"Many commentators have suggested that the complexity of this governance challenge will dwarf the difficulties of finding governance mechanisms for reducing global carbon emissions (e.g. Humphreys, 2011; although see Millard-Ball, 2012, for a different reading of the problem) – a task which itself has proved largely intractable. As Robock summarises: “The UK SRMGI is just beginning to address these issues, but it is not obvious that they will be successful. In any case, fundamentally new international rules, observing systems, and enforcement will be needed before we start spraying” (Robock, 2011b:5)." -- Page 10

"But the environmental consequences of SAI extend well beyond the merely climatic. Additional sulphate aerosols in the stratosphere provide surfaces for enhanced heterogenous chemistry thus resulting in potentially increased ozone depletion (Crutzen, 2006; Rasch et al., 2008), although the associated radiation scattering and attenuation effects are complex. The ratio of direct to diffuse radiation, too, would be altered with consequences for photosynthesis, ecosystems (such as coral; Crabbe, 2009) and crop yields (e.g. Pongratz et al., 2012). And if SAI were to be used as a technology for limiting the rate of global sea-level rise then significant contradictions arise between achieving this goal at the same time as stabilising global temperature (Irvine et al., 2012)."  --Page 11