Stephen Robert Miller is an award-winning science journalist and author.
Luke Iseman is unapologetic. If anything, he is emboldened by all the criticism, personal attacks and negative press he has received. This article is guilty of feeding into that feedback loop — of lending some legitimacy to what he’s done. Many of the world’s atmospheric scientists will say this is dangerous, and they’re probably right.
But here we are.
In April 2022, Iseman, through his startup, Make Sunsets, began doing what so many others have only talked about: It launched balloons filled with sulfur dioxide into the atmosphere over Baja California hoping they would burst and start cooling the planet. To help undo some 260 years of warming that resulted from the greatest technological leap in the history of our species.
Tanned from spearfishing and sporting a mohawk, Iseman is at the vanguard of entrepreneurs seeking to put their money where their mouth is. He says he intends to protect from, or even reverse, the damage of climate change through geoengineering, or toying with the planet’s natural systems. And unlike many academic scientists and engineers working on similar problems, he also hopes the venture will be lucrative.
As I called around to sources on this story, many referred to Iseman and his partner as foolish, slipshod and irresponsible cowboys who didn’t need any more press. Climate scientists accuse Make Sunsets of exaggerating its potential impact and attempting to manipulate the atmosphere using shaky science. Iseman has become the geoengineering world’s bogeyman, and that’s something of a change. For decades, the role belonged to the heavy polluters, the fossil fuel industry, which has admitted to investing in geoengineering schemes in the hope of cooling the planet so they could continue with business as usual.
Now, Silicon Valley is getting in the mix. Iseman has been an inventor, startup founder and director of hardware at the startup incubator Y Combinator. He believes he and other bold and business-minded entrepreneurs are uniquely positioned to solve a crisis that academia and government intervention have utterly failed to address.
“This is about acting in an emergency,” he told me. “Nobody asked me whether I wanted to have runaway climate change. And, you know, we shouldn’t have to ask permission to try to fix it.”
Given the risks of screwing with the only habitable planet we have, can we afford the potential costs of letting profit-motivated ventures stab at the problem? A rising tide of climate tinkerers might say that given impending global catastrophe and the pathetic response of world leaders, we can’t afford not to.
Filling A Void
In recent years, private interests have pumped hundreds of millions of dollars into figuring out ways to undo the damage caused by emitting some 2.5 trillion tons of carbon into the atmosphere since the Industrial Revolution. The realistic assumption here is that even with drastic emissions reductions we still face a lingering abundance of atmospheric carbon and all the ills it will bring.
“The models are misleading us,” said Tim Kruger, former director of the Oxford Geoengineering Programme and co-founder of Carbon Gap, a philanthropy-funded non-profit carbon capture think tank. “They give us a false sense of security that we’re on this glide path down in emissions. We’re completely underestimating the extent of the challenge that we face, and because of that we’re woefully unprepared.”
Geoengineering is often described as a gutsy last-ditch effort encompassing a suite of ideas and technologies designed to alter some function of the planet’s natural systems with the goal of cooling it. Some interventions are more plausible, others more terrifying.
Weather modification, like seeding clouds with silver iodide to encourage rain, affects only a specific locale and so falls outside the scope of what most experts today consider global geoengineering. Capturing carbon dioxide from the air with giant filters, however, can affect the planet’s atmosphere, and so sits squarely in the realm of geoengineering. But these days, direct-air carbon capture is generally considered less invasive than other methods, like tampering with the ocean’s chemistry to cause its waters to absorb carbon.
What concerns experts most is solar radiation management technologies, which include bright ideas like spreading reflective material across Arctic sea ice to keep it from melting or releasing chemicals, as Iseman’s bursting balloons are intended to do, like sulfur dioxide into the stratosphere to reflect sunlight. It’s sexy and highly controversial, and so gets much of the attention.
“Nobody asked me whether I wanted to have runaway climate change. And we shouldn’t have to ask permission to try to fix it.”
Global funding for solar geoengineering used to trickle mostly from European governments. Then around 2016, its locus shifted to private, philanthropic and venture capital sources linked to Silicon Valley and Wall Street, according to research by Kevin Surprise, a lecturer in environmental studies at Mount Holyoke College. The biggest funder today is SilverLining; Open Philanthropy was also a significant funder before exiting the area in August 2024. They source their money from the likes of Facebook co-founder Dustin Moskovitz, billionaire Rachel Pritzker, venture capital partner Bill Trenchard and Goldman Sachs’ Steve Strongin.
Like Iseman, these private investment organizations say that their hands were forced; governments have been too slow to act, the academic world is dawdling; the planet is warming and fast approaching tipping points past which we have little hope of return.
“We think that it’s really important that we have more tools on the table,” said Erika Reinhardt, co-founder of the nonprofit Spark Climate Solutions, which she says is the world’s largest funder of atmospheric methane removal. “We’re filling a very important gap of enabling this research to get started.”
Like other enterprises, Spark funds early-stage research in academia and a few private startups. It invests with the goal of laying the groundwork, so the world is prepared when — and if — things get so bad we have to geoengineer our way out of catastrophe. At this early stage, commercialization isn’t the goal, Reinhardt told me.
“You don’t necessarily have or want strong commercial incentives. You want to be able to explore lots of different ideas, and you don’t want to be tied to proving that anything works.”
Reinhardt also noted that profit-seeking opens the door to influence. “Imagine if we took some forms of corporate interest money, how that might percolate into the type of research that’s happening and what’s expected of the scientists,” she said.
Elsewhere in the geoengineering world, paths to profitability are already here.
The Market For Carbon
For two months beginning in September 2023, Canadian startup Planetary Technologies, Inc. released magnesium hydroxide in the shadow of a gas-burning electricity plant in Tufts Cove, Nova Scotia, a hub for marine geoengineering research. In theory, the chemical, added to the plant’s cooling water before it is returned to the bay, will neutralize carbon dioxide dissolved in the water’s surface, creating space for the ocean to absorb more carbon from the atmosphere. Planetary gets its funds from private investors and by selling carbon credits.
Companies that set goals or operate in states or countries that have set goals for reducing carbon emissions buy credits to offset pollution they otherwise can’t — or won’t — address. Purchases are supposed to fund work that reduces greenhouse gas emissions, like reforestation and renewable energy. The market for these voluntary carbon offsets is expected to grow from $2 billion in 2020 to around $250 billion by 2050, according to Morgan Stanley, and that means big payouts for entrepreneurs who can find geoengineering ideas to help solve climate change.
Iseman is trying to do something similar by selling “cooling credits,” which anyone can buy online to have Make Sunsets eject a gram of sulfur dioxide per credit into the sky on their behalf. However, “The ocean carbon removal space has been moving much more quickly to commercial activities and commercial rollout, because we live in a world where you can make money out of carbon credits, but not out of cooling credits,” said Lili Fuhr, director of the Fossil Economy Program at the Center for International Environmental Law.
One of Planetary’s largest backers is Shopify, a Canadian e-commerce platform worth more than $75 billion. Since 2019, it has invested $55 million in 40 startups focused on removing carbon dioxide from the atmosphere. According to Shopify, we “must innovate our way to a sustainable future” through tech-driven entrepreneurship.
Indeed, private capital has long claimed that minimally regulated, profit-motivated enterprise is our best means of driving world-saving innovation, but geoengineering critics like Fuhr aren’t lulled into thinking these investments are purely altruistic.
“Big tech companies that have no way to get their emissions down are facing a world in which the traditional carbon credits and offsets have been completely debunked,” she told me. “Their new attempt is to rely on highly speculative technologies and push startups to build out their business models right now.”
Iseman argues that we now find ourselves at the point where geoengineering may be necessary because governments have failed to innovate away from carbon emissions. That’s partly because governments shy away from risk. They can’t afford to fail, but Iseman can.
“Iseman argues that we now find ourselves at the point where geoengineering may be necessary because governments have failed to innovate away from carbon emissions.”
“Governments just talk about the climate crisis. They don’t actually fund solutions,” he told me. To be sure, governments are funding solutions, but even those who disagree with Make Sunsets’ methods agree that whatever is being done is not enough.
Make Sunsets has already launched close to 80 sulfur-dioxide-filled balloons. Although many climate scientists question its efficacy, the process is cheap and relatively simple. If he lands a federal Small Business Innovation Research grant, Iseman told me his startup could become profitable this year. “It’s kind of a fun challenge,” he said, “but more importantly, that means our runway is infinite.”
The idea of Make Sunsets launching balloons in perpetuity might make some experts cringe, but the startup didn’t come out of nowhere.
“This ecosystem has been brewing for the better part of a decade,” said Mount Holyoke’s Surprise. SilverLining, Harvard’s experts and others that have been critical of Iseman’s brash, profit-seeking approach have also invited venture capital, hedge funds and billionaires to invest in their own climate research, he told me. “They have basically laid the groundwork for [profit] to occur. That’s the next logical step.”
Cowardly Colleges
When a tech startup fails, employees shuttle off to the next gig, founders to the next idea. Investors take a calculated ding, which they write off as losses on their taxes. The world misses out on one more digital distraction. But geoengineering is not a disruptive app promising to turn our consumptive world on its head.
When a solar geoengineering startup fails, the consequences may be benign — or billions of people could suffer. The consequences of its unfinished efforts could cause monsoons to shift, falter or hit with destructive fury. Fisheries could collapse. Crops might wither. The world could find itself committed to an expensive and problematic experiment, because, once put in motion, pulling the plug would be disastrous.
Although the oft-stated goal of geoengineering is to return the planet to its pre-industrial temperatures, solar radiation management, in particular, “doesn’t bring us back to the climate that we had before, it creates a different climate,” Fuhr told me. “People compare stratospheric aerosol injection with volcano eruptions. Yes, they’ve cooled the climate in the past. They’ve also brought famines.”
Back in 2010, the author Eli Kintisch referred to geoengineering as “a bad idea whose time has come.”
That may be true, Kruger says, “but solar geoengineering is also just not a particularly good idea.”
Making a real impact would require more than one person launching balloons; it would depend on a synchronized global effort with dozens of planes spraying chemicals in the stratosphere for decades or even hundreds of years. We still don’t have a way of knowing for sure whether changes we might witness could be directly attributed to the effort, and all the world’s nations would need to accept the result, even if it results in bizarre or damaging weather.
If we could pull off such international agreement and coordination, we probably wouldn’t be in this predicament.
In 2022, the risks spurred a consortium of scholars to call for an across-the-board, international full stop on the use of solar geoengineering. As of May, more than 500 scholars from 67 countries have signed on (as have nearly 5,000 other people). Global organizations like the Convention on Biological Diversity, London Protocol, Carnegie Climate Governance Initiative and the Degrees Initiative (formerly the Solar Radiation Management Governance Initiative) have also called for solar geoengineering moratoriums, strict regulation or increased governance.
John Moore, a British glaciologist whose signature is not among the more than 500 dissenters believes we should at least be exploring the potential of more ambitious intervention, but not by blocking out the sun. Moore is decades into tracking the retreat of massive glaciers at the Earth’s poles.
“You can’t negotiate with the melting point of ice,” he told me. “Once we’re past 1.5 degrees Celsius, the writing’s on the wall, and that’s pretty much where we are.” Climate scientists have long warned that allowing the global average temperature to surpass 1.5 degrees Celsius above pre-industrial levels would take us past a climatic point of no return.
Simply put, Moore has been exploring the possibility of slowing the rate of glacier melt by redirecting the flow of warm water eating away at ice deep in the ocean by constructing a kind of seawall on the ocean’s floor. In theory, a curtain about 50 miles long and maybe 330 feet high, anchored in front of an ice shelf, could deflect warm water before it reaches the ice, save the glacier and slow sea-level rise. He describes it as geoengineering at a “pinch point.”
“When a solar geoengineering startup fails, the consequences may be benign, but also billions of people could suffer.”
Moore has been onto this idea for at least eight years, but he still isn’t satisfied that he understands it well enough. “We know the model is not perfect, and the key worry is, well, is it missing something that’s really important?” he told me. But to find out, he needs money. Perhaps $10 million. “You’d be amazed how far a stupid little amount of money could actually go toward answering these key questions that could literally cost [the world] trillions of dollars in a couple of decades’ time.”
So far, though, academia has been reluctant to back geoengineering research. Moore attributes it to “cowardice” over anything controversial. In March, Harvard University shut down its solar geoengineering project, SCoPEx, short for “Stratospheric Controlled Perturbation Experiment,” in response to public backlash championed by Indigenous groups including the Sámi of Scandinavia.
Private philanthropy is less afraid, Moore told me. For some independent investors, the risk that his idea could go nowhere “kind of doesn’t matter. Even if there’s a 1% chance it works, you’re still going to get a payoff at the end of the day.” He says that his models show preventing 50 cm, or about 20 inches, of sea-level rise over a century could save coastal countries $2 trillion in potential losses and damages.
Moore isn’t looking to profit off research on manipulating deep sea currents, he told me, and even if he was, he’d have a hard time commercializing the construction of a seawall 1,000 feet below the ocean’s surface. For making a profit by saving the world, there are much better ideas. Glacier brightening, for instance.
The Problem With Patents
The nonprofit Bright Ice Initiative is the brainchild of Leslie Field, a Stanford University adjunct professor who began her career by helping Chevron devise ways to get lead out of gasoline. Her nonprofit seeks to combat sea-level rise by covering melting glaciers in tiny reflective balls made from a clay-based material. Field, who is also the founder and managing member of an engineering consulting firm, has been issued more than 60 U.S. patents, some of which cover methods for cooling water with sunlight-reflecting materials.
Outside of carbon markets, patents are perhaps the most available means to profit from geoengineering. Patent owners can control how and where their technology is deployed and reap the royalties paid for its use. Many experts worry patenting geoengineering technologies will open the door to Dr. Evil-style villains who could hold the world ransom. But Field argues that the public-facing patent process keeps the field transparent and allows owners to ensure their ideas are used responsibly. She told me she does not intend to profit from her climate-related patents and plans to direct any patent-related profits to Bright Ice.
Bright Ice, she claims, has searched extensively for what they deem environmentally safe reflective materials, and by patenting her methods Field withholds the power to determine who is worthy of following in her footsteps. “I just don’t want somebody using some toxic material that’s cheaper,” Field says. “That’s the big risk that motivated me on [patenting], because you got to be careful on this stuff.”
Today, most geoengineering patents are held by a small number of corporations, but as the field has grown, there has been a surge in new patent applications. The anti-corruption organization Transparency International has termed the scramble to claim ownership of this new sector of technology a “patent land-grab” with dire implications.
Most concerning is the likelihood that certain well-endowed private interests will gobble up “building-block patents,” according to Transparency International. Such patents include everything used or derived from an invention. Whoever secures these foundational patents first will end up with a tight grip on a slew of future geoengineering technologies.
“There is a need to enable developers to actually make money from what they’re doing, otherwise, it won’t happen,” Kruger told me. However, “there is a key element about public trust. If the private sector is involved, and people see a profit motive, it undermines the public’s view on the motivations of people doing things.”
With the profits from concentrated intellectual property rights, mega-patent holders could wield undue influence over geoengineering technologies, leverage legislators to ensure their solutions are greenlighted and funded, and conceal negative results from public scrutiny. For a glimpse of how that might look, consider the American pharmaceutical industry.
“Whoever secures these foundational patents first will end up with a tight grip on a slew of future geoengineering technologies.”
Kruger has been harping on the risks of patenting geoengineering technology since at least 2013, when he and other concerned researchers published The Oxford Principles to safely guide research. Today, he told me there is a safe and necessary role for the private sector, especially in helping to capture and store carbon, but he worries about geoengineering cowboys piling onto slipshod solar or ocean experiments with little oversight.
As it stands, there is no national or international body and hardly any regulation to govern geoengineering. To launch his balloons in California, Iseman needs only to report his launches to the Federal Aviation Administration. But when the public gets wind that someone is experimenting in their backyard, there is often a backlash. “Governments respond to that,” Kruger told me. In January 2023, for instance, Mexico responded to Make Sunsets’ balloon launches by announcing it would ban geoengineering within its borders.
Instead of reacting to bad actors with restrictions, Kruger wants governments to facilitate safe research and development by setting the conditions for success. He points to the Covid-19 vaccine: Governments put out the call, and the world’s microbiologists, backed by significant private investment (and $32 billion from the US government), quickly delivered, saving untold numbers of lives. After all, it would appear that geoengineering on a massive scale is inevitable — we exist at the threshold of immutable climatic tipping points, there is zero chance that the world’s governments and corporations will stop burning fossil fuels fast enough, and some damage is already baked in — shouldn’t we regulate it carefully?
Surprise thinks this is idealistic. In a perfect world, he says, scientists inform policymakers, who install regulations that companies comply with. “I think we can agree that that’s simply not how the real world works.”
Green Capital, Same As The Old Capital
When Surprise looked into who was behind solar geoengineering funding today, he didn’t find the fossil fuel industry trying to delay emissions reductions. He found uber-rich, Silicon Valley and Wall St. philanthropists who advertised themselves as wanting to save the world. But if the ends they seek are different from the oil and gas industry, their means are surprisingly similar.
The world has so far responded to climate change with a new green economy: carbon pricing, privatized conservation, renewable energy investment, carbon capture technologies and green consumerism. The idea is that this sustainability minded economic engine, driven by competition for profit, will spur innovation that ripples through society, changing the energy economy and keeping pace with our climate crisis. So far, that hasn’t been the case.
“There’s recognition that [the green economy] is unlikely to work in the timescales necessary to stave off the worst of the crisis,” Surprise told me. Global gross domestic product could fall by up to 18% by 2050 if climate mitigation isn’t successful enough. According to Moore, seven feet of sea-level rise would cost the world $100 billion a year.
Solar geoengineering is often framed as a massive humanitarian effort, but “there is no grassroots climate justice movement crying out for these technologies,” he said. Instead, his research shows that funding for solar engineering is comprised of a core group including, “at least 11 billionaires or billionaire-founded philanthropies, and a slew of wealthy individuals with direct ties to venture capital firms and billionaire-led hedge funds.” The largest bloc among them are financial firms in the high-tech sector. Surprise argues that this pool of capital, which depends on continued economic growth, can’t stomach the potential future economic losses forecasted for a warming planet. So, it is investing in solar engineering.
“This is basically a hedge on the bet of the green economy,” he told me. “We can’t move away from the profit motive. We can’t move away from capitalism. We’ve got to double down. We’ve got to use this as the solution.”
From Surprise’s perspective, geoengineering is part of an effort to buy time for gradual, market-driven climate and energy transitions that will keep the economy cooking. And his concerns echo those of others who stand opposed to solar radiation management and the geoengineering field as a whole: While entrepreneurs invest their time and money into speculative technologies, the real climate action of reducing carbon emissions is delayed.
For his part, Iseman agrees that what we’ve been doing to address climate change isn’t working. That’s why geoengineering is inevitable, he told me. “By starting to do it, hopefully, I’ve speeded up when this happens at scale by a couple years. Hopefully, people oppose the privatization of this. Hopefully, I can serve as this bogeyman” that pushes governments to step in and say: “‘We need to do this as responsible adults, because otherwise these startup guys are going to do it.’”
Update: On Oct. 1, 2024, this essay was updated to indicate that Open Philanthropy is no longer a significant funder for solar engineering. It exited doing so in August 2024.
