There is a version of this story that sounds like it belongs in a 1970s science fiction book, complete with secret atmospheric experiments, shadowy elites, and a plot to actually dim the sun. However, this is currently taking place, financed by actual funds, and proceeding more quickly than most people are aware.
In 2023, George Soros took the podium at a security conference in Munich and proposed an idea that shocked even those who were familiar with the fringes of climate science. In order to create clouds that would reflect sunlight away from the melting ice below, he suggested stationing a fleet of boats in Arctic waters to spray saltwater into the low atmosphere. It wasn’t a metaphor. Soros intended it to be a serious policy recommendation supported by research and, most likely, the kind of assurance that comes from years of trusting your gut.
He wasn’t by himself. Bill Gates had already been discreetly supporting a Harvard University project at the same time that was investigating whether spraying calcium carbonate high into the atmosphere over Scandinavia might give the planet some breathing room. Due to opposition from environmental organizations and Indigenous communities, the project was ultimately shelved—a fact that is frequently overlooked in discussions of the concept. Jeff Bezos used Amazon’s computing power to simulate the effects of pumping enormous amounts of sulfur dioxide into the stratosphere. One of the founders of Facebook, Dustin Moskovitz, gave researchers in Thailand, Brazil, and Mali almost a million dollars to investigate possible impacts. In order to “offset” warming, a small startup called Make Sunsets has been sending weather balloons filled with sulfur dioxide into Nevada skies for as little as $1 per unit. They may be reckless or visionary, depending on who you ask.
Solar radiation modification, or more colloquially, solar geoengineering, is the technical term for all of this. The fundamental idea is derived from nature: when volcanoes erupt violently enough, they can cause the planet to momentarily cool by dispersing incoming sunlight through particles that are pumped into the upper atmosphere.
The Philippines’ Mount Pinatubo eruption in 1991 caused a year-long drop in global average temperatures of about half a degree Celsius. In essence, the billionaires and the researchers they fund are investigating whether or not humans are able to duplicate that effect on demand and on a schedule. Even cautious scientists agree that the answer is probably, but the real complexity lies in the side effects.
The planet is not only cooled by sulfur dioxide in the stratosphere. It can harm the ozone layer, interfere with monsoon patterns, and alter the distribution of rainfall across continents. Acid rain is another effect of it. For decades, mainstream climate scientists refused to take geoengineering proposals seriously because of these concerns, which are not minor ones. In recent years, the scientific debate has subtly changed, more because of the worsening emissions picture than because the risks have decreased. Some researchers now contend that it is responsible science, not wild speculation, to comprehend the dangers of solar geoengineering at least sufficiently to make an informed choice. A study plan on the topic was published by the White House. The discussion has shifted.
A more recent American-Israeli startup, Stardust Solutions, raised $60 million in 2025 by claiming to have created a proprietary reflective particle that completely avoids the sulfur issue—no acid rain, no ozone damage, and comparable cooling power. It’s a remarkable claim, and Stardust is aware that managing public skepticism in addition to engineering is a challenge.
It’s worth enduring a discomfort that isn’t mentioned explicitly in the majority of this space’s coverage. Almost to a person, the billionaires most interested in geoengineering are those who have amassed extraordinary wealth via technology, believing that the right system, implemented at scale, can solve seemingly insurmountable problems. That’s not exactly a critique. It’s an observation about how solutions that seem natural are shaped by a particular perspective on the world. Changing consumption patterns, reorganizing economies, and asking businesses and people to make sacrifices are all necessary to reduce emissions. In contrast, you can finance and initiate the process of spraying particles into the sky. It appeals to a certain kind of problem-solving instinct that decarbonization’s laborious, slow process just doesn’t.
This is not to argue that investigating these options is intrinsically reckless or that the science is flawed. It’s still unclear if any of these strategies can be implemented sufficiently safely and widely without having negative effects that disproportionately affect nations that were not involved in the decision. There are currently no clear answers to those questions. There’s no doubt that those who are working on this the fastest aren’t waiting for those answers.
