CS3 In the News

Jennifer Chu | MIT News Office 

Volkswagen’s use of software to evade emissions standards in more than 482,000 diesel vehicles sold in the U.S. will directly contribute to 60 premature deaths across the country, a new MIT-led study finds.

In September, the Environmental Protection Agency discovered that the German automaker had developed and installed “defeat devices” (actually software) in light-duty diesel vehicles sold between 2008 and 2015. This software was designed to sense when a car was undergoing an emissions test, and only then engage the vehicle’s full emissions-control system, which would otherwise be disabled under normal driving conditions — a cheat that allows the vehicles to emit 40 times more emissions than permitted by the Clean Air Act.

That amount of excess pollution, multiplied by the number of affected vehicles sold in the U.S. and extrapolated over population distributions and health risk factors across the country, will have significant effects on public health, the study finds.

Assessing health outcomes

According to the study, conducted by researchers at MIT and Harvard University and published in the journal Environmental Research Letters, excess emissions from Volkswagen’s defeat devices will cause around 60 people in the U.S. to die 10 to 20 years prematurely. If the automaker recalls every affected vehicle by the end of 2016, more than 130 additional early deaths may be avoided. If, however, Volkswagen does not order a recall in the U.S., the excess emissions, compounding in the future, will cause 140 people to die early.

In addition to the increase in premature deaths, the researchers estimate that Volkswagen’s excess emissions will contribute directly to 31 cases of chronic bronchitis and 34 hospital admissions involving respiratory and cardiac conditions. They calculate that individuals will experience about 120,000 minor restricted activity days, including work absences, and about 210,000 lower-respiratory symptom days.

In total, Volkswagen’s excess emissions will generate $450 million in health expenses and other social costs, the study projects. But a total vehicle recall by the end of 2016 may save up to $840 million in further health and social costs.

Steven Barrett, the lead author of the paper and an associate professor of aeronautics and astronautics at MIT, says the new data may help regulatory officials better estimate the effects of Volkswagen’s actions.

“It seemed to be an important issue in which we could bring to bear impartial information to help quantify the human implications of the Volkswagen emissions issue,” Barrett says. “The main motivation is to inform the public and inform the developing regulatory situation.”

Cheating (and) death

To estimate the health effects of Volkswagen’s excess emissions, Barrett and his colleagues at MIT and Harvard based their calculations on measurements by researchers at West Virginia University, who found that the vehicles produced up to 40 times the emissions allowed by law. They then calculated the average amount that each vehicle would be driven over its lifetime, and combined these results with sales data between 2008 and 2015 to estimate of the total excess emissions during this period.

The group then calculated the resulting emissions under three scenarios: the current scenario, in which 482,000 vehicles have already emitted excess emissions into the atmosphere; a scenario in which Volkswagen recalls every affected vehicle by the end of 2016; and a future in which there is no recall, and every affected vehicle remains on the road, continuing to emit excess pollution over the course of its lifetime.

The group then estimated the health effects under each emissions scenario, using a method they developed to map emissions estimates to public exposure to fine particulate matter and ozone. Diesel vehicles emit nitrogen oxides, which react in the atmosphere to form fine particulate matter and ozone. Barrett’s approach essentially maps emissions estimates to population health risk, accounting for atmospheric transport and chemistry of the pollutants.

“We all have risk factors in our lives, and [excess emissions] is another small risk factor,” Barrett explains. “If you take into account the additional risk due to the excess Volkswagen emissions, then roughly 60 people have died or will die early, and on average, a decade or more early.”

Barrett says that, per kilometer driven, this number is about 20 percent of the number of deaths caused by road transport accidents.

“So it’s about the same order of magnitude, just from these excess emissions,” Barrett says. “If nothing’s done, these excess emissions will cause around another 140 deaths. However, two-thirds of the total deaths could be avoided if the recalls could be done quickly, in the course of the next year.”

Daniel Kammen, the editor-in-chief of Environmental Research Letters and a professor of energy at the University of California at Berkeley, says the group’s study provides a “rigorous evaluation of the scale of the impacts, which are potentially exceedingly serious.

“The analysis demonstrates the value of policy-inspired fundamental research where the air quality and health impacts of transgressions such as the VW issue can be calculated, and made available for public discussion,” says Kammen, who did not contribute to the research.

Photo: Workers inspect a car on the production line in a Volkswagen factory in Poznan, Poland

See article in the New York Times

David L. Chandler | MIT News Office

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Within this century, parts of the Persian Gulf region could be hit with unprecedented events of deadly heat as a result of climate change, according to a study of high-resolution climate models.

The research reveals details of a business-as-usual scenario for greenhouse gas emissions, but also shows that curbing emissions could forestall these deadly temperature extremes.

The study, published today in the journal Nature Climate Change, was carried out by Elfatih Eltahir, a professor of civil and environmental engineering at MIT, and Jeremy Pal PhD ’01 at Loyola Marymount University. They conclude that conditions in the Persian Gulf region, including its shallow water and intense sun, make it “a specific regional hotspot where climate change, in absence of significant mitigation, is likely to severely impact human habitability in the future.”

Running high-resolution versions of standard climate models, Eltahir and Pal found that many major cities in the region could exceed a tipping point for human survival, even in shaded and well-ventilated spaces. Eltahir says this threshold “has, as far as we know … never been reported for any location on Earth.”

That tipping point involves a measurement called the “wet-bulb temperature” that combines temperature and humidity, reflecting conditions the human body could maintain without artificial cooling. That threshold for survival for more than six unprotected hours is 35 degrees Celsius, or about 95 degrees Fahrenheit, according to recently published research. (The equivalent number in the National Weather Service’s more commonly used “heat index” would be about 165 F.)

This limit was almost reached this summer, at the end of an extreme, weeklong heat wave in the region: On July 31, the wet-bulb temperature in Bandahr Mashrahr, Iran, hit 34.6 C — just a fraction below the threshold, for an hour or less.

But the severe danger to human health and life occurs when such temperatures are sustained for several hours, Eltahir says — which the models show would occur several times in a 30-year period toward the end of the century under the business-as-usual scenario used as a benchmark by the Intergovernmental Panel on Climate Change.

The Persian Gulf region is especially vulnerable, the researchers say, because of a combination of low elevations, clear sky, water body that increases heat absorption, and the shallowness of the Persian Gulf itself, which produces high water temperatures that lead to strong evaporation and very high humidity.

The models show that by the latter part of this century, major cities such as Doha, Qatar, Abu Dhabi, and Dubai in the United Arab Emirates, and Bandar Abbas, Iran, could exceed the 35 C threshold several times over a 30-year period. What’s more, Eltahir says, hot summer conditions that now occur once every 20 days or so “will characterize the usual summer day in the future.”

While the other side of the Arabian Peninsula, adjacent to the Red Sea, would see less extreme heat, the projections show that dangerous extremes are also likely there, reaching wet-bulb temperatures of 32 to 34 C. This could be a particular concern, the authors note, because the annual Hajj, or annual Islamic pilgrimage to Mecca — when as many as 2 million pilgrims take part in rituals that include standing outdoors for a full day of prayer — sometimes occurs during these hot months.

While many in the Persian Gulf’s wealthier states might be able to adapt to new climate extremes, poorer areas, such as Yemen, might be less able to cope with such extremes, the authors say.

Christoph Schaer, a professor of atmospheric and climate science at ETH Zurich who was not involved in this study, provided an independent commentary in the journal, writing that while deadly heat waves have occurred recently in Chicago, Russia, and Europe, in these cases infants and the elderly were most affected. The new study, Schaer writes, “concerns another category of heat waves — one that may be fatal to everybody affected, even to young and fit individuals under shaded and well-ventilated outdoor conditions.”

Schaer writes that “the new study shows that the threats to human health may be much more severe than previously thought, and may materialize already in the current century.” He told MIT News, “I think the study is of great importance, since it indicates where heat waves could get worst if climate change proceeds.”

The research was supported by the Kuwait Foundation for the Advancement of Science.

Photo: Rub' al Khali desert in the Arabian Peninsula (courtesy of Eltahir Group/MIT)

Video: Melanie Gonick/MIT 

MIT News Office

MIT is launching a multifaceted five-year plan aimed at fighting climate change, representing a new phase in the Institute’s commitment to an issue that, the plan says, “demands society’s urgent attention.”

Citing “overwhelming” scientific evidence, “A Plan for Action on Climate Change” underscores the “risk of catastrophic outcomes” due to climate change and emphasizes that “the world needs an aggressive but pragmatic transition plan to achieve a zero-carbon global energy system.”

To that end, MIT has developed a five-year plan to enhance its efforts in five areas of climate action, whose elements have consensus support within the MIT community:

• research to further understand climate change and advance solutions to mitigate and adapt to it;
• the acceleration of low-carbon energy technology via eight new research centers;
• the development of enhanced educational programs on climate change;
• new tools to share climate information globally; and
• measures to reduce carbon use on the MIT campus.

The plan calls for MIT to convene academia, industry, and government in pursuit of three overlapping stages of progress.

“The first step,” according to the plan, “is to imagine the future as informed by research: e.g., What is the optimal mix of energy sources in 15, 25 and 35 years, in order to meet emissions targets and eventually reach a zero-carbon global energy system? And how can societies across the globe best adapt to damaging climate impacts in the meantime?”

“Next,” the plan continues, “it will be vital to establish the policy and economic incentives to achieve that future. Finally, clear technological goals and aligned incentives will focus and accelerate the research and development required to achieve success. All three phases need to be continuously refreshed: Research and development should continuously inform timelines and targets. The success of this strategy depends on the best efforts of all three sectors.”

The plan specifically asserts the need for a price on carbon in order to align the incentives of industry with the imperatives of climate science.

The plan also announces that MIT will not divest from the fossil fuel industry. This decision and the overall plan emerged from more than a year of broad consultation with the MIT community, including extensive public discussion led by the Committee on the MIT Climate Change Conversation, and engagement with the student-led group Fossil Free MIT. This group originally petitioned MIT to divest from 200 companies and more recently has asked for “reinvestment in campus sustainability, and a reinvention of the approach that MIT takes toward climate change.”

In his announcement letter today to the MIT community, President L. Rafael Reif said the plan would not have taken the shape it did without Fossil Free MIT’s “willingness to work with us toward the shared goal of meaningful climate action.” He encouraged the group’s members to join in the work ahead.

A call to service, on campus and beyond

In his letter, Reif called upon all members of the MIT community to take action. “There is room and reason for each of us to be part of the solution,” he wrote. “I urge everyone to join us in rising to this historic challenge.”

Alumni are being called upon to imagine how they can help MIT execute the plan. A competition announced in the plan has been created in order to elicit the most effective ways for the MIT alumni community to take personal and combined action.

“MIT’s 130,000 alumni represent an exceptional untapped resource for driving substantive progress on climate change,” the plan says, “and we are certain that our graduates will know better than we do how to make the most of their strength, from their technical expertise to their professional and community networks.”

The competition will be hosted by the MIT Climate CoLab, a digital community that engages nearly 50,000 people from over 170 countries to crowdsource climate priorities and novel solutions. The plan calls for the Climate CoLab to expand its overall capacity, so that MIT can serve as a vital hub of crowdsourced solutions to climate change.

A year and more in the making

The plan is the result of an MIT-wide initiative on climate launched in May 2014, and led by Provost Martin Schmidt; Vice President for Research Maria Zuber; MIT Energy Initiative (MITEI) Director Robert Armstrong; and Susan Solomon, founding director of MIT’s Environmental Solutions Initiative.

In September 2014, the initiative appointed the Committee on the MIT Climate Change Conversation, chaired by Roman Stocker, then associate professor of civil and environmental engineering, to lead public discussion of MIT’s options for addressing climate change.

The plan credits members of the committee, as well as members of Fossil Free MIT, for having “brought climate change to the top of MIT’s institutional agenda by urging that MIT assume a role of public leadership.”

“Today’s plan is truly MIT’s plan,” Zuber says. “There is a hunger across the Institute to apply MIT’s strengths to the problem. With a firm theory of the case for how to bring cohesion to our work in science, engineering, and policy, we are now poised to set forth on five years of critical work. Today is an important beginning.”

In his letter to the MIT community, Reif wrote that MIT will rely on Zuber to lead MIT’s research, outreach, and convening efforts.

“President Reif and Vice President for Research Zuber have led us to a very important day in the Institute’s history,” says Diana Chapman Walsh, a member of the Executive Committee of the MIT Corporation (MIT’s board of trustees) and former president of Wellesley College. “The world is calling for leadership at a time of urgency and uncertainty. Today, MIT is deepening its commitment to meaningful action.”

Intensifying MIT’s impact

The plan outlines five areas for “direct action”:

1. An improved understanding of climate change, and practical solutions to mitigate and adapt to it. As part of its Environmental Solutions Initiative (ESI), now led by Professor John E. Fernandez, who was named as ESI’s second director earlier this week, MIT is providing $5 million to back further research on a series of cross-disciplinary projects and will seek outside support for promising new work.

2. Accelerating progress on low-carbon technologies. Building on decades of faculty research, the MIT Energy Initiative is planning to launch eight new low-carbon energy centers, in cooperation with corporate partners, each focused on the advancement of a specific type of technology. Each center will seek about $8 million in annual funding, or more than $300 million in total over the five-year period — which the plan says represents “far and away the greatest opportunity for MIT to make a difference on climate change.” The eight centers will be in the areas of solar energy; energy storage; materials; carbon capture, use, and sequestration; nuclear energy; nuclear fusion; energy bioscience; and the electrical grid.

1. In addition, MIT plans additional research intended to help transform at least four major types of energy-related systems. These projects will concern the future of the utility industry, ground transportation, air transportation, and cities. And MIT is commissioning a multidisciplinary report to envision the pathway to accelerate the transition to a zero-carbon future.

3. Education. MIT plans to create an Environment and Sustainability degree option; develop an online Climate Change and Sustainability credential; and, in a joint effort between MIT’s School of Engineering and School of Architecture and Planning, find ways to insert principles of “benign and sustainable design” throughout MIT’s engineering and design instruction.

4. Additional knowledge-sharing tools. MIT will expand its range of short courses and seminars for executives (including through online tools); create a new web portal on climate change; expand its Climate CoLab crowdsourcing tool (as noted above); and continue to focus on climate issues through Solve.

5. Reducing emissions on the MIT campus, and using the campus as a “test bed” for climate action. MIT plans to reduce campus emission by at least 32 percent by 2030 (the amount set as a goal by the federal government); eliminate the use of fuel oil on campus by 2019; enact “carbon shadow pricing,” to explore the effects of assigning a self-imposed cost to campus carbon emissions; pursue more carbon-efficient technologies as it renews its stock of campus buildings and systems; and build an open data platform on campus energy use.

Former Secretary of State George P. Shultz, who earned a PhD from MIT in 1949 and served on the economics faculty in the 1950s, has urged the MIT community to take action on climate change and endorses today’s plan, calling it “a terrific document. It is inspirational that MIT is working on the subject with such energy and impact.” Shultz chairs the External Advisory Board of the MIT Energy Initiative.

Robert Armstrong, director of the MIT Energy Initiative, says, “The plan recognizes the central role that climate change will have in driving transformation of the global energy system. The eight low-carbon energy centers leverage MIT’s strengths in working across disciplines and in deeply engaging with industry to tackle society’s greatest challenges.”

Investment questions

The plan announces that in the interest of fighting climate change, MIT will not divest from companies in the fossil fuel sector.

“We believe that divestment — a dramatic public disengagement — is incompatible with the strategy of engagement with industry to solve problems that is at the heart of today’s plan. Combatting climate change will require intense collaboration across the research community, industry and government,” the plan states.

Divestment has been a principal aim of Fossil Free MIT, which had gathered 3,400 signatures from members of the MIT community, asking for divestment from 200 companies in the fossil-fuel industry. MIT hosted a public debate on the issue in April, in which MIT faculty, professors from other institutions, and investment executives addressed the potential merits and drawbacks of divestment.

The plan states that MIT is “not naïve about the pernicious role of some segments of the fossil fuel industry in creating the current policy deadlock. We deplore the practice of ‘disinformation,’ through which some industry players and related groups have actively obstructed clear public understanding of the problem of climate change.”

MIT’s position, the plan states, is that “well-crafted policies can harness the creative forces of industry to serve the common good.” Further, it argues “that growing awareness of climate change may be generating a tipping point in that policy dynamic now. Witness the fact that in Paris last Friday, October 16, the CEOs of ten of the world’s largest oil and gas companies declared that their ‘shared ambition is for a 2°C future,’ and called for ‘an effective climate change agreement’ at next month’s 21st session of the United Nations Conference of Parties to the UN Framework on Climate Change (COP21).”

“Six of those companies — BP, Eni, Saudi Aramco, Shell, Statoil, and Total — are members of MITEI,” the plan continues. “We believe we have greater power to build on such momentum not by distancing ourselves from fossil fuel companies, but by bringing them closer to us.”

Ultimately, the plan states, massive changes are needed in the production, distribution, and consumption of energy to avert a potential climate catastrophe: “To solve this global problem, humanity must reorder the global energy status quo.”

Robert Millard, chairman of the MIT Corporation, calls the plan “bold, respectful, complete, honest, and well-reasoned. It therefore reflects,” he says, “the highest aspirations of MIT."

Photo: Christopher Harting/AboveSummit

by David L. Chandler | MIT News

John E. Fernandez, a professor of building technology in the Department of Architecture, has been named as the new director of MIT’s Environmental Solutions Initiative (ESI), a campuswide initiative launched in 2014. Fernandez succeeds Susan Solomon, the Ellen Swallow Richards Professor in the Department of Earth, Atmospheric and Planetary Sciences, who has served as the Initiative’s founding director.

“I’m honored to be taking over from such an eminent scientist,” says Fernandez, who has served on the MIT faculty for 16 years. “It’s really humbling to hear her talk about her work and be given the opportunity to extend the reach of the ESI.”

Fernandez’s appointment was announced today in a letter to the MIT community from Provost Martin Schmidt and Vice President for Research Maria Zuber.

“Professor Fernandez approaches this role as a world expert on high-performance, sustainable building materials, as a leading scholar on the resources and infrastructure of cities — home to more than half the human population — and as a practicing architect who has led the design for more than 2.5 million square feet of new construction in cities from Washington, D.C., New York, and Los Angeles to Jakarta, Tokyo, and Shanghai,” Schmidt and Zuber wrote. “A member of our faculty since 1999, he founded and directs the Urban Metabolism Group, a highly multidisciplinary research group that studies how intelligent design and technology can reduce the resource intensity of cities.”

Since its founding in May of last year, ESI has awarded nine seed grants for research projects, on efforts that include promoting sustainable consumption in cities, improving methods for safe mining on land and at sea, and improving air quality and plans to mitigate global climate change. Such highly multidisciplinary projects can be difficult to fund through traditional channels.

“I’m delighted to be passing the reins to such a well-qualified and distinguished scholar,” Solomon says. “John Fernandez has a deep understanding of MIT’s strengths across a very diverse suite of environmental challenges, and he brings a clear commitment to excellence and breadth. I’ll be looking forward to seeing him take ESI to the next level.”

Fernandez says ESI’s broad scope is illustrated by the very different backgrounds of its first two directors. “I’m very optimistic about the vision for ESI,” he says: If this initiative can embrace leaders from fields as different as atmospheric science, architecture, and building technology, “It speaks to the breadth of MIT, and the commitment to the ESI.”

Fernandez’s research looks at the environmental consequences of societal activities — which tend to be concentrated in the world’s cities. “Decisions that architects and planners make can have huge ramifications, because the built environment accounts for the consumption of enormous quantities of energy and materials,” he says. Such environmental consequences, he says, “should be integral to a designer’s thinking process.”

“The Intergovernmental Panel on Climate Change has shown the built environment to be one of the major contributors to global emissions,” Fernandez says. “What is less well known is that a majority of raw materials extracted and processed are used in the construction and operation of buildings, roads and other large-scale infrastructure. For that reason, much of my work has been focused on understanding the environmental benefits of resource-efficient buildings and cities.”

Since more than half of the world’s population now lives in urban areas, Fernandez says, he has focused on systems involved in the functioning of modern cities, from buildings and transportation to the delivery of food, water, sanitation services, and goods — and the resource intensities associated with these services. The research outcomes from his group contribute to a field known as “urban metabolism,” because it treats the city as an interconnected whole, rather than focusing on individual components or economic sectors. This is best done through a multidisciplinary approach.

In the work of the ESI, Fernandez says, “many solutions will require multiple perspectives” — which underscores the importance of communication and collaboration among disciplines, and an understanding of different modes for tackling problems through science, engineering, design, and policy.

Fernandez sums up his vision for the Initiative by considering the three components of its name: environmental, solutions, and initiative.

On the environment, he says, “the priority is to progress beyond the discussion of the uncertainties about climate change, to delve deeper into research that tells us more about the consequences of climate change, and to do research in targeted ways that will tell us about the kinds of risks we are facing.” Researchers tackling those issues should be provided with resources to do their work, but also to help them in communicating “a very simple but unequivocal message that the science of the climate is well-established and the most conclusive it can be, and is telling us very dire things that we should really pay attention to.”

The second priority, Fernandez says, lies in solutions. It’s essential, he says, “to propose pathways toward mitigation and adaptation in every aspect of society, with regard to every important human activity, enlisting engineers, scientists, architects, economists, political scientists, and others, and with regard to all regions of the world.” For example, hundreds of millions of people live in coastal cities, which face significant threats from sea-level rise. Designers need to converge on integrated solutions with other disciplines to enlist multiple systems for adapting these cities, he says “so that we’re not approaching this in a siloed way.”

The initiative part of the ESI’s name, Fernandez says, “is the part that I hope will bear important short-term and local results for MIT. I believe this initiative has the critical responsibility to initiate action across diverse communities at MIT.”

The ESI, Fernandez adds, should involve all sectors of our community — undergraduate and graduate students, postdocs, faculty, researchers, and staff. “We will be working to initiate a great many actions for the environment, both local and global,” Fernandez says. “Some will be very targeted and modest, and others extraordinarily ambitious, broad and sweeping.”

One example of a way in which Fernandez hopes to implement this agenda, he says, is in funding student projects, including some that might relate directly to residential life: “Support for even very modest but very immediate grassroots projects, where it’s right there in front of you, is something I’m very keen to launch as soon as possible,” he says.

by Jennifer Chu | MIT News Office

Over two weeks in December, delegates from virtually every country in the world will gather in Paris for the 21st annual United Nations Climate Change Conference. Their ambitious goal: to hammer out a binding international agreement on climate action.

In advance of the conference, organizers have requested that countries submit Intended Nationally Determined Contributions — pledges to reduce greenhouse gas emissions, by an amount that should be “fair and ambitious,” in order to limit global warming to no more than 2 degrees Celsius above pre-industrial levels.

Now a new study by researchers at MIT and the Center for International Climate and Environmental Research in Oslo, Norway, has found that pledges by the three largest emitters — the United States, the European Union, and China — leave very little room for the rest of the world to emit.

Based on the pledges submitted, the U.S. plans to reduce emissions by 28 percent by 2025, and 83 percent by 2050, while the EU will work toward reductions of 40 percent by 2030, and 80 percent by 2050. China has not pledged a reduction, but has indicated that its emissions will peak by 2030; China also aims to improve its energy efficiency by 60 to 65 percent.

Despite these substantial commitments, the researchers found that the rest of the world’s nations would be forced to adopt per capita emissions 7 to 14 times lower than the EU, U.S., or China, by 2030, in order to keep global temperatures from rising higher than 2 C.

“The challenge of this problem is, we have about 7 billion people on the planet, and about 1 billion of us live pretty well,” says Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT. “The other 6 billion are struggling to develop, and if they develop using carbon as we did, the planet is going to get quite hot. And hot is, of course, just the beginning of the story in terms of what climate change actually means.”

Solomon and her colleagues have published their results in the journal Environmental Research Letters.

What’s fair?

While countries were asked to demonstrate that their pledges were fair and ambitious, conference organizers provided no framework with which to make such an assessment.

In the new study, the MIT and Norwegian scientists gauged the fairness and ambition of the top three emitters’ pledges using a “cumulative emissions” approach developed by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.

The cumulative emissions approach finds that a best estimate of 3.7 trillion tons of carbon dioxide can be emitted globally before temperatures rise 2 C above pre-industrial levels. Given the amount of carbon dioxide emitted thus far, and accounting for other greenhouse gases, land-use change, and other factors, the remaining amount is about 1 trillion tons — about 30 years’ worth of current emissions.

How to fairly allocate the remaining allowable emissions among the world’s nations is a complex and contentious issue. Solomon and her colleagues examined two scenarios for fairly reducing emissions by the EU, U.S., and China: an equity approach, which divides the global quota of emissions among all nations based on population; and an inertia approach, which divides the quota based on the current shares of global emissions.

Based on their calculations, they found all three emitters’ pledges fall short of fair: The U.S. and EU pledges may be considered in line with keeping global warming at 2 C only under the inertia scenario, in which the high emitters continue to emit based on their current shares. If, however, both were to adopt an equity scenario, they would have to pledge significantly more emissions reductions, to account for their relatively small share of the world’s population.

China’s pledge deviates significantly from both scenarios, as both would require the country to immediately begin drastic reductions. Instead, China has pledged to begin reducing its emissions in 2030, so as to improve the quality of living for its millions of citizens now living under the poverty line.

“The environment we ask for”

In sum, Solomon and her colleagues conclude that even if the three largest emitters fulfill their pledges, they would “lock the world into a higher long-term temperature increase” of around 3 C.

“People don’t realize that 2 degrees Celsius is a big change,” Solomon says. For instance, she points to the summer of 2003, in which an unprecedented hot summer killed more than 10,000 people throughout Europe.

“That summer was about 2 degrees Celsius hotter than an average European summer,” Solomon says. “By 2050, every summer in Europe will probably be 2 degrees hotter than average, if we keep going the way we’re going right now. Three degrees, in my opinion, is a really frightening change.”

To stave off additional warming, Solomon says countries will need to significantly ramp up efforts to decarbonize. In the short term, she says, international climate talks must integrate discussions on research and development, to spur technological innovation.

“We have to decarbonize the energy system via research and development, changes in technologies and policies, and we need to encourage those to happen,” Solomon says.  “We’ll get the environment we ask for. History has proven time and again that public engagement is essential in making anything change on this planet.”

Vicki Ekstrom | Laur Fisher | MIT Climate CoLab

Solar panel system wins $10,000 prize for technology that makes energy and water more accessible in the developing world

An MIT initiative is using the global crowd to help solve climate change. And with the United Nations’ climate agreement anticipated to fall short of the 2 degree Celsius carbon emissions target, it’s never been a more critical time to take this approach.

MIT’s Climate CoLab initiative is a growing community of 50,000 people from around the world who work together online through a series of interrelated contests focused on different aspects of the climate change problem. Yesterday, MIT hosted the Crowds and Climate conference, where the Climate CoLab awarded its 2015 contest winners.

Eden Full from the non-profit SunSaluter won the $10,000 Grand Prize for its technology that makes energy and water more accessible in the developing world. Their product uses gravity and water to rotate a solar panel throughout the day, generating 30 percent more electricity than a standard panel and four liters of clean drinking water each 24-hour period. The rotator is cheaper than motorized solar trackers and has already achieved success: there are already 130 SunSaluters in 16 countries.

"This prize is especially important now," said Full, founder of the project. "We just decided that SunSaluter will become fully volunteer-led, supported by our non-profit and corporate partners. This funding will go toward making that possible."

In addition, two proposals received honorable mention awards:

• A national campaign on energy conservation and renewable energy in Indian schools that is working towards building a network of energy ambassadors. The campaign already has support from the Indian government, and is well on its way to fostering a more environmentally-aware generation of Indians.
• A mechanism for internalizing marine emissions that combines charging a levy on emissions from international maritime shipping, with a fuel levy on fuel consumption by domestic shipping

These proposals were selected by Robert Armstrong, director of the MIT Energy Initiative; Jason Jay, director of the MIT Sloan Sustainability Initiative; John Reilly, co-director of the Joint Program on the Science and Policy of Global Change.

The grand prize and honorable mention awards were selected from the 34 winners of the 24 contests run on the Climate CoLab in 2015. The winners are a diverse group of non-profits, entrepreneurs, scholars and climate experts, students, business people, and concerned citizens looking to confront the climate challenge, who hail from 11 countries.

The Climate CoLab also announced the winner of its United States Climate Action Plan contest, which sought regional solutions to climate change. Unlike the other contests, which target specific sub-problems that contribute to climate change, this contest asked participants to take different actions and combine them to form a regional strategy.

The winner for the United States Climate Action Plan contest suggested a pathway to engineer cities so that they are built for livability, sustainability, resiliency, energy-efficiency and affordability.

An important addition to this round of contests is a tool — and a team of climate modelers — to help people to evaluate the impact their ideas will have on global emissions. The public can also combine regional plans to form global strategies. The Global Climate Action Plan contest is still open and accepting submissions until Oct. 17th.

All the winners were recognized at the Crowds and Climate conference, held this week alongside MIT’s Solve conference. Crowds and Climate brought together leaders from businesses, non-profit organizations, governments, and communities around the world to advance an online global problem-solving effort to more effectively tackle climate change. This bottom-up approach enables large communities of people to work together to shift business practices, influence policy makers, and reshape public attitudes and behavior on climate change.

“Our goal is to open up the elite conference rooms and meeting halls where climate strategies are developed today and bring that discussion into an online forum where anyone with a good idea can contribute,” says Professor Thomas Malone, director of the Center for Collective Intelligence at the MIT Sloan School of Management and principal investigator for the Climate CoLab project.

“We are very proud of this year’s winners, and we see this as just the beginning of new ways to use our global collective intelligence to tackle important societal problems like climate change.”

The Joint Program is a cosponsor of the Crowds & Climate conference.

Photo: Grand prize and honorable mention award winners, with Professor Thomas Malone (center) and Laur Fisher (second from right) of the MIT Climate CoLab (Photo by Justin Saglio)

The latest Obama-Xi announcement sends a strong message: the two nations are acting fast to enable a global low carbon transition. Friday’s joint announcement is an unprecedented step by the world’s #1 and #2 emitters to commit, at the highest levels, to a strong set of domestic policies and to reinforce global mechanisms that will help to engage peers ahead of the upcoming landmark climate change negotiations in Paris. 

Pricing Carbon

Xi has committed China to launching a national emissions trading system for CO2 in 2017. An emissions trading system will directly constrain a large share of China’s CO2 emissions and, by putting a price on emissions, encourage reductions where they cost least. This is impressive in that China is pledging to reduce emissions at a time when its per-capita income is less than one-fifth of the U.S. and its economy faces headwinds. It recognizes the long-term benefits of action now—for local air quality, global climate, and its own long-term leadership in delivering innovative solutions that all nations will eventually need.

While China is not the first to establish an emissions trading system, China’s is likely to be the largest when it comes online in 2017. While the European Union has built an emissions trading system over the past two decades, the U.S. has so far not been successful in adopting a national system for greenhouse gases. In 2009 the Waxman-Markey Bill, which would have established an emissions trading system in the U.S., failed to pass Congress, leaving the U.S. to rely on a piecemeal approach that largely repurposed existing regulations, such as vehicle fuel economy standards and power plant emissions limits established under the Clean Air Act, to mandate CO2 emissions reduction. Indeed, these measures formed the cornerstone of the U.S. domestic action pledged on Friday, and they will have impact. However, an emissions trading system that could deliver the same reductions at lower aggregate cost has so far proven politically unpalatable. China’s latest move could prompt a rethink on emissions trading in the U.S.

Linking Global and Local Action

Along with a strong portfolio of coordinated domestic actions, Xi and Obama made progress on defining the architecture of a global climate agreement. The two leaders have agreed on the need for an enhanced system that monitors domestic action through reporting and review of progress, recognizing that some developing nations will still need time to put these capacities into place. Both sides also recognized the need to increase ambition over time. This is essential because even with all present contributions, the global emissions trajectory is not expected to bend down anytime soon. Recognizing that this will likely not be fully resolved in Paris, setting in place a timeline for assessing and revisiting commitments going forward will go a long way towards ensuring that the goal Xi and Obama reaffirmed at the outset of their remarks—deep reductions in GHG emissions that will markedly limit global temperature rise—does not slip off the radar.

Beyond generating momentum ahead of Paris, U.S.-China joint action will have far-reaching consequences at home when it comes to enabling a low carbon transition. Although many insiders anticipated that an emissions trading system in China would be established, efforts to codify this effort in a new Climate Change Law were moving more slowly—this high-level pledge will redouble the pressure. Beyond emissions trading, China has also pledged to promote “green dispatch” in the electricity sector, which will prioritize lower emitting plants. In China, generators are powerful interests entitled to supply a “fair share” of annual generation—now, their “fair share” will need to reflect environmental impact more strongly and directly.

Leading on Climate and Development

Perhaps the greatest promise of the latest announcement by China and the U.S. lies in its invitation to all parties to increase ambition, if not before Paris then as soon as possible as part of ongoing negotiations. On the eve of Paris, the world is poised to miss the 2 degree target—by a large margin. Stronger action will be needed by developed and developing countries alike. By committing to limit CO2 emissions, China has shown that domestic action on climate change does not need to undermine long-term development goals. In recent years, it has developed the domestic capability to assess—through research, modeling, and real-world experimentation—the advantages and disadvantages of various instruments for limiting fossil energy use and CO2 emissions. The results suggest that some opportunities, such as industrial energy efficiency and new energy development, can support cleaner air, better operational performance, and—in the case of, say, solar energy—open opportunities as a leading global provider of clean technology. Every developing country will have its unique set of opportunities. The architecture emerging on the road to Paris is shaping up in a way that will accommodate these differences, allowing the countries that are poised to grow the fastest over the next several decades to find ways to power this growth with clean, affordable, low carbon energy sources. Greater action from the developed world will also be essential. Ideally, the steps Xi and Obama have taken last week will inspire a broad-based, cooperative effort to deliver more than promised that carries both local and global benefits.

Dr. Valerie Karplus is a ChinaFAQs Expert at the Massachusetts Institute of Technology (MIT). She is an Assistant Professor in the Global Economics and Management Group at the MIT Sloan School of Management and Director of the China Energy and Climate Project (CECP) at MIT.

ChinaFAQs is a project facilitated by the World Resources Institute that provides insight into critical questions about Chinese policy and action on energy and climate change. The ChinaFAQs network is comprised of U.S.-based experts, including researchers at U.S. universities and government laboratories, independent scholars, and other professionals.

Photo Credit: U.S. Embassy the Hague via Flickr Creative Commons License

CAMBRIDGE, Mass. — On the Blue Nile in Ethiopia, construction is underway on a public works project of gigantic physical proportions and exquisite political delicacy. The Grand Ethiopian Renaissance Dam, now about halfway finished, amounts to a test: With water becoming precious enough to be the stuff of war, can nations find ways to share it?

So far, so good. The project is moving toward completion, and a recent joint declaration of principles by the leaders of Egypt, Ethiopia and Sudan pledges cooperation and no “significant” downstream harm. That is critical, given that the dam will control nearly two-thirds of the water on which Egypt depends. But for the cooperation to be meaningful, these three countries will need serious technical analysis. Poor assessment of such matters as the variability of annual rainfall or minimum flows required to maintain downstream water quality could undermine a decent agreement, leading to conflict of unpredictable intensity.

That’s because the flow of the Nile is climatic roulette. It experiences periods of plentiful water and periods of extended drought, and it always has: Remember the story (in both the Bible and the Quran) of seven years of plenty, and then seven lean years? But now the stakes are much higher: Egypt’s population is 90 million, and growing. That country’s Aswan High Dam, downstream from the Ethiopian dam, helps to moderate these fluctuations, but a second large dam and its reservoir higher upriver are going to complicate things.

Egypt now receives virtually all its water from the Nile — about 60 billion cubic meters a year, slightly above the amount provided for in its treaty agreement with Sudan. That amounts to the withdrawal of 700 cubic meters per capita per year. Compare that with California, which annually withdraws about 1,400 cubic meters per capita from multiple sources, including 30 percent of the Colorado River’s annual flow, and you understand just how scarce and precious the Nile’s water is to Egypt’s welfare.

California depends heavily on Lake Powell and Lake Mead, the reservoirs behind dams on the Colorado River, which together store slightly more than three years’ worth of that river’s total flow. The new dam in Ethiopia will have an even larger storage capacity than that of Powell and Mead combined, but still amounts to just 1.5 years of the flow of the Blue Nile alone. Adding in the very large reservoir behind Egypt’s Aswan High Dam gives a storage of about 1.75 years of the total flow of the Nile. It’s not a wide margin of safety for a long drought — as Californians will attest.

The monsoon rains in Ethiopia that will feed the new dam come mainly during just three months, so by storing that water, the new dam will moderate and smooth out the flow of the Blue Nile, the 900-mile-long headstream of the Nile itself. It will also generate huge amounts of electricity, the sale of which could finance much-needed development in Ethiopia — except that transmission lines to export the power are not yet being built.

Just as California has used stored water to become an agricultural powerhouse, Sudan will benefit by using the more stable flow of water from the new dam to raise its agricultural productivity. This will allow Sudan, which sits between Ethiopia and Egypt, to finally employ its full treaty allotment of river water, which in turn will reduce what is available to Egypt.

It’s clear that a cooperative agreement among Ethiopia, Sudan and Egypt is needed to avoid conflict and downstream harm. This includes agreement on what amounts to “significant” harm, given that, in the past, Egypt has been willing to go to war to protect its water.

All three countries stand to benefit if they work together. The dam’s huge storage capacity could help both Sudan and Egypt during drought years. And if Egypt were to agree to buy the power that the new dam will generate (and to build the transmission lines to connect to it, perhaps with international help), then Ethiopia will benefit economically from stored water that has to flow downstream eventually.

Here is where the technical issues will be critical. Last November, the Abdul Latif Jameel World Water and Food Security Lab at M.I.T. convened experts on Nile Basin water resources. They pointed out that management of a river system with multiple dams required sophisticated joint management with a shared knowledge base and scientific modeling framework. The hard negotiations ahead to achieve detailed agreements on such things as reservoir operation policy, power trading, dam safety and irrigation practices will require that foreign policy and water experts from each of the three countries have a shared understanding of the technical issues and a willingness to compromise.

In May 2015, the three countries engaged technical consultants to assist with these problems, but that arrangement has since collapsed over disagreements about project management. It behooves the international community to help, through support of regional efforts like the Nile Basin Initiative, to build scientific and engineering coordination and knowledge among the three countries, provide impartial expertise, set up a management system and perhaps offer a process to resolve disputes.

The world needs to get good at sharing water, and right away. The alternative is frequent regional conflicts of unknowable proportions.

John H. Lienhard V is a professor at M.I.T. and director of the Abdul Latif Jameel World Water and Food Security Lab. Kenneth M. Strzepek is a research scientist at the M.I.T. Joint Program on the Science and Policy of Global Change.

On the eve of President Xi's visit to the US and summit with President Obama, Professor Karplus participated in the panel discussion on Meeting China’s Climate Goals at Columbia University today, September 21, 2015, at 12:30-2:00 p.m. David Sandalow, Inaugural Fellow, Center on Global Energy Policy, and former senior official at the White House, State Department, and U.S. Department of Energy moderated the discussion among the expert speakers who include Valerie Karplus, Assistant Professor of Global Economics and Management, MIT Sloan School, and Director of the Tsinghua-MIT China Energy and Climate Project; Zhu Liu, Fellow, Resnick Sustainability Institute, California Institute of Technology and Associate, Kennedy School, Harvard University; and Kelly Sims Gallagher, Professor of Energy and Environmental Policy, the Fletcher School, Tufts University, and former Senior Policy Advisor, Office of Science and Technology Policy, the White House.
 
A podcast of this event will be available three-five days after the date of the event through iTunes or via the Center on Columbia Global Energy Policy’s website.

Peter Dizikes | MIT News Office

The politics of climate change are often depicted as a simple battle, between environmentalists and particular industries, over government policy. That’s not wrong, but it’s only a rough sketch of the matter. Now a paper co-authored by MIT economist Christopher Knittel fills in some important details of the picture, revealing an essential mechanism that underlies the politics of the climate battle.

Specifically, as Knittel and his colleagues demonstrate, at least one climate policy enacted by Congress — on transportation fuels — contains a crucial asymmetry: It imposes modest costs on most people, but yields significant benefits for a smaller group. Thus, most people are politically indifferent to the legislation, even though it hurts them marginally, but a few fight hard to maintain it. The same principle may also apply to other types of climate legislation.

In 2005, Congress introduced the Renewable Fuel Standard (RFS), which mandates a minimum level of ethanol that must be used in gasoline every year, as a way of reducing greenhouse gas emissions. Ethanol can indeed reduce emissions, but as Knittel and other economists have argued, it is not the most efficient way of doing so: He estimates that mandating ethanol use is at least 2.5 times as costly, per ton of greenhouse gas reduction, as a cap-and-trade (CAT) policy, which would price the carbon emitted by all transportation fuels.

But corn-based ethanol production has strong political support in the Midwest, where much of the corn industry is based. In the new paper, Knittel and his colleagues quantify that effect in unique detail. They model what U.S. fuel consumption would likely look like through 2022 under both RFS and CAT scenarios, among others. Compared with a cap-and-trade system, the average American would lose $34 annually due to the RFS policy. But 5 percent of U.S. counties would gain more than $1,250 per capita, and one county gains $6,000 per capita.

Thus, most people are indifferent to the shortcomings of the RFS policy, but those who care tend to support it vigorously.

“Because of the skew in the distribution, you have the typical voter who doesn’t find it in their interest to fight against the inefficient policy, but the big winners are really going to fight for the inefficient policy,” says Knittel, adding: “If the typical voter is losing $30 a year, that’s not enough for me to write to my congressman. Whereas if you have someone on the upper end who is going to gain $6,000 — that’s enough for me to write my congressman.”

The political economy of energy

As the study shows, some folks do more than write to their representatives. Knittel and his colleagues found that members of the House of Representatives in districts that gain greatly from the RFS policy received an average of $33,000 more from organizations that opposed one particular piece of legislation — the 2009 Waxman-Markey bill, which would have created a CAT system, and likely would have reduced ethanol use. That bill passed in the House in July 2009, but was never taken up by the U.S. Senate.   

That difference in campaign contributions holds up strongly even when the researchers controlled for factors such as ideology, state, and overall emissions. That is, other things being equal, representatives of the specific areas benefitting most from RFS were given far more in donations from opponents of the Waxman-Markey bill than other congressmen. Representatives were also 39 percentage points more likely to oppose Waxman-Markey, other things being equal, if they were in districts that benefit strongly from the RFS policy.

“It’s a very robust finding,” Knittel says. “One interpretation is that these people or corporations who were donating money have a model very similar to ours, and are able to predict winners and losers under different policies. This is a very sophisticated group.”

On one level, the results confirmed something that was broadly understood: Areas with corn-based economies support ethanol. On another level, the study reveals the deep asymmetry that structures the politics of the issue: on one side, widespread indifference; on the other, narrow but deep support.

“It wasn’t until we got the results that we were able to think through the political economy of it,” Knittel says.

Tax the externality

The paper, “Some Inconvenient Truths About Climate Change Policy: The Distributional Impacts of Transportation Policies,” is forthcoming in the Review of Economics and Statistics.  

The paper’s co-authors are Knittel; Stephen P. Holland of the University of North Carolina at Greensboro; Jonathan E. Hughes of the University of Colorado; and Nathan C. Parker of the Institute of Transportation Studies at the University of California at Davis.

To conduct the study, the researchers used modeling by Parker that estimates where ethanol production will be located in coming years, as well as projecting the overall costs of various potential transportation fuel policies, were they to be implemented. The work also drew extensively on methods the other co-authors have used in evaluating both the potential impact of biofuels as a gasoline replacement and the relationship between policy options and politics.

On the general question of picking the optimal emissions–reduction policy, Knittel says, “The efficient policy is to tax the externality.” That is, to tax the additional cost or problem imposed on people — in this case, greenhouse gas emissions. That forces consumers to account for the costs of their own decisions, such as buying fuel-efficient vehicles.

Other scholars in the field regard the paper as a significant contribution to the study of energy politics. Mark Jacobsen, an associate professor of economics at the University of California at San Diego who has read the paper, says the “voting and donations models are both quite convincing.”

Jacobsen adds: “A very important contribution of this paper is in pointing out that we need to be alert to distribution [of energy resources] across states, making sure that it does not stand in the way of otherwise good policy.”

Knittel suggests the same kind of political asymmetry is probably at work in other aspects of climate politics. When it comes to coal-burning power plants, most people are only marginally affected by policy changes — but people living in coal-mining areas are deeply affected, and so have a much larger impact on the policy debate.

“We hope this paper sparks a literature that can do the same thing for other fuels,” Knittel says.

Kelsey Damrad | Department of Civil and Environmental Engineering

With approximately 70 percent of all freshwater consumption worldwide used for agriculture, the reliance on large-scale irrigation development continues to spread and ultimately augments crop yields in many regions.

But the ongoing expansion of cropland irrigation, just as with any human-made land-cover change, holds potential for unintended consequences. The consequences of such human activity should be well understood before being implemented.

In a new paper, an MIT team in the department of Civil and Environmental Engineering (CEE) investigates the impacts of large-scale cropland irrigation on rainfall patterns in the East African Sahel around the Gezira Irrigation Scheme, now considered one of the largest irrigation projects in the world. The researchers piloted their exploration by combining theoretical modeling analyses with observational evidence gathered over several decades since 1930 — an unprecedented approach in previous studies.

The CEE team studied 60 years' worth of data of rainfall, temperature, and river flow to empirically deduce the atmospheric impacts of irrigation development.

"Large-scale development of irrigation systems is a good example of human activity that has changed land cover and the environment significantly in many regions of the world,” says co-author Professor Elfatih Eltahir, associate department head of CEE. “In all development projects, we need to better understand the potential impacts of our actions on the environment before we mindlessly develop.”

According to the theory developed by the researchers based on their investigation, when a large area is irrigated, surface air temperature is cooled and surface pressure increased. This reaction was conjectured to reduce rainfall over the irrigated land while generating a clockwise circulation that interacts with the prevailing regional wind. Depending on that interaction, the theory predicts that specific areas of convergence would be created, which would boost the rainfall in some of the surrounding areas.

After the researchers concluded their deep analysis of regional climate data, they concurred that large-scale irrigation development in the East African Sahel has consistently enhanced rainfall in areas to the east of the irrigated lands, while reducing rainfall directly over them.

Spatially and over time, the changes in rainfall and temperature matched up in a way that exceeded the group’s expectations and almost perfectly aligned with the original theory, says co-first author of the paper and CEE postdoc Ross Alter.

"You don’t often achieve that type of clear-cut match when attributing regional climate change from both theory and observations,” Alter says.

The team’s findings, says Eltahir, are indicative of the need for further consideration of potential agricultural, hydrological, and economic repercussions from irrigation expansion.

The paper was published today in the journal Nature Geoscience, by Alter, co-first author Eun-Soon Im of the Singapore-MIT Alliance for Research and Technology (SMART), and Eltahir.
 
Quantifying impacts

To define a climate, one must consider a breadth of at least 30 years' worth of data. Therefore, the team studied records gathered from 1930 to 1999, with a 10-year gap for irrigation system erection, in order to quantify the environmental impacts of irrigation.

The study’s first step was to employ a complementary analysis of numerical simulations and modeling. Using a sophisticated regional climate model — developed in the Eltahir group over the past 25 years, and which represents conditions in the atmosphere as well as over land — the authors conducted simulations using both irrigated and non-irrigated settings.

Their objective, in this regard, was to enumerate the effects of the irrigated land in the Gezira Scheme on the rainfall in a theoretical sense. The researchers then verified their conjectures by comparing with real occurrences observed throughout the 60-year span of time.

When the research team cross-compared their simulations to the collected empirical evidence, the mapped depictions of the changes in rainfall from pre- to post-irrigation expansion revealed strong decreases over the Gezira Scheme and distinct increases in eastern lands. The effects of enhanced rainfall are particularly apparent in Gedaref — a region east of Gezira. For the past half-century, concurrent with the irrigation expansion in the Gezira Scheme, Gedaref has received plenty of rainfall and has emerged as a successful rain-fed agricultural region.

This climate behavior is a stark contrast to the ongoing drought experienced by the majority of the African Sahel.

To pinpoint the impacts of irrigation on climate, it is important to identify areas of relative change, not absolute change,” Alter explains. “Because rainfall in that region strongly decreased overall, any larger changes in rainfall — even zero change between the two periods in question — would still be seen as increases.” Stable rainfall, in this case, is still better in comparison to the lands experiencing droughts.

Optimizing efficiency

Though the researchers acknowledge irrigation as an ideal solution to agricultural challenges, all agree that comprehension of human-made land-cover change and its influence on the natural environment is necessary for sustainable development.

“The knowledge gained from this study provides a more fundamental understanding of the impacts of land use and land cover changes on the atmosphere,” Alter says.

The researchers specify that their study does not take into account other possible processes than irrigation development that disturb the climate such as changes in the chemical composition of the atmosphere and the resulting global climate change.

Now with an established spectrum of probable impacts from significant irrigation development, the researchers suggest that this new knowledge about the impacts of land cover change on the climate system should help in achieving more rigorous attribution of the regional and local impacts of global climate change.

“While there are many studies that show landscape has such effects, the use of real-world observed data makes this a particularly important research contribution,” says Roger Pielke Sr., a senior research scientist of the University of Colorado not involved in this study. “Irrigated landscapes worldwide, indeed all human modified landscapes, based on the Alter et al. study, should be expected to play a major role in local and regional weather and climate. This human effect on the climate system has been underestimated in past assessments of climate change. The Alter et al. paper is a very significant contribution in expanding our understanding of the human role on the climate system."

“There is undoubtedly a pressing need for large-scale irrigation in Africa and other regions,” Eltahir says. “We now have a foundation of the likely impacts of human-induced land-cover changes, and can use this new knowledge in the design stage of irrigation systems as opposed to after the fact.”

Funding for this research was provided by the Cooperative Agreement between the Masdar Institute and MIT, and by the Singapore-MIT Alliance for Research and Technology.

Jennifer Chu | MIT News Office

"Grey swan" cyclones — extremely rare tropical storms that are impossible to anticipate from the historical record alone — will become more frequent in the next century for parts of Florida, Australia, and cities along the Persian Gulf, according to a study published today in the journal Nature Climate Change.

In contrast with events known as “black swans” — wholly unprecedented and unexpected occurrences, such as the 9/11 attacks and the 2008 financial collapse — grey swans may be anticipated by combining physical knowledge with historical data.

In the case of extreme tropical cyclones, grey swans are storms that can whip up devastating storm surges, beyond what can be foreseen from the weather record alone — but which may be anticipated using global simulations, along with historical data.

In the current paper, authors Kerry Emanuel, the Cecil and Ida Green Professor in Earth and Planetary Sciences at MIT, and Ning Lin of Princeton University simulated the risk of grey swan cyclones, and their resulting storm surges, for three vulnerable coastal regions. They found a risk of such storms for regions such as Dubai, United Arab Emirates, where tropical storms have never been recorded. In Tampa, Florida, and Cairns, Australia — places that experience fairly frequent storms — storms of unprecedented magnitude will be more likely in the next century.

“These are all locations where either no one’s anticipated a hurricane at all, such as in the Persian Gulf, or they’re simply not aware of the magnitude of disaster that could occur,” Emanuel says.  

Beyond forecasts

To date, the world has yet to see a black swan or grey swan cyclone: Every hurricane that has ever occurred in recorded history could, in retrospect, have been predicted, given the previous pattern of storm activity.

“In the realm of storms, I can’t really think of an example in the last five or six decades that anybody could call a black swan,” Emanuel says. “For example, Hurricane Katrina was anticipated on the timescale of many years. Everybody knew New Orleans was going to get hammered. Katrina was not meteorologically unusual at all.”

However, as global warming is expected to significantly alter the Earth’s atmosphere and oceans in the coming decades, the track and magnitude of hurricanes may skew widely from historical patterns.

To get a sense of the frequency of grey swan cyclones in the next century, Emanuel and Lin employed a technique that Emanuel’s team developed 10 years ago, in which they embed a detailed hurricane model into a global climate model.

For this paper, the team embedded the hurricane model into six separate climate models, each of which is based on environmental data from the past, or projections for the future. For each simulation, they generated, or “seeded,” thousands of randomly distributed nascent storms, and observed which storms produced unprecedented storm surges, given environmental factors such as temperature and location.

From their simulations, the researchers observed that storm surges from grey swan cyclones could reach as high as 6 meters, 5.7 meters, and 4 meters in Tampa, Cairns, and Dubai, respectively in the current climate. By the end of the century, surges of 11 meters and 7 meters could strike Tampa and Dubai, respectively.

Changing risk

To put this in perspective, the last big hurricane to hit Tampa, in 1921, produced a devastating storm surge that measured 3 meters, or about 9 feet high.

“A storm surge of 5 meters is about 17 feet, which would put most of Tampa underwater, even before the sea level rises there,” Emanuel says. “Tampa needs to have a good evacuation plan, and I don’t know if they’re really that aware of the risks they actually face.”

Emanuel says that Dubai, and the rest of the Persian Gulf, has never experienced a hurricane in recorded history. Therefore, any hurricane, of any magnitude, would be an unprecedented event.

“Dubai is a city that’s undergone a really rapid expansion in recent years, and people who have been building it up have been completely unaware that that city might someday have a severe hurricane,” Emanuel says. “Now they may want to think about elevating buildings or houses, or building a seawall to somehow protect them, just in case.”

Upper limit shift

The team also found that as storms grow more powerful in the coming century, with climate change, the most extreme storms will become more frequent.

The team’s results show that the expected frequency for a grey swan cyclone with a 6-meter storm surge in Tampa would fall from 10,000 years today to as little as 700 years by the end of the century. Put another way, today Tampa has a one in 10,000 chance of being struck by a devastating grey swan cyclone in any given year — odds that will remain the same next week, or next year.  

“Hurricanes, unlike earthquakes, are like a roll of the die,” Emanuel says. “Just because you had a big hurricane last year doesn’t make it more or less likely that you’d have a big hurricane next year.”

But in 100 years, Tampa’s odds of a 6-meter storm surge will be 14 times higher, as the world’s climate shifts.

“What that really translates to is, you’re going to see an increased frequency of the most extreme events,” Emanuel says. “Whereas the upper limit of hurricane wind speeds today might be 200 mph, 100 years from now it might be 220 mph. That means you’re going to start seeing hurricanes that you’ve never seen before.”

The group’s estimates of extreme storm intensity, while high, are not unrealistic for the coming century, says Greg Holland, senior scientist at the National Center for Atmospheric Research.

“This is an excellent example of the type of study needed to fill out our knowledge of what is possible with damaging events such as storm surge,” says Holland, who was not involved in the study. “Although the events listed are … rare, a knowledge of their possibility helps considerably with assessing more likely events in planning.”

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