Atmos. Chem. Phys., 16, 2843–2862, 2016 

Sulfate (SO4) aerosols have featured predominantly in SAI research because of the volcanic analogue

(e.g., in the Geoengineering Model Intercomparison Project, GeoMIP, Kravitz et al., 2013). General

Circulation Model (GCM) sim- ulations suggest that, while sufficient sulfate injection could

effectively reduce global-mean temperature, possible side effects include changes to regional

precipitation (e.g., Bala et al., 2008; Tilmes et al., 2013), ozone (e.g., Tilmes et al., 2009; Pitari et al.

, 2014), stratospheric dynamics (Aquila et al., 2014) and sea-ice extent (Berdahl et al., 2014).

Precipitation changes could result from changes to the moist static stability of the atmosphere and a

concomitant weakening of the hydrological cycle (Bala et al., 2008); furthermore, the regional

precipitation changes under GeoMIP simulations have been shown to be reasonably consistent

across a range of climate models (Tilmes et al., 2013). Ozone concentra- tions could change as a result

of enhanced heterogeneous chemistry on the surface of sulfate aerosols or indirectly by changes to

the stratospheric dynamics and chemistry (e.g., Tilmes et al., 2009). Stratospheric dynamical changes

could occur as the result of tropical heating in the sulfate layer and by changes to wave propagation

from the troposphere (e.g., Aquila et al., 2014).