Leslie Alm presents what may be the best study yet produced on the acid rain policy debate, at least with regard to its scientific underpinnings. The book describes the evolution of the current U.S.-Canadian acid rain policy agreement and focuses on the role of scientists in the formulation and implementation of acid rain policy. Alm found that most natural scientists believe they have little influence on the policy process. He suggests they are not trained to understand policymakers, and policymakers are not trained to understand science. Both have a narrow focus that causes them to perceive selectively what the other is saying. As does Lynton K. Caldwell (Between Two Worlds: Science, the Environmental Movement, and Policy Choice, 1990), Alm informs us that scientists and policymakers operate in two totally different worlds using two different languages and two different time scales; this complicates the policy process.