Climate model response from the Geoengineering Model Intercomparison Project (GeoMIP)

Ben Kravitz*, Ken Caldeira, Olivier Boucher, Alan Robock, Philip J. Rasch, Kari Alterskjaer, Diana Bou Karam, Jason N. S. Cole, Charles L. Curry, James M. Haywood, Peter J. Irvine, Duoying Ji, Andy Jones, Jon Egill Kristjansson, Daniel J. Lunt, John C. Moore, Ulrike Niemeier, Hauke Schmidt, Michael Schulz, Balwinder SinghSimone Tilmes, Shingo Watanabe, Shuting Yang, Jin-Ho Yoon

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

181 Citations (Scopus)

Abstract

Solar geoengineeringdeliberate reduction in the amount of solar radiation retained by the Earthhas been proposed as a means of counteracting some of the climatic effects of anthropogenic greenhouse gas emissions. We present results from Experiment G1 of the Geoengineering Model Intercomparison Project, in which 12 climate models have simulated the climate response to an abrupt quadrupling of CO2 from preindustrial concentrations brought into radiative balance via a globally uniform reduction in insolation. Models show this reduction largely offsets global mean surface temperature increases due to quadrupled CO2 concentrations and prevents 97% of the Arctic sea ice loss that would otherwise occur under high CO2 levels but, compared to the preindustrial climate, leaves the tropics cooler (-0.3K) and the poles warmer (+0.8K). Annual mean precipitation minus evaporation anomalies for G1 are less than 0.2mmday(-1) in magnitude over 92% of the globe, but some tropical regions receive less precipitation, in part due to increased moist static stability and suppression of convection. Global average net primary productivity increases by 120% in G1 over simulated preindustrial levels, primarily from CO2 fertilization, but also in part due to reduced plant heat stress compared to a high CO2 world with no geoengineering. All models show that uniform solar geoengineering in G1 cannot simultaneously return regional and global temperature and hydrologic cycle intensity to preindustrial levels.

Original languageEnglish
Pages (from-to)8320-8332
Number of pages13
JournalJournal of Geophysical Research: Atmospheres
Volume118
Issue number15
DOIs
Publication statusPublished - 16 Aug 2013

Keywords

  • geoengineering
  • model intercomparison
  • LAND-SURFACE SCHEME
  • SOLAR-RADIATION MANAGEMENT
  • CARBON-CYCLE
  • TERRESTRIAL BIOSPHERE
  • HYDROLOGICAL CYCLE
  • VEGETATION MODEL
  • GISS MODELE
  • SYSTEM
  • IMPACT
  • PRECIPITATION

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