ABSTRACT
Its strength lies in the cooperation mechanisms it installed, which pushed forward scientific and political dialogue on international air pollution issues (see Science), instituting a decisive forum for sharing knowledge on air pollution issues (Wettestad 2002) but also for proposing new policy instruments. The encounter of science and policy crystallized in progressively imposing differential national obligations based on the carrying capacity of local ecosystems (Lidskog and Sundqvist 2011), making central the concept of “critical load,” the quantitative estimate of an exposure to one or more pollutants below which significant harmful effects on specified sensitive elements of the environment do not occur according to current knowledge. The strong reliance on science was also soon demonstrated by the crucial role given to modeling for assessing the presence and impact of air pollution (see Assessment), among which the Regional Acidification Information System (RAINS) model (Tuinstra et al. 2006).
