TY - JOUR
T1 - Halving warming with idealized solar geoengineering moderates key climate hazards
AU - Irvine, Peter
AU - Emanuel, Kerry
AU - He, Jie
AU - Horowitz, Larry W.
AU - Vecchi, Gabriel Andres
AU - Keith, David
N1 - Publisher Copyright:
© 2019, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - Solar geoengineering (SG) has the potential to restore average surface temperatures by increasing planetary albedo 1–4 , but this could reduce precipitation 5–7 . Thus, although SG might reduce globally aggregated risks, it may increase climate risks for some regions 8–10 . Here, using the high-resolution forecast-oriented low ocean resolution (HiFLOR) model—which resolves tropical cyclones and has an improved representation of present-day precipitation extremes 11,12— alongside 12 models from the Geoengineering Model Intercomparison Project (GeoMIP), we analyse the fraction of locations that see their local climate change exacerbated or moderated by SG. Rather than restoring temperatures, we assume that SG is applied to halve the warming produced by doubling CO 2 (half-SG). In HiFLOR, half-SG offsets most of the CO 2 -induced increase of simulated tropical cyclone intensity. Moreover, neither temperature, water availability, extreme temperature nor extreme precipitation are exacerbated under half-SG when averaged over any Intergovernmental Panel on Climate Change (IPCC) Special Report on Extremes (SREX) region. Indeed, for both extreme precipitation and water availability, less than 0.4% of the ice-free land surface sees exacerbation. Thus, while concerns about the inequality of solar geoengineering impacts are appropriate, the quantitative extent of inequality may be overstated 13 .
AB - Solar geoengineering (SG) has the potential to restore average surface temperatures by increasing planetary albedo 1–4 , but this could reduce precipitation 5–7 . Thus, although SG might reduce globally aggregated risks, it may increase climate risks for some regions 8–10 . Here, using the high-resolution forecast-oriented low ocean resolution (HiFLOR) model—which resolves tropical cyclones and has an improved representation of present-day precipitation extremes 11,12— alongside 12 models from the Geoengineering Model Intercomparison Project (GeoMIP), we analyse the fraction of locations that see their local climate change exacerbated or moderated by SG. Rather than restoring temperatures, we assume that SG is applied to halve the warming produced by doubling CO 2 (half-SG). In HiFLOR, half-SG offsets most of the CO 2 -induced increase of simulated tropical cyclone intensity. Moreover, neither temperature, water availability, extreme temperature nor extreme precipitation are exacerbated under half-SG when averaged over any Intergovernmental Panel on Climate Change (IPCC) Special Report on Extremes (SREX) region. Indeed, for both extreme precipitation and water availability, less than 0.4% of the ice-free land surface sees exacerbation. Thus, while concerns about the inequality of solar geoengineering impacts are appropriate, the quantitative extent of inequality may be overstated 13 .
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U2 - 10.1038/s41558-019-0398-8
DO - 10.1038/s41558-019-0398-8
M3 - Letter
AN - SCOPUS:85062840775
SN - 1758-678X
VL - 9
SP - 295
EP - 299
JO - Nature Climate Change
JF - Nature Climate Change
IS - 4
ER -