveraging its members’ expertise to meet the charge of exploring and assessing existing and in-development solutions to decarbonize the MIT campus by 2050. The group is specifically charged with informing MIT’s efforts to decarbonize the campus’s district energy system.

      Co-chaired by Director of Sustainability Julie Newman and Department of Architecture Professor Christoph Reinhart, the working group includes members with deep knowledge of low- and zero-carbon technologies and grid-level strategies. In convening the group, Newman and Reinhart sought out members researching these technologies as well as exploring their practical use. “In my work on multiple projects on campus, I have seen how cutting-edge research often relies on energy-intensive equipment,” shares PhD student and group member Ippolyti Dellatolas. “It’s clear how new energy-efficiency strategies and technologies could use campus as a living lab and then broadly deploy these solutions across campus for scalable emissions reductions.” This approach is one of MIT’s strong suits and a recurring theme in its climate action plans — using the MIT campus as a test bed for learning and application. “We seek to study and analyze solutions for our campus, with the understanding that our findings have implications far beyond our campus boundaries,” says Newman.

      The efforts of the working group represent just one part of the multipronged approach to identify ways to decarbonize the MIT campus. The group will work in parallel and at times collaboratively with the team from the Office of the Vice President for Campus Services and Stewardship that is managing the development plan for potential zero-carbon pathways for campus buildings and the district energy system. In May 2023, MIT engaged Affiliated Engineers, Inc. (AEI), to support the Institute’s efforts to identify, evaluate, and model various carbon-reduction strategies and technologies to provide MIT with a series of potential decarbonization pathways. Each of the pathways must demonstrate how to manage the generation of energy and its distribution and use on campus. As MIT explores electrification, a significant challenge will be the availability of resilient clean power from the grid to help generate heat for our campus without reliance on natural gas.

      When the Decarbonization Working Group began work this fall, members took the time to learn more about current systems and baseline information. Beginning this month, members will organize analysis around each of their individual areas of expertise and interest and begin to evaluate existing and emerging carbon reduction technologies. “We are fortunate that there are constantly new ideas and technologies being tested in this space and that we have a committed group of faculty working together to evaluate them,” Newman says. “We are aware that not every technology is the right fit for our unique dense urban campus, and nor are we solving for a zero-carbon campus as an island, but rather in the context of an evolving regional power grid.”

      Supported by funding from the Climate Nucleus, evaluating technologies will include site visits to locations where priority technologies are currently deployed or being tested. These site visits may range from university campuses implementing district geothermal and heat pumps to test sites of deep geothermal or microgrid infrastructure manufacturers. “This is a unique moment for MIT to demonstrate leadership by combining best decarbonization practices, such as retrofitting building systems to achieve deep energy reductions and converting to low-temperature district heating systems with ‘nearly there’ technologies such as deep geothermal, micronuclear, energy storage, and ubiquitous occupancy-driven temperature control,” says Reinhart. “As first adopters, we can find out what works, allowing other campuses to follow us at reduced risks.”

      The findings and recommendations of the working group will be delivered in a report to the community at the end of 2024. There will be opportunities for the MIT community to learn more about MIT’s decarbonization efforts at community events on Jan. 24 and March 14, as well as MIT’s Sustainability Connect forum on Feb. 8. More

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      in Environment

      Q&A: A blueprint for sustainable innovation

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      Atacama Biomaterials is a startup combining architecture, machine learning, and chemical engineering to create eco-friendly materials with multiple applications. Passionate about sustainable innovation, its co-founder Paloma Gonzalez-Rojas SM ’15, PhD ’21 highlights here how MIT has supported the project through several of its entrepreneurship initiatives, and reflects on the role of design in building a holistic vision for an expanding business.

      Q: What role do you see your startup playing in the sustainable materials space?

      A: Atacama Biomaterials is a venture dedicated to advancing sustainable materials through state-of-the-art technology. With my co-founder Jose Tomas Dominguez, we have been working on developing our technology since 2019. We initially started the company in 2020 under another name and received Sandbox funds the next year. In 2021, we went through The Engine’s accelerator, Blueprint, and changed our name to Atacama Biomaterials in 2022 during the MITdesignX program. 

      This technology we have developed allows us to create our own data and material library using artificial intelligence and machine learning, and serves as a platform applicable to various industries horizontally — biofuels, biological drugs, and even mining. Vertically, we produce inexpensive, regionally sourced, and environmentally friendly bio-based polymers and packaging — that is, naturally compostable plastics as a flagship product, along with AI products.

      Q: What motivated you to venture into biomaterials and found Atacama?

      A: I’m from Chile, a country with a beautiful, rich geography and nature where we can see all the problems stemming from industry, waste management, and pollution. We named our company Atacama Biomaterials because the Atacama Desert in Chile — one of the places where you can best see the stars in the world — is becoming a plastic dump, as many other places on Earth. I care deeply about sustainability, and I have an emotional attachment to stop these problems. Considering that manufacturing accounts for 29 percent of global carbon emissions, it is clear that sustainability has a role in how we define technology and entrepreneurship, as well as a socio-economic dimension.

      When I first came to MIT, it was to develop software in the Department of Architecture’s Design and Computation Group, with MIT professors Svafa Gronfeldt as co-advisor and Regina Barzilay as committee member. During my PhD, I studied machine-learning methods simulating pedestrian motion to understand how people move in space. In my work, I would use lots of plastics for 3D printing and I couldn’t stop thinking about sustainability and climate change, so I reached out to material science and mechanical engineering professors to look into biopolymers and degradable bio-based materials. This is how I met my co-founder, as we were both working with MIT Professor Neil Gershenfeld. Together, we were part of one of the first teams in the world to 3D print wood fibers, which is difficult — it’s slow and expensive — and quickly pivoted to sustainable packaging. 

      I then won a fellowship from MCSC [the MIT Climate and Sustainability Consortium], which gave me freedom to explore further, and I eventually got a postdoc in MIT chemical engineering, guided by MIT Professor Gregory Rutledge, a polymer physicist. This was unexpected in my career path. Winning Nucleate Eco Track 2022 and the MITdesignX Innovation Award in 2022 profiled Atacama Biomaterials as one of the rising startups in Boston’s biotechnology and climate-tech scene.

      Q: What is your process to develop new biomaterials?

      A: My PhD research, coupled with my background in material development and molecular dynamics, sparked the realization that principles I studied simulating pedestrian motion could also apply to molecular engineering. This connection may seem unconventional, but for me, it was a natural progression. Early in my career, I developed an intuition for materials, understanding their mechanics and physics.

      Using my experience and skills, and leveraging machine learning as a technology jump, I applied a similar conceptual framework to simulate the trajectories of molecules and find potential applications in biomaterials. Making that parallel and shift was amazing. It allowed me to optimize a state-of-the-art molecular dynamic software to run twice as fast as more traditional technologies through my algorithm presented at the International Conference of Machine Learning this year. This is very important, because this kind of simulation usually takes a week, so narrowing it down to two days has major implications for scientists and industry, in material science, chemical engineering, computer science and related fields. Such work greatly influenced the foundation of Atacama Biomaterials, where we developed our own AI to deploy our materials. In an effort to mitigate the environmental impact of manufacturing, Atacama is targeting a 16.7 percent reduction in carbon dioxide emissions associated with the manufacturing process of its polymers, through the use of renewable energy. 

      Another thing is that I was trained as an architect in Chile, and my degree had a design component. I think design allows me to understand problems at a very high level, and how things interconnect. It contributed to developing a holistic vision for Atacama, because it allowed me to jump from one technology or discipline to another and understand broader applications on a conceptual level. Our design approach also meant that sustainability came to the center of our work from the very beginning, not just a plus or an added cost.

      Q: What was the role of MITdesignX in Atacama’s development?

      A: I have known Svafa Grönfeldt, MITdesignX’s faculty director, for almost six years. She was the co-advisor of my PhD, and we had a mentor-mentee relationship. I admire the fact that she created a space for people interested in business and entrepreneurship to grow within the Department of Architecture. She and Executive Director Gilad Rosenzweig gave us fantastic advice, and we received significant support from mentors. For example, Daniel Tsai helped us with intellectual property, including a crucial patent for Atacama. And we’re still in touch with the rest of the cohort. I really like this “design your company” approach, which I find quite unique, because it gives us the opportunity to reflect on who we want to be as designers, technologists, and entrepreneurs. Studying user insights also allowed us to understand the broad applicability of our research, and align our vision with market demands, ultimately shaping Atacama into a company with a holistic perspective on sustainable material development.

      Q: How does Atacama approach scaling, and what are the immediate next steps for the company?

      A: When I think about accomplishing our vision, I feel really inspired by my 3-year-old daughter. I want her to experience a world with trees and wildlife when she’s 100 years old, and I hope Atacama will contribute to such a future.

      Going back to the designer’s perspective, we designed the whole process holistically, from feedstock to material development, incorporating AI and advanced manufacturing. Having proved that there is a demand for the materials we are developing, and having tested our products, manufacturing process, and technology in critical environments, we are now ready to scale. Our level of technology-readiness is comparable to the one used by NASA (level 4).

      We have proof of concept: a biodegradable and recyclable packaging material which is cost- and energy-efficient as a clean energy enabler in large-scale manufacturing. We have received pre-seed funding, and are sustainably scaling by taking advantage of available resources around the world, like repurposing machinery from the paper industry. As presented in the MIT Industrial Liaison and STEX Program’s recent Sustainability Conference, unlike our competitors, we have cost-parity with current packaging materials, as well as low-energy processes. And we also proved the demand for our products, which was an important milestone. Our next steps involve strategically expanding our manufacturing capabilities and research facilities and we are currently evaluating building a factory in Chile and establishing an R&D lab plus a manufacturing plant in the U.S. More

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      in Energy

      MIT researchers outline a path for scaling clean hydrogen production

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      Hydrogen is an integral component for the manufacture of steel, fertilizer, and a number of chemicals. Producing hydrogen using renewable electricity offers a way to clean up these and many other hard-to-decarbonize industries.

      But supporting the nascent clean hydrogen industry while ensuring it grows into a true force for decarbonization is complicated, in large part because of the challenges of sourcing clean electricity. To assist regulators and to clarify disagreements in the field, MIT researchers published a paper today in Nature Energy that outlines a path to scale the clean hydrogen industry while limiting emissions.

      Right now, U.S. electric grids are mainly powered by fossil fuels, so if scaling hydrogen production translates to greater electricity use, it could result in a major emissions increase. There is also the risk that “low-carbon” hydrogen projects could end up siphoning renewable energy that would have been built anyway for the grid. It is therefore critical to ensure that low-carbon hydrogen procures electricity from “additional” renewables, especially when hydrogen production is supported by public subsidies. The challenge is allowing hydrogen producers to procure renewable electricity in a cost-effective way that helps the industry grow, while minimizing the risk of high emissions.

      U.S. regulators have been tasked with sorting out this complexity. The Inflation Reduction Act (IRA) is offering generous production tax credits for low-carbon hydrogen. But the law didn’t specify exactly how hydrogen’s carbon footprint should be judged.

      To this end, the paper proposes a phased approach to qualify for the tax credits. In the first phase, hydrogen created from grid electricity can receive the credits under looser standards as the industry gets its footing. Once electricity demand for hydrogen production grows, the industry should be required to adhere to stricter standards for ensuring the electricity is coming from renewable sources. Finally, many years from now when the grid is mainly powered by renewable energy, the standards can loosen again.

      The researchers say the nuanced approach ensures the law supports the growth of clean hydrogen without coming at the expense of emissions.

      “If we can scale low-carbon hydrogen production, we can cut some significant sources of existing emissions and enable decarbonization of other critical industries,” says paper co-author Michael Giovanniello, a graduate student in MIT’s Technology and Policy Program. “At the same time, there’s a real risk of implementing the wrong requirements and wasting lots of money to subsidize carbon-intensive hydrogen production. So, you have to balance scaling the industry with reducing the risk of emissions. I hope there’s clarity and foresight in how this policy is implemented, and I hope our paper makes the argument clear for policymakers.”

      Giovanniello’s co-authors on the paper are MIT Energy Initiative (MITEI) Principal Research Scientist Dharik Mallapragada, MITEI Research Assistant Anna Cybulsky, and MIT Sloan School of Management Senior Lecturer Tim Schittekatte.

      On definitions and disagreements

      When renewable electricity from a wind farm or solar array flows through the grid, it’s mixed with electricity from fossil fuels. The situation raises a question worth billions of dollars in federal tax credits: What are the carbon dioxide emissions of grid users who are also signing agreements to procure electricity from renewables?

      One way to answer this question is via energy system models that can simulate various scenarios related to technology configurations and qualifying requirements for receiving the credit.

      To date, many studies using such models have come up with very different emissions estimates for electrolytic hydrogen production. One source of disagreement is over “time matching,” which refers to how strictly to align the timing of electric hydrogen production with the generation of clean electricity. One proposed approach, known as hourly time matching, would require that electricity consumption to produce hydrogen is accounted for by procured clean electricity at every hour.

      A less stringent approach, called annual time matching, would offer more flexibility in hourly electricity consumption for hydrogen production, so long as the annual consumption matches the annual generation from the procured clean electricity generation. The added flexibility could reduce the cost of hydrogen production, which is critical for scaling its use, but could lead to greater emissions per unit of hydrogen produced.

      Another point of disagreement stems from how hydrogen producers purchase renewable electricity. If an electricity user procures energy from an existing solar farm, it’s simply increasing overall electricity demand and taking clean energy away from other users. But if the tax credits only go to electric hydrogen producers that sign power purchase agreements with new renewable suppliers, they’re supporting clean electricity that wouldn’t have otherwise been contributing to the grid. This concept is known as “additionality.”

      The researchers analyzed previous studies that reached conflicting conclusions, and identified different interpretations of additionality underlying their methodologies. One interpretation of additionality is that new electrolytic hydrogen projects do not compete with nonhydrogen demand for renewable energy resources. The other assumes that they do compete for all newly deployed renewables — and, because of low-carbon hydrogen subsidies, the electrolyzers take priority.

      Using DOLPHYN, an open-source energy systems model, the researchers tested how these two interpretations of additionality (the “compete” and “noncompete” scenarios) impact the cost and emissions of the alternative time-matching requirements (hourly and annual) associated with grid-interconnected hydrogen production. They modeled two regional U.S. grids — in Texas and Florida — which represent the high and low end of renewables deployment. They further tested the interaction of four critical policy factors with the hydrogen tax credits, including renewable portfolio standards, constraints of renewables and energy storage deployment, limits on hydrogen electrolyzer capacity factors, and competition with natural gas-based hydrogen with carbon capture.

      They show that the different modeling interpretations of additionality are the primary factor explaining the vastly different estimates of emissions from electrolyzer hydrogen under annual time-matching.

      Getting policy right

      The paper concludes that the right way to implement the production tax credit qualifying requirements depends on whether you believe we live in a “compete” or “noncompete” world. But reality is not so binary.

      “What framework is more appropriate is going to change with time as we deploy more hydrogen and the grid decarbonizes, so therefore the policy has to be adaptive to those changes,” Mallapragada says. “It’s an evolving story that’s tied to what’s happening in the rest of the energy system, and in particular the electric grid, both from the technological as policy perspective.”

      Today, renewables deployment is driven, in part, by binding factors, such as state renewable portfolio standards and corporate clean-energy commitments, as well as by purely market forces. Since the electrolyzer is so nascent, and today resembles a “noncompete” world, the researchers argue for starting with the less strict annual requirement. But as hydrogen demand for renewable electricity grows, and market competition drives an increasing quantity of renewables deployment, transitioning to hourly matching will be necessary to avoid high emissions.

      This phased approach necessitates deliberate, long-term planning from regulators. “If regulators make a decision and don’t outline when they’ll reassess that decision, they might never reassess that decision, so we might get locked into a bad policy,” Giovanniello explains. In particular, the paper highlights the risk of locking in an annual time-matching requirement that leads to significant emissions in future.

      The researchers hope their findings will contribute to upcoming policy decisions around the Inflation Reduction Act’s tax credits. They started looking into this question around a year ago, making it a quick turnaround by academic standards.

      “There was definitely a sense to be timely in our analysis so as to be responsive to the needs of policy,” Mallapragada says.

      The researchers say the paper can also help policymakers understand the emissions impacts of companies procuring renewable energy credits to meet net-zero targets and electricity suppliers attempting to sell “green” electricity.

      “This question is relevant in a lot of different domains,” Schittekatte says. “Other popular examples are the emission impacts of data centers that procure green power, or even the emission impacts of your own electric car sourcing power from your rooftop solar and the grid. There are obviously differences based on the technology in question, but the underlying research question we’ve answered is the same. This is an extremely important topic for the energy transition.” More

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      in Environment

      Satellite-based method measures carbon in peat bogs

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      Peat bogs in the tropics store vast amounts of carbon, but logging, plantations, road building, and other activities have destroyed large swaths of these ecosystems in places like Indonesia and Malaysia. Peat formations are essentially permanently flooded forestland, where dead leaves and branches accumulate because the water table prevents their decomposition.

      The pileup of organic material gives these formations a distinctive domed shape, somewhat raised in the center and tapering toward the edges. Determining how much carbon is contained in each formation has required laborious on-the-ground sampling, and so has been limited in its coverage.

      Now, researchers from MIT and Singapore have developed a mathematical analysis of how peat formations build and develop, that makes it possible to evaluate their carbon content and dynamics mostly from simple elevation measurements. These can be carried out by satellites, without requiring ground-based sampling. This analysis, the team says, should make it possible to make more precise and accurate assessments of the amount of carbon that would be released by any proposed draining of peatlands — and, inversely, how much carbon emissions could be avoided by protecting them.

      The research is being reported today in the journal Nature, in a paper by Alexander Cobb, a postdoc with the Singapore-MIT Alliance for Research and Technology (SMART); Charles Harvey, an MIT professor of civil and environmental engineering; and six others.

      Although it is the tropical peatlands that are at greatest risk — because they are the ones most often drained for timber harvesting or the creation of plantations for palm oil, acacia, and other crops — the new formulas the team derived apply to peatlands all over the globe, from Siberia to New Zealand. The formula requires just two inputs. The first is elevation data from a single transect of a given peat dome — that is, a series of elevation measurements along an arbitrary straight line cutting across from one edge of the formation to the other. The second input is a site-specific factor the team devised that relates to the type of peat bog involved and the internal structure of the formation, which together determine how much of the carbon within remains safely submerged in water, where it can’t be oxidized.

      “The saturation by water prevents oxygen from getting in, and if oxygen gets in, microbes breathe it and eat the peat and turn it into carbon dioxide,” Harvey explains.

      “There is an internal surface inside the peat dome below which the carbon is safe because it can’t be drained, because the bounding rivers and water bodies are such that it will keep saturated up to that level even if you cut canals and try to drain it,” he adds. In between the visible surface of the bog and this internal layer is the “vulnerable zone” of peat that can rapidly decompose and release its carbon compounds or become dry enough to promote fires that also release the carbon and pollute the air.

      Through years of on-the-ground sampling and testing, and detailed analysis comparing the ground data with satellite lidar data on surface elevations, the team was able to figure out a kind of universal mathematical formula that describes the structure of peat domes of all kinds and in all locations. They tested it by comparing their predicted results with field measurements from several widely distributed locations, including Alaska, Maine, Quebec, Estonia, Finland, Brunei, and New Zealand.

      These bogs contain carbon that has in many cases accumulated over thousands of years but can be released in just a few years when the bogs are drained. “If we could have policies to preserve these, it is a tremendous opportunity to reduce carbon fluxes to the atmosphere. This framework or model gives us the understanding, the intellectual framework, to figure out how to do that,” Harvey says.

      Many people assume that the biggest greenhouse gas emissions from cutting down these forested lands is from the decomposition of the trees themselves. “The misconception is that that’s the carbon that goes to the atmosphere,” Harvey says. “It’s actually a small amount, because the real fluxes to the atmosphere come from draining” the peat bogs. “Then, the much larger pool of carbon, which is underground beneath the forest, oxidizes and goes to the air, or catches fire and burns.”

      But there is hope, he says, that much of this drained peatland can still be restored before the stored carbon all gets released. First of all, he says, “you’ve got to stop draining it.” That can be accomplished by damming up the drainage canals. “That’s what’s good about this mathematical framework: You need to figure out how to do that, where to put your dams. There’s all sorts of interesting complexities. If you just dam up the canal, the water may flow around it. So, it’s a neat geometric and engineering project to figure out how to do this.”

      While much of the peatland in southeast Asia has already been drained, the new analysis should make it possible to make much more accurate assessments of less-well-studied peatlands in places like the Amazon basin, New Guinea and the Congo basin, which are also threatened by development.

      The new formulation should also help to make some carbon offset programs more reliable, because it is now possible to calculate accurately the carbon content of a given peatland. “It’s quantifiable, because the peat is 100 percent organic carbon. So, if you just measure the change in the surface going up or down, you can say with pretty good certainty how much carbon has been accumulated or lost, whereas if you go to a rainforest, it’s virtually impossible to calculate the amount of underground carbon, and it’s pretty hard to calculate what’s above ground too,” Harvey says. “But this is relatively easy to calculate with satellite measurements of elevation.”

      “We can turn the knob,” he says, “because we have this mathematical framework for how the hydrology, the water table position, affects the growth and loss of peat. We can design a scheme that will change emissions by X amount, for Y dollars.”

      The research team included Rene Dommain, Kimberly Yeap, and Cao Hannan at Nanyang Technical University in Singapore, Nathan Dadap at Stanford University, Bodo Bookhagen at the University of Potsdam, Germany, and Paul Glaser at the University of Minnesota. The work was supported by the National Research Foundation Singapore through the SMART program, by the U.S. National Science Foundation, and Singapore’s Office for Space Technology and Industry. More

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      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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      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