The acidification problem is still an area of great concern. Many areas in the world are subject to large, in some cases increased, deposition ofacidifying substances. Scientific research has played a crucial role in the discovery and exploration of the problems as well as a basis for the development ofcontrol strategies for the more than 25 years that have passed since Svante Oden first presented his results. Even today scientific research is important as a tool for policy, most clearly observed in the effect-oriented second sulphur protocol under the Convention on Long-range Transboundary...