Some ship emissions may help cool planet - Environmental Science

Some ship emissions may help cool planet. Kellyn S. Betts. Environ. Sci. Technol. , 2000, 34 (3), pp 65A–65A. DOI: 10.1021/es003105a. Publication Da...
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on the status of federal research activities into indoor air pollution. Henry Waxman, ranking minority member of the House Committee on Government Reform, commissioned the report out of concern for the slow pace of progress in understanding and devising effective solutions to the problem of indoor air pollution. EPA officials and others have consistently identified indoor pollution as one of the most serious environmental risks to public health, according to the GAO

report. But with no legislatively mandated goals or time frames to give indoor pollution the clout that leads to strong programs within the agency, indoor air pollution remains a poor stepchild, the GAO found. EPA's Science Advisory Board in 1998 criticized the agency for failing to commit sufficient funds to indoor air pollution research, but despite these concerns, EPA eliminated the budget item in its fiscal year 2000 budget, according to the GAO report.

In 1997, the Presidential and Congressional Commission on Risk Assessment and Risk Management concluded that indoor pollution can pose a substantial public health risk. The Commission noted that, "while outdoor air pollution is extensively regulated, problems in offices, public buildings, and homes remain relatively unrecognized and unaddressed." Such neglect was likely to persist unless Congress mandated a change, the commission concluded. —REBECCA RENNER

Some ship emissions may help cool planet Levels of nitrogen oxides (NOJ over the ocean along popular shipping lanes may be elevated by more than 2 orders of magnitude, according to modeling simulations performed by researchers at Germany's Max Planck Institute for Chemistry. Ultimately, both NOj. and S0 2 ship emissions could have a cooling effect on the climate, according to the researchers. In November, the researchers reported results obtained from using a global tropospheric chemistry transport model called MATCH-MPIC (Lawrence, M.; Crutzen, J. Nature 1999, 40 (6758), 167-170). The NO, levels are a lot higher than what anybody expected over the ocean, said Spyros Pandis, associate professor of chemical engineering at Carnegie Mellon University (CMU). Pandis coauthored a research letter describing modeling data that shows how S0 2 in ship emissions could exert an important cooling influence by enhancing cloud formation (Nature 1999, 400 (6746), 743-746). The Max Planck modelers found that the elevated NOx levels could have a cooling effect because they significantly raise the concentrations of ozone and hydroxyl radicals along the shipping routes and across the ocean.

Although the ozone would contribute to global warming, the increase in hydroxyl radicals above the ocean could have the opposite effect by speeding up the breakdown of other greenhouse gases, notably methane. Hydroxyl radicals may also decrease the lifetime of the S0 2 spewed from ship stacks. This encourages more rapid formation of aerosols, which enhance cloud formation and solar Models show that both the NO, and S0 2 discharged by oceanreflection. going ships may cool the atmosphere. Because these comBecause there is very pounds are also pollutants, what effect this finding may have little empirical data on ship on policy is unclear. A thorough assessment of ship emissions' environmental impacts is due by the end of the year. emissions over the open ocean, the Max Planck modelers relied on calculations made by CMU researchers tion branch of EPA's Stratospheric based on international shipping Protection Office. But she noted data (Corbett, J., Fischbeck, E, and that EPA contributed funds to an Pandis, S. /. Geophys. Ress.999, International Maritime Organiza104 (D3), 3457-3470). Some of the tion project begun in 1999 to asdata needed to verify the model sess the environmental effects of observations will be collected by ship emissions, which has been the National Oceanic and Atmocontracted to researchers at CMU spheric Administration and the and three Norwegian organizaPacific Northwest National Labotions: Marintek, Det Norske Veritas, ratory on a research ship voyage and the Centre for Economic Anallater this year, Pandis said. ysis. The results of the project, which will include an evaluation of It is too early to tell what effect technologies that could cut ship _ these modeling results could have emissions, are expected later thus on policy, said Sue Stendebach, year. —KELLYN S. BETTS chief of the program implementaFEBRUARY 1, 2000 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 6 5 A