Environment

The world’s oceans are a vast repository for gases including ozone-depleting chlorofluorocarbons, or CFCs. They absorb these gases from the atmosphere and draw them down to the deep, where they can remain sequestered for centuries and more.
Marine CFCs have long been used as tracers to study ocean currents, but their impact on atmospheric concentrations was assumed to be negligible. Now, MIT researchers have found the oceanic fluxes of at least one type of CFC, known as CFC-11, do in fact affect atmospheric concentrations. In a study appearing today in the Proceedings of the National Academy of Sciences, the team reports that the global ocean will reverse its longtime role as a sink for the potent ozone-depleting chemical.
The researchers project that by the year 2075, the oceans will emit more CFC-11 back into the atmosphere than they absorb, emitting detectable amounts of the chemical by 2130. Further, with increasing climate change, this shift will occur 10 years earlier. The emissions of CFC-11 from the ocean will effectively extend the chemical’s average residence time, causing it to linger five years longer in the atmosphere than it otherwise would. This may impact future estimations of CFC-11 emissions.
The new results may help scientists and policymakers better pinpoint future sources of the chemical, which is now banned worldwide under the Montreal Protocol.
“By the time you get to the first half of the 22nd century, you’ll have enough of a flux coming out of the ocean that it might look like someone is cheating on the Montreal Protocol, but instead, it could just be what’s coming out of the ocean,” says study co-author Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “It’s an interesting prediction and hopefully will help future researchers avoid getting confused about what’s going on.”
Solomon’s co-authors include lead author Peidong Wang, Jeffery Scott, John Marshall, Andrew Babbin, Megan Lickley, and Ronald Prinn from MIT; David Thompson of Colorado State University; Timothy DeVries of the University of California at Santa Barbara; and Qing Liang of the NASA Goddard Space Flight Center.
An ocean, oversaturated
CFC-11 is a chlorofluorocarbon that was commonly used to make refrigerants and insulating foams. When emitted to the atmosphere, the chemical sets off a chain reaction that ultimately destroys ozone, the atmospheric layer that protects the Earth from harmful ultraviolet radiation. Since 2010, the production and use of the chemical has been phased out worldwide under the Montreal Protocol, a global treaty that aims to restore and protect the ozone layer.
Since its phaseout, levels of CFC-11 in the atmosphere have been steadily declining, and scientists estimate that the ocean has absorbed about 5 to 10 percent of all manufactured CFC-11 emissions. As concentrations of the chemical continue to fall in the atmosphere, however, it’s predicted that CFC-11 will oversaturate in the ocean, pushing it to become a source rather than a sink.
“For some time, human emissions were so large that what was going into the ocean was considered negligible,” Solomon says. “Now, as we try to get rid of human emissions, we find we can’t completely ignore what the ocean is doing anymore.”
A weakening reservoir
In their new paper, the MIT team looked to pinpoint when the ocean would become a source of the chemical, and to what extent the ocean would contribute to CFC-11 concentrations in the atmosphere. They also sought to understand how climate change would impact the ocean’s ability to absorb the chemical in the future.
The researchers used a hierarchy of models to simulate the mixing within and between the ocean and atmosphere. They began with a simple model of the atmosphere and the upper and lower layers of the ocean, in both the northern and southern hemispheres. They added into this model anthropogenic emissions of CFC-11 that had previously been reported through the years, then ran the model forward in time, from 1930 to 2300, to observe changes in the chemical’s flux between the ocean and the atmosphere.
They then replaced the ocean layers of this simple model with the MIT general circulation model, or MITgcm, a more sophisticated representation of ocean dynamics, and ran similar simulations of CFC-11 over the same time period.
Both models produced atmospheric levels of CFC-11 through the present day that matched with recorded measurements, giving the team confidence in their approach. When they looked at the models’ future projections, they observed that the ocean began to emit more of the chemical than it absorbed, beginning around 2075. By 2145, the ocean would emit CFC-11 in amounts that would be detectable by current monitoring standards.

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This animation shows (at right) the CFC-11 stored in the ocean over time, and (at left) the corresponding change in the chemical’s total atmospheric lifetime.

The ocean’s uptake in the 20th century and outgassing in the future also affects the chemical’s effective residence time in the atmosphere, decreasing it by several years during uptake and increasing it by up to 5 years by the end of 2200.
Climate change will speed up this process. The team used the models to simulate a future with global warming of about 5 degrees Celsius by the year 2100, and found that climate change will advance the ocean’s shift to a source by 10 years and produce detectable levels of CFC-11 by 2140.
“Generally, a colder ocean will absorb more CFCs,” Wang explains. “When climate change warms the ocean, it becomes a weaker reservoir and will also outgas a little faster.”
“Even if there were no climate change, as CFCs decay in the atmosphere, eventually the ocean has too much relative to the atmosphere, and it will come back out,” Solomon adds. “Climate change, we think, will make that happen even sooner. But the switch is not dependent on climate change.”
Their simulations show that the ocean’s shift will occur slightly faster in the Northern Hemisphere, where large-scale ocean circulation patterns are expected to slow down, leaving more gases in the shallow ocean to escape back to the atmosphere. However, knowing the exact drivers of the ocean’s reversal will require more detailed models, which the researchers intend to explore.
“Some of the next steps would be to do this with higher-resolution models and focus on patterns of change,” says Scott. “For now, we’ve opened up some great new questions and given an idea of what one might see.”
This research was supported, in part, by the VoLo Foundation, the Simons Foundation, and the National Science Foundation. More

The Sustainability DataPool, powered by the Office of Sustainability (MITOS), gives the MIT community the opportunity to understand data on important sustainability metrics like energy, water use, emissions, and recycling rates. While most visualizations share data from past events, the newest dashboard — the MIT Climate Resiliency Dashboard (MIT certificate required to view) — looks to potential future events in the form of flooding on campus. The dashboard is an essential planning tool for ongoing work to build a climate-resilient MIT, one that fulfills its mission in the face of impacts of climate change. It’s also a tool that highlights the importance of collaboration in devising sustainability solutions.
Development of the dashboard began in 2017 when the City of Cambridge, Massachusetts, released the first version of its FloodViewer. The viewer allowed users to map climate change threats from flooding in Cambridge. Scanning the map in the viewer, one could see all of Cambridge — except for MIT. At the time, the City of Cambridge did not have a full account of MIT’s stormwater drainage system, so the viewer was launched without it. That unmapped area served as a call to action for MITOS. 
MITOS Assistant Director Brian Goldberg and MITOS Faculty Fellow and research scientist at the MIT Center for Global Change Science Ken Strzepek reached out to the Cambridge Community Development Department — with which MIT has long worked on climate action — and made a plan to populate the missing map information, working with the city to understand how to map MIT’s data to fit the FloodViewer model. Harmonizing MIT’s data with that of the city would complete the potential flooding picture for Cambridge, give MIT new insight on its own potential flooding threats, and enable a common climate change baseline for planning decisions about campus and city building and infrastructure projects. “We saw this as an opportunity to expand our understanding of our own threats on campus and to team with the city to explore how we could develop a common picture of climate change impacts,” says Strzepek.
From there, Strzepek, Goldberg, and a number of MITOS student fellows began work on what would become the Climate Resiliency Dashboard. MITOS partnered with the Department of Facilities; Center for Global Change Science; Office of Emergency Management; Office of Campus Planning; Department of Earth, Atmospheric and Planetary Sciences; Urban Risk Lab; and other members of the MIT Climate Resiliency Committee for assistance on data, design, and user testing. These partnerships helped create the most accurate picture of potential flooding impacts on campus by looking at topography, stormwater management systems, and past trends.
The beta version of the tool went live in November 2020 and functions much like the Cambridge FloodViewer: Projected flooding data is laid over a campus map of MIT, allowing users to zoom in on a portion of campus under a specific scenario — say, a 100-year storm occurring in 2030 — and see the projected potential peak rain or storm surge water depth at that location. The dashboard explains not only how these numbers were calculated, but what types of rain and storm surge events can cause them to happen. But the flood mapping is only part of the story. “Flooding itself isn’t necessarily a problem — it’s the potential of that flooding to interrupt MIT’s critical research, education, and campus operations,” explains Goldberg.
The dashboard is already informing new building designs, such as the MIT Schwarzman College of Computing, which is designed to be resilient to a 100-year flood event anticipated under a changed climate 50 years from today. “By enabling MIT to understand flood risk for new buildings, we can respond holistically to that risk and integrate flood mitigation strategies as part of the overarching design,” explains Randa Ghattas, senior sustainability project manager in the Department of Facilities. “This could include intentionally elevating buildings or a combination of gray- and green-infrastructure site-level strategies to mitigate flooding and support multiple benefits like stormwater management, urban heat island mitigation, and enhanced outdoor comfort.”
Information displayed in the dashboard is continually being refined as the science and engineering of flood risk modeling progress. Goldberg explains, “While the dashboard projects water depth next to campus buildings, we’re still testing methods for informing whether water will actually enter buildings via doorways, low windows, or ground-level air vents.”
Although the dashboard will always contain a certain level of uncertainty, the plan is to continue to evolve a more robust tool. “We called it the MIT Climate Resiliency Dashboard, and not the MIT Flood Viewer, because we plan to visualize more data related to climate resiliency, like extreme and prolonged heat events,” says Goldberg, noting that heat information is expected to be added in late 2021. “As the science advances, understanding heat impacts today and going forward will bring more of that into this dashboard.” Cambridge has already modeled some aspects of future heat risk and developed preparedness plans, allowing MIT to build upon the city’s heat risk modeling, communicate findings through the Climate Resiliency Dashboard, and anticipate how MIT can protect its community, research, academics, and operations from changes in heat over time.
This Climate Resiliency Dashboard joins many other data sets and visualizations available to the MIT community in the Sustainability DataPool — part of the fulfillment of Pillar E of MIT’s Plan for Action on Climate Change, which calls for using the campus as a test bed for change. “By testing these ideas on campus and sharing our data, findings, and planning frameworks, we’re not only supporting a more climate-resilient MIT, but also providing the tools for others to learn from us, solving these same challenges in their own communities and institutions,” says Goldberg. More

Shortly after he sold TRACE, the fast-growing, New York-based media company he founded at age 24, Claude Grunitzky came to MIT as a Sloan Fellow. He chose MIT because he wanted to learn more about digital media and the ways he could leverage it for his next company. He was also interested in MIT’s approach to building new technologies that could scale through network effects.
While at MIT Sloan, the Togolese-American entrepreneur spent considerable time at the MIT Media Lab, working with Joost Bonsen, a lecturer in media arts and sciences, and Professor Alex “Sandy” Pentland, the Media Lab Entrepreneurship Program director, on shaping what would become TRUE Africa, his digital media company focused on championing young African voices all over the world. Grunitzky graduated in 2012, earning an MBA.
TRUE Africa was launched as a news and culture website in 2015. Grunitzky used new publishing technologies to promote African perspectives instead of relying on Western perceptions of what Africa was becoming. Grunitzky and his editorial team chose to document Africans and Afro-descendants’ innovations and contributions to global popular culture.
In 2019, Grunitzky realized that, while useful for telling a different story about modern Africa, a media platform was not enough. He decided to pivot to education. His new vision was to create, for higher education, a remote learning platform for African youth. The pandemic, which led to the closure of many universities in Africa, gave a sense of urgency to his launch plans for the new venture, which he called TRUE Africa University (TAU). The venture is currently being incubated at the Abdul Latif Jameel World Education Lab (J-WEL).
TAU currently consists of a webinar series focused on sustainable development in Africa. Grunitzky, serves as a host, interviewing thinkers, shapers, and doers he sees as the inventors of the future of Africa. Produced in collaboration with the MIT Center for International Studies, the webinar series features guests including Taiye Selasi, the Ghanaian-Nigerian author; Jeffrey Sachs, the American economist; and Iyinoluwa Aboyeji, the Nigerian serial entrepreneur behind some of Africa’s most valuable startups.
Here, Grunitzky describes his inspiration for and goals for the TAU project.
Q: What is the purpose of TRUE Africa University?
A: Ever since I came to MIT as a Sloan fellow a decade ago, I’ve wanted to find new ways to tap into MIT’s can-do spirit of innovation and entrepreneurship to help me launch a new type of African company that would play a sizable role in solving some of Africa’s biggest problems.
At MIT, I met kindred spirits who encouraged our experiments, but I eventually settled on launching another media company, which I named TRUE Africa. With the TRUE Africa website, I relied on my expertise in media, but three years after launching TRUE Africa online, I realized that I wanted to solve a bigger problem than what we could accomplish through reporting about young Africans and their creativity.
Having seen excellence in motion at MIT, I came to believe that what young Africans need more than anything is quality education. I had been deeply inspired by Salman Khan ever since he launched Khan Academy, and I wanted to achieve something on that scale. I was thinking, conceptually, of a pivot to education, but I didn’t have the confidence to take on something so ambitious until I found myself in another defining MIT moment, in May 2019.
It happened on the terrace of the Grafenegg Castle outside Vienna, in Austria. I had gone to the MIT Grafenegg Forum as a speaker on media and society in Africa, and I saw an opportunity to pitch my TRUE Africa University idea to Sanjay Sarma, the vice president for open learning at MIT who was one of the forum’s organizers. I was an admirer of Sanjay’s work overseeing edX and MIT’s other digital learning platforms, and I made my case during a short break from the seated dinner.
He gave the TRUE Africa University idea his blessing on the spot, and three months later my Moroccan co-founder and I were camping out at Sanjay’s office and ideating, with his teams at MIT J-WEL, on curricula for digital learning in developing nations. Another person I became close to at MIT is John Tirman, the political theorist who is also the executive director at MIT’s Center for International Studies (CIS). I have been a research affiliate at CIS since 2011, and I’d organized webinars for CIS before. John and I agreed that the best way to launch the TRUE Africa University platform was through a webinar series. That is when I got to work on the programmatic aspects of the series.
Q: Why are webinars the medium of choice for accomplishing your goals with TAU?
A: With my background and aspirations as a storyteller, I’ve been writing, publishing, broadcasting, and operating across various media platforms since I was 21-year-old journalist. I know that content is king. The problem is, there is way too much content out there now. Social media has opened the floodgates, and the various social networks have dramatically increased content output globally, but not all that content is interesting, or engaging, or useful.
I wanted to launch the TRUE Africa University webinar series with a film screening. It’s actually a film I executive produced, alongside Fernando Meirelles, the director of some of my favorite films, including “City of God,” “The Constant Gardener,” and last year’s “The Two Popes.” Our documentary, “The Great Green Wall,” premiered at the Venice Film Festival in 2019, and won many awards in many countries. 
“The Great Green Wall” is an African-led movement with an epic ambition to grow an 8,000-kilometer natural wonder of the world across the entire width of Africa. It’s actually a wall of trees being planted from Senegal in the west all the way to Djibouti in the east. A decade in and roughly 15 percent under way, the initiative is already bringing life back to Africa’s degraded landscapes at an unprecedented scale, providing food security, jobs, and a reason to stay for the millions who live along its path. We launched the webinar series with a screening of that film, and a post-screening panel discussion that I moderated with Meirelles.
Most people, including in Africa, are not aware of the devastating effects of climate change on the African continent, and on the prospects for African youth. That screening and first webinar discussion sets the tone for our higher learning ambitions with TRUE Africa University, while helping us to bring in experts who can frame some of the major issues facing young Africans, as many of them seek new pathways to a more sustainable future for the continent.
Q: What are your longer-term goals for the project?
A: The webinars are meant to provide fresh ideas, out-of-the-box solutions, and new ways of thinking of Africa’s future, post-pandemic. We are exploring the new digital solutions to some of Africa’s problems, and how technology can create a virtuous circle for African development. Consider this: At the end of 2000 there were just 15 million Africans with access to mobile devices. Now, more than a quarter of Africa’s population of 1.3 billion have adopted the mobile internet.
In 2100, there will be close to 800 million people living in Nigeria alone, quadrupling the current population of 200 million. Nigeria will be the world’s second-most populated country, after India. I am launching TRUE Africa University because those young Africans need to be educated, and there is just no way that African governments will have the resources to build enough classrooms for all those students.
The solution will have to be online, and in my wildest dreams I see TRUE Africa as a daily resource for millions of young Africans who demand quality education. The journey is just beginning, and I am aware of the hurdles on this long road. I am so fortunate that we have MIT in our corner, as we embark on this ambitious endeavor. More

On March 1, MIT Solve launched its 2021 Global Challenges, with over $1.5 million in prize funding available to innovators worldwide.
Solve seeks tech-based solutions from social entrepreneurs around the world that address five challenges. Anyone, anywhere can apply to address the challenges by the June 16 deadline. Solve also announced Eric s. Yuan, founder and CEO of Zoom, and Karlie Kloss, founder of Kode With Klossy, as 2021 Challenge Ambassadors. 
To help with the challenge application process, Solve runs a course with MITx entitled “Business and Impact Planning for Social Enterprises,” which introduces core business model and theory-of-change concepts to early stage entrepreneurs. 
Finalists will be invited to attend Solve Challenge Finals on Sept. 19 in New York during U.N. General Assembly week. At the event, they will pitch their solutions to Solve’s Challenge Leadership Groups, judging panels comprised of industry leaders and MIT faculty. The judges will select the most promising solutions as Solver teams.
“After a year of turmoil, including a major threat to our collective health, disruption in schooling, lack of access to digital connectivity and meaningful work, a reckoning in the U.S. after centuries of institutionalized racism, or worsening natural hazards — supporting diverse innovators who are solving these challenges is more urgent than ever,” says Alex Amouyel, executive director of MIT Solve. “Solve is committed to bolstering communities in the U.S. and across the world by supporting innovators who are addressing our 2021 Global Challenges — wherever they are — through funding, mentorship, and an MIT-backed community. Whether you’re a prospective Solve partner or applicant, we hope you’ll join us!” 
Solver teams participate in a nine-month program that connects them to the resources they need to scale. Thanks to its partners, to date Solve has provided over $40 million in commitments for Solver teams and entrepreneurs.
Solve’s challenge design process collects insights and ideas from industry leaders, MIT faculty, and local community voices alike. 
Solve’s 2021 Global Challenges are:
Funders include the Patrick J. McGovern Foundation, General Motors, Comcast NBCUniversal, Vodafone Americas Foundation, HP, Ewing Marion Kauffman Foundation, American Student Assistance, The Robert Wood Johnson Foundation, Andan Foundation, Good Energies Foundation and the Elevate Prize Foundation. The Solve community will convene at Virtual Solve at MIT on May 3-4 with 2020 Solver teams, Solve members, and partners to build partnerships and tackle global challenges in real-time. 
As a marketplace for social impact innovation, Solve’s mission is to solve world challenges. Solve finds promising tech-based social entrepreneurs around the world, then brings together MIT’s innovation ecosystem and a community of members to fund and support these entrepreneurs to help scale their impact. Organizations interested in joining the Solve community can learn more and apply for membership here. More

According to United Nations estimates, the global population is expected to grow by 2 billion within the next 30 years, giving rise to an expected increase in demand for food and agricultural products. Today, biotic and abiotic environmental stresses such as plant pathogens, sudden fluctuations in temperature, drought, soil salinity, and toxic metal pollution — made worse by climate change — impair crop productivity and lead to significant losses in agriculture yield worldwide.
New work from the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, and Temasek Life Sciences Laboratory (TLL) highlights the potential of recently developed analytical tools that can provide tissue-cell or organelle-specific information on living plants in real-time and can be used on any plant species.
In a perspective paper titled “Species-independent analytical tools for next-generation agriculture” published in the journal Nature Plants, researchers from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) Interdisciplinary Research Group (IRG) within SMART review the development of two next-generation tools, engineered plant nanosensors and portable Raman spectroscopy, to detect biotic and abiotic stress, monitor plant hormonal signalling, and characterize soil, phytobiome, and crop health in a non- or minimally invasive manner. The researchers discuss how the tools bridge the gap between model plants in the laboratory and field application for agriculturally relevant plants. The paper also assesses the future outlook, economic potential, and implementation strategies for the integration of these technologies in future farming practices.
An estimated 11-30 percent yield loss of five major crops of global importance (wheat, rice, maize, potato, and soybean) is caused by crop pathogens and insects, with the highest crop losses observed in regions already suffering from food insecurity. Against this backdrop, research into innovative technologies and tools is required for sustainable agricultural practices to meet the rising demand for food and food security — an issue that has drawn the attention of governments worldwide due to the Covid-19 pandemic.
Plant nanosensors, developed at SMART DiSTAP, are nanoscale sensors — smaller than the width of a hair — that can be inserted into the tissues and cells of plants to understand complex signalling pathways. Portable Raman spectroscopy, also developed at SMART DiSTAP, encompases a laser-based device that measures molecular vibrations induced by laser excitation, providing highly specific Raman spectral signatures that provide a fingerprint of a plant’s health. These tools are able to monitor stress signals in short time-scales, ranging from seconds to minutes, which allows for early detection of stress signals in real-time.
“The use of plant nanosensors and Raman spectroscopy has the potential to advance our understanding of crop health, behavior, and dynamics in agricultural settings,” says Tedrick Thomas Salim Lew SM ’18, PhD ’20, the paper’s first author. “Plants are highly complex machines within a dynamic ecosystem, and a fundamental study of its internal workings and diverse microbial communities of its ecosystem is important to uncover meaningful information that will be helpful to farmers and enable sustainable farming practices. These next-generation tools can help answer a key challenge in plant biology, which is to bridge the knowledge gap between our understanding of model laboratory-grown plants and agriculturally-relevant crops cultivated in fields or production facilities.”
Early plant stress detection is key to timely intervention and increasing the effectiveness of management decisions for specific types of stress conditions in plants. Tools capable of studying plant health and reporting stress events in real-time will benefit both plant biologists and farmers. Data obtained from these tools can be translated into useful information for farmers to make management decisions in real-time to prevent yield loss and reduced crop quality.
The species-independent tools also offer new plant science study opportunities for researchers. In contrast to conventional genetic engineering techniques that are only applicable to model plants in laboratory settings, the new tools apply to any plant species, which enables the study of agriculturally relevant crops previously understudied. Adopting these tools can enhance researchers’ basic understanding of plant science and potentially bridge the gap between model and non-model plants.
“The SMART DiSTAP interdisciplinary team facilitated the work for this paper and we have both experts in engineering new agriculture technologies and potential end-users of these technologies involved in the evaluation process,” says Professor Michael Strano, the paper’s co-corresponding author, DiSTAP co-lead principal investigator, and the Carbon P. Dubbs Professor of Chemical Engineering at MIT. “It has been the dream of an urban farmer to continually, at all times, engineer optimal growth conditions for plants with precise inputs and tightly controlled variables. These tools open the possibility of real-time feedback control schemes that will accelerate and improve plant growth, yield, nutrition, and culinary properties by providing optimal growth conditions for plants in the future of urban farming.”
“To facilitate widespread adoption of these technologies in agriculture, we have to validate their economic potential and reliability, ensuring that they remain cost-efficient and more effective than existing approaches,” the paper’s co-corresponding author, DiSTAP co-lead principal investigator, and deputy chair of TLL Professor Chua Nam Hai explains. “Plant nanosensors and Raman spectroscopy would allow farmers to adjust fertilizer and water usage, based on internal responses within the plant, to optimize growth, driving cost efficiencies in resource utilization. Optimal harvesting conditions may also translate into higher revenue from increased product quality that customers are willing to pay a premium for.”
Collaboration among engineers, plant biologists, and data scientists, and further testing of new tools under field conditions with critical evaluations of their technical robustness and economic potential will be important in ensuring sustainable implementation of technologies in tomorrow’s agriculture.
DiSTAP Scientific Advisory Board members Professor Kazuki Saito, group director of Metabolomics Research Group at RIKEN Center for Sustainable Resource Science, and Hebrew University of Jerusalem Professor Oded Shoseyov also co-authored the paper.
The research is carried out by SMART and supported by the National Research Foundation (NRF) Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) program.
DiSTAP is one of the five IRGs of SMART. The DiSTAP program addresses deep problems in food production in Singapore and the world by developing a suite of impactful and novel analytical, genetic, and biosynthetic technologies. The goal is to fundamentally change how plant biosynthetic pathways are discovered, monitored, engineered, and ultimately translated to meet the global demand for food and nutrients. Scientists from MIT, TLL, Nanyang Technological University, and National University of Singapore are collaboratively developing new tools for the continuous measurement of important plant metabolites and hormones for novel discovery, deeper understanding and control of plant biosynthetic pathways in ways not yet possible, especially in the context of green leafy vegetables; leveraging these new techniques to engineer plants with highly desirable properties for global food security, including high-yield density production, drought and pathogen resistance, and biosynthesis of high-value commercial products; developing tools for producing hydrophobic food components in industry-relevant microbes; developing novel microbial and enzymatic technologies to produce volatile organic compounds that can protect and/or promote growth of leafy vegetables; and applying these technologies to improve urban farming. More

In an ongoing series, Solving Climate: Humanistic Perspectives from MIT, faculty, students, and alumni in the Institute’s humanistic fields share scholarship and insights that are significant for solving climate change and mitigating its myriad social and ecological impacts.Clare Balboni is the 3M Career Development Assistant Professor of Environmental Economics at MIT and an affiliate of MIT’s Center for Energy and Environmental Policy Research. Her research centers on environmental economics, trade, and development economics. In this Q&A with MIT SHASS Communications, she describes the burgeoning influence of economics in understanding climate, energy, and environmental issues, as well as informing related policy.Q: In what ways are the research, insights, and perspectives from economics significant for addressing global change and its myriad ecological and social impacts?A: There is tremendous and growing interest in environmental questions within economics. Economic models and methods can help to enhance our understanding of how to balance the imperative for continued growth in prosperity and well-being — particularly for the world’s poorest — with the need to mitigate and adapt to the environmental externalities that this growth creates.Environmental economists have taken advantage of economic tools and methodologies, and the rapid proliferation of new data sources, to study how local pollutants and greenhouse gas emissions affect a huge range of outcomes spanning such areas as mortality, health, agriculture, labor productivity, income, migration, education, crime, and conflict. Building a strong evidence base on the consequences of environmental quality, and developing techniques for measuring environmental benefits and harms, is key in informing the design of emissions reduction policies.Another important contribution of economics is to provide robust analysis of policies that aim to tackle environmental externalities through, for instance, taxation, tradable emissions permits, regulation, and innovation policy. Recent work provides rigorous empirical evidence evaluating key environmental policies and considering important aspects of the design of economic instruments; this work builds on a longstanding body of literature within economics studying environmental policy instruments.A growing body of empirical work in environmental economics focuses on particular issues relating to environmental quality and instrument design in developing countries, where energy use is increasing rapidly; political economy considerations may raise distinct challenges; and where both local pollutant concentrations and projected climate damages are often particularly acute.Q: When you confront an issue as formidable as climate change, what gives you hope?A: I draw hope from the rapidly increasing focus and attention on environmental questions across fields in economics, across disciplines in the social and natural sciences, and more broadly in the academic, policy, and popular discourse. Given the scale and breadth of the challenge, it is crucial that this combined focus from a range of perspectives continues to advance this important agenda.
Series prepared by MIT SHASS CommunicationsSeries editor and designer: Emily HiestandCo-editor: Kathryn O’Neill More

A potent ozone-depleting chemical whose emissions unexpectedly spiked in recent years has quickly dropped back to much lower levels, putting the recovery of the stratospheric ozone layer back on track, according to a new study by scientists at MIT, the University of Bristol, and other institutions in South Korea, the U.S., Japan, Australia, and Switzerland.
The chemical in question is CFC-11, a chlorofluorocarbon that was once commonly used for refrigeration, insulation, and other purposes. When emitted to the atmosphere, CFC-11 can loft into the stratosphere, where the sun’s ultraviolet radiation breaks the chemical down to release chlorine — a noxious chemical that then eats away at ozone, stripping away the Earth’s natural shield against UV rays.
CFC-11 and other chlorofluorocarbons are now banned under the Montreal Protocol, an international treaty under which every country agreed to phase out the chemicals’ production and use by 2010. But in 2018, a team of scientists reported a concerning spike in global emissions of the chemical beginning in 2013.  In 2019, a second team reported that a significant portion of the emissions could be traced to eastern China, predominately the Shandong and Hebie provinces.
Now, in two papers published today in Nature, the same teams report that global annual emissions of CFC-11 into the atmosphere have declined sharply, by about 20,000 U.S. tons, from 2018 to 2019. The researchers traced a substantial fraction of the global emission reductions to the very same regions of eastern China where they had previously reported the original spike. The results are consistent with evidence that the country has taken successful actions to stamp out illegal production of this ozone-depleting chemical.
“This is tremendously encouraging,” says Ronald Prinn, the director of the Center for Global Change Science at MIT and a co-author on both papers. “If emissions of CFC-11 had continued to rise or even just leveled off, there would have been a much bigger problem building up. The global monitoring networks really caught this spike in time, and subsequent actions have lowered emissions before they became a real threat to recovery of the ozone layer.”
A brief history of the spike
Both the original spike and subsequent drop in CFC-11 emissions were detected by the researchers using two independent networks.
One is a global monitoring network operated by the National Oceanographic and Atmospheric Administration (NOAA), comprising about 30 stations. Researchers at each site collect air samples and send them to a central laboratory, where the air is analyzed for CFC-11 and many other trace gases. The weekly measurements, from sites around the world, give an accurate average picture of the chemical species circulating in the global atmosphere.
The other network is the Advanced Global Atmospheric Gases Experiment, or AGAGE, an MIT-led effort funded in part by NASA, with more than a dozen monitoring stations situated on coastal and mountain sites around the world. The AGAGE stations take automated on-site measurements of passing air parcels about every hour, monitoring for more than 50 trace gases, including CFC-11, to provide detailed records of the regional and global atmosphere.
In a 2018 Nature report, the researchers analyzed measurements from NOAA and observed that, from 2014 to 2016, global emissions of CFC-11 grew by more than 14,000 U.S. tons a year — a 25 percent increase from emissions between 2002 and 2012. In a subsequent 2019 Nature report, regional measurements taken by AGAGE stations in Hateruma, Japan, and Gosan, South Korea, along with three-dimensional modeling, showed that about half or more of these emissions came from eastern China, primarily from the factory-heavy Shandong and Hebei provinces.
Following these 2018 and 2019 reports, the scientists continued to track the chemical through the atmosphere, at both global and regional levels.
In the first of the two new Nature papers, they analyze both NOAA and AGAGE global data and report a dramatic turnaround: From 2018 to 2019, CFC-11 annual emissions dropped throughout the global atmosphere by about U.S. 20,000 tons, returning to levels prior to 2012, following the chemical’s 2010 global phaseout.
In the second paper, based on AGAGE measurements, the scientists observed that CFC-11 emissions specifically from eastern China hit a peak around 2017. At some point soon afterward, levels began to drop, although the researchers cannot say exactly when the regional turnaround occurred, as the South Korean station sustained typhoon-related damage that resulted in some data gaps. Despite these gaps, the group observed a decline in CFC-11 annual emissions, by about 11,000 U.S. tons from eastern China, through 2019.  
As the researchers write in the paper, “it seems that any substantial delay in ozone-layer recovery has been avoided, perhaps owing to timely reporting, and subsequent action by industry and government in China.”
“Continuous vigilance”
However, there is still work to be done. While it appears that CFC-11 emissions from eastern China have declined, indicating that significant illegal production of the chemical there has ceased, these emissions only account for roughly half of the global emissions. Where the remainder could have come from is still unknown.
In general, CFC-11 is currently emitted in large amounts through leakages during new production and during subsequent use in refrigeration and manufacture of foams. The chemicals can also leak out from “banks” of old, discarded refrigerators and foams, though at a much slower and more diffuse rate than the rapid regional increase observed in 2013.
“The challenge now is to ask, where’s the rest of it coming from?” says Prinn, the  TEPCO Professor of Atmospheric Science in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “We will need to expand measurements and modeling to identify new sources, and continue to keep watch. Hopefully, emission levels will continue to drop.”
Going forward, the scientists hope to add more stations to the AGAGE network, so that they might identify and quantify other regional sources of CFC-11, particularly in rapidly industrializing parts of the world.
“Clearly this story shows that, in order to ensure that countries are adhering to international agreements like the Montreal Protocol, continuous vigilance is required,” Prinn says. “You can’t stop measuring these chemical species and assume the problem is solved.”
This research was supported, in part, by NASA and NOAA. More

George P. Shultz PhD ’49, former U.S. secretary of labor, state, and of the treasury, died peacefully at his home on Feb. 6, at the age of 100. A champion of bipartisanship who for decades urged action on climate change, he leaves a rich legacy forged during more than 70 years of leadership in government, academia, and business.
“A beloved teacher, a brilliant scholar, a visionary leader, a public servant of the highest integrity, and a relentless champion for the breakthrough energy technologies on which the future of our society depends, George Shultz represented the very best of MIT and of our nation,” says MIT President L. Rafael Reif. “We will remember Secretary Shultz for the boundless energy, piercing clarity, and innovative ideas he brought to every role and every conversation. And we are profoundly grateful for the eloquence of his example: a life lived in service to the common good.”
Born in New York City on Dec. 13, 1920, Shultz grew up in Englewood, New Jersey. He graduated from Princeton University in 1942. He was admitted to MIT for a master’s degree program and planned to enroll in 1943, but paused his academic pursuits to enlist in the U.S. Marine Corps during World War II. He served from 1942 to 1945, rising to the rank of captain.
Following his military service, Shultz began what would become more than a decade of scholarship and teaching at MIT. After earning his PhD in industrial economics, he taught economics at the Institute in the Department of Economics and at the Sloan School of Management, first as an assistant professor, then as an associate professor.
“George and I were assistant professors together. That was seventy years ago,” says Robert M. Solow, a professor emeritus of economics. “We remained friends ever after. Even once he got used to being in high office, there was always a bit of that young researcher in him. I can remember his going door-to-door in Nashua, New Hampshire, learning about the lives of the unemployed. Everyone will miss him.”
In 1955, he took a leave of absence from MIT to serve as a senior staff economist on President Dwight D. Eisenhower’s Council of Economic Advisers. From 1957 to 1968, he served at University of Chicago Graduate School of Business as a professor of industrial relations and then as the school’s dean.
He was appointed U.S. secretary of labor under President Richard Nixon in 1969; in this role, he prioritized reduction of poverty and equal employment opportunities, among other initiatives. In 1970, he became the first director of the Office of Management and Budget, a Cabinet-level office, where he worked to advance school desegregation efforts. He then served as U.S. secretary of the treasury, where he co-founded the international organization that later became known as the Group of Seven (G7) nations, formed to pursue shared economic objectives. Shultz served as chairman of the President’s Economic Policy Advisory Board from 1981 to 1982. In the private sector, he held executive roles at Bechtel Group, Inc, from 1974 to 1982.
He is perhaps best known for his tenure as U.S. secretary of state under President Ronald Reagan, from 1982 to 1989. Shultz was a key figure in facilitating de-escalation of tensions between the U.S. and the Soviet Union, helping to draft agreements that led to the end of the Cold War. In 1989, he received the Presidential Medal of Freedom, the nation’s highest civilian honor. From 1989 until his death, he was a distinguished fellow at Stanford University’s Hoover Institution.
Shultz’s affiliation with MIT remained strong over the years. When accepting the Robert A. Muh Award for noteworthy achievement in the humanities, arts, and social sciences at MIT in 2003, Shultz gave a talk on national security. He asserted that “as a country, we need to do things that are broadly beneficial to the world.”
This philosophy extended to topics including climate change and the transition to low-carbon energy. In recent decades, Shultz became an outspoken advocate for farsighted action to address climate change. He urged the U.S. to cut its dependence on oil in favor of clean energy production, championed sustained federal support for basic research, and built bipartisan support for a revenue-neutral carbon tax proposal — ideas he advocated publicly and discussed over the years with the MIT community.
In 2007, as the Institute was launching the MIT Energy Initiative (MITEI), he became the inaugural chair of its External Advisory Board, a leadership role he held until 2019, when he chose to step down as chair. He remained a member of the board until his death, working closely with his successor and longtime friend Norman Augustine.
“George inspired those of us working on clean energy and climate change. It was a pleasant surprise when he agreed to be the inaugural chair of the MIT Energy Initiative’s External Advisory Board and, because of his enthusiasm, we didn’t need a second chair for a dozen years!” says Ernest J. Moniz, professor emeritus of physics post-tenure, thirteenth U.S. secretary of energy, and the founding director of MITEI. “I am deeply saddened by the loss of this remarkable statesman and friend.”
“Secretary Shultz was generous with his time, his wisdom, and his friendships, creating critically needed communities of shared concern — which he recognized was the way to get things done, and to have lots of fun doing so,” says MIT President Emerita Susan Hockfield. “As founding chair of the External Advisory Board of MIT’s Energy Initiative, Secretary Shultz integrated the insights of industry with the ambitions of the academy, to apply lab-based discoveries to the pressing problem of climate change. He made MITEI and MIT better, and we all enjoyed every minute of the time he shared with us.”
“George taught us much about the importance of a principled vision coupled with persistence in engaging with government on the energy and climate challenge,” says MITEI Director Robert C. Armstrong. “He also reminded us to focus on the hard problems like energy in the developing world — which led to our launch of the Tata Center for Technology and Design and other initiatives since then. We will miss him and his guidance greatly here at MITEI.”
“George Shultz is the iconic example of the contributions MIT individuals make to the country. We should honor his memory by producing many more.” says John Deutch, Institute Professor Emeritus and former U.S. director of Central Intelligence who held numerous leadership positions in the U.S. Department of Defense and U.S. Department of Energy.
Christopher Knittel, the George P. Shultz Professor of Applied Economics at the Sloan School, says, “It is a tremendous honor to hold the George P. Shultz chair, and I feel privileged to have known George, whose wit, wisdom, and statesmanship were unmatched and irreplaceable. I will miss our conversations spanning climate policy to mainstream economics research. Rest in peace, Secretary Shultz.”
Shultz authored numerous books and articles, including “Turmoil and Triumph: My Years as Secretary of State” (1993), “Learning from Experience” (2016), and “Thinking about the Future” (2019). He was an editor of “Beyond Disruption: Technology’s Challenge to Governance” (2018). His most recent book, “Hinge of History: Governance in an Emerging New World,” was published in November 2020.
Shultz’s remarkable life was built on the foundation of two long marriages. He and his first wife, Lieutenant Helena “O’Bie” O’Brien, a military nurse, met while stationed in Hawaii during the war. The couple raised five children together and were married until her death in 1995. He later married Charlotte Mailliard Swig, the City of San Francisco’s chief of protocol; they were married for 23 years until his death. In addition to Swig, his survivors include his children, 11 grandchildren, and nine great-grandchildren.
He will be deeply missed by his family, colleagues, students, and friends around the world, many of whom shared warm wishes virtually for his 100th birthday celebration in December 2020. To mark the occasion, Shultz wrote in The Washington Post about 10 things he’d learned about trust in his 100 years, underscoring the importance of developing, maintaining, and rebuilding our trust in each other. “Trust is fundamental, reciprocal and, ideally, pervasive. If it is present, anything is possible. If it is absent, nothing is possible,” he wrote. More