Study indicates sulfur dioxide emissions shifting from Northeast to Midwest
(The on-line version of the research paper cited below is available on the American Chemical Society's ASAP (As Soon As Publishable) web site. Journalists desiring full access to papers at the ASAP site must submit their requests in writing to newsroom@acs.org in the ACS Department of News & Information.)
The controversial "emissions trading" provision of the federal government's Clean Air Act is improving the environment and public health, especially in the Northeast and East, according to a new study by researchers at Resources For the Future (RFF), an independent think tank in Washington, D.C. Emissions trading allows power plants to trade, sell and bank allowances for sulfur dioxide emissions as a way for plants to hold down the cost of pollution reduction. Sulfur dioxide (SO2) is a primary cause of "acid rain."
The research report is in the Oct. 15 print issue of the peer-reviewed journal Environmental Science & Technology, published by the American Chemical Society, the world's largest scientific society. The study was initially published Aug. 31 on the journal's web site.
"The environmental consequences of trading have been the subject of considerable speculation and acrimony, especially in the Northeast," says the RFF's Dallas Burtraw, Ph.D., co-author of the study. However, he points out, the study - based on computer simulations of the trading program - shows that "pollutant concentrations are expected to decrease and health benefits actually to increase in the East and Northeast due to trading."
The findings contradict some critics of the program who believe the Northeast, particularly New York state, is receiving additional pollution from the Midwest as a result of trading.
The study indicates that emissions trading has actually shifted sulfur dioxide emissions away from the populated areas of the east coast toward the less populated Midwest. But Burtraw adds a cautionary note: "The shift could have gone the other way, so health or environmental effects of trading remain legitimate issues of concern." Nonetheless, Burtraw still believes SO2 trading and banking have "led to health-related benefits nationally."
"Health-related benefits resulting from trading in 2005 are estimated to be $125 million," according to the study. The health estimate does not take into account future health benefits as emission caps are lowered, it notes. Overall, the study's authors expect savings in the cost of compliance to total $531 million per year by 2005.
The study comes on the heels of one issued earlier this month by the U.S. Environmental Protection Agency that credits reductions in SO2 emissions for a decrease in acid rain and improvement in the quality of lakes and streams in Europe. That report noted that while acid rain also has been reduced in the U.S., the acidity of most of the country's lakes and streams has not yet declined, although improvement is expected in the future.
The RFF study used an integrated computer assessment model to evaluate changes in SO2 emissions and atmospheric concentrations, sulfur deposition and public health benefits from reduced exposure.
Title IV of the 1990 Clean Air Act Amendments established trading and banking as a way to encourage the electricity industry to minimize the cost of reducing SO2 emissions. It gives electric generating plants one emission allowance credit per ton of sulfur dioxide emitted and sets an annual cap on overall average emissions. To stay in compliance, plants that exceed their individual emission caps can obtain additional allowances from other facilities that have surplus allowances as a result of not exceeding their caps. Plants with surplus allowances also can bank them for use in future years.
The allowance banks that many plants are compiling will slowly be depleted as emission caps are gradually tightened, the study points out. Eventually, total sulfur dioxide emissions are expected to be cut in half as a result of the program, according to the report. "However," it adds, "the full effect of the emission reductions will not be felt until about 2010." That's when the buildup of allowances in the banks is expected to be depleted.
The U.S. Environmental Protection Agency describes sulfur dioxide trading as the "centerpiece" of its Acid Rain Program.
A similar regional trading program for nitrous oxide (NOx), a contributor to ground-level ozone and acid rain, has been proposed by the EPA.
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Environmental Science & Technology