Problems with Deliberate Sulphate Injection

Now, if any of you reading this have any knowledge of stratospheric ozone loss then you will see an obvious problem. With injection of sulphate aerosols, it is expected that ozone depletion will occur (Crutzen, 2006), with recent model output showing a 15 to 60 year extension to the recovery of the Antarctic ozone hole (this is dependent on partical size and vertical extension). This is added to Arctic ozone losses expected between 60 to 80 DU (Dobson units) in 75% of all winters (Tilmes et al., 2008).

Modelling has also shown deliberate injection of sulphates could disrupt the Asian and African monsoons (Robock et al., 2008). Volcanic eruption responses suggest the Arctic Oscillation would be shifted to a stronger positive phase, associated with stronger westerlies and winter warming over Northern Eurasia and North America (Stenchikov et al. 2002, 2006).

Model predictions of the effects of a deliberate reduction of incoming solar radiation (mentioned in an earlier post about mirrors in orbit), including reduced precipitation, should be broadly applicable to sulphate aerosol loading.

Stratospheric aerosol loading will affect the ratio of direct to diffuse light. This will affect terrestrial (and potentially marine) photosynthesis (Rasch et al., 2008).

Rasch et al. (2008) has stated that further research on side effects is required, particularly into impacts on the biosphere. The uncertainties surrounding the effects of sulphate aerosol addition to the stratosphere are much greater and more meteorologically complicated than those relating to mitigating CO2 emissions (Tuck et al., 2008).