The report appears in the October 13, 2003 edition of Environmental Science & Technology, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.
The Kyoto Protocol, drafted in 1997, was designed to provide binding commitments for reducing national emissions of greenhouse gases, with a special emphasis on carbon dioxide. Some countries, however, like the United States and China, have been reluctant to fully adopt the standards because of their potential economic burden.
In the new study, researchers from Columbia (N.Y.), Harvard and Princeton acknowledge the need to regulate carbon dioxide emissions, but they propose that a treaty dealing with air pollutants like ozone and aerosols, which can cause health problems, could be a better first step, uniting the interests of all countries involved.
"We suggest that it may be time to consider an international treaty to control air pollution on a hemispheric scale," said lead researcher Tracey Holloway, Ph.D. "The Kyoto Protocol addresses carbon dioxide emissions, which have no direct health impact, so they are not regulated currently as air pollutants." Holloway was at Columbia University when the study was done and is now with the University of Wisconsin-Madison.
An air pollution treaty that targets health-related pollutants "would tie in to regulations that most countries are already pursuing on a domestic basis," according to Holloway. One obvious example of this in the United States is the Clean Air Act, which regulates various pollutants, such as those that contribute to acid rain, smog, and ozone depletion. Holloway and her colleagues focused their research on ozone and aerosols. Both have lifetimes of about one week - long enough to be transported from Asia to the United States, as well as shorter distances across the Atlantic - and both pose health risks associated with respiratory disease, which Holloway says makes them more immediate concerns to countries than carbon dioxide.
But ozone and aerosols also contribute to large-scale climate problems, Holloway said, so the implications of controlling them go beyond air pollution into the realm of climate change.
The case for controlling greenhouse gases other than carbon dioxide was first presented three years ago by James Hansen of NASA's Goddard Institute for Space Studies, according to Holloway.
Holloway believes an international air pollution treaty would not encounter the roadblocks that the Kyoto Protocol has faced. "It would be serving the self-interest of participating countries to address short-term health risks," she said. "Regulation could take shape without immediate reform of the domestic or international energy economy, and energy savings implemented to achieve air quality goals could have the win-win effect of reducing carbon dioxide emissions as well."
Holloway suggests a treaty based loosely on the 1979 Convention on Long-Range Transboundary Air Pollution (LRTAP), which initially addressed acid rain deposition in Europe through voluntary participation. The convention has since been amended to cover a broad range of pollutants, and participants include countries from Western and Eastern Europe as well as the United States and Canada.
Expanding such a treaty to include Asia would give the United States even more incentive to participate, Holloway says, since westerly winds spread pollution from that part of the world to North America. "Asian countries are already concerned about air pollution," she added, "and are making significant strides toward domestic control."