News + Media

 By: Vicki Ekstrom, Joint Program on the Science and Policy of Global Change

EPA's top air official, Gina McCarthy, leads roundtable discussion.

Looking to tap the knowledge of some of the nation's leading energy and environment experts, and update them on new and proposed standards, the U.S. Environmental Protection Agency's top air official visited MIT's campus last Friday, Jan. 27. Gina McCarthy, EPA's assistant administrator for the Office of Air and Radiation who led a roundtable discussion which was hosted by MIT's Joint Program on the Science and Policy of Global Change and moderated by the program's co-director, John Reilly.

A return home for the Massachusetts native who spent more than 25 years working on environmental issues in the state, McCarthy said she saw the meeting as an opportunity to "learn from the experts who have been so valuable in providing the research and the science" her office needs to be successful.

Robust science, and clear cost-benefits associated with that science, is critical, McCarthy said — a lesson roundtable participant and environmental economics Professor Michael Greenstone helped her realize when he was the chief economist for President Obama's Council of Economic Advisers during the first year of the administration.

"I think the agency has tremendously benefitted from that, specifically the air program because we are under constant scrutiny," McCarthy said. "Everything these people know intersects very directly with the work I've been doing for the president."

The visit came just days after President Obama's State of the Union address, where he laid out his intention to take an "all-of-the-above" approach toward America's energy future.

"In this administration we are looking for everything from commitments to renewables, that would be wind and solar, but also recognizing that coal will have a place in the mix," McCarthy said of the president's vision. "We're asking ourselves from the EPA side what that means for our upcoming rules on greenhouse gases and source performance standards for powerplants. How do you write it in a way that's consistent with the rules and still allows a place for new coal and new technologies?"

Leadership on mercury
 

Joint Program on Global Change
Co-Director John Reilly

Noelle Selin, who participated in the discussion, was also excited to hear the president mention mercury.

"I do think that the Mercury and Air Toxics Standards are something we've been waiting for, for a long time, and they are a really forward-looking rule," Selin said.

She noted that Massachusetts has lead the way in controlling mercury, perhaps due to McCarthy's earlier leadership, and that the state will especially gain from the national rule because it is upwind of polluting coal-mining states to its south.

• See "MIT researcher: U.S. taking leadership on mercury in the environment" to learn more about Selin's view of the mercury standards.

Mentioning the global negotiations on mercury — scheduled to wrap up in January 2013, after the next presidential election — Selin asked what role the new standards might play in the global arena as China's mercury emissions continue to grow and endanger the gains made by the new rule.

"We were hoping that if we put out the powerplant rule [mercury standards] that would bolster our role in the discussion," McCarthy said. "It was one of the issues we considered when we were going through the process of forming the rule. We had to do our part … we had to have a legitimate position in the international discussion." 

Tapping the value of natural gas

McCarthy acknowledged that the mercury standards come while the cost of natural gas is low, which she said is "changing the energy world" and making some coal-fired powerplants "ineffective, inefficient and not competitive."

MIT Energy Initiative Director Ernest Moniz agreed: "I think we all agree that the mercury rules are absolutely critical in terms of displacing some coal, in addition to the economics of coal and gas with natural gas prices below $3 per million Btu."

But Christopher Knittel, an energy economics professor at the MIT Sloan School of Management, pointed out that natural gas deposits can be viewed as a huge opportunity — but also, a huge risk.

One of the challenges with natural gas is that the extraction process — a process called hydraulic fracturing — emits Volatile Organic Compounds (VOCs), such as methane, which cause smog and are associated with some health effects such as cancer. Methane is also a greenhouse gas that contributes to climate change.

Richard Schmalensee, director of the Center for Energy and Environmental Policy Research, addressed another challenge: the role that states play.

"The state's roles are problematic because you've got all this gas in places that have never had experience with anything like it," Schmalensee said.

McCarthy said there is a need for standard best practices within the industry — a topic the president addressed in his speech, as he challenged natural gas companies not to follow in the footsteps of the oil industry in terms of polluting now and worrying about it later.

"The good news about that is when you capture the VOCs you capture the methane. When you capture methane you sell it," McCarthy said. "So the cost-effectiveness of those strategies is quite good."

The EPA is close to finalizing a rule in April 2012 that would reduce VOCs from the oil and natural gas industry.

Meeting the Climate Challenge

The inclusion of climate change was another exciting point for McCarthy in the president's address.

But Susan Solomon, a professor of atmospheric chemistry who recently joined MIT from the National Oceanic and Atmospheric Administration (NOAA), said she thought the president missed an opportunity to expand on that point.

"This issue of climate change isn't one that's going to be solved by everyone pitching in. It's not like recycling where if we can all do our part we'll be better off," Solomon said. "It really does require new technologies and investments. So the most important thing that a citizen can do is to engage in a discussion about that and I think he missed an opportunity to call for engagement, including by Republicans."

McCarthy said one of the challenges of the present situation is that nobody wants to invest in anything that doesn't offer an immediate payback. The innovative new technologies needed to actually make a difference in the climate challenge are years, perhaps decades, away and require significant investments.

"And I think it's the government's job to look way beyond the immediate payback by establishing priorities for research and innovation," McCarthy said.

EPA's new greenhouse gas reporting data is one sign of progress that McCarthy believes has helped advance the climate change conversation.

"I actually think that has spurred tremendous amounts of opportunity for climate change to get back into a reasonable, rational discussion," McCarthy said. "I'm excited that the president is talking about that — as well as clean energy. Not replacing one for the other. Because it is a challenge we need to meet head on."

 

 

 

By: Vicki Ekstrom, Joint Program on the Science and Policy of Global Change

SOURCE: EPA

Americans have long known the dangers of mercury in our environment, with doctors repeatedly warning pregnant women to remove fish from their daily diets. But despite this solid knowledge of the health impacts, the United States has never regulated mercury emissions from powerplants — our nation’s number one source of mercury — until now.

Last month, the Environmental Protection Agency (EPA) issued Mercury and Air Toxics Standards. The standards require coal-fired powerplants to install scrubbing technology that will cut 90 percent of their mercury emissions by 2015.

To better inform local residents about the new protections, Noelle Eckley Selin — an assistant professor in MIT's Engineering Systems Division and Department of Earth, Atmospheric and Planetary Sciences and a researcher in MIT’s Joint Program on Global Change — this week joined EPA Regional Administrator Curt Spalding and other public health experts at a public availability session at the East Boston Neighborhood Health Center.

“These mercury standards help prevent the developmental delays and neurological damages that could come from eating contaminated fish,” Selin said at the Thursday event.

At MIT, Selin looks at the pathways by which mercury reaches the environment and the effect it has on human health once it gets there. She also analyzes the steps regulators could take — and in some cases have taken — to prevent further contamination.

“There’ve been proposals for a long time to regulate these emissions from coal-fired powerplants,” Selin said in an interview with the Los Angeles Times when the rules were first released on Dec. 21, 2011. “The earlier incarnation of this was the Clean Air Mercury Rule, which was a cap-and-trade proposal for mercury, and that was challenged in the courts and then thrown out. And now this is another try at regulating, but it’s been a long time in coming.”

Massachusetts began controlling mercury in the 1990s. Since then, the state has reduced mercury emissions by 91 percent, according to Massachusetts Department of Environmental Protection Commissioner Kenneth Kimmell.

“It has been a major source of frustration for us that even though we’ve reduced our mercury rates by so much, many of our water bodies are still off limits to fishing because of pollution from upwind states,” Kimmell said at the Thursday event.

Selin, 2009 Annual Review

Massachusetts’s experience shows that tough standards can have a substantial effect on the environment, Selin said. But federal regulations such as the Mercury and Air Toxics Standards are necessary because of the pollution that comes from powerplants in coal mining and producing states.

Health benefits

Rachel Murphy of Cambridge has a 6-year-old daughter with severe asthma. Her daughter’s asthma is so bad that at times she coughs hard enough to burst blood vessels in her eyes.

“Rachel can get the best medicine possible, but she can’t control the air her daughter breathes,” New England’s American Lung Association President Jeffrey Seyler said at the event.

The air toxics standards are expected to help tens of thousands of children such as Murphy’s daughter by preventing 30,000 cases of childhood asthma symptoms and about 6,300 fewer cases of acute bronchitis among children each year, according to EPA estimates.

Vulnerable populations such as infants will also be helped specifically because of the mercury standards under the new rule.

“These will especially protect newborns who are at a greater risk during their development,” Selin said. “It’s estimated more than 300,000 newborns in the U.S. are exposed in utero to dangerous levels of mercury. This can cause lower IQ and neurological damages.”

Dr. Alan Woolf, the director of the Pediatric Environmental Health Center at Children's Hospital in Boston, agrees.

“Mercury is associated with long-lasting and potentially irreversible effects on the brain and nervous system,” Woolf said at the event. “These effects can reduce a child’s intelligence, can change their behavior, and can cause seizures, muscle weakness, paralyses and other neurologic injuries limiting their future as productive citizens.”

International implications

The United States’s leadership in regulating mercury comes at an important time, as countries around the world have been negotiating a global, legally binding mercury treaty since June 2010.

The third of five planned United Nations negotiating sessions occurred in November in Nairobi, Kenya, and Selin plans to attend the fourth in June in Uruguay. She will also be bringing six graduate students, as part of a National Science Foundation grant, to the final negotiating session set to take place in early 2013.

SOURCE: EPA

In an earlier interview with MIT News, Selin said domestic politics would likely continue to be a challenge for U.S. implementation of environmental regulations and international cooperation on mercury. But with these standards — now the most stringent mercury standards of its kind in the world — she says the country has proven their leadership.

“These standards show that the U.S. is taking leadership at home to address a widespread and substantial global problem.”

By: Leda Zimmerman, MIT Energy Initiative

As Assistant Professor of Engineering Systems at MIT, Jessika Trancik focuses her research on the evolution of technologies and on decomposing performance trajectories of energy systems. She is particularly interested in understanding the dynamics and limits of costs and carbon intensities of energy technologies, in order to inform climate change mitigation efforts. Photo: Justin Knight

In the fall of 2010, Leah Stokes walked into Energy Systems and Climate Change Mitigation (ESD.124) on the first day the graduate seminar was offered. “The class seemed perfect for me,” says the PhD student in environmental policy and planning in the Department of Urban Studies and Planning, “so I had to take it. I ended up loving it.” While no novice to the complex questions involved in transforming a carbon-centric world, Stokes, a 2010-2011 Siemens Energy Fellow, credits ESD.124 instructor Jessika Trancik, assistant professor of engineering systems, with “getting me thinking in a different way.”

Stokes and other students describe an ambitious class that encompasses the multidimensional challenges entailed in tackling climate change. “Professor Trancik frames the problem in terms of multiple impacts,” says first-year graduate student Morgan Edwards. “She shows how we can make choices in different areas to reduce emissions … She puts it all together as one picture.”

Trancik acknowledges this “distinctive feature” of ESD.124: “I combine a focus on technologies with a broader quantitative picture,” she says, which means “working across scales and at different levels of abstraction.” By semester’s end, Trancik says, students acquire “a comprehensive, integrated framework for comparing different energy supply technologies to one another, and the capacity to compare these energy technologies to climate change mitigation goals.”

Quantitative and analytical tools are central to ESD.124. Through lectures and problem sets, students learn statistical methods and models as they study such topics as carbon intensity, water scarcity, and the change in performance of technologies over time. Trancik situates these subjects in the context of larger questions: How energy systems now, and in the future, may contribute to climate change; and which technologies might best meet actual greenhouse gas targets. Trancik is also intent on giving students insight into research methodology, so she asks them to pore over journal articles with a critical eye, and present their findings to classroom peers.

“I’m a big proponent not just of reading articles but of understanding how researchers find their results, and questioning those results," Trancik says.

In their final projects, students deploy newly sharpened analytical and quantitative skills in original research. With Trancik’s assistance, students devise “discrete research questions” and select appropriate methods for seeking answers. Edwards focused on the lifetimes of bio-based jet fuel emissions versus those produced by conventional jet fuels, and explored how “the timing and composition of emissions is important in terms of meeting climate goals.” Stokes analyzed the carbon budget for a planet where temperatures are limited to an increase of 2° Celsius. “I had to determine the mix of energy systems to make that target,” Stokes says. With Trancik’s guidance, Stokes showed “step by step what was required to decarbonize the energy system,” and how to “grapple with uncertainty in forecasting” over a timescale of 60-plus years. Trancik says her students don’t “want solutions handed to them,” and sometimes produce work that leads to publishable articles. Other ESD.124 projects deepen into continued research (Edwards now works in Trancik’s lab).

Trancik, with her heterogeneous background in materials science, energy modeling, complex systems, and U.N. sustainable development practice, brings something unique to the classroom, say students. “Her approach ties technological understanding of innovation and systems to policy understanding of the scale of the problem,” Stokes says. “She is ultimately an engineer but quite adept in communicating to a policy audience. She empowers other people to bring what they know to the table, and can draw out their best qualities.” From Edwards’s perspective, Trancik “really motivates students to see where we are now, and what needs to be done to change the climate’s trajectory — that it is an ambitious and difficult thing we’re setting out on, but definitely possible.”

Trancik says that while she teaches “standard tools and concepts,” she also tries to “help students see new connections.” She looks forward to extending this approach to her new spring course, Mapping and Evaluating New Energy Technologies (ESD.125). Teaching at MIT, she says, is both “uplifting and a great privilege,” because of “students who can pose very challenging questions and who have the ability — and want — to solve difficult problems. I’m thankful for that every day.”

 

SOURCE: EPA

Dr. Noelle Eckley Selin, an Assistant Professor at the Massachusetts Institute of Technology (MIT) and a researcher in MIT’s Joint Program on Global Change, participated in a public availability session to discuss the Environmental Protection Agency’s recent Mercury and Air Toxics Standards. Noelle was joined by EPA’s Regional Administrator Curt Spalding, New England’s American Lung Association President Jeffrey Seyler, Commissioner of the Massachusetts Department of Environmental Protection Kenneth Kimmell and other public health experts. The event was held at the East Boston Neighborhood Health Center.

The Mercury and Air Toxics Standards – issued December 21, 2011 – are the nation’s first standards to protect American families from power plant emissions of mercury and toxic air pollution like arsenic. To learn more about the standards, click here.

The following are Dr. Selin’s remarks from the event:

Thank you for having me here today. I’m pleased to be here to talk about these historic standards.

I’m at MIT and I do research in atmospheric science. I look at the pathways by which mercury actually reaches the environment and what it does once it gets there. So I’ve spent much of my career studying the ways in which mercury reaches the environment where it then affects human health. I’ve tracked the path that mercury travels from power plants – which are our nation’s number one source of mercury – through the air, into our waterways and then eventually the fish we eat.  And I’ve also analyzed the steps we could take to prevent further contamination. These standards do represent a strong step towards that goal.

These mercury standards help prevent the developmental delays and neurological damages that could come from eating contaminated fish. This is in addition to the tens of thousands of cases of asthma and acute bronchitis that are avoided by controlling other air toxics other than mercury. Specifically on the mercury standards, these will especially protect newborns who are at a greater risk during their development. It’s estimated more than 300,000 newborns in the US are exposed in utero to dangerous levels of mercury. This can cause lower IQ and neurological damages.

Importantly, this standard will have a large impact right here in the Northeast, especially for people who eat fish caught in local waterways. And that’s because mercury released from U.S. power plants contaminates what’s nearby. This standard will especially benefit residents here in Massachusetts and the Northeast because we’re down wind of the emitting power plants in coal mining and producing states. You can see this from our map (below), which shows the fraction of mercury entering the environment that comes from domestic sources.  Here in the Northeast, most of the mercury that enters our waterways comes from the sources in the US that will be controlled by these standards.

Here in Massachusetts, efforts to cut mercury from local power plants have led to significant mercury declines in fish in recent years. This experience has shown that tough standards can have a substantial effect on the environment. But these reductions are not enough, and mercury levels in fish here are still too high. Much of the mercury in our local fish comes from sources outside the region, which is why federal regulations are needed.

In addition, countries around the world are currently negotiating a global treaty to limit mercury pollution because mercury is a problem worldwide. These standards show that the US is taking leadership at home to address a widespread and substantial global problem.

Percentage contribution from North American primary anthropogenic sources to total (wet plus dry) annual mercury deposition simulated by the GEOS-Chem global mercury model for 2004–2005. Reproduced from the Selin, Global Biogeochemical Cycling of Mercury: A Review, Annual Review of Environment and Resources, 34: 43-63, 2009, MIT Joint Program on the Science and Policy of Global Change Reprint Series.

By: Mason Inman, National Geographic News

SOURCE: AP

Shale gas has transformed the U.S. energy landscape in the past several years—but it may crowd out renewable energy and other ways of cutting greenhouse gas (GHG) emissions, a new study warns.

By Jennifer Chu, MIT News Office

SOURCE: NASA

If you’re planning to build that dream beach house along the East Coast of the United States, or would like to relocate to the Caribbean, a new study by economists and climate scientists suggests you may want to reconsider.

Researchers from MIT and Yale University have found that coastal regions of North America and the Caribbean, as well as East Asia, are most at risk for hurricane damage — a finding that may not surprise residents of such hurricane-prone communities. However, the researchers say by the year 2100, two factors could more than quadruple the economic damages caused by tropical storms in such regions and around the world: growing income and global warming.

In a paper published this week in Nature Climate Change, researchers developed a model to predict hurricanes around the world, looking at how hurricane activity might change in the next 100 years both with and without climate change.

Even in a world without climate change, where rates of greenhouse gas emissions remain stable, the researchers found that annual economic damages from hurricanes could double in the next century: Global population is expected to reach 9 billion by 2100, likely leading to more development along hurricane-prone coastlines. Given such growth, the researchers projected that worldwide annual damage from hurricanes — currently $26 billion — could increase to $56 billion in the next century.

Under a similar economic scenario, but with the added factor of climate change, the team found that annual hurricane damage could quadruple to $109 billion by 2100. According to the researchers’ model, proliferating greenhouse gases would likely increase the incidence of severe tropical cyclones and hurricanes, which would increase storm-related damage.

Furthermore, the researchers found that the distribution of damage is not even across the world. Their model indicates that climate change would cause the most hurricane-related damage in North America, followed by East Asia, Central America and the Caribbean. The rest of the world — particularly the Middle East, Europe and South America — would remain relatively unscathed, experiencing little to no hurricane activity.

Treading new territory

Kerry Emanuel, the Cecil and Ida Green Professor of Atmospheric Science at MIT, says results from the model developed by the team may have wide-ranging implications for regional planning and emergency preparedness.

“It could be used by lots of different people … to understand what resources to put into certain countries to mitigate or adapt to tropical cyclone changes resulting from climate change,” says Emanuel, a co-author of the paper. “For example, urban planners in cities might want to know how high to make the flood barriers if sea levels go up.”

Emanuel worked with researchers at Yale to develop the hurricane prediction model, an effort that combined two disparate disciplines: atmospheric modeling and economics. Emanuel describes the work as “treading new territory,” and the researchers had to “do a lot of back and forth to understand each other’s terminology.”

After sorting out semantics, the group set out to predict tropical cyclone and hurricane activity around the world. The researchers relied on four existing climate models commonly used by the Intergovernmental Panel on Climate Change to assess climate risks. Each of the models track and forecast certain climate variables such as wind, temperature, large-scale ocean currents and ocean temperatures. However, the models only track these variables at a relatively coarse resolution of 100 to 200 kilometers. Since a tropical cyclone that may whip into a massive hurricane under certain weather conditions requires resolutions of a few kilometers, using climate models to simulate storms is highly problematic.

Seeds of a cyclone

Instead, Emanuel and his colleagues embedded a tropical-cyclone model within each climate model. The combination allowed the team to see where storms may develop around the world, based on regional weather systems. The researchers randomly scattered hundreds of thousands of “seeds,” or potential tropical cyclones, throughout each of the four models, then ran the models to see where the seeds developed into significant storms. There was some variation between models, but in general, they revealed that 95 percent of storms simply dissipate, leaving 5 percent that were likely to turn into hurricanes under favorable conditions such as warm ocean water and high winds. They used enough seeds to generate 17,000 surviving storms in each simulation.

The team also looked at each country’s hurricane-related damage after adjusting for its gross domestic product (GDP). The researchers found that wealthier nations like the United States are able to absorb economic losses from a hurricane better than many others, such as island nations in the Caribbean.

“These are all small islands, and most of their GDPs are exposed,” Emanuel says. “In the United States , you take all this damage and divide it by the GDP of the whole country, and you get a smaller relative impact.”

Dan Osgood, a lead scientist in the financial instruments sector team for the Earth Institute at Columbia University, sees the new model as a useful tool, particularly for the insurance industry.

“Insurance companies [are] hungry for climate research such as this,” says Osgood, who was not involved in the research. “Having solid science, they can often offer more reasonable and more accurate prices, providing better deals to consumers, as well as accurate price incentives to help people [avoid] taking unreasonable building risks.”

The researchers stress that there was a fair amount of uncertainty in predictions made among the four climate models. For example, in estimating the effect of climate change on tropical-cyclone damage, the models’ predictions ranged from $14 billion to $80 billion a year.

Emanuel also points out that “looking at natural disasters strictly through an economic lens doesn’t tell you the whole story.” For example, despite a growing economy and population, if severe tropical cyclones become more frequent, people may choose to build elsewhere — a phenomenon Emanuel says an improved model will have to take into account.

Other authors on the paper are Robert Mendelsohn, Shun Chonabayashi and Laura Bakkensen from the Yale School of Forestry and Environmental Studies.

By: Vicki Ekstrom, Joint Program on the Science and Policy of Global Change

Regional climate policies depend largely on fiscal strategies and can have spiraling effects throughout the globe, a new MIT report further proves in the January edition of the Journal of Transport Economics and Policy. The report — titled “Biofuels, Climate Policy, and the European Vehicle Fleet” — uses the European transportation system as a test case and shows the significant impact various fiscal policies can have on emission reductions.

“The effectiveness of climate policies in isolation might depend crucially on the fiscal rules and environment,” says Sebastian Rausch, a co-author of the study and a research scientist at MIT’s Joint Program on the Science and Policy of Global Change. “So if you want to think about effective emissions-reduction policies and climate policies you have to take into consideration their interaction with other mechanisms like taxes and tariffs.”

For decades, Europeans have relied on diesel to power their cars. While better for the environment, these drivers have traditionally chosen diesel because higher taxes on gasoline make diesel the cheaper alternative. But now, Europe is encouraging its drivers to consider greener options. The European Union has imposed a renewable fuel mandate that requires 10 percent of fuel to be based in renewable sources like biodiesel or ethanol by 2020.

But will the higher price tag that often comes with renewables cause the mandate to have a negative effect? The MIT researchers say no. Studying the system with and without the mandate, they find that the number of drivers using diesel and biodiesel continues to increase with time because of rising oil prices and a tax system that balances out the additional expense of using renewables.

“So fueling up with biodiesel would still be 69 cents a gallon cheaper than gas,” Rausch says, “and it has the added benefit of reducing European emissions by about 8 percent by 2030.”

The report further analyzes the impact of tax or tariff changes, in combination with the imposed mandate. As one might expect, when gas and diesel have an equal tax rate almost a quarter fewer drivers choose diesel by 2030. The renewable fuel mandate also does not have a large impact on emissions because more drivers turn to gas. But if biodiesel and ethanol tariffs are removed, Europe can achieve significant emission reductions — about 45 percent — as these renewable fuels become cheaper to import and use. At the same time, diesel vehicles would all but disappear as ethanol blends crowd out the diesel market.

Looking at a global scale, the report shows that while renewable initiatives can cut emissions within that country, they can also cause spikes in emissions in other countries — or what is known as “leakage.”

Rausch explains: “You’re still driving a fair amount of diesel vehicles, but the fuel to drive those vehicles now comes from Brazil and other countries because you’ve removed your tariffs. You don’t have to produce as much diesel in the EU, so your emissions there are little bit lower. But the countries now producing more fuel to import to the EU see higher emissions.”

But there is still a positive side, Rausch says: “Because there’s a switch in imports from diesel to biofuels, emissions do get reduced in other countries as well because biofuel production releases fewer emissions than diesel production.”

These fuel changes in Europe can have a “snowballing effect,” Rausch says. Along with “leakage,” there can be other consequences. If Europe evens out its tax system, for example, increased demand for gasoline in Europe would drive up gasoline prices outside of Europe and lower gas consumption and emissions in general.

Automakers have made great strides in fuel efficiency in recent decades — but the mileage numbers of individual vehicles have barely increased. An MIT economist explains the conundrum.

By: Peter Dizikes, MIT News Office

Contrary to common perception, the major automakers have produced large increases in fuel efficiency through better technology in recent decades. There’s just one catch: All those advances have barely increased the mileage per gallon that autos actually achieve on the road.

Sound perplexing? This situation is the result of a trend newly quantified by MIT economist Christopher Knittel: Because automobiles are bigger and more powerful than they were three decades ago, major innovations in fuel efficiency have only produced minor gains in gas mileage.

Specifically, between 1980 and 2006, the average gas mileage of vehicles sold in the United States increased by slightly more than 15 percent — a relatively modest improvement. But during that time, Knittel has found, the average curb weight of those vehicles increased 26 percent, while their horsepower rose 107 percent. All factors being equal, fuel economy actually increased by 60 percent between 1980 and 2006, as Knittel shows in a new research paper, “Automobiles on Steroids,” just published in the American Economic Review (download PDF).

Thus if Americans today were driving cars of the same size and power that were typical in 1980, the country’s fleet of autos would have jumped from an average of about 23 miles per gallon (mpg) to roughly 37 mpg, well above the current average of around 27 mpg. Instead, Knittel says, “Most of that technological progress has gone into [compensating for] weight and horsepower.”

And considering that the transportation sector produces more than 30 percent of U.S. greenhouse gas emissions, turning that innovation into increased overall mileage would produce notable environmental benefits. For his part, Knittel thinks it is understandable that consumers would opt for large, powerful vehicles, and that the most logical way to reduce emissions is through an increased gas tax that leads consumers to value fuel efficiency more highly.

“When it comes to climate change, leaving the market alone isn’t going to lead to the efficient outcome,” Knittel says. “The right starting point is a gas tax.”

Giving the people what they want

While auto-industry critics have long called for new types of vehicles, such as gas-electric hybrids, Knittel’s research underscores the many ways that conventional internal-combustion engines have improved.

Among other innovations, as Knittel notes, efficient fuel-injection systems have replaced carburetors; most vehicles now have multiple camshafts (which control the valves in an engine), rather than just one, allowing for a smoother flow of fuel, air and exhaust in and out of engines; and variable-speed transmissions have let engines better regulate their revolutions per minute, saving fuel.

To be sure, the recent introduction of hybrids is also helping fleet-wide fuel efficiency. Of the thousands of autos Knittel scrutinized, the most fuel-efficient was the 2000 Honda Insight, the first hybrid model to enter mass production, at more than 70 mpg. (The least fuel-efficient car sold in the United States that Knittel found was the 1990 Lamborghini Countach, a high-end sports car that averaged fewer than nine mpg).  

To conduct his study, Knittel drew upon data from the National Highway Transportation Safety Administration, auto manufacturers and trade journals. As those numbers showed, a major reason fleet-wide mileage has only slowly increased is that so many Americans have chosen to buy bigger, less fuel-efficient vehicles. In 1980, light trucks represented about 20 percent of passenger vehicles sold in the United States. By 2004, light trucks — including SUVs — accounted for 51 percent of passenger-vehicle sales.

“I find little fault with the auto manufacturers, because there has been no incentive to put technologies into overall fuel economy,” Knittel says. “Firms are going to give consumers what they want, and if gas prices are low, consumers are going to want big, fast cars.” And between 1980 and 2004, gas prices dropped by 30 percent when adjusted for inflation.

The road ahead

Knittel’s research has impressed other scholars in the field of environmental economics. “I think this is a very convincing and important paper,” says Severin Borenstein, a professor at the Haas School of Business at the University of California at Berkeley. “The fact that cars have muscled up rather than become more efficient in the last three decades is known, but Chris has done the most credible job of measuring that tradeoff.” Adds Borenstein: “This paper should get a lot of attention when policymakers are thinking about what is achievable in improved automobile fuel economy.”

Indeed, Knittel asserts, given consumer preferences in autos, larger changes in fleet-wide gas mileage will occur only when policies change, too. “It’s the policymakers’ responsibility to create a structure that leads to these technologies being put toward fuel economy,” he says.

Among environmental policy analysts, the notion of a surcharge on fuel is widely supported. “I think 98 percent of economists would say that we need higher gas taxes,” Knittel says.

Instead, the major policy advance in this area occurring under the current administration has been a mandated rise in CAFE standards, the Corporate Average Fuel Economy of cars and trucks. In July, President Barack Obama announced new standards calling for a fleet-wide average of 35.5 mpg by 2016, and 54.5 mpg by 2025.

According to Knittel’s calculations, the automakers could meet the new CAFE standards by simply maintaining the rate of technological innovation experienced since 1980 while reducing the weight and horsepower of the average vehicle sold by 25 percent. Alternately, Knittel notes, a shift back to the average weight and power seen in 1980, along with a continuation of the trend toward greater fuel efficiency, would lead to a fleet-wide average of 52 mpg by 2020.

That said, Knittel is skeptical that CAFE standards by themselves will have the impact a new gas tax would. Such mileage regulations, he says, “end up reducing the cost of driving. If you force people to buy more fuel-efficient cars through CAFE standards, you actually get what’s called ‘rebound,’ and they drive more than they would have.” A gas tax, he believes, would create demand for more fuel-efficient cars without as much rebound, the phenomenon through which greater efficiency leads to potentially greater consumption.

Fuel efficiency, Knittel says, has come a long way in recent decades. But when it comes to getting those advances to have an impact out on the road, there is still a long way to go.

By: Vicki Ekstrom, Joint Program on the Science and Policy of Global Change

Shale gas — a resource that has grown significantly in just the last few years to one-quarter of the domestic gas supply — is cheaper and involves fewer emissions than traditional coal or oil. But recent environmental concerns, combined with shale gas's important role in the global economy, have prompted the Obama administration and MIT researchers to investigate the resource and its potential impacts.

“People speak of [natural] gas as a bridge to the future, but there had better be something at the other end of the bridge,” Henry Jacoby, co-director emeritus of MIT’s Joint Program on the Science and Policy of Global Change, said earlier this year after co-authoring a report by the MIT Energy Initiative (MITEI) on The Future of Natural Gas.

Jacoby’s nagging thoughts prompted him and other researchers to further study shale gas and how its success could impact U.S. energy policy, including future technological development. Built on the MITEI study, the researchers' new report — The Influence of Shale Gas on U.S. Energy and Environmental Policy — is in this month's inaugural edition of the journal Economics of Energy and Environmental Policy.

“Prior to this we hadn’t compared U.S. gas production with and without shale,” Jacoby says of the new research. “This report makes that comparison. And we found much of what we already knew — which is a good thing — that shale makes a big difference. It helps lower gas prices, it stimulates the economy and it provides greater flexibility to ease the cutting of emissions. But it also suppresses renewables.”

The researchers came to these conclusions by considering what our nation would look like with shale and without shale under several policy scenarios. They found that gas prices would rise by about five times the current levels by 2050 without shale gas, under one scenario; electricity prices would also grow. But with shale gas, prices should only about double. The shale input also reduces electricity price growth by 5 percent in 2030 and 10 percent in 2045, compared to a scenario without shale gas.

A report released last month by IHS Global Insight, a global research firm commissioned by America’s Natural Gas Alliance, shows similar results. Prices would drop 10 percent in 2036 with shale, according to IHS, and the industry would add 870,000 U.S. jobs by 2015.

John Deutch, MIT professor and chair of a special U.S. Department of Energy panel studying shale, agrees with the significant economic contribution the shale industry can provide. Deutch, who was associated with the earlier MITEI report but not the new MIT study, said that the most recent employment estimates showed that there are three-quarters of a million jobs in the shale gas industry.

“More jobs are being created in Pennsylvania and Ohio by shale gas production than anything else that I’m aware of,” Deutch said at a recent MIT lecture, suggesting the significance of those two battleground states in U.S. elections.

“Over the last couple of years I’ve realized that what’s happening with unconventional natural gas [shale] is the biggest energy story that’s happened in the 40-plus years that I’ve been watching energy development in this country,” says Deutch, who served as undersecretary of the Department of Energy in the 1970s.

Shale’s low price tag is one of the reasons for its boom. For every $4 we pay for energy from natural gas, we pay $25 for oil, according to recent statistics from the U.S. Energy Information Administration.

Jacoby and Deutch agree this is not sustainable, and that there is a great incentive to continue to tap into the shale market — with Deutch calling shale “remarkably inexpensive” compared to other forms of natural gas.

This successful outlook has prompted some of the world’s leading oil companies to further invest in natural gas, and specifically shale gas production. Last month, Shell announced it would double gas production in North America in the next three years and that it has recently expanded its work to China.

But Jacoby warns, “Natural gas is a finite resource. We will eventually run into depletion and higher cost.” He adds, “It still releases greenhouse gas emissions. So if we’re going to get to a point where we strictly limit those emissions, we need renewables.”

The continued need for strong renewables prompts concerns, as the study finds that shale use suppresses the development of renewables. Under one scenario, for example, the researchers impose a renewable-fuel mandate. They find that, with shale, renewable use never goes beyond the 25 percent minimum standard they set — but when shale is removed from the market, renewables gain more ground.

These findings are significant in light of several concerns surrounding the unpredictable shale gas market and future environmental regulations.

One concern about shale gas extraction, and the most headline-grabbing concern, is that fluids from the gas production — a process called hydraulic fracturing, or simply fracking — could seep into and contaminate groundwater supplies. While the report found these concerns to be “overstated,” the Deutch shale panel said in November that “environmental issues need to be addressed now.”

This conclusion, along with uncertainties about how stringent greenhouse gas emission targets will be going forward, leaves the regulatory environment in question.

There’s also the concern that the global gas market is unpredictable because the shale revolution is still in its early stages.

Jacoby says the development of the industry in the United States is important because prices here are much cheaper than in other gas markets — namely, Europe and Asia. While we pay less than $4 per thousands of cubic feet, other markets pay up to $16. Because it is so much cheaper here, there’s the potential for us to become exporters.

But Jacoby calls this really a “matter of timing.”

“In the near term, our supplies are cheap enough that we should have the ability to export,” Jacoby says. “But over time, we likely won’t be able to compete with places like Russia and the Middle East that have lower costs, and eventually we’ll again turn to importing gas.”

Jacoby compares the global gas market to the oil industry. As shale resources are developed in places such as China, which recently announced that it was tapping at least 20 new reserves, prices will likely drop overseas and the United States will turn to cheaper imports as it has for oil.

An uncertain international gas market, an unpredictable regulatory environment with more stringent emission goals and decreasing natural gas reserves over time all point to the growing need to continue developing renewable technologies.

“Effective use of renewables, namely wind and solar, are still many years away,” Jacoby says. “How we tap into those resources and effectively work them into our electric grid still needs to be figured out. To get us there we need a robust R&D program so we’ll have renewable energies up and working effectively later in future decades when emissions regulations are stricter, and gas reserves are depleting.”

Shale might provide the flexibility to meet reduction targets at lower costs today, making it a strong “bridge” in the short term to a low-carbon future. But the report concludes that we can’t let “the greater ease of the near term … erode efforts to prepare a landing at the other end of the bridge.”