Rush to Judgment
Does Illinois export acid rain?
March 22, 1984
The dispute about whether and to what extent Illinois contributed to acidic precipitation in the Northeast U.S. and Canada was heated. Illinois’s attempts to protect the quality of its own air by injecting power plant emissions into upper air layers using taller smokestacks moved pollution but not remove it.
Politicians often rush in where scientists fear to tread. Unlike the scientist's, the politicians' propositions need not be proven, only plausible. No controversy better illustrates the point than acid rain. The distance between the statements, "Power plants cause acid rain" and "Emissions from the Kincaid station at Pawnee cause acid rain on Whiteface Mountain in the Adirondacks," is the distance between the stump and the lab.
Acid rain is a campaign packager's dream—a punchy phrase, the right villains, and a phenomenon complex enough that the average voter won't recognize a half-truth when he hears it, provided it's spoken with conviction. Best of all it's a cause which appeals to the bourgeois environmentalist constituency. A Dartmouth biologist spoke to an acid rain conference at the University of Illinois last fall, and suggested delicately that acid rain would not be the burning issue it has become in the Northeast were it not for trout fisherman aggrieved at the loss of their idylls on the stream away from the hurly burly of the office. (It's interesting to speculate how the acid rain issue would have evolved had the finger of evidence pointed to camp stoves in New Hampshire rather than power plants in Ohio.) Few Illinois coal miners are likely to have read William Tucker's 1982 book, Progress and Privilege. But most of them would endorse his view of environmentalism as a campaign to preserve wilderness as a playground for the well-off. Trout fishermen are a vested interest just as coal and utility companies are, albeit with rather better manners.
That sulfur emissions from coal-fired power plants are a major source of acidic precipitation falling in the northeastern U.S. and eastern Canada is not disputed. Nor is the fact that acid rain is bad for some living things. Much of the rest is inference, not evidence. Take the crucial issue of pollutant transport. Taylor Pensoneau of the Illinois Coal Association puts the industry's view like this: "This fight—and it is a fight—is being fought on two battlegrounds, political and scientific. On the scientific front, for the first time we're getting in-depth research. Proponents of acid rain controls in the Midwest, we feel, grossly underestimated the effect of local emissions right there in New England."
Did they? In a position statement released last month, the Illinois Acid Rain Task Force, a coalition of seven state and local groups with environmental interests, took issue with the coal industry's "scare tactics." The task force stated, "The long-range transport of sulfates is the dominant source of deposition over much of the eastern U.S."
But what is long-range? To date, the most prestigious opinion expressed on the point is that of the National Academy of Sciences, which released its own exhaustive review of the acid rain evidence last summer. The NAS confirmed a link between acid rain in the Northeast and sulfur emissions from power plants. But whose power plants? Michael Witte is the director of the Illinois Department of Energy and Natural Resources. Witte notes the NAS conclusion that cause-effect relationships could be reliably drawn between emission sources and receptor sites across distances of 300–600 kilometers—roughly 190 to 380 miles. In round figures, the distance from Illinois to Whiteface Mountain is twice that. "All they say is that every once in a while, emissions from Illinois have some effect at a distance of 1,000 kilometers," Witte explains, "but those effects are intermittent and vary with conditions."
A certain regrettable imprecision is inevitable when any issue as complex as acid rain enters public debate. In an earlier report, the NAS concluded that acidic precipitation in ecologically sensitive areas such as the Northeast would have to be cut by at least 50 percent to significantly reduce the risks of damage. However, what goes up doesn't necessarily come down. The NAS insisted that uncertainties about the chemical and physical interactions in the atmosphere made it impossible to state by what percentage acid-causing emissions would have to be reduced to achieve the hoped-for 50 percent reduction in acid precipitation downwind. The environmentalists' Illinois Acid Rain Task Force nevertheless insists, "Achieving this goal means cutting sulfur dioxide emissions in half." But the equation cannot yet be made between cutting acid rain in half and cutting Midwest emissions in half.
Even the most basic questions about the acid rain problem still await answers, at least in the opinion of some respected researchers. Prior to the 1970s, for example, rainfall samples had been gathered only twice in the U.S.—a single year's data collected from roughly half the lower forty-eight states in the mid-1950s, and again for several years in the mid-1960s. It was from this data, in 1976, that researchers from Cornell detected a trend toward increased acidity in the rain and snow of the eastern U.S.
Richard Semonin is not so sure. Semonin is a meteorologist who has served on several major scientific panels on acid rain. He is also assistant chief of the Illinois State Water Survey in Urbana, at whose labs the rainfall samples collected as part of the present national acid-rain monitoring program are analyzed. Semonin has described the data from the sporadic samplings in the '50s and '60s as "questionable" because of differences in sampling techniques and monitoring sites.
Speaking at the U of I last fall, Semonin noted that pH readings (the pH scale is used to measured acidity and alkalinity of substances) can vary considerably even within small geographic areas. Sampling techniques can affect data too. Sampling has been done by many different agencies, often using different procedures and equipment.
More crucial is the complex nature of pH itself. In an attempt to confirm the trend toward increased acidity since the '50s, Semonin and his colleagues compared their own Illinois samples from 1960 and 1977 to the key mid-'50s data. Like many other researchers, they found that acidity had increased, especially between 1954 and 1960.
However, re-analysis showed that the concentrations of acids in the samples had not increased markedly. What was found were higher concentrations of alkalines. By buffering the acids, the alkalines caused the resulting pH reading to be atypically alkaline, with the further result that samples from subsequent years, whose balances of acids and alkalines were more typical, seemed more acidic by comparison. Semonin speculates that the samples from the '50s were contaminated in the field by dust blown about during the drought that afflicted the nation's midsection during much of that decade. Rainfall in the '60s and '70s was not more acidic than usual, he suggests. Rather, rainfall in the '50s was less acidic than usual.
Adjusting the '50s data nationwide for normal concentrations of alkaline dust, Semonin found, resulted in changes in precipitation acidity much more subtle and geographically more diffuse than has been generally believed. A recent survey of surface water data by the U.S. Geological Survey tends to confirm that finding, Semonin says. The USGS concluded that increased acidity in the Northeast happened prior to the 1950s and has stabilized since the 1960s (although it seems to be increasing in other parts of the country). The trend toward acid rain may not be much of a trend after all.
Are environmentalists arguing for controls that aren't needed? Maybe, but the point remains unproven, at least insofar as controls would apply in Illinois. Acid rain is not the first environmental "crisis" in which political pressure forced experts into the practice of what some have called "anticipatory science." One thinks of the ozone panic, or the mandatory chlorination of sewage effluent which may be a graver threat to human health than the bacteria it was installed to kill.
In the past, the costs of such caution were modest. In the case of acid rain the costs could be anything but modest. Gov. Thompson has joined the Reagan administration and the coal and utility industries in a call for more research. The fact that there is as much convenience as conscience in the appeal should make the rest of us suspicious of their motives, to be sure. But it should make us suspicious of ours, too. More research is a way to delay the imposition of needed controls, but it is also a way to avoid imposition of the wrong controls, or controls that are more expensive than they need to be. No one can make sense of the acid rain issue unless he is willing to consider that many environmentalists are willing to be wrong for the right reasons—or that corporation presidents can sometimes be right for the wrong ones. ●