Solar geoengineering—also referred to as solar radiation management—describes a set of proposed approaches to reflect sunlight to rapidly cool the Earth. The implications of the same would be on the global commons.
Within solar geoengineering, researchers are considering two main approaches. The first—stratospheric aerosol injection, or SAI—would involve injecting tiny reflecting particles, known as aerosols, into the upper atmosphere to cool the planet. The second—marine cloud brightening, or MCB—would use sea salt to stimulate cloud formation over the ocean, which would also help reflect sunlight in the region.
Researchers are bullish on Solar Geoengineering's "potential to reduce the risks of climate change if used as a complement to emissions cuts." However, they are quick to point out that a much better understanding is needed: "We don't know enough about its potential, limits and risks to make recommendations on whether or not to deploy it."
The concept of Solar Geoengineering is actually rather simple technologically, and relatively inexpensive. The challenges are not so much technical or financial, they are political and ethical.