Unanticipated Impacts of Aerosol Composition and Phase on Stratospheric Albedo Modification Proposals
The Earth has warmed since pre-industrial times, due primarily to the anthropogenic addition of greenhouse gases to the atmosphere. Most strategies to address this warming have called for a reduction of emissions and, often, accompanying removal of greenhouse gases. Alternative proposals suggest masking warming by increasing particles and/or clouds to scatter incoming solar radiation. The purpose of this talk is to discuss unanticipated impacts of ‘designer’ aerosols suggested for increasing Earth’s albedo. We will specifically discuss calcite particles which have a more complex atmospheric lifetime than has been previously considered; this includes aqueous and hydrate phases that can lead to ozone loss. Laboratory studies also suggests particle addition to the atmosphere can also perturb global radiative balance by affecting high altitude cloud formation and properties. These results show that an overly simplistic set of assumptions regarding intentional particle emissions to the atmosphere can lead to incorrect estimates of the radiative effect and fail to identify unintended consequences.