During the time when scientists were debating about SDI and nuclear winter, some of the same scientists also debated acid rain: “As in the debate over tobacco, opponents of regulating the pollution that caused acid rain would argue that the science was too uncertain to justify action” (66).

In 1955, the US Department of Agriculture established the Hubbard Brook Experimental Forest to examine the effects of acid rain. Although naturally occurring acid rain—from volcanoes or other natural phenomena—and man-made acid rain was widely recognized as occurring, Hubbard Brook found that acid rain existed even in the most remote places in America, which was worrisome to many scientists. The Hubbard Brook work coincided with a shift in American thinking about environmentalism from broadly popular land preservation to science-based government regulation, an idea that was unpopular in conservative circles. People began to realize that reasonable-seeming private actions—such as spraying crops with pesticides—could have global repercussions, as in the usage of DDT: “Pollution was not simply a matter of evil industries dumping toxic sludge in the night: people with good intentions might unintentionally do harm” (68).

Hubbard Brook, and especially scientist Gene Likens, demonstrated that acid rain was a part of collateral damage from emissions, in a paper declaring that acid rain or snow fell in most of northeastern America.