Solar Radiation Management (SRM) is the final climate change technology to be discussed in this book. This is because SRM represents a last chance effort to slow down the rate at which we are changing the climate. It is a brute force effort who use implies a failure of all the other responses. It raises the concern that, if we were unable to develop solutions in so many other areas, why do we think that we will succeed with SRM? The topic is a poignant reminder of our inability as a society to recognize and respond to a problem that affects us all.
All the other techniques that we have discussed work by reducing the concentration of greenhouse gases in the atmosphere, either by generating energy without using carbon-based fuels, or by directly removing CO2 from the atmosphere. Solar radiation management, on the other hand, accepts that these endeavors have failed, and that the only remaining response is to reflect the sun’s incoming rays so as to slow down, or even reverse the warming effect. This is done either by placing reflectors in space or at the Earth’s surface, or by modifying cloud patterns. In all cases, SRM controls only the atmospheric temperature; it does not address other serious climate change consequences such as ocean acidification.
All of the SRM techniques are at the Concept stage of development — it is not known how they would work if actually used, partly because they cannot be easily tested on a limited scale. Moreover, there is a high level of risk associated with “fooling around with the climate”. SRM is likely to have many unintended consequences.
A final concern is to do with the international cooperation that would be needed to implement SRM technology. Given the lack of success of international programs to date, there is little reason to believe that the needed cooperation is likely to happen.
Risks and Concerns
Stratospheric Aerosol Injection
Marine Cloud Brightening
Articles and Blogs
The following articles, blogs and videos provide more information on the topics discussed in this chapter.