What goes up must come down: impacts of deposition in a sulfate geoengineering scenario

• Published in: Environmental research letters Vol. 15; no. 9; pp. 94063 - 94069
• Main Authors: Visioni, Daniele, Slessarev, Eric, MacMartin, Douglas G, Mahowald, Natalie M, Goodale, Christine L, Xia, Lili
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.09.2020
• Subjects: acid rain; Aerosols; Aluminum; Anthropogenic factors; climate change; Deposition; Emissions; ENVIRONMENTAL SCIENCES; Geoengineering; GEOSCIENCES; Greenhouse effect; Greenhouse gases; Human influences; Soil chemistry; Soil pH; Solar radiation; solar radiation management; Spatial distribution; Stratosphere; sulfate deposition; sulfate geoengineering; Sulfates; Sulfur; Sulfur dioxide; Toxicity; Volcanoes
• ISSN: 1748-9326; 1748-9326
• DOI: 10.1088/1748-9326/ab94eb

The problem of reducing the impacts of rising anthropogenic greenhouse gas on warming temperatures has led to the proposal of using stratospheric aerosols to reflect some of the incoming solar radiation back to space. The deliberate injection of sulfur into the stratosphere to form stratospheric sulfate aerosols, emulating volcanoes, will result in sulfate deposition to the surface. We consider here an extreme sulfate geoengineering scenario necessary to maintain temperatures at 2020 levels while greenhouse gas emissions continue to grow unabated. We show that the amount of stratospheric sulfate needed could be globally balanced by the predicted decrease in tropospheric anthropogenic SO2 emissions, but the spatial distribution would move from industrialized regions to pristine areas. We show how these changes would affect ecosystems differently depending on present day observations of soil pH, which we use to infer the potential for acid-induced aluminum toxicity across the planet.