Data from: An approach to sulfate geoengineering with surface emissions of carbonyl sulfide
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These files contain data along supporting all results reported in Quaglia et al, "An approach to sulfate geoengineering with surface emissions of carbonyl sulfide". In Quaglia et al. we found: Sulfate geoengineering (SG) methods based on lower stratospheric tropical injection of sulfur dioxide have been widely discussed in recent years, focusing on the direct and indirect effects they would have on the climate system. Here a potential alternative method is discussed, where sulfur emissions are located at the surface or in the troposphere in the form of carbonyl sulfide (COS) gas. Two time-dependent chemistry-climate model experiments are designed from year 2021 to 2055, assuming a 40 Tg-S/yr artificial global flux of COS, geographically distributed following the present day anthropogenic COS surface emissions (SG-COS-SRF), or a 6 Tg-S/yr injection of COS in the tropical upper troposphere (SG-COS-TTL). The budget of COS and sulfur species is discussed, as well as the effects of both SG-COS strategies on the stratospheric sulfate aerosol optical depth, aerosol effective radius, surface SOx deposition and tropopause radiative forcing (RF). Indirect effects on ozone, methane and stratospheric water vapor are also considered, along with the COS direct contribution. According to the model results, the resulting UVB perturbation at the surface accounts for -4.3% as a global-annual average (versus -2.4% in the SG-SO2 case), with a springtime Antarctic decrease of -2.7% (versus a +5.8% increase in the SG-SO2 experiment). Overall, we find that an increase in COS emissions may be feasible, and produce a more latitudinally-uniform forcing without the need for the deployment of stratospheric aircrafts. However, our assumption that the rate of COS uptake by soils and plants does not vary with increasing COS concentrations will need to be investigated in future works, and more studies are needed on the prolonged exposure effects to higher COS values in humans and ecosystems.