Assessing the regional disparities in geoengineering impacts

Solar Radiation Management (SRM) Geoengineering may ameliorate many consequences of global warming but also has the potential to drive regional climates outside the envelope of greenhouse-gas induced warming, creating 'novel' conditions, and could affect precipitation in some regions disproportionably. Here, using a fully coupled climate model we explore some new methodologies for assessing regional disparities in geoengineering impacts. Taking a 4 x CO2 climate and an idealized 'sunshade' SRM strategy, we consider different fractions of the maximum theoretical, 4 x CO2-cancelling global mean cooling. Whilst regional predictions in particularly relatively low resolution global climate models must be treated with caution, our simulations indicate that it might be possible to identify a level of SRM geoengineering capable of meeting multiple targets, such as maintaining a stable mass balance of the Greenland ice sheet and cooling global climate, but without reducing global precipitation below pre-industrial or exposing significant fractions of the Earth to 'novel' climate conditions. Citation: Irvine, P. J., A. Ridgwell, and D. J. Lunt (2010), Assessing the regional disparities in geoengineering impacts, Geophys. Res. Lett., 37, L18702, doi:10.1029/2010GL044447.