In the heart of Silicon Valley in Palo Alto, California, there’s a group of retired physicists and engineers working on a nozzle to save their grandchildrens’ lives. The team, affectionately dubbed “the Old Salts,” designed the nozzle to spray sea salt particles in a specific size and concentration into the air. Once finished, it’ll be used to inject the substance into the skies over certain regions of the world.
It’s all part of an experiment to see if this approach can “brighten” clouds so they’re capable of reflecting more sunlight away from the Earth. While the tests would be small, they will attempt to uncover whether a larger scale operation like this could cool down the planet—albeit temporarily. Then, maybe, the Old Salts’ grandchildren might have a fighting chance at surviving a dangerously warming world.
Facilitating this experiment is the Marine Cloud Brightening Project, a University of Washington nonprofit that’s researching technologies and strategies to intentionally and artificially cool the world’s climate patterns through new and emerging technologies—a process also known as “geoengineering.” The inspiration for the project came from the “observation of particulates—like those that waft up from various sources like ships, coal plants, and cars—mix into clouds” making them brighter, Kelly Wanser, co-founder and senior adviser of the MCB Project, told The Daily Beast. “They’re creating a little bit of an umbrella effect that’s reflecting a bit more sunlight, and it’s cooling the planet.”
The project is part of a growing number of scientists and climate experts out there researching and, sometimes, advocating for radical solutions to prevent the worst climate-related catastrophes that lay ahead.
The term geoengineering itself typically refers to two methods of manipulating climate. The first is carbon dioxide removal, where harmful greenhouse emissions are extracted from the atmosphere. The other, more controversial approach that the MCB Project deals in is solar radiation management (SRM), or solar geoengineering. This involves using experimental technologies to reflect sunlight away from the Earth and, theoretically, cool global temperatures to prevent further damage to vulnerable ecosystems and communities.
Though geoengineering might seem like science fiction (paging Neal Stephenson), we’ve actually witnessed many forms of natural SRM in the past. Global temperatures sink in the months following large volcanic eruptions that emit large clouds of gas and debris into the atmosphere. For example, 1816 was known as “the year without a summer” in parts of Europe and North America after the massive eruption of the Tambora Volcano in Indonesia—one of the most powerful volcanic eruptions ever recorded—reduced enough sunlight that global temperatures dropped by as much as 3 degrees Celsius.
SRM is effectively a version of what these volcanic eruptions do. “It’s like increasing the size of the mirror, basically, that’s reflecting sunlight back to space,” Sarah Doherty, an affiliate associate professor of atmospheric sciences at the University of Washington and the program manager for the MCB Project, told The Daily Beast.
And by some accounts, anthropogenic climate change can already be seen as a form of geoengineering. After all, the greenhouse gasses emitted into the atmosphere by the burning of fossil fuels have changed the Earth’s climate patterns—though for the worse. If we could replicate these effects in a more controlled, targeted approach, we could potentially combat the negative impacts of climate change.
It’s not a permanent fix, mind you. For example, the Old Salts’ nozzle’s droplets would brighten clouds only for a few days or weeks at the most before dissipating and allowing the global climate to revert to its previous state. Maintaining the effects would require regular spraying, which is currently unfeasible—partly because of limited resources and partly because it could result in unforeseen negative consequences like threatening wildlife species or diminishing crop growth.
Instead, it’s helpful to think of marine cloud brightening and similar solar geoengineering measures as a band-aid solution—a temporary fix that might help us buy time while we attempt to lower greenhouse gas emissions to a stable level.
“It’s almost more of a tourniquet at this point,” Doherty said. “Because even with significant emissions reductions, we're looking at major climate disruption. And so the question is whether removing some of the heat from the system is going to help with that.”
The researchers behind the MCB Project and similar efforts into radical climate intervention aren’t necessarily full-throated supporters of geoengineering, but they’re interested in seeing whether it could be a viable approach to sparing us from the worst climate disasters imaginable. “As a scientist, it’s my role to pull apart ideas and to be skeptical of ideas like this,” Robert Wood, a professor of atmospheric sciences at the University of Washington and principal investigator for the MCB Project, told The Daily Beast. “And so [I am] approaching it with a very open mind to it potentially not working or working.”
It’s the environmental policy equivalent of health insurance—you might not need it now, but you’ll sure as hell be glad you have it with you when an emergency comes up. In the case of geoengineering, that emergency would come in the form of out-of-control global warming and carbon emissions. In the past few years, we’ve already seen extreme weather events—from hurricanes, to floods, to derechos—caused and exacerbated by anthropogenic climate changes. The steep rise in temperatures have created droughts and ecosystem depletion. There may be a time when these events become so frequent or so catastrophic that a temporary cool down in the climate could provide a much-needed reprieve in a pinch.
And current projections are only adding to the urgency to plan for a grim future. “The jury has reached a verdict, and it is damning,” António Guterres, the secretary general of the UN, told reporters on April 5 after the United Nations’ Intergovernmental Panel on Climate Change (IPCC) released its latest report. “We are on a fast track to climate disaster. This is not fiction or exaggeration, it is what science tells us will happen.” Many experts are skeptical that the world’s nations will do enough to limit the rise in global temperatures to less than 1.5 degrees Celsius.
Despite this, though, there are those out there who are understandably hesitant to embrace even research into geoengineering—believing it could result in nations endorsing and deploying measures like SRM without fully understanding its consequences.
“It’s dangerous to be supporting geoengineering research,” Jennie Stephens, a professor of sustainability science and policy at Northeastern University and director of the School of Public Policy and Urban Affairs, told The Daily Beast. “It’s a distraction from the transformative policies that we actually need.”
Stephens is one of more than 60 scholars and academics who initially co-signed an open letter published in January 2022 calling on world governments to agree not to fund or pursue solar geoengineering research. The letter—which has since garnered more than 320 signatures—was written by a group of scholars including Frank Biermann, a professor of global sustainability governance at Utrecht University in the Netherlands, and asserts that “proliferating calls for solar geoengineering research and development are cause for alarm.”
Biermann told The Daily Beast that efforts like SRM are unnecessary, and a distraction from focusing on more permanent fixes to climate change like eliminating fossil fuels and reducing carbon emissions. In fact, he said that there’s “clear evidence” from the IPCC that keeping global warming under 1.5 degrees is completely achievable.
So instead, Biermann believes that geoengineering could potentially be a mitigation deterrent—giving bad actors an opportunity to continue their work pumping greenhouse gasses and extracting fossil fuels because, hey, we can always just geoengineer the climate.
That doesn’t hold much water for Doherty though, who believes that SRM projects could actually encourage the world to put more work into limiting carbon emissions. “If you present it in a realistic way, which means there will be limits to marine cloud brightening and it won’t perfectly offset greenhouse gas impacts, then people can have higher incentive to reduce emissions,” she explained.
But there’s also the risks involved with geoengineering—what if things work too well? These risks could negatively affect the vulnerable communities geoengineering was deployed to help. In fact, some simulations and modeling have shown that while SRM can cool the climate, it can also cause unintended consequences like the spread of diseases and also the intensifying of catastrophic weather events. “This is one of the things that we're mainly concerned with,” Biermann said. “There are always risks with these technologies that are difficult to anticipate and they're difficult to foresee."
“Some country's rain and precipitation patterns changing drastically could result in drought and food insecurity and all kinds of disruptions that are unpredictable,” Stephens said. “It’s very complicated to minimize those risks.”
Biermann also argues that world governance structure just isn’t there to support solar geoengineering. In his open letter, he wrote that governments are “unfit to develop and implement far-reaching agreements needed to maintain fair, inclusive, and effective political control over solar geoengineering deployment.”
“One of the real risks there is that it’s really an ungovernable technology,” Stephens said. “If you think about global manipulation of the Earth's systems, the way it would actually be developed and deployed would be unilaterally by either a rich person, organization, or country. How would this ever be managed and governed in a way that is equitable?
“Who has control and who’s making decisions for others?” she added. “Who’s making decisions for everyone else that impacts everybody?”
But therein lies the very uncomfortable elephant in the room. With carbon emissions running rampant and temperatures rising higher than they ever have in recorded history, we might not have much of a choice but to pursue a largely untested and experimental approach in order to stop the worst of climate catastrophe. Stephens remains optimistic that the world can meet goals like the UN’s 1.5-degree Celsius limit. But if it doesn’t, countries may start treating solar geoengineering with deadly seriousness.
“We have to zoom out and think more holistically,” Stephens said. “We don't want to have this narrow climate isolationist approach—that climate is a problem that we can solve with this narrow technological perspective. It’s just not the way the world works.”