Acid Rain Resists '90s Fix, Study Says
Scientists urge new emissions cut
By Beth Daley, Globe Staff, 3/26/2001
New England's forests and lakes are not recovering from the toxic effects of acid rain despite significant cuts in the power plant emissions that cause it, a team of 10 leading scientists will announce today.
Acid rain, which corrodes car paint and kills trees, has caused far more environmental damage than projected a decade ago, the researchers report in the journal BioScience. To bolster 1990 limits placed on acid rain's main component, sulfur dioxide, the team says, an additional 80 percent reduction is needed to bring sensitive streams back to non-acidic levels within 25 years.
''In 1990, the businesses, politicians, and public took a collective sigh of relief and said `that problem is over,' and it's not,'' said Gene E. Likens, one of the report's authors and director of the Institute of Ecosystem Studies in Millbrook, N.Y. Likens first identified acid rain in North America in 1972 in the Hubbard Brook Experimental Forest in New Hampshire. The recent study also took place there.
''Acid rain continues to have a significant ecological effect,'' he said.
The news is worrisome to conservationists, who fear that President Bush - who recently reversed a campaign pledge to regulate carbon dioxide from power plants - will be unwilling to place any new limits on electric utilities. About 60 percent of the sulfur dioxide found in the atmosphere comes from power plants that rely on burning fossil fuels, such as coal, to generate electricity.
Electric industry officials say any new limits are unfair because it is too early to judge the effectiveness of the 1990 Clean Air Act amendments. Strict acid rain regulations were not implemented until 1995, they say. By 2010, power plants are required to reduce their sulfur dioxide emissions to 50 percent of 1980 levels.
''The environmental benefit of the reduction has not been given time to work,'' said Dan Riedinger of the Edison Electric Institute, an association of electric utilities. ''It was with the understanding it would take a couple of decades to see the results. We are confident we will see improvement under the acid rain program.''
Acid rain was cited as one of the world's most vexing environmental problems in the 1970s and 1980s. The problem is particularly apparent in the Northeast because the region is downwind from Midwest power plants that release high levels of sulfur dioxide.
The plants also produce nitrogen oxides, the second largest contributor to acid rain, which motor vehicles also emit at high levels. The gases react in the atmosphere over New England, causing smog and acid rain.
That rain falls, making lakes and streams more acidic. As a result, some lakes in the region are too acidic for fish. Fifteen percent of lakes in New England are either chronically or periodically acidic, the study says.
At high elevations, thin soil also becomes acidic from these pollutants and dissolves nutrients that trees need to thrive. The study's authors estimate 25 percent of the red spruces in the White Mountains have been wiped out because of acid rain.
Although the sulfur content of acid rain has decreased 38 percent since controls were put into effect, the forests and trees have not recovered as expected, the study found. Mineral buffers in the soil such as calcium, which neutralizes the acid much the way drugstore antacids ease indigestion, have been depleted. With that buffer gone, deeper levels of soil are that much more sensitive to acid rain.
''When the 1990 Clean Air Act went into effect, [the loss of buffers] wasn't widely known,'' said Charles T. Driscoll, one of the study's authors and a professor of civil and environmental engineering at Syracuse University. ''These forests have been bathed by acids for 30 years.''
Some buffers, including calcium, are also important nutrients for trees. In their absence, trees are more susceptible to insect infestation and weather change.
Federal legislation has recently been filed to cut sulfur emissions an additional 50 percent to 75 percent. But scientists say reductions need to be made as soon as possible if the Northeast is to recover anytime soon.
This story ran on page A01 of the Boston Globe on 3/26/2001.