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Alli Gold Roberts
MIT Joint Program on the Science and Policy of Global Change

Black carbon is one of the most potent air pollutants that contributes to global climate change, and is produced by the incomplete combustion of fossil fuels and forest fires. While scientists have known about the role of black carbon for decades, there’s been limited research to calculate global emissions. Now, MIT and National University of Singapore (NUS) researchers have developed a new method to calculate global black carbon emissions.

In a study published in last week’s Journal of Geophysical Research, the researchers calculated the global total of black carbon emissions at 17 teragrams a year between 2000 and 2005.  This result is significantly larger than the majority of global air pollution modeling studies, which employ a bottom-up approach. One such study found humans emitted only 7.5 teragrams of black carbon per year during the same five-year period—less than half the new estimate.

“Our results are the first to produce a global top-down estimation of the emissions of black carbon,” says Chien Wang, a senior research scientist with the Joint Program on the Science and Policy of Global Change and co-author of the study.

The top-down method used by Wang and his co-author Dr. Jason Cohen of NUS relies on gathering data from air measurement stations and satellites to sufficiently cover every region of the globe. In this study, data was collected from 238 different stations. They then compiled this data and used inverse modeling to determine the emissions from each of the major pollution regions.

“Current emissions inventories are mainly obtained by adding up estimates of emissions from ever sector of the economy and the environment to obtain a global estimate. This method creates uncertainty in the projections,” says Wang. “Our method eliminates some of these uncertainties by more accurately factoring in population and economic changes around the globe.”

The differences in the emissions estimates are most apparent in China and Southeast Asia. Wang predicts this is the result of the bottom-up method not capturing the rapid socioeconomic growth that has occurred in this region over the past 15 years.

Black carbon enters the atmosphere as small particles and warms the planet by absorbing heat and reducing the ability of the Earth to reflect light back out to space.

Because black carbon plays a key role in air pollution and global climate change, it is essential for policymakers to have an accurate picture of the severity of the problem.

“This top-down method isn’t perfect and still creates some unknowns in the estimates produced,” Wang says, but he suggests that combining both approaches would potentially improve estimates and further eliminate uncertainty. “We hope this work will open the door to further efforts to better quantify and reduce uncertainty in black carbon emissions estimates.”

More: Reprint 2014-1

The Global Young Academy (GYA) is an international group of two hundred young (up to ten years post PhD) scientists selected based on research excellence and commitment to impact. Through GYA, members are linked to the senior international academy network IAP, meet outstanding leaders of the international science community and may be nominated to contribute to international policy statements and working groups. Appointments are for a period of four years.

Selin's research focuses on using atmospheric chemistry modeling to inform decision-­â€making strategies on air pollution, climate change and toxic substances including mercury and persistent organic pollutants. She has also published articles and book chapters on the interactions between science and policy in international environmental negotiations, in particular focusing on global efforts to regulate hazardous chemicals and persistent organic pollutants. 

Selin, who will be formally appointed at a GYA symposium on May 21st, says she is very much looking forward to leveraging her new appointment to expand the reach of her science-policy work and educational initiatives.

By Michael Craig, Amanda Giang, Colin Thackrayʉ۬

What’s the difference between climate change, the Northern spotted owl, and acid rain?

That question is not the beginning of a bad joke. Rather, it was the type of question that lay at the heart of the class ‘Science, Politics, and Environmental Policy’ offered this past fall at the Massachusetts Institute of Technology. For the first time, the class was co-taught by Professors Susan Solomon of Earth, Atmospheric and Planetary Sciences and Judy Layzer of Urban Studies and Planning – an interdisciplinary team that drew students from diverse backgrounds across MIT’s schools and departments. Through weekly case studies, the class aimed to better understand how the United States has dealt with environmental problems and the multifaceted role of science in that process.

Each week, students focused on a different environmental issue, ranging from historical examples like the use of lead in gasoline, to currently unfolding debates, like the environmental impacts of unconventional shale gas production. Through reading, writing, and discussion, students explored how and why these issues entered the policy agenda (or didn’t), evolving policy responses, and how science fit into the picture. While fast and hard conclusions were elusive, as the class drew to a close students reflected on several themes that emerged over the course of the semester: the complexity of the policy-making process, the convoluted path that science takes from its origin to its use in policy, and the importance of storytelling for communicating science effectively.

Opening the black box of policy-making

Many of us initially saw the policy process as a black box – we could see the inputs (mainly science) and outputs (environmental policy), but did not fully grasp how one led to the other. Over the course of the semester, we came to a far better understanding of what levers exist to influence the policy-making process.

Some of those levers are litigation, direct involvement in the political process, and communication to the public. Each can influence the conversion of inputs to outputs, but vary in effectiveness under different circumstances. In part, such circumstances emerge from existing economic and political institutions, which can constrain policymaking and create path dependency. Recognizing these realities through case studies demonstrated the importance of looking at policy issues from different angles and thinking carefully about the best strategy for effecting change.

The path from science to policy

As we peeled the lid off the black box of policymaking, we also began to recognize how convoluted the path science travels from generation to use in policymaking can be. Science does not pass directly from academics to policymakers, but rather is filtered and translated by many individuals. These individuals – and even scientists themselves – have differing values, biases, and goals that can lead them to different interpretations of, and conclusions from, science. What role, if any, should scientists play along science’s path from lab to policy? Do scientists who act as advocates harm the credibility of science as a whole, and if so, does this harm outweigh the potential benefits? For scientists who act as the ‘experts’ that communicate the scientific basis of environmental issues to non-scientists, how do their biases and values shape their actions and their interpretation of science? If science is being filtered and reinterpreted, how can we ensure the veracity of information we receive that is purportedly "based on science”?

Stories matter

Over the course of the semester, the importance of storytelling also emerged as a major theme. In many of the cases we studied, public engagement was a key driver for policy action, so effectively communicating with and reaching the public is crucial. Doing so requires the ability to tell a clear story – to communicate information (scientific or otherwise) clearly, concisely, and in a way that is relevant to the audience. Focusing on what you know can help in putting forth a clear narrative, and while uncertainties are important to convey, they do not need to be the focus of communication.

There is no easy formula for developing strong environmental policies, nor are there simple rules for how science should be involved. That said, 'Science, Politics, and Environmental Policy' helped us develop a more nuanced understanding of the complex policy-making process, and gave us tools to engage in it strategically, and with self-awareness. Rarely is there an opportunity to discuss the many-layered environmental policy system with students with such diverse expertise. The confluence of ideas and points of view from the varied backgrounds of both the students and professors resulted in a unique learning experience for this collection of young environmental scholars.

Colin Thackray is a graduate student in MIT's Department of Earth, Atmospheric and Planetary Sciences working with Noelle Selin. Amanda Giang and Michael Craig are graduate students in MIT's Engineering Systems Division.

Sergey Paltsev, assistant director for economic research at the MIT Joint Program on the Science and Policy of Global Change, presented at the 2014 Gaidar Forum entitled "Russia and the World: Sustainable Development."

The expert discussion “Green growth” and sustainable development” was dedicated to such topics as energy efficiency and renewable energy as the drivers of economic growthas economic growth drivers. Besides it focused on the perspectives of “the third industrial revolution”, which is not a new idea, however it opens the prospects for efficient energy use.

Oleg Lugovoy, Research Advisor, Center for Economic Modeling of Energy and Environment, RANEPA, Jeffrey Sachs, Director of the Earth Institute and Professor of Columbia University, Hillard Huntington, Executive Director of Energy Modeling Forum, Stanford University, Emmanuel Guérin, Associate Director of Sustainable Development Solutions Network (SDSN), Frederic Vidal, President of Université de Nice Sophia-Antipolis, Sergey Paltsev, Assistant Director for Economic Research of MIT Joint Program on the Science and Policy of Global Change of the Massachusetts Institute of Technology, John Laitner, Resource Economist and Independent Consultant of Economic and Human Dimensions Research Associates and Glen Peters, Senior Research Fellow of the Center for International Climate and Environmental Research of Norway, took part in the discussion.

In his opening remarks, the moderator Oleg Lugovoy defined the vector of the discussion: “It’s a discussion on how to achieve high growth rates and improve life quality without causing harm to the environment.” He also noted that the problem could not be solved by the efforts of business and public organizations alone, but depends on economic regulation.

John Laitner turned the participants’ attention to the task of increasing the quality of energy efficiency giving USA as an example, where 86% of all energy is spent to no purpose. Inefficient use of energy leads to huge costs and is a factor limiting, in Russia as well, the potential for economic development. The expert underlined that the idea of the third industrial revolution which consists of combination of interactive communications and new green technologies is getting more important.

Jeffrey Sachs reminded the participants of the discussion about the idea of a prominent Russian economist Nikolai Kondratyev on periodic economic cycles (waves) linking it to the concept of a shift in technological modes. Each of them had limited resources, but never before has the scale of economic activity been so impressive and the number of population so huge (7.2 billion people). “90 trillion dollars – this is the volume of the annual economic output,” Jeffrey Sachs noted, “and this figure tends to grow progressively. So do the CO2 emissions as well. Already today 38 billion tons of СО2 are annually emitted into the Earth’s atmosphere,” the expert noted.

However, changing the energy system profoundly and substantially over 40-50 years is quite a challenge. One of the possible solutions is to switch to alternative types of fuel or renewable energy sources. Nuclear energy, if it is safe, also has a high potential. But the most important thing, according to the expert, is to reduce coal consumption, in particular, “convince China, the country which consumes this fuel in huge volumes, to do so.”

The report by Hillard Huntington marked a turn in the discussion to the subject of shale gas. The expert noted numerous uncertainties pertaining to shale gas extraction. It is still difficult to evaluate the outlook for price policy in this field unambiguously, which is caused not only by the way it is extracted, but also the volumes of gas supply.

Sergey Paltsev agreed with his colleague. He immediately dotted the i’s noting the “platitude” of shale gas: “It does not differ from the common methane, the difference lies in the method of extraction which consists in subsurface fracture.” Answering the question “whether Gazprom has overslept shale gas revolution or not”, the expert agreed with the estimation given by the Prime Minister of the Russian Federation Dmitry Medvedev who said that “this question is quite complicated.” “Gazprom has enough gas and it can go without shale gas, given proper investment and price policy,” Mr. Paltsev summarized. He also noted that the consequences of fraction are difficult to predict. Besides, the use of huge amount of water during extraction makes its benefits ambiguous, at the same time CO2 emissions from the use of natural gas are far from zero, therefore it is impossible to say that its production can address the problem of emissions globally.

In many public discussions of climate change, science takes a back seat to political agendas and rhetoric. But 12.340x (Global Warming Science), a new massive open online course from MITx now open for enrollment on the edX platform, aims to change that dynamic by providing a solid scientific view of what is really happening with global warming.

“We are trying to bring back some of the intellectual excitement that belongs to the field,” says Professor Kerry Emanuel, a co-teacher of the course whose research focuses on hurricanes. “This is a serious science course.”

The MITx course will use many of the lecture materials developed for the on-campus version of the course, along with new videos and visuals. The course will also include new exercises, problem sets, and a final exam, all tailored to the assessment tools available on the edX platform and developed with an eye on preserving the rigor of the course. “You have to have a background in mathematics up through differential equations, and a background in physics,” says Emanuel, the Cecil and Ida Green Professor of Atmospheric Science. “Our intent is that it will be as challenging as the classroom course.”

12.340x will also bring simulations used in the MIT residential course to a wider audience, including the single-column model simulation. Emanuel describes this unique tool as “a computer climate model that takes inputs such as solar radiation and atmospheric greenhouse gas content and calculates the temperatures of the surface and atmosphere, and the moisture and cloud distributions in the atmosphere. Students can change the intensity of sunlight, the time of year, the greenhouse gas concentrations, and other inputs to see how they affect climate change.”

Emanuel expects a wide range of people to take 12.340x. “You’re going to find a lot of students in climate and energy. They will want to know the physics, chemistry, and biology (of climate change).” He also expects professionals working in energy and public policy to be interested in the course. Even a politician has expressed interest in 12.340x, but Emanuel is keeping the individual’s name confidential.

Emanuel and the Department of Earth, Atmospheric and Planetary Sciences also hope to change the dynamic around the study of climate change on the MIT campus. In part because the course is not a requirement, and in part because of the perception among students that climate-change study is mostly about politics and not hard science, the on-campus course has not seen the enrollment levels Emanuel would like to see. “Part of the problem is all the publicity of global warming has sent out a message that global warming is highly politicized, and has nothing to do with science,” he says. “Nothing could be further from the truth.”

Channel News Asia interviews Michael Davidson on the Business Central show. Michael Davidson is Research Assistant for the China Energy and Climate Project and a doctoral student in the Engineering Systems Division.

Alli Gold Roberts
MIT Joint Program on the Science and Policy of Global Change

Population growth and increasing social pressures on global water resources have required communities around the globe to focus on the future of water availability. Global climate change is expected to further exacerbate the demands on water-stressed regions. In an effort to assess future water demands and the impacts of climate change, MIT researchers have used a new modeling tool to calculate the ability of global water resources to meet water needs through 2050.

The researchers expect 5 billion (52 percent) of the world’s projected 9.7 billion people to live in water-stressed areas by 2050.  They also expect about 1 billion more people to be living in areas where water demand exceeds surface-water supply. A large portion of these regions already face water stress—most notably India, Northern Africa and the Middle East.

The study applies the MIT Integrated Global System Model Water Resource System (IGSM-WRS), a modeling tool with the ability to assess both changing climate and socioeconomics—allowing the researchers to isolate these two influencers. In studying the socioeconomic changes, they find population and economic growth are responsible for most of the increased water stress. Such changes will lead to an additional 1.8 billion people globally living in water-stressed regions.

“Our research highlights the substantial influence of socioeconomic growth on global water resources, potentially worsened by climate change,” says Adam Schlosser, the assistant director of science research at the Joint Program on Global Change and lead author of the study. “Developing nations are expected to face the brunt of these rising water demands, with 80 percent of this additional 1.8 billion living in developing countries.”

Looking at the influence of climate change alone, the researchers find a different result. Climate change will have a greater impact on water resources in developed countries.  This is because, for instance, changes in precipitation patterns would limit water supplies needed for irrigation.

When researchers combine the climate and socioeconomic scenarios, a more complicated picture of future water resources emerges. For example, in India, researchers expect to see significant increases in precipitation, contributing to improved water supplies. However, India’s projected population growth and economic development will cause water demands to outstrip surface-water supply.

“There is a growing need for modeling and analysis like this, which takes a comprehensive approach by studying the influence of both climatic and socioeconomic changes and their effects on both supply and demand projections,” says Schlosser. “Our results underscore this need.”

The MIT team plans to continue this work by focusing on specific regions and conducting more detailed analysis of future climate changes and risks to water systems. They plan to refine and add to the model as they research other regions of the globe.
 

By Laura Barron-Lopez

Global warming may be contributing to the "polar vortex" causing frigid temperatures across most of the nation on Monday, according to some climate change researchers.

While it seems counter-intuitive, the research argues that plunging temperatures could come from changes in the jet stream caused by climate change.

Rutgers University climate scientist Jennifer A Francis has released a number of papers about changes in the jet stream brought about by warming Arctic temperatures.

Her conclusions suggest that warming Arctic air caused by greenhouse gas emissions has caused changing to the jet stream that is pushing colder Arctic air further south, causing temperatures to plunge from the High Plains to the Deep South.

The jet stream shift has sent frigid air across the central part of the country, and deeper into the south than normal.

Alaska, meanwhile, is being hit by unusually warm conditions and California is facing record-breaking drought, Francis said.

She said the strange weather is becoming more likely because of climate change.

"We can't say that these are extremes are because of climate change but we can say that this kind of pattern is becoming more likely because of climate change," Francis said.

NASA analysis has also drawn a link between the jet stream, climate change and colder temperatures.

A 2010 NASA analysis tied colder temperatures over the course of 2009 to an event similar to the wavy jet stream, called "Arctic oscillation" — a see-sawing pressure system over the North Pole. That oscillation pushed cold air to teh south.

The NASA analysis also said that despite cold snaps, and other weather changes being a part of naturally occurring patterns, they are still in line with a "globally warming world."

According to Francis, big fluctuations in the jet stream cause extreme weather conditions to hang around longer.

She argues greenhouse gas emissions are a key factor.

"The process of warming the Arctic is intensified due to greenhouse gas emissions," Francis said. "The Arctic is warming two to three times faster than the rest of the Northern Hemisphere."

MIT atmospheric scientist Kerry Emanuel said long-term climate change can only be seen by looking at detailed statistics.

“It's certainly plausible, at lease for awhile that a changing jet stream, may cause colder winters,” Emanuel said.

But he added that it is difficult to tie a direct link between individual events like the cold snap occurring in the Midwest and East Coast to global warming.

Emanuel added that that doesn't mean you can disregard global warming.

“If you cherry pick you can always find an excuse to go against [global warming,” Emanuel said.

Image Credit: Satellite Image Shows Entry of the Polar Vortex into the Northern U.S.

Alli Gold Roberts
MIT Joint Program on the Science and Policy of Global Change

Despite global treaties and national regulations limiting toxic chemicals known as persistent organic pollutants (POPs), many of these chemicals still remain in the environment for long periods of time and accumulate in our land, water and air. These chemicals reach remote regions of the globe, like the Arctic, through air currents and have dangerous effects on humans and animals. Warming of the atmosphere and changing patterns of wind and rain, due to climate change, can affect where and when these pollutants travel.  However, the impact of climate on POPs—how these patterns will change, and in what direction—is not well known.

In a new study published in Environmental Science and Technology, MIT researchers assess the impacts of both climate change and future emissions on a group of POPs called polycyclic aromatic hydrocarbons (PAHs)—toxic byproducts of burning wood, coal and oil. They are the first to address the influence of climate change on the transport of PAHs. 

They find that decreases in human emissions are expected to cause PAH concentrations to decline by up to 37 percent by 2050. But, climate change can either reduce or enhance that decline depending on the physical and chemical properties of different PAHs. 

“We are interested in PAHs because they continue to be released into the atmosphere and their concentrations have been increasing in Arctic marine life, in contrast to most other POPs,” says Carey Friedman, a postdoctoral associate with the MIT Joint Program on the Science and Policy of Global Change and the lead author of the study. “We find that projected decreases in human emissions will have a stronger impact on atmospheric PAH levels in the future than changes in climate.”

However, the authors find that this statement has important caveats. As temperatures rise, due to climate change, more volatile PAHs that are currently deposited in soil and vegetation are expected be emitted—actually re-emitted—into the atmosphere.

“This represents a ‘climate penalty’ for atmospheric concentrations of more volatile PAHs, meaning that emissions reductions will not be as effective as they would have been if the climate wasn’t changing,” explains Noelle Selin, co-author of the study and an assistant professor of engineering systems and atmospheric chemistry.

In contrast, atmospheric levels of non-volatile PAHs are expected to decrease under 2050 climate conditions because their ability to be deposited into the soil and land will be enhanced.

“Our results suggest that ratios of the different types of PAHs (volatile to non-volatile) in the Arctic can be used to diagnose whether the atmosphere is experiencing greater influence from climate change or reductions in human emissions,” says Friedman. 

This raises the possibility that such a technique could be used to measure the effectiveness of emissions reduction activities in the context of ongoing climate change.

The study is part a series of NSF-funded research tracking how chemicals travel to remote Arctic environments and how they can be better managed. Researchers have presented the results of these studies to help inform policymakers on the most effective methods of addressing POPs like PAHs, which are affecting humans and the environment.

Read about the team’s earlier research results: http://globalchange.mit.edu/research/publications/search