Long-Range Transboundary Air Pollution

In one line

Sulphur from British and central European chimneys was killing Scandinavian lakes, and the 1979 Convention was the first treaty to accept that a pollutant can travel a thousand miles and still be somebody's responsibility.

In exam wording: the Convention on Long-range Transboundary Air Pollution was done at Geneva on 13 November 1979 under the auspices of the United Nations Economic Commission for Europe and entered into force on 16 March 1983; article 1 defines air pollution and long-range transboundary air pollution; article 2 states the fundamental obligation to endeavour to limit and as far as possible gradually reduce and prevent air pollution including long-range transboundary air pollution; and articles 3 to 12 provide for policies and strategies, consultations, research and development, exchange of information, the cooperative programme for monitoring and evaluation, and an Executive Body.

What the science forced

By the early 1970s Swedish and Norwegian researchers had shown that lakes and forests were acidifying, that the cause was sulphur dioxide and nitrogen oxides, and that most of the sulphur was not Scandinavian. It had been emitted hundreds of miles away and carried by the wind.

That was legally awkward. Trail Smelter was about two neighbours and a plume that travelled seven miles. Here the emitting States were many, the receiving States were several, and no individual source could be shown to have caused any particular lake to die.

The Convention's response was to treat the problem as collective rather than as bilateral, and that decision is what makes it the ancestor of the ozone and climate regimes.

Article 1: the definitions

Air pollution means the introduction by man, directly or indirectly, of substances or energy into the air resulting in deleterious effects of such a nature as to endanger human health, harm living resources and ecosystems and material property and impair or interfere with amenities and other legitimate uses of the environment, and air pollutants shall be construed accordingly.

Long-range transboundary air pollution means air pollution whose physical origin is situated wholly or in part within the area under the national jurisdiction of one State and which has adverse effects in the area under the jurisdiction of another State at such a distance that it is not generally possible to distinguish the contribution of individual emission sources or groups of sources.

Read that second definition twice. The impossibility of attributing the harm to any particular source is not an obstacle the Convention had to overcome; it is written into the definition of the problem the Convention addresses. That is a legal drafting decision of the first importance, and it is what allowed a collective regime to be built where a liability regime was impossible.