While there is still debate concerning the causes and effects of acid rain, most scientists agree that extreme interpretations of the issue can now be eliminated. This is one conclusion drawn from a major international conference convened in February in Hilton Head, S.C., to examine and critique the findings of the National Acid Precipitation Assessment Program (NAPAP), a 10-year federally sponsored research and assessment effort.
When NAPAP was initiated in 1981, scientific opinion on acid rain was divided. The issue was viewed by some as a rapidly intensifying disaster requiring immediate remediation, and by others as a speculative hypothesis without sufficient substantiation. The NAPAP International Conference confirmed that most scientific opinion now lies well inside both of these two positions. The NAPAP work indicates that acid rain has damaged certain lakes and streams in the eastern United States and Canada, and that it contributes to decline of high-evaluation spruce-fir forests, materials degradation, and visibility impairment.