Acidification

A presentation shown at the Comenius meeting in Uddevalla 2011-10-14

Lake in Svartedalen, south of Uddevalla, heavily affected by acidification.

Connection between low pH- values and previously unexplained fish death found in 1967, by Ulf Lundin, who worked with the Fishery Department in Uddevalla.

Map shows vulnerability to acidification. The bedrock in Sweden and Norway has very little ability to handle acid rain.

It all began in Southern SwedenIn prior times an angler´s EdenTall chimney stacks to stop thesmogsAnd distribute them in Scottishbogs

Authorities in ScandinaviaBlamed it on the Brits´ behaviour

Succeeded in their prime objectiveBut led to heightened Scaninvective,

Since air pollution blithely coastsEastwards over frontier posts

On prevailing winds to roamTowards the ancient Vikings home

There to fall in rain or snowMaking lakes` pH too low.Fish populations throughaciditySuccumbed with unforeseen rapidity..

pH 4,5

Animation of pH-poem by Ian M. Torrens

Coniferous forests are particullary vulnerable to acid rain.

The rock carvings in Tanum (on Unesco´s World Heritage List) are endangered.

And so are medeival buildings and monuments.

Things are getting better. There is considerably less sulphur (as in sulphuric acid, H2SO4) in our rainwater nowadays.

Less sulphur in petrol as well as new techology for cleaning emissions from factories etc. help.

Swedish regions. Uddevalla is in Götaland

Sulphur improvment

When it comes to Nitrogen (and nitric acid, HNO3) nothing much has happened during the last ten years. Catalythic converters in cars do help, but more cars means more emissions.

Thousands of Swedish lakes are affected. Some of them get a twice yearly ”treatment” with limestone (CaCO3).

tThe limestone treatment is very costly. This picture shows a limestone mine on the island of Gotland.

pH in precipitation 1985 - 1997