E&S scientist Timothy Sullivan worked with scientists from the State University of New York and U.S. Geological Survey to measure how the chronic acidiﬁcation of forests, lakes, and streams has affected the potential economic and cultural beneﬁts they provide to society. Because most impacts of acid rain affect ecosystem functions that are poorly understood by policy-makers and the public, an ecosystem services (ES) framework can help to measure how pollution affects human well-being. Focused on the Adirondack region (USA), a global ‘hot-spot’ of acid pollution, the team estimated that acid-impaired hardwood forests provide roughly half of the potential beneﬁts to forests on moderate to well-buffered soils, an estimated loss of ~$10,000/ha in net present value of wood products, maple syrup, carbon sequestration, and visual quality. As pH declines in lakes, the estimated value of recreational ﬁshing decreases signiﬁcantly due to loss of desirable ﬁsh such as trout. Hatchery stocking programs have partially offset the pollution-mediated losses of ﬁshery value, most effectively in the pH range 4.8-5.5, but are costly and limited in scope. This project spanned the years 2015 – 2017.