An estimate on the rainout of atmospheric CO_2

Article type: Research Article

Authors: LIU, Chun-jiang^; | Ilvesniemi, Hannu | Kutsch, Werner | MA, Xiang-qing | Westman, Carl J. | Kauppi, Pekka

Affiliations: Ecology Center, University of Kiel, Schauenburgerstr 112, DE-24118 Kiel, Germany | Department of Forest Ecology, 00014 University of Helsinki, Finland | Forestry College, Fujian Agriculture and Forestry University, Nanping 353001, China | Department of Environmental Protection, 00014 University of Helsinki, Finland

Note: [] Corresponding author. E-mail: cliu@ecology.uni-kiel.de

Abstract: The CO_2 in the atmosphere is in contact with water vapor and rain droplets forming CO_2 ˙ H_2O, HCO^{-}_3 and CO^{2-}_3. Global precipitation is about 505 × 10^{15} kg/a. Based on theoretical calculation for unpolluted air and measurement observations, we estimated that 100-270 × 10^{12} gC/a are scavenged from the air by global precipitation. This roughly equals carbon emissions from volcanic sources or 2-6 per cent of current CO_2 emissions. An inventory-based estimate on carbon removal in northwestern Europe supports the above calculation on global scale. With increasing CO_2 concentration in the air, precipitation scavenging may increase.

Keywords: atmospheric CO[TeX:] _2, dissolution, dissociation, precipitation scavenging, rainwater

Journal: Journal of Environmental Sciences, vol. 16, no. 1, pp. 86-89, 2004