The decreasing acidification of Swedish lakes, streams and forest soils is a good example of the benefits of international agreements and focused environmental efforts.
Acidification has decreased
The main source of acidification – emissions of sulphur from the combustion of oil and coal – has decreased.
Between 1989–1991 and 2005–2007 sulphur deposition in Sweden declined by 61 percent. Deposition of nitrogen, a contributory cause of acidification, declined by 23 percent. Another, growing, source of acidification is the removal of base cations through forest harvesting.
Fewer acidified lakes
About five percent of Sweden’s lakes exceeding one hectare in area were acidified and unlimed in 2005. The problem is worst in southwest Sweden.
Soil acidification persists
New data shows that the state of acidification is relatively unchanged except in the southwestern part of the country, where acidification has increased since the beginning of the 2000s.
Acidified forest soil (in Swedish)
Sweden’s heritage under threat
Acidifying substances in rain, air, water and soil accelerate the deterioration of buildings, bridges, statues and decorations. Buried objects such as pipes and historical remains are also attacked.
Reduced acid rain
Sulphur and nitrogen deposition in Sweden has declined. However, emissions of these substances must be reduced still further to stop acidification. The interim target for emissions of sulphur dioxide to air within the envionmental quality objective Natural Acidification Only has already been met.
Sulphur dioxide emissions (in Swedish)
World-leaders in liming
Sweden’s liming programme, the largest in the world, began in 1976. Today over 5,000 lakes and 9,000 kilometres of streams are limed each year.
International cooperation
Further reduction of acidification depends on greater international cooperation, with all countries agreeing to cut their emissions of acidifying substances. Sweden is a strong promoter of this cause in the UN and the EU.
Summary of EU legislation, Air pollution
Convention on Long-range Transboundary Air Pollution