One of the more iconic storylines from The Simpsons was from the 1995 "Who Shot Mr. Burns?" episode. To force the city to rely on his power plant nonstop, Mr. Burns, the richest man in Springfield, built a giant mechanical shade that literally blocked out the sun. When he was shot and left for dead, literally every person in town was a suspect. It turned out that Maggie shot him for an unrelated candy-taking offense, but his blotting out the sun was why everyone else would want him dead. The sun-blocker was supposed to be an implausible rich-person fantasy, a dumb and literal attempt to control the basic aspects of nature. Now, decades later, a similar method is gaining popularity as a way to fight climate change.

"Geoengineering" is the umbrella term for a bunch of different propositions that involve physically manipulating the climate to cool the planet. "Dimming the sun" (spraying sulfates into the air to reflect sunlight back into space) is actually one of those proposed options. Another is "cloud brightening," spraying saltwater to make clouds more reflective for the same reason. And there's also "ocean fertilization," encouraging algae blooms to soak up carbon.

Millionaire entrepreneur and Democratic presidential candidate Andrew Yang has called for putting massive mirrors in orbit to shield the planet from sunlight. And Bill Gates is officially funding the first high-altitude geoengineering tests. As CNBC reports, thousands of planes would spray millions of tons of particles into the air to replicate the effects of a massive volcanic eruption.

There's some non-Bond-villain rationale behind this. Proponents of this specific kind of volcano-replicating geoengineering point to the 1991 eruption of Mount Pinatubo in the Philippines. It blew 20 million tons of ash into the stratosphere, creating a cloud hundreds of miles wide and reflecting about 2 percent of sunlight hitting the earth back into space. The next year, global temperatures dipped significantly. If we could re-create that in a controlled way, proponents argue, then we can save the ice at the poles and fight sea-level rise.

The problem is it's hard to do anything in a controlled way when we're talking about endlessly complex natural systems. There's already evidence volcanic eruptions like Pinatubo interfere with monsoons in Asia and Africa, completely throwing off the rain cycles that millions of people depend on for food and water. But we don't know what else could develop as the geoengineering effects settle into atmospheric, oceanic, and ecological systems around the world. There's even a chance that, with so many particles spread through the world, we would lose blue skies forever to a hazy, shiny gray. It's impossible to run traditional tests on any of these techniques, because we don't have multiple habitable planets to experiment on. And that says nothing of the fact that it doesn't actually address the key cause of global warming, which is the buildup of carbon. The world may not warm as rapidly, but the oceans would still absorb carbon and quickly acidify, resulting in mass die-offs like we see with the Great Barrier Reef.

According to reporter and climate activist Naomi Klein, the fact that geoengineering does not address the root causes of climate change is exactly its allure. In her 2012 book, This Changes Everything: Capitalism vs. the Climate, she writes that for a long time, scientists were unwilling to advocate for geoengineering because they worried it would seem more enticing than safer, surer ways to fight climate change: