Solar Radiation Management

Solar radiation management basically involves increasing the reflectivity of the planet so that less solar radiation is absorbed and the planet is cooler as a result. SRM proposals include:

• Increasing the reflectivity of the planet by painting structures white. This approach is often considered quite benign and would need to be implemented on a massive scale to have a discernible impact.

• Marine cloud brightening. The overall concept here is that albedo of clouds could be increased by making the clouds brighter. One way to do this would be to spray clouds with seawater.

• Atmospheric sulphate injections. This proposal aims to mimic the effect of volcanic eruptions.

• ”Placing shields or deflectors in space to reduce the amount of solar energy reaching the Earth”

(Shepherd, 2012: 4169)

SRM is at the heart of the controversy that surrounds geoengineering. This controversy is for number of reasons, including:

• The ethics of deliberate manipulation of the global climate.

• The military origins and associations with some geoengineering proposals.

• The known side-effects of SRM, which we are aware of and (we think) we understand.

• The side-effects that we do not understand and have not considered, or unknown unknowns (unless you take exception to that phrase).

The above is not an exhaustive list of SRM proposals, but it is representative of the main ideas. SRM proposals are complex and each one has its own advantages and disadvantages that must be carefully considered before ever being implemented.

One of my concerns with SRM is that it does not address the root of the problem: CO2 emissions. So in some regards SRM can be viewed as making an allowance for CO2 emissions to continue. This effort to maintain current energy consumption and pollution creation patterns serves to diminish efforts to tackle the wider causes of global environmental issues, such as unsustainable societal and economic patterns (Corner & Pidgeon, 2010).

Bickel and Lane, in their report, “An Analysis of Climate Engineering as a Response to Climate Change”, seem to view climate engineering as a substitute for reduced emissions. Despite stating in the opening pages that “the reader should not interpret our focus on climate engineering as implying that other responses to climate change are unneeded”, the authors then go on to discuss the “economic freedom” that flourishes under climate engineering options as opposed to emission controls which are portrayed as an “infringement of economic freedom”. This comparison between climate engineering and emission controls serves to directly contravene the idea that geoengineering should only be implemented in conjunction with emission cuts.

If SRM methods were to be employed they could create “an artificial, approximate and potentially delicate balance between continuing increased greenhouse gas concentrations and reduced solar radiation, which would have to be maintained potentially for many centuries” (Shepherd, 2012: 4170).

Because SRM does not address the root of the problem it does not address the consequences of increased CO2 concentrations in the atmosphere, such as ocean acidification. SRM also adds its own side-effects to the mix, including changed precipitation patterns, ozone depletion and reduced potential for solar power (Tuana et al., 2012 / Shepherd, 2012).

The one big draw of SRM proposals is the time frame in which they would work. They could be called upon in an emergency, such as at the brink of a tipping point, and be implemented to relatively quickly reverse some potentially disastrous climate change trajectory (Tuana et al., 2012). The caution to this is that all of the risks and drawbacks of SRM would be diminished in the face of an impending global environmental disaster and so risky and radical policies could be implemented while a vulnerable public are unable to resist. This in some ways echoes Naomi Klein’s Shock Doctrine theory.

I think that solar radiation management merits further research and full public engagement so that if it is ever to be implemented policy makers and the public can have full confidence in the approach or conversely have the knowledge and power to resist its implementation.