13 - Solar Radiation Management Alternatives

Summary

In this chapter we leap over the divider in our geoengineering toolbox to examine the implements on the other side of our portfolio by considering several prospective solar radiation management techniques. These begin with surface modifications that might in some way increase the albedo of the earth and cause it to absorb less solar energy, including lightening roofs and other built structures, bioengineering crops to be slightly lighter, and manipulating ice to reflect more sunlight. Glaciers could be reinforced to slow their slides into the sea. Turning our gaze upward, marine cloud brightening is a technique that could increase the reflectivity of clouds, while cirrus cloud thinning could reduce the heat-trapping effect of these high wispy clouds. Yet higher up, it may someday be possible to deploy assets in space the might deflect some of the incoming sunlight. However, the surface modification techniques don’t appear to be properly scaled to the problem, and the cloud and space-based ideas remain too speculative to rely upon.