Acid rain researchers support greater emissions reductions

WASHINGTON – New England lakes, forests and streams will die without stronger controls on power plant emissions, concludes a group of researchers studying the effects of acid rain for nearly 30 years in a report being released today.

Ten leading acid rain researchers returned to the New Hampshire forest where the effects of acid rain were first detected in 1972 and found that the reduction of sulfur emissions from power plants, particularly in the Midwest, was not high enough to bring parts of the ecosystem back to non-acidic levels.

The Hubbard Brook Research Foundation, which organized the study and manages the New Hampshire forest, is calling for an additional 80 percent reduction in sulfur emissions from electric utilities. This level would bring the forest back to nonacidic levels in about 25 years.

Sulfur dioxide emissions have dropped 38 percent since changes to the Clean Air Act in 1990, but at that rate it could take up to 50 years before the ecosystem fully recovers, researchers said.

“Recovery from years of acid deposition will require much deeper cuts than called for 10 years ago,” said Charles Driscoll, a professor at Syracuse University and the primary author of the report, which will be published in BioScience, a journal containing articles reviewed by fellow scientists.

Sulfur dioxide and nitrogen oxides are the primary causes of acid rain. The majority of all sulfur dioxide and a portion of nitrogen oxides come from electric power generation that relies on burning fossil fuels like coal.

Acid rain occurs when these gases react in the atmosphere with water, oxygen and other chemicals to form various acidic compounds. Sunlight increases the rate of most of these reactions. The result is a mild solution of sulfuric acid and nitric acid.

Acid rain can be either wet or dry. The wet form is acid rain, fog and snow and seeps into the ground, affecting plants and animals. The dry form is in acidic gases and particles and blows onto buildings, cars, homes and trees.

About 15 percent of New England lakes are either chronically or periodically acidic and still show reduced aquatic life and species diversity, according to the study.

In addition, acid rain has caused the depletion of large quantities of available calcium, a plant nutrient in soils. The loss of nutrients such as calcium and magnesium from soil and foliage weakens trees, making them more susceptible to climatic and insect stress.

Northeastern states get the brunt of sulfur dioxide emissions, primarily from power plants in the Midwest. Power plants emit about 60 percent of all sulfur dioxide. Winds carry pollutants to New England and Canada in the form of acidic rain, snow, fog, gases and particles.

The electric utilities industry argues that the Environmental Protection Agency’s acid rain reduction program has a long way to go before the reduction of emissions should be judged.

“The acid rain program has been in effect for five years and only a portion of reductions have occurred in the late 1990s,” said Dan Riedinger, a spokesman for the Edison Electric Institute, a trade group that represents investor-owned electric companies. “That’s why our feeling is that there are much greater reductions to come due to more requirements. The report doesn’t account for reductions already under way but not yet complete.”

The political landscape for an 80 percent reduction is uncertain.

President Bush recently announced that he would not force power companies to regulate nitrogen oxides, sulfur dioxide, mercury and carbon dioxide. Soon after that announcement, Sen. Joseph Lieberman, D-Conn., introduced a measure he says would do the opposite and force power plants to reduce these types of emissions.