News this Week

Science  27 Jun 2014:
Vol. 344, Issue 6191, pp. 1432
  1. This Week's Section

    Ebola outbreak sets sobering record

    Protective clothing used by workers treating Ebola victims dries in Guéckédou, Guinea.

    PHOTO: SEYLLOU/AFP/GETTY IMAGES

    The outbreak of Ebola virus disease in West Africa has surpassed a grim milestone: It is now the largest and deadliest outbreak of its kind. According to a 24 June report from the World Health Organization (WHO), 599 people have been infected and 338 have died in the outbreak, which likely started in Guinea in December 2013 and has spread to Liberia and Sierra Leone. Those numbers are a significant undercount, says Robert Garry, a virologist at Tulane University in New Orleans, Louisiana, who this month helped trace the outbreak in Sierra Leone. “There have been many, many deaths, most of them unrecorded,” he says. The main organizations that have been working to stop the outbreak—WHO, Doctors Without Borders, the U.S. Centers for Disease Control and Prevention, and national health ministries—are stretched to the limit, Garry says. There is no vaccine or specific treatment for Ebola. The only way to stop the outbreak is to convince patients to come to medical centers and families to bury the dead without directly touching the body. “We need to think about nontraditional ways” to fund and ramp up the containment effort, Garry adds, because the virus is “not going away anytime soon.”

    “The titles are horrible. … The public gets the impression that all NSF funds are these silly studies.”

    Representative Donna Edwards (D–MD), urging scientists to write better headlines for their National Science Foundation–funded projects, last week at the American Geophysical Union's Science Policy Conference in Washington, D.C.

    By the Numbers

    87.1—Percent of people who inject drugs who are infected with HIV in Tripoli, according to a study published on 17 June in PLOS Medicine.

    500—Percent increase since 2011 in orders for exome sequencing, which helps clinicians identify potentially important DNA mutations, according to Allen Bale, director of the DNA Diagnostics Laboratory at the Yale School of Medicine. But insurance companies are balking at paying.

    60—Years ago that 12 nations launched CERN, the European Organization for Nuclear Research. Today, CERN has 21 member nations and collaborates with many more.

    A cleaner, greener french fry

    Shorter fries could mean less fertilizer runoff.

    PHOTO: GETTY IMAGES/ISTOCKPHOTO

    WASHINGTON, D.C.—Prince Edward Island (PEI) has a nitrogen pollution problem—and shorter french fries could be a solution. PEI's farmers are Canada's biggest potato producers, and they use a lot of fertilizer, which leaks nitrates into ground water and the nearby Northumberland Strait. One way to soak up the pollutants: Sow a fast-growing “catch crop”, such as oil seed radishes, after the potatoes are harvested, suggested geochemist Martine Savard of the Geological Survey of Canada and George Somers of PEI's environment department at last week's American Geophysical Union Science Policy Conference. But there's a hitch: Demand for longer fast-food fries has farmers planting longer, slower growing tubers, reducing the window for a catch crop. Persuading consumers that a shorter fry is a greener fry, however, could reopen the door to stubbier taters—and cleaner waters.

    Come together now

    The last decade has seen a boom in biomedical consortia—collaborations between academic researchers, industry, disease advocacy groups, and others aimed mainly at speeding drug development. At least 369 such alliances have emerged since the mid-1990s, according to Mark Lim of FasterCures in Washington, D.C., who scoured press releases, the Internet, and other sources for data. Most are in Europe, followed by North America and Asia, Lim reports this week in Science Translational Medicine. Many aim to generate shared tools, such as transgenic mice and biomarkers for predicting vaccine safety, and they often focus on specific diseases, with cancer, Alzheimer's disease, diabetes, and rare diseases topping the list. It's too soon to assess the effectiveness of consortia, but Lim says the growing number launched by industry “is one indicator that competing research organizations are not waiting” for proof of principle before partnering with other groups to “solve unmet needs.”

    Around the World

    Los Angeles, California

    Chemist, prosecutors settle suit

    Federal prosecutors and a chemistry professor at the University of California, Los Angeles (UCLA), have settled a long-running case arising from the 2009 death of research assistant Sheharbano Sangji in a laboratory fire. Chemist Patrick Harran and UCLA had faced criminal charges. The university settled and accepted responsibility in 2012. Harran, who faced up to 4.5 years in prison, admitted no wrongdoing but agreed to pay a $10,000 fine and do 800 hours of community service, according to a 20 June statement. He will brief incoming UCLA students on “the importance of lab safety” and teach a chemistry course for inner-city students. In a statement, Sangji's family said they were “extremely disappointed. … We do not understand how this man is allowed to continue running a laboratory.” http://scim.ag/labfire

    Atlanta

    Anthrax accident at CDC

    Anthrax

    PHOTO: CDC/MEGAN MATHIAS AND J. TODD PARKER

    The U.S. Centers for Disease Control and Prevention (CDC) is treating or monitoring 84 staff members for possible anthrax exposure after workers botched a new protocol for killing the dangerous bacteria. “[E]stablished safety practices were not followed” at the agency's Bioterror Rapid Response and Advanced Technology Laboratory, officials said in a 19 June statement. In the incident, which occurred between 6 and 13 June, researchers used a chemical alternative to radiation to “inactivate” anthrax in a biosafety level 3 laboratory before transferring it to less secure level 2 laboratories. Days later, workers raised the alarm after finding live anthrax flourishing in growth plates. CDC has reassigned the lab's director, Michael Farrell, and the accident has led to renewed media scrutiny of facilities working with dangerous “select agents.” http://scim.ag/CDCanthrax

    Bethesda, Maryland

    Dieting mouse colony to close

    The National Institute on Aging (NIA) at the U.S. National Institutes of Health has announced it will shutter its colony of calorie-restricted mice. Slashing rations for mice and many other kinds of animals dramatically extends their lives, and for nearly 20 years NIA has provided the hungry rodents to researchers. Just eight to 10 researchers, however, request animals from the colony each year, says NIA's Nancy Nadon, chief of the Biological Resources Branch. “The way the usage has changed over the last few years, it wasn't the best way to go about using NIA funds,” she says. Most researchers who are investigating aging don't use the rodents, so they won't be affected. Scientists who depend on NIA's animals will have to adapt. http://scim.ag/mousecolony

    Chile

    Blast clears way for telescope

    Big bang for a big telescope.

    PHOTO: EUROPEAN SOUTHERN OBSERVATORY

    Workers on 19 June blasted away part of the top of Cerro Armazones, a 3000-meter peak, preparing for construction of the world's largest telescope: the 39-meter European Extremely Large Telescope. Construction of a road leading to the summit began in March; first light on the completed telescope is expected in 2024. Construction won't begin in earnest, however, until Brazil's National Congress ratifies an agreement to join the European Southern Observatory (ESO), which oversees the project. In 2010, Brazil's science ministry signed the agreement—which would make Brazil ESO's first non-European member—but it has languished ever since. Under the agreement, Brazil would contribute €270 million over 10 years to ESO's budget, or one-quarter of the telescope's €1.083 billion cost.

    Des Moines

    Criminal charges in AIDS case

    An AIDS researcher who has admitted to research misconduct is now facing four felony criminal charges of misusing U.S. government funds. Federal prosecutors on 19 June alleged that Dong Pyou Han, a former researcher at Iowa State University (ISU) in Ames, made false statements related to millions of dollars in grant funding. Han left ISU this past September after investigators suggested he had added chemicals to rabbit blood in order to make it appear that an experimental AIDS vaccine was working. The case attracted the attention of U.S. Senator Charles “Chuck” Grassley (R–IA), who expressed concern that the government was not acting strongly enough to punish Han and recover misspent funds. Each charge Han faces carries a maximum prison sentence of 5 years.

    Yasny, Russia

    Rocket launches wildlife tracker

    Common cuckoo

    PHOTO: SHUTTERSTOCK

    A Russian rocket carried 37 satellites into space on 19 June, including Iraq's first spacecraft, which will track dust storms, and the cube-shaped DTUsat, which is designed to track small animals, such as the common cuckoo, that have been outfitted with tiny tags. It's about “solving the mysteries of migrations,” says zoologist Kasper Thorup of the University of Copenhagen, which built the craft with the Technical University of Denmark. The goal is to test technologies for an ambitious effort to track wildlife from the International Space Station. http://scim.ag/wildlifetrack

    Washington, D.C.

    Bill would nix Chu's brainchild

    Lawmakers in the U.S. House of Representatives moved to kill a signature project of former Secretary of Energy Steven Chu. In their version of the proposed 2015 budget for the Department of Energy (DOE), released 18 June, House appropriators zeroed out funding for the Joint Center for Artificial Photosynthesis (JCAP), which seeks ways to convert sunlight to fuels such as hydrogen. Chu championed such work and in 2010 launched JCAP, headquartered at the California Institute of Technology in Pasadena, as one of five Energy Innovation Hubs. JCAP's original funding expires this year and DOE must decide whether to continue it for five more years. But the White House requested only a 1-year, $24 million extension. The Senate and the White House would have to agree to kill JCAP. http://scim.ag/DOEartphoto

    Newsmakers

    Three Q's

    In her new novella The Collapse of Western Civilization: A View from the Future, Harvard University science historian Naomi Oreskes describes a planet devastated by centuries of global warming. The book, co-written with science historian Erik Conway of NASA's Jet Propulsion Laboratory, helped Oreskes win an outreach award last week from the American Geophysical Union.

    PHOTO: NAOMI ORESKES

    Q:Why fiction?

    A:I struggle with finding the right emotional tenor for talking about this issue. With fiction, I can sound an alarm … be emotional … [and] upset about things that are upsetting.

    Q:You write as a Chinese historian looking back 4 centuries to the present.

    A:I'm a scientist but also a historian, so a humanist. I got to thinking—what would a historian in the future say about us?

    Q:How did you choose which climate scenario to depict?

    A:The book is a worst-case scenario, but not a made-up scenario. What if it turns out that something—like sea level rise—is at the top of the error bars from the projections of the Intergovernmental Panel on Climate Change? Everything [in the story] that happens before 2013 is true, and everything that happens after is from the high end of the projections.

  2. Will fracking put too much fizz in your water?

    1. Erik Stokstad

    Leaky gas wells loom large in debate over drilling's impact on water quality.

    On New Year's Day 2009, the well in Norma Fiorentino's backyard exploded. An electric pump ignited methane that had seeped into her water well, and the blast was powerful enough to tear apart a concrete pad. That was just the beginning of the fireworks. Nineteen families in rural Dimock Township, Pennsylvania, blamed well contamination on stray methane leaking from nearby boreholes. They had been rapidly drilled by Cabot Oil & Gas Corp., which was searching for natural gas in the deep Marcellus Shale. After a lawsuit and government investigations, Cabot agreed to provide the families with cash settlements and water purification systems, but insisted that the methane had come from natural sources, not its gas wells.

    The Dimock controversy, featured in the popular movie Gasland, shone a spotlight on the potential risks associated with the U.S. shale gas boom. Around the world, media have highlighted dramatic ruptures of pipelines, waste spills, well blowouts, and tanker truck crashes. The problems helped persuade officials in nearby New York state to declare a moratorium on fracking—the hydraulic fracturing that cracks rocks and coaxes natural gas from the Marcellus and other shale formations (see p. 1464). France, Bulgaria, and other countries have also banned fracking.

    Perhaps the biggest fear is the potential to pollute drinking water. Although the new wave of high-volume fracking typically targets geological formations that are more than a kilometer down—far deeper than most drinking water wells and aquifers—many communities worry that they could become the next Dimock, their water tainted with methane or chemicals. Fracking opponents point to widespread complaints of contamination near gas wells. But industry advocates claim that there has never been a documented case of fracking harming drinking water.

    Who's right? A growing corps of researchers is trying to find out. Some are testing water wells, while others comb through state environmental records. One team is trying to take advantage of an unusual natural experiment, documenting water quality along the border between frack-free New York and frack-heavy Pennsylvania. Meanwhile, gas companies are funding their own vast surveys of predrilling water quality—if only to defend themselves against postdrilling lawsuits. And many eyes are on the Environmental Protection Agency (EPA), which later this year is expected to release a much anticipated national study of fracking's effect on water.

    Big money is at stake. If fracking is shown to be a major threat to water quality, companies could face potentially expensive regulation and lawsuits that could keep them from tapping shale formations holding natural gas worth billions of dollars. If not, the finding could hasten the end of moratoriums in New York and elsewhere. The research “will impact what counties, states, and countries will do, whether they give incentives to drill or put bans in place,” says Robert Jackson, a hydrogeologist at Stanford University in Palo Alto, California.

    Fracking operations, such as this Pennsylvania well, produce ample amounts of contaminated wastewater.

    PHOTO: MARTHA RIEL

    WATER IS AN ESSENTIAL INGREDIENT in fracking. Once a company has drilled a deep horizontal borehole, workers pump in an average of 15 million liters of pressurized water to break open the shale—10 to 100 times more water than in a conventional, vertical gas well. About 20% of this fluid, which is mixed with sand and chemicals to keep the fractures open, then flows back out of the well. With it comes so-called produced water, the mildly radioactive brine that permeates the shale itself.

    Improperly managed, flowback waste can cause serious pollution. In Pennsylvania, Marcellus well operators now recycle most of the flowback to frack new wells. (In other regions, they dispose of the fluid by pumping it deep underground.) But until 2011, some trucked the fluids to municipal sewage treatment plants, which weren't equipped to deal with them. Worse, onsite storage ponds failed and rogue contractors dumped the dregs into streams. Such problems are not unique to fracking; conventional oil and gas wells create waste, too, although in smaller amounts. But once the pace of Marcellus fracking slows, some analysts fear, companies may be faced with an excess and nowhere to put it. “We see this potential train wreck on the horizon,” says Mark Brownstein of the Environmental Defense Fund in New York City.

    One irony of the fracking controversy is that the fracturing itself doesn't worry scientists. Because it typically takes place at great depths, any larger cracks are quickly squeezed shut by the weight of the overlying rock. So experts have assumed that gas or fluids are unlikely to escape. A 2004 study by EPA, for example, concluded that fracking posed little threat to underground supplies of drinking water; the finding helped persuade Congress in 2005 to exempt the practice from regulation under the federal Safe Drinking Water Act.

    More recent studies are also finding scant evidence that contaminants are migrating up through fractures created by fracking. In Pennsylvania, scientists at the Department of Energy (DOE) have spent 9 months monitoring tracers injected into six commercial wells drilled into the Marcellus Shale. So far, there is no sign that gas or fracking fluids are moving toward the surface, reported DOE's Richard Hammack and colleagues this past August at the Society of Petroleum Engineers Eastern Regional Meeting. (A lingering concern, however, is the presence of countless abandoned oil and gas wells, some dating back a century, which could also provide a conduit for gas or fluids.)

    The greater risk—for all wells—is that fluids or gas will escape through a faulty casing into shallow aquifers. To prevent leaks, crews pump cement into the 2-centimeter space between the pipe and the surrounding rock. But if the cement has gaps, contaminants can bubble up. Rarely, the steel pipe fractures or its threaded joints leak.

    Poor cementing is a well-known hazard in conventional wells. In one tragic incident in 2004, gas escaped from a conventional well in Jefferson County, Pennsylvania, collected in a home basement, and exploded, killing a couple and their grandson. But before the media attention to the fracking surge, few people heard of the disaster. “It barely got a mention in the newspaper,” says Fred Baldassare of ECHELON Applied Geoscience Consulting in Murrysville, Pennsylvania.

    Now, researchers are examining how often Pennsylvania's fracking wells encounter similar problems by analyzing a well inspection database assembled by the state's Department of Environmental Protection (DEP). One effort, led by Susan Brantley of Pennsylvania State University (Penn State), University Park, concluded that inspectors found well construction problems at 3.4%, or 219, of the 6466 wells examined between 2008 and 2013; 16 were cited for leaking methane into ground water, her team reported in a review in Science (17 May 2013, p. 826), updated this month in the International Journal of Coal Geology. “From what we can see,” she says, “the frequency of big problems is pretty low.”

    That estimate is probably too low, says engineer Anthony Ingraffea of Cornell University, who has also been analyzing the DEP records. He and colleagues pored over some 75,000 records for 41,000 gas wells inspected between 2000 and 2012. Using statistical techniques to make up for variations in how thoroughly inspectors scrutinize wells and document their visits, they estimate that at least 6% of Pennsylvania's more than 7000 fracking wells have compromised casings, compared with 1% of conventional wells. The findings are in review at the Proceedings of the National Academy of Sciences (PNAS), but the team is already trying to figure out why fracking wells have the much higher rate of problems. The numbers also suggest that more than 45% of wells fracked in northeast Pennsylvania since 2009 will end up leaking.

    And worse is yet to come, he fears. The number of wells is still climbing, despite a recent slowdown. Drillers may be just 8% of the way toward exhausting the Marcellus Shale, he notes, although estimates of the amount of recoverable gas vary. “The cumulative impact will be unbelievable,” Ingraffea predicts.

    Sherry Vargason can ignite her kitchen faucet.

    PHOTO: MARK THIESSEN

    Although methane itself isn't toxic, the gas can stir up metals and minerals, particularly in old water wells. The key question for most people is whether any of the leaking methane is reaching their drinking water.

    In a heavily drilled part of northeastern Pennsylvania, one study suggests that the answer is yes. A team led by Stanford's Jackson, then at Duke University in Durham, North Carolina, measured concentrations of methane at 141 drinking water wells in six counties, an area that includes Dimock. Wells within 1 kilometer of a natural gas well had methane concentrations that were six times greater than those of more distant water sources, they reported in PNAS in July 2013. And the chemical signature of the gas (determined by isotopic studies) closely resembled that of gas from the Marcellus Shale. The problem, they believe, was defective casings in fracking wells.

    Industry experts agree that the errant gas leaked from faulty well casings. But they doubt that the source was the Marcellus. Instead, they think it came from younger, shallower geological formations not touched by fracking. About 80% of water wells in the region have some level of this methane, they note, which may be leaking into water wells through natural fractures. This possibility is suggested by several studies, including work in the May/June 2013 issue of Groundwater by geochemist Lisa Molofsky and colleagues at Cabot and at GSI Environmental Inc. in Houston, Texas. After analyzing methane data from 1701 water wells in northeastern Pennsylvania, Molofsky's team concluded that higher concentrations were linked to water wells located in valleys, where abundant natural fractures allow gas to escape from shallow sources. In addition, Molofsky and others suspect that the study by Jackson's team may have been biased, because it focused on an atypical contamination incident.

    Some landowners complain about leaks from pipes carrying wastewater from fracking sites.

    PHOTO: SCOTT GOLDSMITH

    Industry experts also argue that leak risks are going down as drilling companies better understand the complexities of local geology and fracking well design. They are using cements enhanced with latex and other additives to plug natural fractures in the rock, for instance. And they routinely run geophysical tests during drilling to check for problems. It's the kind of practical experience that can't be gained in a research lab or during a drilling moratorium, ECHELON's Baldassare notes. Ingraffea and others, however, remain dubious that leaks will decline.

    RESOLVING WHETHER FRACKING is a serious threat to water quality will take time. EPA's ambitious nationwide study, which Congress requested in 2009, has been slowed by political controversies over its scope. It's also a technical and logistical challenge, involving far-flung field studies. Another major obstacle is the lack of predrilling data about water quality in many areas. Although gas companies have tested tens of thousands of water wells above active and potential fracking zones, they haven't widely shared the data. “The lack of baseline information is a really serious issue,” says Kate Sinding of the Natural Resources Defense Council in New York City.

    Some clarity could come from an unusual situation found along the New York. Pennsylvania border. New York hasn't yet allowed fracking in its part of the Marcellus Shale, so researchers are parachuting into the border zone to quickly document water quality before a single new well is drilled. Laura Lautz of Syracuse University in New York, for example, is analyzing samples from more than 200 homeowner wells chosen at random in southern New York.

    A coarser but cheaper approach to assembling predrilling baselines could come from researchers at the U.S. Geological Survey (USGS) and partner institutions. Rather than sample scores of individual wells, they are measuring methane in streams, which collect ground and surface water from a large area. Preliminary work in Utah, North Carolina, and Pennsylvania suggests that the methane persists long enough in some types of streams to provide meaningful measurements, USGS hydrologist Victor Heilweil and colleagues reported in the July/August 2013 issue of Groundwater. If perfected, the approach “gives a better chance of seeing the big picture,” Heilweil says.

    This approach could also allow concerned citizens to monitor the effects of drilling. Local groups, for example, could collect water samples, add chemicals to kill microbes that would otherwise consume any methane, and send the samples to a lab for analysis. Such monitoring methods need to mature, however, and researchers say it's also crucial to have more detailed and complete databases of drilling violations. Until then, the debate over fracking's impact on water quality is likely to endure. And for communities already experiencing drilling, says Penn State's Brantley, the shale gas boom is like “a giant experiment being run in our backyard.”

  3. Searching for life in the deep shale

    1. Elizabeth Pennisi

    Energy developers and researchers alike want to find out what's living in the Marcellus Shale's deep layers of rock.

    For energy developers, the geological formation known as the Marcellus Shale represents a rich new source of natural gas. For environmental engineer Paula Mouser and geochemist Shikha Sharma, it represents a potentially rich source of new microbes.

    Following up on some tantalizing but unconfirmed clues, the pair is looking for life in the deep, hot layers of rock—and considering how the gas boom might affect long-isolated ecosystems. Drilling companies care, too, because deep-dwelling microbes could corrode equipment, clog pipes, and even contaminate the gas. Microbes can “really affect the bottom line,” says Mouser, who works at Ohio State University, Columbus.

    A chunk of Marcellus Shale, where fracking could affect microbes.

    PHOTO: MARK THIESSEN

    “Next to nothing is known about the biodiversity of shale deposits,” says Simon Malcomber of the National Science Foundation (NSF) in Washington, D.C., which is funding the work. Indeed, it's hard to imagine a more inhospitable environment than the Marcellus and similar gas-bearing formations (see map). The beds typically sit a kilometer or more down, where pressures are 500 times greater than those found at the surface, and temperatures exceed 70°C. One study in the 1990s, however, was able to culture microbes from shallower deposits of shale, but it came before genomic technologies made a more comprehensive look possible.

    In 2012, Sharma—who works at West Virginia University in Morgantown—began to think deeper shale also hosted microbes. She was analyzing carbon isotopes in water from various kinds of wells and aquifers, looking for clues that would distinguish water coming from different underground sources. While studying a fracking well in Pennsylvania's Marcellus Shale, Sharma noticed that the water flowing out of the well “had a very different signature” than what had been injected. The data suggested that the returning fluid had mixed with deep water that either today or in the past was filled with microbes that produce methane, known as methanogens.

    At about the same time, a team led by Mouser was finding similar hints in a study that screened flowback water from another Marcellus fracking well for microbial DNA. The early flowback contained a variety of salt-tolerant microbes that were not present in the injected water, the team reported online on 6 May in Environmental Science & Technology.

    Mouser and Sharma suspect microbes are thriving in the brine that fills the shale's pores—and they are hoping their new NSF-funded study will prove it. This year, they plan to work with fracking companies to collect pristine shale samples from new boreholes, before injected surface water contacts the rock. They will get a full sense of what's down there by sequencing the microbial DNA. Then they will try to grow laboratory samples of any deep-living microbes they discover.

    The information ultimately could help energy companies improve their methods, the researchers say. Drillers already add biocides to fracking fluids to protect against corrosion caused by bacteria, Mouser notes, but the chemicals might not be effective against deep-dwelling microbes. At the same time, certain fracking additives may actually promote the growth of some microbes, helping gum up wells. And if sulfide-producing microbes establish themselves, their waste products can contaminate the gas, lowering its value.

  4. Hunting a climate fugitive

    1. Eli Kintisch*

    Plugging methane leaks in the urban maze could be key to making shale gas climate-friendly.

    On a windy morning in May, graduate student Kathryn McKain crouches by a ledge near the top of one of Boston's tallest skyscrapers, checking some air sampling equipment. McKain, of Harvard University's engineering department, likes more than just the commanding view: From 215 meters up, the greenhouse gas measurements she's making aren't biased by pollution from individual sources below. “You're really getting measurements representative of the whole city,” she says.

    Sometimes a falcon lands nearby, presumably using the perch to spot pigeons. The scientists are hunting something else: methane, an invisible but potent heat-trapping gas. They're trying to figure out how much is leaking from the city's vast network of natural gas pipes and tanks.

    It's a question that is haunting academics, politicians, and executives who have hailed the boom in shale gas production (see p. 1467) as aiding a critical transition to climate-friendlier energy sources. Burning natural gas releases about half as much carbon dioxide (CO2) per unit of energy as burning coal and a third less than oil. And as hydraulic fracturing (fracking) methods have helped flood energy markets with relatively cheap natural gas, it has begun to replace coal as the fuel of choice for producing power in the United States. About 28% of the nation's electricity now comes from natural gas, up from 19% in 2005. From 2005 to 2012, U.S. CO2 emissions dropped by about 11%, and one study said that fuel-switching to gas is responsible for as much as half of that drop. President Barack Obama's proposed new restrictions on carbon pollution from power plants are likely to accelerate the transition.

    Many climate policy analysts believe that natural gas can provide a “bridge” to a future energy economy by buying time to develop renewable energy technologies. But that bridge may be more rickety—and less helpful—than envisioned. The reason: Methane, the primary component of natural gas, is itself a potent greenhouse gas, with a warming effect between eight and 72 times stronger than that of CO2, depending on the time period over which one does the accounting. And recent studies have suggested that large quantities of unburned methane are leaking into the atmosphere—not just from production wells and major pipelines but also from gas lines and tanks that distribute the fuel in cities. The leaks could negate much of the climate benefit of switching to gas.

    “Clearly natural gas has potential to help,” says Steve Hamburg, chief scientist of the Environmental Defense Fund (EDF) in Boston. “But to meet that potential we have to minimize methane emissions.” EDF and other government and private groups have launched a flurry of studies, including McKain's research in Boston, to pin down just how much methane is escaping, and where. At the same time, the concerns are fueling fresh debate over methane's importance as a warming gas—and whether regulators should be doing more to control it.

    Infrared imaging of pipes and tanks can reveal methane leaks (dark clouds, lower image).

    PHOTOS: ENVIRONMENTAL DEFENSE FUND (2)

    METHANE PLAYS AN OUTSIZED ROLE in climate. Although it is 200 times less abundant in the atmosphere than CO2, the way its four carbon-hydrogen bonds jiggle when struck by infrared radiation makes it a highly effective warmer. Overall, methane concentrations are now three times higher than in the preindustrial era, and the molecule may be responsible for as much as one-quarter of current global warming. So climate researchers took notice in 2008, when methane concentrations in Earth's atmosphere began rising after a decade of flat or declining levels.

    Some of that atmospheric methane comes from natural sources, such as gas seeps or wetlands. But an estimated one-fifth of the global total—and about 30% of U.S. methane emissions—comes from the natural gas infrastructure, from wells to end users, and the fracking boom is adding thousands of potential new sources of emissions. Getting a handle on well emissions is proving particularly difficult, with recent studies coming to opposite conclusions. Last year, in the biggest study of its kind to date, researchers from the University of Texas, Austin, measured emissions at 190 gas industry sites, including 150 production sites. This bottom-up approach, part of the EDF effort, concluded that existing Environmental Protection Agency (EPA) estimates of industry methane emissions were a little low.

    But a top-down study published last year, using more than 10,000 measurements taken from aircraft- and tower-mounted instruments nationwide, concluded that EPA estimates are roughly 1.5 times too low. The study, published in the Proceedings of the National Academy of Sciences (PNAS) and led by McKain's adviser, geochemist Steven Wofsy of Harvard, used a weather model to track emissions back to their sources.

    What might explain the discrepancy? One answer may be so-called superemitters. Just a few components at a drill site—a leaky pipe, valve, or compressor, for example—may be responsible for the lion's share of emissions. Bottom-up studies that miss sites with superemitters may underestimate leaks, while top-down studies might come up with numbers that are dominated by a few major leaks. Overall, some researchers estimate that just 20% of production leaks could account for some 80% of emissions.

    To resolve the issue, last October EDF convened 12 research teams using a variety of ground-, air-, and mobile-based measurement methods to conduct a coordinated analysis of emissions at one center of the fracking boom, the Barnett Shale formation in north Texas. The teams are expected to release results soon. But a major role for superemitters would raise hopes that production leaks might be relatively easy to plug. “It raises the possibility of … mitigating them for a big impact,” Brandt says.

    PLUGGING PIPELINE LEAKS could be a tougher task. A 2005 Nature study of Russia's massive pipeline system concluded that 1.4% of the total methane it moves escapes into the atmosphere—three times more than the estimated well losses. Researchers believe the loss rate is similar in the U.S. system, which includes nearly 500,000 kilometers of pipe. To confirm that suspicion, researchers at Colorado State University are now working with seven gas firms to use tracer gases to track leaks.

    In Boston, ground-based measurements made in 2012 suggest methane leaks are everywhere.

    PHOTO: N. G. PHILLIPS ET AL., ENVIRONMENTAL POLLUTION 173 (FEBRUARY 2013), WITH PERMISSION FROM ELSEVIER

    Meanwhile, Harvard's McKain and other researchers are trying to understand how much methane escapes at the far end of the supply chain, including the maze of small pipes and tanks that feed industrial and household consumers in major cities such as Boston, Los Angeles, and Washington, D.C. It's no simple task: It's challenging to differentiate emissions from natural gas systems from those originating in landfills, wetlands, or geologic formations. One solution is to track ethane, which is found alongside methane from natural gas pipelines, but usually not in emissions from other sources. In Los Angeles, however, gas from ubiquitous natural oil and gas seeps has virtually the same ethane signature as pipeline gas, making it very hard to tell the two apart.

    As in gas well studies, urban researchers are taking bottom-up and top-down approaches. In Washington, D.C., and Boston, scientists have gotten behind the wheel to conduct street-by-street surveys with car-mounted instruments, uncovering previously undocumented—and occasionally dangerous—methane leaks. The Boston project, co-led by Harvard's Wofsy and biogeochemist Lucy Hutyra of Boston University, is taking a broader view, mounting static instruments on buildings in the city and suburbs to get the big picture. A computer model built by McKain combines weather patterns with methane measurements to infer where the emissions are coming from and how they vary over time.

    The team is still crunching the numbers, but it appears that methane emissions in Boston “are really higher than people are expecting them to be,” Wofsy says. The total includes leaks and deliberate venting by industry, but it's not clear that there are superemitters that will be easy to target for reductions, Hutyra says. “This is a distributed problem,” she says, created by a multitude of relatively small sources.

    That pattern could create huge headaches for companies and policymakers aiming to reduce methane emissions. The industry has made a “continued effort” to reduce leakage, says Richard Meyer of the American Gas Association in Washington, D.C. But the financial incentive for chasing down thousands of tiny leaks is essentially nonexistent—especially if gas prices remain relatively low. The irony, notes EDF's Hamburg, is that a 1% or 2% loss rate might do little damage to a company's bottom line—but have a real impact on warming. Still, his group has commissioned a study suggesting that the gas industry could cost-effectively plug about 40% of existing leaks, and it argues that society overall would reap even greater economic benefits if regulators stepped in to require greater reductions. Some states, meanwhile, are already taking steps to require gas companies to do more to identify leaks—sometimes by using infrared cameras that can “see” invisible methane—perhaps with stricter regulation in mind.

    JUST HOW MUCH ATTENTION methane should get from regulators is the subject of debate. Many scientists argue for aggressively cutting methane leaks, saying that “could buy us time” to avoid climate tipping points, as atmospheric scientist Drew Shindell of NASA's Goddard Institute for Space Studies in New York City puts it.

    Others say CO2 should remain the key target. Although it is a weaker warmer than methane, it is fiendishly stable, able to survive in the atmosphere—and continue trapping heat—for centuries. Atmospheric methane, in contrast, dies relatively young, typically lasting just a dozen years or so before being dismantled by chemical reactions. What's more, asking policymakers to tackle methane might slow already lagging efforts to cut CO2, these researchers note. That scenario is “[c]onsistent with limited capital and political will,” wrote Harvard researchers Julie Shoemaker and Daniel Schrag last year in Climatic Change.

    To see how a focus on methane might affect CO2 mitigation, Shoemaker ran modeling experiments simulating various delays in cutting CO2 pollution. Each 15-year delay in curbing CO2, they found, caused the planet to warm by an additional 0.75°C by 2400. (A delay in cutting methane emissions has little long-term effect because methane doesn't accumulate.) Such sobering results suggest “it can't be cutting carbon dioxide or cutting methane,” Schrag says. “We've got to develop policies that do both.”

  5. The bond breaker

    1. Robert Service

    By transforming methane, chemist Roy Periana aims to turn natural gas into cheap feedstocks for chemical firms.

    Many chemists strive to be grand architects, building imposing molecular edifices with dozens or even hundreds of atoms, bonds twisting this way and that. Not Roy Periana. He has spent his career focused on just one bond, a link between a carbon and a hydrogen atom in a molecule of methane, the main component of natural gas. “You might say it's kind of sad,” Periana says, chuckling. “But if I can control the reactivity of this one bond, I can change the world.”

    He's getting close. Working with colleagues at the Scripps Research Institute in Jupiter, Florida, Periana has come up with a new way to tweak this bond. If he can perfect his technique, it would give chemists a cheap, efficient way to convert natural gas to methanol and other key starter materials for the petrochemical industry—materials that can then be turned into liquid fuels and commodity chemicals. It's a simple change that could have profound effects—especially as the shale drilling boom provides abundant new supplies of natural gas. It could upend the petrochemical industry, the world's largest economic enterprise, because it would allow the industry to rely on gas rather than oil. It could also profoundly alter global energy security, by providing gas-rich nations with a way to break their dependence on imported oil. The potential financial impact, Periana notes, is enormous: “You're looking at a gazillion dollars.”

    Given such weighty implications, it's not surprising that chemists have been trying to orchestrate the methane transformation for decades, mostly by using catalysts that can cause the reaction without being consumed themselves. “This has been one of the holy grails of catalysis,” says George Huber, a chemist at the University of Wisconsin, Madison. But to date, the methods have been balky or too expensive.

    PHOTO: MAGGIE STEBER

    That's where Periana's approach comes in. He's using a different set of would-be catalysts—cheap, abundant metals—plus some extra chemical tricks to convert methane to methanol at low temperatures. But his team still faces major technical obstacles—and some critics suggest Periana is prone to premature hype. Still, many researchers are watching closely. “Roy,” says James Mayer, a chemist at the University of Washington, Seattle, “is one of the most imaginative people in the community.”

    “MY WHOLE VISION was to be a scientist,” says Periana, who is 57. But he grew up in the small capital city of Georgetown in what was then British Guiana—now Guyana—in South America. His school had meager science facilities, and Periana spent countless hours in the city's public library, alone with musty, outdated encyclopedias and textbooks. He taught himself how to build a telescope using his grandfather's glasses, constructed his own Bunsen burner, and, of course, synthesized every type of explosive a teenage boy could desire. “The pivotal moment was reading a book that said if you could invent a machine that duplicated photosynthesis, you could feed an entire city,” Periana recalls. “I knew then I was going to be an inventor.”

    Periana's father, a photographer, befriended a U.S. diplomat, who helped secure a U.S. residence permit for Roy. Periana studied at the University of Michigan, Ann Arbor, and ultimately earned his Ph.D. at the University of California (UC), Berkeley, in 1985. There he discovered the problem he's been trying to solve ever since: finding a cheaper, better way to transform gaseous methane—a member of a large class of molecules known as hydrocarbons—into liquid chemical feedstocks.

    The conventional way of producing those feedstocks starts with crude oil, a collection of liquid hydrocarbon molecules that are far larger than methane. Chemical engineers first distill out midsize hydrocarbons. Then, they use heat and catalytic minerals to break apart the larger “heavy” hydrocarbons, in a process known as cracking.

    An alternative approach starts with much smaller hydrocarbons, such as the methane, ethane, and propane in natural gas. Chemists then try to stitch them together to form larger, liquid hydrocarbons. The challenge is the way methane is put together. The molecule consists of one carbon atom surrounded by four hydrogen atoms (CH4). Each hydrogen shares two electrons with the central carbon, an extremely stable configuration that makes the atoms unwilling to react.

    One way to trigger a reaction is to ignite methane. The heat gives methane's carbon atom enough energy to shake free from its hydrogens and react with oxygen. Unfortunately, burning methane obliterates all of its C-H bonds, converting the hydrocarbon to CO2 and heat. That's nice if you want to heat your house, but not if you want to make liquid fuels.

    Nearly a century ago, chemists came up with molecular knitting technologies that leave some of methane's bonds intact. But they are too expensive for most uses because they require relatively high temperatures (between 800°C and 900°C) and costly facilities. (The cost is one reason oil companies each year burn off roughly $40 billion worth of natural gas recovered with oil.)

    In the 1970s and 1980s, some researchers thought they'd found a better solution. They discovered that when lithium and a few other metals were paired with oxygen, they would form catalysts that broke those C-H bonds without so much heat, and some even produced small amounts of methanol. But the catalysts were so hungry for C-H bonds that they cannibalized the methanol as fast as it was created. So, after decades of frustration, most researchers gave up. “We ran out of ideas,” says George Whitesides, a chemist at Harvard University.

    EARLY ON, Periana realized that the failed cannibal catalysts had something in common. They worked by generating other compounds that were “radicals” in chemistry lingo, meaning they have a lone electron in one orbital around the nucleus. That makes the radical eager to either gobble up an additional electron to fill the orbital or cough one out to empty the orbital.

    Periana thought a less radical approach might work better. While at UC Berkeley, he helped discover catalysts that didn't use radicals to split C-H bonds in hydrocarbons. But these catalysts, which belong to a part of the periodic table called transition metals, were too fragile and expensive for industrial use. In 1993, while working in California at Catalytica Inc., he and his colleagues developed a potentially practical catalyst that also split the bonds, this time based on mercury 2+ (Hg2+). On the periodic table, Hg2+ is next to a cheaper, more abundant class of metals known as main group metals. Again, however, difficulties jacked up the cost; in particular, the team couldn't figure out how to get around a problem involving excess water, which stalled the reaction by quenching the catalyst's thirst for electrons. So he circled back to other transition metals, spending decades on essentially fruitless experiments. “We were stuck,” Periana says.

    Until last year, when his lab again shifted course to work on thallium (Tl), lead (Pb), and other more abundant main group metals. To their surprise, they found that Tl3+ and Pb4+ generated methanol—even in the presence of the water that had stalled the earlier mercury catalyst. “Then the eureka moment hit us,” Periana says.

    To be successful, Periana's team will need to scale up their laboratory experiments.

    PHOTO: MAGGIE STEBER

    The key insight, he says, involved something called the water exchange rate constant. It refers to the fact that atoms don't bond in the static way we typically imagine. Instead, they are more like the shifting partners at a swirling square dance than couples at a formal ball who never separate. And it turns out that different metals “exchange” their water partners at vastly different rates. Thallium's trading rate, for example, is 19 orders of magnitude higher than platinum's.

    Such speed dating presents thallium with plenty of opportunities to chassé up to a methane molecule and snag a pair of electrons from a C-H bond. And in the presence of acetic acid and other solvents, the thallium connects what's left of the methane to a molecule in the solvent, creating an alcohol ester. Add water, and you get methanol and more acetic acid.

    Periana's team still faces a thorny problem, however: Thallium ions wind up with two extra electrons that must be stripped off to start the cycle anew. To make that process economical, the chemists can't use expensive compounds. Instead, they'll likely need to use just oxygen from air, but have yet to demonstrate that they can do it.

    As a result, most chemists are reluctant to call the Periana lab's findings a true breakthrough. “It's still a long way from something that is practical,” says John Hartwig, a hydrocarbon chemist at UC Berkeley. Privately, others go further, arguing that Periana routinely overstates his findings, making it sound like they will soon revolutionize the petrochemical business. “With Roy there tends to be more hand waving and less deliverable on the ground” says one U.S.-based chemist.

    That said, many outsiders think Periana's scheme just might work. The new insights into metal catalysts are “really important,” says Harvard's Whitesides, and “whenever you open the door to a new possible class of reactions, people will take advantage of it.”

    Periana's team believes it has a solution to the extra electrons. In the 1960s, researchers developed a broad literature on using oxygen in air to snatch electrons from copper, in a process used to make a commodity chemical called acetaldehyde. A similar process will enable them to economically tap air to fuel the metal catalysts, predicts Michael Konnick, a research chemist in Periana's group. “I have no doubt,” he says, that “the laws of the universe say it can be done.”

    It appears that some venture capitalists agree. Periana says he's already seen interest from investment firms and large chemical companies in starting a company to develop the technology. If it works, Periana will finally achieve his goal of cheaply tweaking his favorite chemical bond, and just maybe change the world in the process.

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