GRID-Arendal : State of the Environment Norway - Acid rain

Depositions and effects

Graph:Excess depositions of sulphur in Norway (in percentage of total area). Source: NIVA (Norwegian Institute for Water Research).

Map: Regional distribution of areas with fish stocks affected by acidification in Norway 1950-1990. Source: DN, Directorate for Nature Management.



Natural sustainability against acidification of fresh water has been exceeded in approximately 82,000 km², or 25 per cent of the area of Norway.

The situation is worst in southern Norway:
The sulphur content in precipitation has been reduced by more than 40 per cent since 1980. The water courses in this area have subsequently become less acidic. However, the critical load has been exceeded in large areas in southern Norway. The situation is worst in the Agder counties, where the critical load has been exceeded by more than 90 per cent.

There are indications that there is an increasing acid rain problem in the eastern region of Finnmark county (the northernmost in Norway) as a result of emissions from industry in Russia (Nikel and Zapoljarnij).

Excess depositions of SO2 in Europe

Excess depositions of SO2 in Europe (in tons per square kilometer). No colour=no data. Source: EMEP

In the sulphur protocol signed in Oslo in 1994, Norway commited itself to reduce SO2 emissions by 76 per cent by the year 2000. Excess depositions in Europe are to be reduced by 60 per cent. Most countries will have reached this goal in the year 2000, but some countries will not have reached their commitments before the year 2010. Great Britain, Germany, Poland and Russia contributing the most to the acidification in Norway, will reduce their emissions by 80, 87, 66 and 40 per cent respectively.
In the year 2000, the emission reductions will be 40-50 per cent. Calculations based on the sulphur protocol, show that the areas in Norway where the critical load has been exceeded, will be reduced to about 11 per cent in the year 2010.

Effects

Acid rain leads to corrosion of buildings. The acids corrode e.g. metals, paints and concrete. In Europe this is an increasing problem because historical constructions have become severely damaged. In Norway, this type of corrosion causes damages for NOK 2-300 million each year. Estimates show that Norway's total acid rain bill is approx. NOK 3,2 billion per year.

The damages are most severe where the ground consists of hard rock species with low contents of calcium and which weather slowly, such as granite and gneiss. Acid rain has had catastrophic consequences on fresh water fish stocks in Agder, Telemark and Rogaland counties.