Recovery of acidified European surface waters

Acid rain! Dead fish! Forest dieback! In the 1980s and 1990s, these headlines appeared frequently in environmental news coverage in Europe and North America. Air pollutants from highly industrialized regions had caused widespread damage to pristine ecosystems far downwind. The victims-people living in regions such as eastern Canada and Norway-pressured the polluters. In Europe, 30 countries engaged in tough negotiations that finally resulted in international treaties to reduce the emissions of sulfur and nitrogen oxides. Acid deposition has now declined by similar to60%, and some lakes and streams have begun to recover. Will all waters recover, or must emissions be reduced even more? And how long will recovery take? In this article, we try to answer these questions by using models to predict future acidification of surface waters in 12 acid-sensitive regions in Europe