In fact, the cost came in far lower than anyone expected — just $500 million to $2 billion a year, by current estimates. But the real surprise was that the benefits were so large, between $59-$116 billion a year. Moreover, these benefits had far less to do with reduced acid rain than with unpredicted corollary effects on human health from reducing air pollution. At the time, the paradigm was that “like politics, all pollution is local,” says Joseph Goffman, executive director of Harvard’s Environmental and Energy Law Program, who helped write the original legislation as an attorney for the Environmental Defense Fund. The soot and other pollution that made a difference for human health was thought to come from nearby sources.