The idea of injecting particles into the atmosphere to cool the earth also seems outright futile considering what scientists are trying to mimic - volcanic eruptions. If we look at the second largest eruption of the 20th century, Mount Pinatubo, which erupted in the Philippines in 1991, it injected 20 million tons of sulfur dioxide aerosols into the stratosphere. Scientists from the USGS estimated that this 20 million tons only lowered the temperature of the planet by about 1°F (0.5°C) and this only lasted a year because the particles eventually fell to back to Earth.
While this talk of geoengineering may sound like something out of a dystopian science fiction movie, the reality is that it has long been on the table of governments and think tanks from around the world. In fact, just last November, a study published in Environmental Research Letters, talked about doing the exact same thing—geoengineering and planes spraying particulates into the atmosphere to curb global warming.
What’s more, that study echoed the sentiments of then-CIA director John Brennan when he addressed the Council on Foreign Relations in 2016, detailing a similar process of spraying chemical particulates in the atmosphere to cool the planet.
At the meeting, Brennan addressed instability and transnational threats to global security at a meeting with the Council on Foreign Relations. During his long-winded talk of threats to US interests and how the largely CIA-created ISIL threat is impacting the world, Brennan brought up the topic of geoengineering.
Another example is the array of technologies—often referred to collectively as geoengineering—that potentially could help reverse the warming effects of global climate change. One that has gained my personal attention is stratospheric aerosol injection, or SAI, a method of seeding the stratosphere with particles that can help reflect the sun’s heat, in much the same way that volcanic eruptions do.
Brennan went on to echo the calls from some scientists who have called for aerial spraying.