Climate impacts of geoengineering in a delayed mitigation scenario. Issue 15 (13th August 2016)

• Record Type: Journal Article
• Authors: Tilmes, S.; Sanderson, B. M.; O'Neill, B. C.
• Is Part Of: Geophysical research letters. Volume 43:Issue 15(2016)
• Page Start: 8222
• Page End: 8229
• Publication Date: 2016-08-13
• Subjects: geoengineering -- mitigation -- climate impacts; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL070122
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Decarbonization in the immediate future is required to limit global mean temperature (GMT) increase to 2°C relative to preindustrial conditions, if geoengineering is not considered. Here we use the Community Earth System Model (CESM) to investigate climate outcomes if no mitigation is undertaken until GMT has reached 2°C. We find that late decarbonization in CESM without applying stratospheric sulfur injection (SSI) leads to a peak temperature increase of 3°C and GMT remains above 2° for 160 years. An additional gradual increase and then decrease of SSI over this period reaching about 1.5 times the aerosol burden resulting from the Mount Pinatubo eruption in 1992 would limit the increase in GMT to 2.0° for the specific pathway and model. SSI produces mean and extreme temperatures in CESM comparable to an early decarbonization pathway, but aridity is not mitigated to the same extent. Key Points: A scenario with aggressive decarbonization after unmitigated warming of 2°C has occurred leads to further warming of 1°C in CESM In this late decarbonization scenario, stratospheric sulfur injection would be necessary for 160 years to limit warming to 2°C in CESM Extremely warm temperatures but only some drying of land can be reduced in a late mitigation scenario including SRM in CESM