CARBONYL SULFIDE - NO REMEDY FOR GLOBAL WARMING

The enhancement of the stratospheric aerosol layer caused by the erupt ion of Mt. Pinatubo (June 15, 1991), and the subsequent cooling of the earth's lower atmosphere [Dutton and Christy, 1992; Minnis et al., 19 93] shows that stratospheric aerosols can have a strong effect on the earth's climate. This supports the notion that the intentional enhance ment of the stratospheric aerosol layer through increased carbonyl sul fide (OCS) emissions might be an effective means for counteracting glo bal warming. Through the use of a one-dimensional photochemical model, we investigate what effect such a program might have on global averag e stratospheric ozone. In addition, we consider the impact of enhanced OCS emissions on rainwater acidity and on the overall health of both plants and animals. We find that while the warming produced by a singl e CO2 doubling (1 to 4-degrees-C) might be offset with ozone losses of less than 5%, any attempt to use carbonly sulfide as a permanent solu tion to global warming could result in depletion of global average ozo ne by 30% or more. We estimate that in order to achieve cooling of 4-d egrees-C rainwater pH would fall to between 3.5 and 3.8. Finally, a 4- degrees-C cooling at the surface will require that ambient near ground OCS levels rise to above 10 ppmv which is probably greater than the s afe exposure limit for humans. Thus, enhanced OCS emissions do not pro vide an environmentally acceptable solution to the problem of global w arming.