Atmospheric acidification in the Asian region.

Atmospheric acidification in the Asian region is discussed from the perspectives of currently available regional measurements, and the knowledge now available from several decades of acidic deposition research in the northern mid-latitudes. The main conclusions emerge: (1) that there is insufficient information currently available to enable a quantitative assessment of the present state or future potential for atmospheric acidification across the whole region; and (2) that within the limitations imposed by (1) the possibility of future acidification in certain areas cannot be ruled out if economic development and energy use on a per capita basis evolve to the levels of the major industrial countries. These two conclusions point to the need for systematic, multidisciplinary studies covering the whole region. The studies should assess quantitatively the current levels of acidic and alkaline emissions (both natural and anthropogenic) to the atmosphere, identify the relevant chemical transformations and transport/deposition pathways in the regional atmosphere, and assess the susceptibility of regional plants, soils and groundwaters to acidification.