This volume contains papers presented at a NATO Advanced Research Institute, sponsored by their Eco-Sciences Panel, on "The effects of acid precipitation on vegetation and soils," held at Toronto, Canada from May 22-26, 1978. The organizing expenses and greater part of the expenses of the speakers and chair~en were provided by N.A.T.O. The scientific programme was planned by T. C. Hutchinson together with an international planning committee of G. Abrahamsen (Norway), G. Likens (U.S.A.), F.E. Last (U.K.), C.O. Tamm (Sweden) and B. Ulrich (W. Germany). Many of the dimensions of the 'acid rain' problem are common to countries of northern Europe and North America. The developing awareness over the past ten years of the international nature of the acid rain phenomenon has lead to studies documenting damaging effects on susceptible freshwater bodies. Large areas of the Canadian Pre-Cambrian Shield, with its extension into the United States, and the granitic areas of southern Norwayand Sweden contain lakes which are in the process of acidification. The biological resources of these affected areas are of considerable national concern. However, while clearly damaging effects of acidification on freshwater systems have been well documented, the impact of acid precipitation on terrestrial systems has not been so well understood.

The climate change reckoning looms. As scientists try to discern what the Earth’s changing weather patterns mean for our future, Rachel Rothschild seeks to understand the current scientific and political debates surrounding the environment through the history of another global environmental threat: acid rain. The identification of acid rain in the 1960s changed scientific and popular understanding of fossil fuel pollution’s potential to cause regional—and even global—environmental harms. It showed scientists that the problem of fossil fuel pollution was one that crossed borders—it could travel across vast stretches of the earth’s atmosphere to impact ecosystems around the world. This unprecedented transnational reach prompted governments, for the first time, to confront the need to cooperate on pollution policies, transforming environmental science and diplomacy. Studies of acid rain and other pollutants brought about a reimagining of how to investigate the natural world as a complete entity, and the responses of policy makers, scientists, and the public set the stage for how societies have approached other prominent environmental dangers on a global scale, most notably climate change. Grounded in archival research spanning eight countries and five languages, as well as interviews with leading scientists from both government and industry, Poisonous Skies is the first book to examine the history of acid rain in an international context. By delving deep into our environmental past, Rothschild hopes to inform its future, showing us how much is at stake for the natural world as well as what we risk—and have already risked—by not acting.

'Acid rain' is a broad term used to describe several ways that acids fall out of the atmosphere. A more precise term is acid deposition, which has two parts: wet and dry. Wet deposition refers to acidic rain, fog, and snow. As this acidic water flows over and through the ground, it affects a variety of plants and animals. The strength of the effects depends on many factors, including how acidic the water is, the chemistry and buffering capacity of the soils involved, and the types of fish, trees, and other living things that rely on the water. Dry deposition refers to acidic gases and particles. About half of the acidity in the atmosphere falls back to earth through dry deposition. The wind blows these acidic particles and gases onto buildings, cars, homes, and trees. Dry deposited gases and particles can also be washed from trees and other surfaces by rainstorms. When that happens, the runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone. Prevailing winds blow the compounds that cause both wet and dry acid deposition across state and national borders, and sometimes over hundreds of miles. This new book combines an excellent background article with over 900 abstracts and book citations. Easy access is provided by title, author, and subject indexes.