A scientific effort backed by Microsoft billionaire Bill Gates aims to cover the Earth in a chemical cloud in an effort to fight global warming, CNBC reports.
The process is called solar geo-engineering and has been around, conceptually at least, since the 1970s, when a Russian scientist proposed burning sulfur in the upper atmosphere to create a reflective cloud that would reflect sunlight back into space, as IOP Science reports.
Throughout the Earth's history, there have been periods of global cooling brought on by reflective materials being in the atmosphere. For example, the K-T asteroid impact, which is believed to have led to the extinction of the dinosaurs, kicked up dust and particulate into the atmosphere that caused a years-long period of cooler temperatures. Similarly, as Forbes explains, volcanic eruptions have launched dust and debris into the atmosphere, causing periods of cooling (and reduced sunlight) that had devastating impact on Europe's agriculture, leading to famine across the continent.
In a more recent example, in 1991, the Philippines' Mt. Pinatubo erupted, sending 20 million tons of sulfur dioxide into the sky, reflecting 2 percent of incoming sunlight back into space. Sure enough, global temperatures were cooler in 1992 than they were in 1991.
The Solar Radiation Management Governance Initiative, which has the backing of Bill Gates, believes that the process can be artificially affected to combat climate change. Specifically, thousands of planes would fly at extremely high altitudes, and would deploy light-reflecting particles into the upper atmosphere. Those particles would reflect some sunlight back into the sky.Andy Parker, project director at the initiative, says that computer modeling shows that the process "could reduce the intensity of heat waves, for instance, apparently it could reduce the rate of sea level rise. It could reduce the intensity of tropical storms."
What's more, the technology is already mostly there, it's affordable, and it can be deployed relatively quickly.
However, you may have noticed a problem. The examples of periods of global cooling mentioned earlier in this article have been followed by localized famine and, at worst, mass extinction. Stephen Gardiner, author of A Perfect Moral Storm: The Ethical Tragedy of Climate Change, warns that the same thing could happen again.
"These consequences might be horrific. They might involve things like mass famine, mass flooding, drought of kinds that will affect very large populations," he warned.
Similarly, the project could effectively make the sky no longer blue, instead turning the sky to a white haze. And, as Alan Robock, a climate scientist at Rutgers University explains, if the project is stopped, once the atmosphere has recovered in a year or so, the Earth would warm back up so rapidly that the effects could be devastating.
Robock recommends focusing instead on eliminating greenhouse gases, at the very least, before deploying artificial means of reflecting sunlight back into space.