Simulated long‐term climate response to idealized solar geoengineering. Issue 5 (15th March 2016)

• Record Type: Journal Article
• Authors: Cao, Long; Duan, Lei; Bala, Govindasamy; Caldeira, Ken
• Is Part Of: Geophysical research letters. Volume 43:Issue 5(2016)
• Page Start: 2209
• Page End: 2217
• Publication Date: 2016-03-15
• Subjects: solar geoengineering -- climate modeling -- climate response -- climate intervention -- ocean meridional overturning; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL068079
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Solar geoengineering has been proposed as a potential means to counteract anthropogenic climate change, yet it is unknown how such climate intervention might affect the Earth's climate on the millennial time scale. Here we use the HadCM3L model to conduct a 1000 year sunshade geoengineering simulation in which solar irradiance is uniformly reduced by 4% to approximately offset global mean warming from an abrupt quadrupling of atmospheric CO2 . During the 1000 year period, modeled global climate, including temperature, hydrological cycle, and ocean circulation of the high‐CO2 simulation departs substantially from that of the control preindustrial simulation, whereas the climate of the geoengineering simulation remains much closer to that of the preindustrial state with little drift. The results of our study do not support the hypothesis that nonlinearities in the climate system would cause substantial drift in the climate system if solar geoengineering was to be deployed on the timescale of a millennium. Key Points: Sunshade geoengineering to offset warming effect from 4 × CO2 is simulated for a 1000 year period Throughout the 1000 year period, solar geoengineering leads to a climate state that is much closer to preindustrial than high‐CO2 world Throughout the 1000 year simulations, little climate drift is observed in the solar geoengineered world