Acidification is one of the most serious environmental problems, especially in Sweden, which suffers most from the consequences of acid rain. Besides international negotiations to reduce sulphur emissions - 85% of the acid load on Sweden can be traced to emissions from outside Sweden - the Swedish Government has employed large-scale operative liming activities to counteract acidification of surface waters. The scientific results show that - although acidification cannot be solved by liming - the measures taken resulted in substantially improved conditions in around 8,000 Swedish lakes and watercourses, and other countries affected by acidification may also profit from the Swedish experience.