How science formed a breakthrough for international acid rain policies

Lars Walloe, University of Oslo

In the late 1960s Svante Odén received strong support from Professor Eilif Dahl at the Norwegian Agricultural University. He invited Odén to Norway and together they gave lectures to Norwegian forest owners and representatives of the wood-processing industry. As a result the technical-industrial and the agricultural research councils in 1972 funded a research programme with the title “The effects of air pollution on soil, vegetation and water”. Fortunately, at the same time the Norwegian public expressed concern about what seemed to be a strong decline in the abundance of fresh water fish in rivers and lakes in southern Norway.

The marine fisheries biologist Alf Dannevig had already in 1959 suggested that this decline was caused by acidification of surface waters. The Ministry of Environment decided to participate in the funding of the research programme on the condition that the possible decline in fresh water fish was also investigated.

The funding increased considerably and the programme changed its title to “Acid precipitation – effects on forest and fish” (SNSF). The programme was planned to last for three years (1973-75) and to end with an international conference in 1976. The programme was managed by a three person steering committee representing the two research councils and the ministry.

Many of the researchers working in the programme were junior scientists attached to applied research institutions or the agricultural university, most of them without a doctoral degree. When the first results from the programme were published in late 1975 and early 1976, indicating effects of the acid precipitation both on forest and fish, the programme received strong and serious criticism from a number of heavyweight professors from the Science Faculty of the University of Oslo, foremost among them Professor Ivan Rosenqvist who was professor of geology.

The criticism was intensified by the representatives of the foreign governments during the international conference in June 1976. Rosenqvist was persuaded to present his arguments in writing, which he did the following autumn, and the SNSF programme responded by a report without a named author, but which was mainly written by Eilif Dahl.

In the meantime the Norwegian parliament had decided to fund the programme for another four years. Gro Harlem Brundtland, who was appointed minister of environment in 1974, was worried, and I was asked to be new chair of the steering committee with free hands to reorganise the programme as I felt necessary. I believed at the time, wrongly, that the conflict mainly was about scientific evidence. I soon discovered that the main conflict was political, both within Norway (industry versus environment) and between Norway and Sweden on one side and especially UK on the other side.

When I started to look into the scientific evidence I was soon convinced that the arguments for sulphur deposition causing surface water acidification and fish death were good. They needed additional investigations to strengthen the evidence, and especially Rosenqvist’s alternative hypotheses needed to be explored. However, on the forest question, I found no convincing evidence of any effect at all. During the next few years we developed a number of different small scale field experiments and computer simulation models to try to find traces of effects, but without any results.

We presented our final results to an international conference in March 1980. Our conclusions were that the long transported sulphur deposition had caused an acidification of surface water in southern Norway with a serious die off of fresh waters fish populations (salmon and trout) as a main consequence. We did not find any effects on forest growth in our ecosystems. Thus Svante Odén’s (and Eilif Dahl’s) main hypothesis was rejected.

Scientists and politicians in UK did not accept our results on fish deaths. When we presented our results in a meeting in the Royal Society in 1980, one senior academy member said: “Every important result obtained by a non-British scientist, must be confirmed.” This ‘confirmation’ happened during the British-Swedish-Norwegian research programme “The Surface Waters Acidification Programme” (1984-90).

Many new details were explored and studied, but the main conclusions from the SNSF programme did not change.

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