Environmental t News Peru’s glacier meltdown threatens water supplies Bryan Mark
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s glacial meltwater trickles down mountainsides in the Andes, some places in Peru may already be seeing temporary increases in water supply, according to new research published in ES&T (pp 6955–6960). But as the ice disappears, researchers say, so will the water that flows from it, and people will be hit especially hard during the dry summers when glaciers normally release water. How severe will local shortfalls be, and how soon will they affect millions of people in South America? In the city of La Paz (Bolivia) and its suburb El Alto, more than 2 million people get about a third of their drinking water from glaciers—and those glaciers have shrunk by more than half since the 1960s, according to Walter Vergara, a World Bank specialist on climate change in Latin America. The situation in less monitored areas is more of a mystery. Satellite images show that glaciers are shrinking, but they don’t provide a reliable estimate of how much water is released or where it goes. Climbing glaciers to get better measurements is risky and expensive. To overcome these limitations, a team led by geographer Bryan Mark of Ohio State University developed a stable-isotope method to determine how much of a community’s water supply is glacier-fed, without scaling the glaciers. The technique relies on differences in the levels of naturally occurring isotopes of hydrogen and oxygen from glaciers compared with rainwater and other sources. Water samples collected from streams are analyzed for isotope levels by mass spectrometry to determine the percentage of glacier-fed water they contain; that fraction can be
People living in Peru’s Huaylas Valley get water for drinking and farming from the snowcapped Cordillera Blanca range to the east.
monitored for changes over time. Mark’s team collected 73 samples from streams in northern Peru’s Cordillera Blanca range, home to the largest glacier chain in the tropics. The results confirm that about two-thirds of the area’s dry-season water comes from glaciers, and that glacier-fed streams received an average of 1.6% more water over the period from 2004 to 2006. The data provide a baseline, and whether the change is “noise in the data will become obvious with a more complete survey,” says Brenda Ekwurzel, a geochemist at the advocacy group Union of Concerned Scientists. “People have the impression that global warming is making things hotter and that melts glaciers” directly, Mark says, but in the tropics, glacier mass loss is more complicated. The balance of snow and rain during the wet season can help determine whether a glacier gains or loses mass for the year. If there’s more snow, glaciers have a bright, white surface that reflects sunlight and reduces melting. Temperature matters, too; warm and dry years tend to melt
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glaciers more quickly. And during cold and dry conditions glaciers also sublimate, converting glacier ice directly to water vapor. This doesn’t mean global warming is not a factor, Mark says; changes in precipitation and humidity are linked closely to temperature. Andean farms rely on glacier water for crop irrigation, and populations depend on it for drinking water as well as hydropower. Instrumentation to monitor water supplies and glaciers is scarce. “Much of the network is quite old and is falling apart,” says Mathias Vuille, a University of Massachusetts Amherst climatologist. The World Bank and Global Environment Fund are working to install more stations, but these will face harsh weather and vandalism. Mark says that people in Peru ask him regularly what they should do. It’s a tricky question, he says, and politically charged in developing countries that caused little of the current warming. In addition to the human cost, “the entire ecology of the mountains is changing and will change forever,” Vergara adds. —ERIKA ENGELHAUPT © 2007 American Chemical Society
Ken Hammond/ USDA
In 2002, Maria José González of the Spanish National Research Council (CSIC) was asked by the Province of Madrid’s Public Health Authority to assess the population’s exposure to persistent organic pollutants (POPs). Experts agree that her findings about the uptake of PBDE flame retardants by the citizens of central Spain, published in ES&T (pp 6961–6968), are intriguing.
Samples of breast milk from mothers in Spain showed the same puzzling PBDE pattern as previously seen in electronics-recycling workers.
One reason the findings are interesting is because of the study’s design, González says. The samples were taken from newborn babies and both of their parents. In all, 391 samples of maternal blood serum, paternal serum, umbilical serum, placental serum, and human milk were collected between October 2003 and May 2004. Researchers from Spain’s Institute of Health Carlos III also collaborated on the project. González and her colleagues looked for 15 PBDE compounds, or congeners, in the samples, including the heaviest BDE-209 molecules associated with the Deca formulation used in electronics products. The majority of human-milk PBDE studies conducted to date haven’t measured BDE-209, points out Åke Bergman, chair of Stockholm University’s environmental chemistry department.
The study population’s overall concentrations of PBDEs were similar to those found elsewhere in Europe—where levels tend to be an order of magnitude lower than those in North America. But the Spanish researchers were surprised to find that the dominant congeners varied within the sample set. As is typical for samples from Europe and North America, the predominant congener in the maternal, paternal, and umbilicalcord samples was BDE-47, which is found in the Penta and Octa formulations banned by the EU in August 2004. However, BDE-209 was the dominant congener in the placental serum and breast milk samples. In the past, this pattern has been seen mainly in people who work in electronics recycling. The only study to report similar findings was conducted by Adrian Covaci of the University of Antwerp (Belgium), who reported dominant concentrations of BDE209 in pooled Belgian umbilical serum (J. Chromatogr. B 2005, 827 [2], 216–223). More data on the toxicokinetics of BDE-209 are needed to explain these findings, he stresses. The new research also provides data for the ongoing debate over whether different PBDE congeners cross the placenta at varying rates. However, “in contrast to most previous studies, maternal serum and cord serum [were] not sampled simultaneously,” points out Kristina Jakobsson, a physician at Lund University Hospital (Sweden). “This is not likely to affect the levels of the low–medium [weight] PBDEs, which have a long half-life (years), as much as it might affect levels of BDE-209, which [has] an apparent half-life as short as 14 days. . . . Thus, from a theoretical standpoint, a steady state cannot be assumed.” —KELLYN BETTS
News Briefs Saving energy at DOE
The U.S. Department of Energy (DOE), the country’s largest energy user, pledged in August to cut its energy intensity by 30%. The agency encompasses 110 million square feet of facilities and more than 14,000 vehicles. DOE estimates that reducing its energy per square foot usage by this percentage will save approximately $90 million in taxpayer dollars per year after projects are paid for. Secretary Samuel Bodman says DOE’s new policy will “fundamentally transform” the way the agency manages energy, ending what the agency refers to as its “incremental approach to saving energy.” DOE’s commitments include maximizing renewable energy usage and aspiring to Leadership in Energy and Environmental Design (LEED) gold certification for new construction.
Food and fuel from crops
Higher crop prices resulting from the global biofuel boom could be a boon to the world’s rural poor, according to a new book from the Worldwatch Institute, a nonprofit research and advocacy group. That conclusion challenges the notion that biofuels harm the poor by raising food prices, known as the “food versus fuel” problem. Biofuels for Transport: Global Potential and Implications for Energy and Agriculture examines sustainability issues facing the biofuels industry in areas such as climate, water, poverty, and conservation. Higher prices could raise farmers’ incomes, “but major agriculture reforms and infrastructure development will be needed to ensure that the increased benefits go to the world’s 800 million undernourished people,” said Christopher Flavin, Worldwatch’s president.
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Are people’s PBDE uptake patterns changing?
Environmentalt News Advancing water-quality credit trading program to incorporate the credit trades into the National Pollutant Discharge Elimination System (NPDES) permits, which are already in place to control effluents from stationary sources. These permits are approved by states or EPA regional offices, depending on the location.
The nonprofit Wetlands Initiative plans to restore this mudflat on the Illinois River to a wetland in order to provide credits for water-quality trading.
“The toolkit is, in some respects, a milestone among several that provides guidance for folks who want to do it,” says consultant Lisa Bacon of CH2M Hill, an engineering company. Bacon says that the existing U.S. trading programs represent only a small percentage of what is possible. Successful water-quality credit trading has occurred in some areas—for example, in the Neuse River and Tar-Pamlico Sound. Under a program initiated by North Carolina in 1995, point and nonpoint sources trade nitrogen and phosphorus credits under NPDES permits. Activity in the Chesapeake Bay Program, which has promoted voluntary trading in Virginia, Pennsylvania, and Maryland since 1999, is intensifying. The cautious optimism for trading comes 5 years after EPA issued nonbinding policies for waterquality credit trading, and more than 10 years after it laid down trading guidelines. The objections and potential benefits remain the same as a decade ago. “We don’t understand how nitrogen moves across the landscape, [which makes it] a slippery molecule from
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Jill Kostel , The Wetl ands Initiative
Expanding its support for market-based trading programs, the U.S. EPA recently issued a permitting “toolkit” to help state regulators and water polluters develop a nutrient credit trading scheme. The toolkit provides ideas for controlling nonpoint-source pollution and for reducing the nitrogen and phosphorus that flow freely into waterways. At a press conference last July, Benjamin Grumbles, EPA assistant administrator for water, pointed to the success of the trading scheme between stationary, “point-source” water treatment plants on Long Island Sound, established in 2002. That program involves pollution credit trades, similar to carbon trades for air polluters, designed to reduce nutrient pollution of waterways. The trading plan has saved these treatment plants $200 million in projected infrastructure investments, Grumbles said. Nonpointsource pollution, or diffuse surface runoff from sources such as urban streets, suburban lawns, and farm fields, however, remains difficult for the U.S. to control, he added. Point-source trading has happened voluntarily for years. Under a nutrient trading scheme, industrial dischargers, for example, can sell pollution credits, each representing pounds of a pollutant, to other stationary water polluters that buy the credit rather than upgrading equipment or taking other steps to control discharge. Polluters can buy the credits from farms, developers that manage construction sites, or other places where owners use best management practices (BMPs) to control surface runoff or other nutrient flows. Examples of BMPs include planting a grove of trees between a barnyard and a stream to reduce runoff, trucking away chicken manure, and even creating an expensive new wetland. Such trading programs allow emitters to pay others to use BMPs to control surface runoff. EPA encourages participants in a trading
a regulatory point of view,” says Alex Echols of the nonprofit Sand County Foundation, which promotes industry conservation efforts. “Unless you can control the rain, you can’t control how nitrogen is going to move,” Echols says. More science may be needed to determine which measures work best, but it’s still possible to act, he emphasizes. Monitoring nutrients as they move into groundwater and streams remains difficult; attempts to determine environmental fate and transport often come from models instead of onthe-ground numbers. Upstream releases at different times could have different, unpredictable effects downstream. Observers worry about the potential for creating hot spots from concentrated discharges, and also that trading may not be limited to projects done on a smaller scale that remain inside affected watersheds. Although large trading programs have been suggested for the Mississippi River, successes have remained limited to smaller watersheds so far. Although proponents hold up the SO2 air-pollution trading program established by EPA in 1995 to control acid rain as an example, creating a thriving market for water-quality credits is a muddier proposition. BMPs to control nonpoint-source water pollution are inherently harder to monitor and enforce than monitoring emissions from power plants, for example, remarks Albert Ettinger of the Environmental Law and Policy Center. Still, the new EPA toolkit gives a positive signal “that this approach is strongly encouraged,” says Kathleen McGinty, secretary of the Pennsylvania Department of Environmental Protection. Supporters and critics insist that to make a trading scheme productive, states need more federal funding to support the new administrative, monitoring, and remediation requirements. All this is necessary, they say, even though most programs remain voluntary. —NAOMI LUBICK
News Briefs
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Truck, train, or airplane—which one has the smallest environmental footprint when it comes to shipping? A new assessment published in ES&T (pp 7138–7144) examines the emissions released over the life cycles of several forms of freight transportation for long-distance deliveries in the U.S. Although rail transportation has the lowest emissions overall, all forms of transportation have phases in
Although trains may be a relatively clean type of transport, other life-cycle stages must be considered.
which emissions are much worse than in others. The researchers conclude that policy actions designed to reduce emissions from one phase of the life cycle can have unintended negative consequences, and they recommend policies that consider each phase carefully. Cristiano Facanha of ICF International, a consulting firm specializing in transportation issues, and Arpad Horvath of the University of California Berkeley focused their life-cycle assessment (LCA) on greenhouse gases, particulate matter (PM), and other emissions from the U.S. freight transportation system. The researchers included data on emissions from building roads, tarmac, and rails, evaluated according to miles traveled by the ton. They also looked at the emissions generated by the machinery used to load a plane or to lift a container onto a railcar as well as emissions from producing the fuel to keep the trains, trucks, and planes
in motion. The assessment did not include the “short run” miles that are toted up by smaller trucks that might deliver goods to an airplane or rail yard for shipping. The researchers also excluded ship emissions, because those are limited mostly to freight on certain stretches of the Mississippi River or Great Lakes in the continental U.S. Facanha and Horvath included tailpipe emissions generally considered for such studies: nitrogen oxides (NOx), SO2, PM less than 10 micrometers in diameter (PM10), carbon monoxide, and CO2. They combined two LCA methods to overcome the limits of each: process-based analysis, which translates inputs and outputs to a representative unit, and economic input–output analysis, which combines economic data with environmental impact. The authors found that CO2 and NOx emissions tend to be underestimated, by up to 38% for airplanes, but less so for trains and trucks. Facanha notes that “most of the time, rail is better than trucking—but you definitely have to qualify it.” The authors’ policy models show that although NOx and SO2 may decline after restrictive regulations are in effect, PM10 might not. “We’re trying to raise the awareness of the decision makers” in both government and business, Horvath says, that “it’s not enough to focus on your fleet for delivering goods; it’s important to focus on other parts of the economy that service your goods, or delivery mechanisms.” What Facanha and Horvath found may not be all that surprising, says Sonia Yeh of the Institute of Transportation Studies at the University of California Davis. And although the authors “used very stylish policy scenarios,” these model cases “beg more questions regarding the feasibility, costs, and the adequateness of current policies to regulate upstream emissions.” —NAOMI LUBICK
Sea ice hits new low
On August 16, satellite images showed less sea ice covering the Arctic than ever before in recorded history, a month before the expected yearly minimum. Satellite measurements showed 5.26 million square kilometers (km2 ) of ice in the Arctic, less than the record minimum of 5.32 million km2 on September 21, 2005, according to researchers at the National Snow and Ice Data Center (NSIDC). After unprecedented ice loss in late June and early July—the equivalent of an area about the size of Kansas vanished each day—the team had predicted a 92% chance that Arctic sea ice extent would reach a new low by its September minimum. NSIDC posted ongoing news, commentary, and satellite images throughout the summer on its website at http://nsidc.org.
Cap and trade trumps CAFE standards
A cap-and-trade system to reduce greenhouse gas levels could be more effective at curbing oil use than increasing vehicle fuel efficiency, according to a new report by the U.S. Government Accountability Office (GAO), available at www.gao. gov/new.items/d07921.pdf. GAO reviewed recent studies and interviewed experts about the strengths and weaknesses of the Corporate Average Fuel Economy (CAFE) program of the U.S. National Highway Traffic Safety Administration. According to the report, released in August, a fuel tax or a carbon cap-and-trade program “would affect a broader range of fuel-saving behaviors among consumers and would likely be more cost-effective than CAFE.” Because designing and gaining support for these measures would take time, GAO recommends increasing CAFE standards and considering options to improve the program in the meantime.
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National Snow and Ice Data Center
Environmental costs of shipping
