Aurelia Butler

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

The temperature of a planet is linked with the diversity of life that it can support. MIT geologists have now reconstructed a timeline of the Earth’s temperature during the early Paleozoic era, between 510 and 440 million years ago — a pivotal period when animals became abundant in a previously microbe-dominated world.
In a study appearing today in the Proceedings of the National Academy of Sciences, the researchers chart dips and peaks in the global temperature during the early Paleozoic. They report that these temperature variations coincide with the planet’s changing diversity of life: Warmer climates favored microbial life, whereas cooler temperatures allowed more diverse animals to flourish.
The new record, more detailed than previous timelines of this period, is based on the team’s analysis of carbonate muds — a common type of limestone that forms from carbonate-rich sediments deposited on the seafloor and compacted over hundreds of millions of years.
“Now that we have shown you can use these carbonate muds as climate records, that opens the door to looking back at this whole other part of Earth’s history where there are no fossils, when people don’t really know much about what the climate was,” says lead author Sam Goldberg, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS).
Goldberg’s co-authors are Kristin Bergmann, the D. Reid Weedon, Jr. Career Development Professor in EAPS, along with Theodore Present of Caltech and Seth Finnegan of the University of California at Berkeley.
Beyond fossils
To estimate Earth’s temperature many millions of years ago, scientists analyze fossils, in particular, remains of ancient shelled organisms that precipitated from seawater and either grew on or sank to the seafloor. When precipitation occurs, the temperature of the surrounding water can change the composition of the shells, altering the relative abundances of two isotopes of oxygen: oxygen-16, and oxygen-18.
“As an example, if carbonate precipitates at 4 degrees Celsius, more oxygen-18 ends up in the mineral, from the same starting composition of water, [compared to] carbonate precipitating at 30 degrees Celsius,” Bergmann explains. “So, the ratio of oxygen-18 to -16 increases as temperature cools.”
In this way, scientists have used ancient carbonate shells to backtrack the temperature of the surrounding seawater — an indicator of the Earth’s overall climate — at the time the shells first precipitated. But this approach has taken scientists only so far, up until the earliest fossils.
“There is about 4 billion years of Earth history where there were no shells, and so shells only give us the last chapter,” Goldberg says.
A clumped isotope signal
The same precipitating reaction in shells also occurs in carbonate mud. But geologists assumed the isotope balance in carbonate muds would be more vulnerable to chemical changes.
“People have often overlooked mud. They thought that if you try to use it as a temperature indicator, you might be looking at not the original ocean temperature in which it formed, but the temperature of a process that occurred later on, when the mud was buried a mile below the surface,” Goldberg says.
To see whether carbonate muds might preserve signatures of their original surrounding temperature, the team used “clumped isotope geochemistry,” a technique used in Bergmann’s lab, which analyzes sediments for clumping, or pairing, of two heavy isotopes: oxygen-18 and carbon-13. The likelihood of these isotopes pairing up in carbonate muds depends on temperature but is unaffected by the ocean chemistry in which the muds form.
Combining this analysis with traditional oxygen isotope measurements provides additional constraints on the conditions experienced by a sample between its original formation and the present. The team reasoned that this analysis could be a good indication of whether carbonate muds remained unchanged in composition since their formation. By extension, this could mean the oxygen-18 to -16 ratio in some muds accurately represents the original temperature at which the rocks formed, enabling their use as a climate record.
Ups and downs
The researchers tested their idea on samples of carbonate muds that they extracted from two sites, one in Svalbard, an archipelago in the Arctic Ocean, and the other in western Newfoundland. Both sites are known for their exposed rocks that date back to the early Paleozoic era.
In 2016 and 2017, teams traveled first to Svalbard, then Newfoundland, to collect samples of carbonate muds from layers of deposited sediment spanning a period of 70 million years, from the mid-Cambrian, when animals began to flourish on Earth, through the Ordovician periods of the Paleozoic era.
When they analyzed the samples for clumped isotopes, they found that many of the rocks had experienced little chemical change since their formation. They used this result to compile the rocks’ oxygen isotope ratios from 10 different early Paleozoic sites to calculate the temperatures at which the rocks formed. The temperatures calculated from most of these sites were similar to previously published lower-resolution fossil temperature records. In the end, they mapped a timeline of temperature during the early Paleozoic and compared this with the fossil record from that period, to show that temperature had a big effect on the diversity of life on the planet.
“We found that when it was warmer at the end of the Cambrian and early Ordovician, there was also a peak in microbial abundance,” Goldberg says. “From there it cooled off going into the middle to late Ordovician, when we see abundant animal fossils, before a substantial ice age ends the Ordovician. Previously people could only observe general trends using fossils. Because we used a material that’s very abundant, we could create a higher-resolution record and could see more clearly defined ups and downs.”
“This is the best recent isotopic study addressing the critical question of whether early animals experienced hot early temperatures,” says Ethan Grossman, a professor of geology at Texas A&M University, who was not a contributor to the study. “We should use all the tools at our disposal to explore this important time interval.”
The team is now looking to analyze older muds, dating back before the appearance of animals, to gauge the Earth’s temperature changes prior to 540 million years ago.
“To go back beyond 540 million years ago, we have to grapple with carbonate muds, because they are really one of the few records we have to constrain climate in the distant past,” Bergmann says.
This research was supported, in part, by NASA and the David and Lucile Packard Foundation. More

State and Local Innovation Initiative seeks government partners to rigorously evaluate policies and programs aiming to address critical social issues. More

Associate professor of technology and urban planning to lead LCAU with a research focus on planning, design, construction, and retrofitting of urban environments for the 21st century. More

Study probes pandemic’s long-term effects on the global effort to reduce greenhouse gas emissions. More

Launched today, the MIT Climate and Sustainability Consortium (MCSC) convenes an alliance of leaders from a broad range of industries and aims to vastly accelerate large-scale, real-world implementation of solutions to address the threat of climate change. The MCSC unites similarly motivated, highly creative and influential companies to work with MIT to build a process, market, and ambitious implementation strategy for environmental innovation. 
The work of the consortium will involve a true cross-sector collaboration to meet the urgency of climate change. The MCSC will take positive action and foster the necessary collaboration to meet this challenge, with the intention of influencing efforts across industries. Through a unifying, deeply inclusive, global effort, the MCSC will strive to drive down costs, lower barriers to adoption of best-available technology and processes, speed retirement of carbon-intensive power generating and materials-producing equipment, direct investment where it will be most effective, and rapidly translate best practices from one industry to the next in an effort to deploy social and technological solutions at a pace more rapid than the planet’s intensifying crises.

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“If we hope to decarbonize the economy, we must work with the companies that make the economy run. Drawing its members from a broad range of industries, the MCSC will convene an alliance of influential corporations motivated to work with MIT, and with each other, to pilot and deploy the solutions necessary to reach their own ambitious decarbonization commitments,” says MIT President L. Rafael Reif. “By sharing solutions across companies and sectors, the consortium has the potential to vastly accelerate the implementation of large-scale, real-world solutions to help meet the global climate emergency. And as an Institute-wide effort, it will also complement MIT’s existing climate initiatives and make them more effective: Just as the Climate Grand Challenges effort is accelerating research on climate science and solutions, the consortium aims to accelerate the adoption of such solutions, at scale and across industries.”
Led by the MIT School of Engineering and engaging students, faculty, and researchers from across the entire Institute, the MIT Climate and Sustainability Consortium has called upon companies from a broad range of industries — from aviation to agriculture, consumer services to electronics, chemical production to textiles, and infrastructure to software — to roll up their sleeves and work closely with every corner of MIT.
“This new collaboration represents the incredible potential for academia and industry to work together on a shared mission to shape research, identify opportunities for innovation, and rapidly advance practical solutions with the sense of urgency needed to address our climate challenge. There are no bounds to what we can achieve together,” says Anantha P. Chandrakasan, dean of the School of Engineering, Vannevar Bush Professor of Electrical Engineering and Computer Science, and chair of the MIT Climate and Sustainability Consortium.
The inaugural members of the MCSC are companies with intricate supply chains that are among the best positioned to help lead the mission to solve the climate crisis. The inaugural member companies of the MCSC recognize the responsibility industry has in the rapid deployment of social and technology solutions. They represent the heart of global industry and have made a commitment to not only work with MIT but with one another, to tackle the climate challenge with the urgency required to realize their goals.
These industry leaders can both help inspire transformative change within their own sectors and demonstrate the value of working together, across sectors, at scale. The inaugural members of the MIT Climate and Sustainability Consortium are:
Accenture is a global professional services company that delivers on the promise of technology and human ingenuity, which includes helping clients across 40 industries reach their sustainability goals by transitioning to low-carbon energy; reducing the carbon footprint of IT, cloud, and software; and designing and delivering net-zero, circular supply chains. 
Apple is a global leader in technology innovation, providing seamless experiences across Apple devices and empowering people with breakthrough services. 
Boeing is the world’s largest aerospace company and leading provider of commercial airplanes, defense, space and security systems, and global services. 
Cargill is a global food manufacturer with the goal of nourishing the world in a safe, responsible, and sustainable way. 
Dow is a global manufacturer of innovative products that solve the materials science challenges of its customers and contribute to a more sustainable world.  
IBM is a hybrid cloud platform and artificial intelligence company. 
Inditex is one of the world’s largest fashion retail groups with eight distinct brands focused on fitting its products to meet customer demands in a sustainable way through an integrated platform of physical and online stores. 
LafargeHolcim is the world’s global leader in building materials and solutions at the forefront of sustainable construction. 
MathWorks develops mathematical computing software used to accelerate the pace of engineering and science. 
Nexplore (Hochtief) is an innovative company that develops technology solutions to digitize the infrastructure sector, using next-generation technologies including artificial intelligence, blockchain, computer vision, natural language processing, and internet of things. Nexplore was founded in 2018 by HOCHTIEF, one of the largest infrastructure construction groups worldwide. 
Rand-Whitney Containerboard (RWCB), a Kraft Group company, is a manufacturer of lightweight, high-performance recycled linerboard for corrugated containers, using the most environmentally sustainable production processes and methods. 
PepsiCo is a global food and beverage company that aims to use its scale, reach, and expertise to help build a more sustainable food system. 
Verizon is one of the world’s leading providers of technology, communications, information and entertainment products and services.
Jeffrey Grossman will serve as director of the MCSC. Grossman is the Morton and Claire Goulder and Family Professor in Environmental Systems, head of the Department of Materials Science and Engineering, and a MacVicar Faculty Fellow. Elsa Olivetti, the Esther and Harold E. Edgerton Associate Professor in Materials Science and Engineering, will serve as associate director. A steering committee comprised of faculty spanning all five of MIT’s schools and the MIT Stephen A. Schwarzman College of Computing, will help to drive the work of the consortium. More