A large number of nationwide research programmes in the field of acidification have been carried out in the last decade. Especially in Western Europe, extensive programmes have resulted in a good overview of all the effects – mostly negative – caused by acidifying substances. There is now consensus that types of acidification damage relate to the unique geography of an area: air pollution affects vegetation; acid aerosol the ozone layer. New in this volume, is the relation between scientific results of integrated research programmes and policy actions to prevent, reduce and limit the widespread damage caused by acidification. The results of many different national research programmes are evaluated and compared to present a unique compilation for the research scientist and policy maker. In this volume thematic reviews on specific topics of acidification research are presented, followed by overviews of acidification policy plans and actual abatement plans. The result is the best review of acidification research carried out worldwide during the last decade and presentation of the critical relation between research results and policy actions.