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Is international cooperation or technological development the answer to an apocalyptic threat?

Christopher Nolan’s film Oppenheimer is about the great military contest of the Second World War, but only in the background. It’s really about a clash of visions for a postwar world defined by the physicist J. Robert Oppenheimer’s work at Los Alamos and beyond. The great power unleashed by the bombs at Hiroshima and Nagasaki could be dwarfed by what knowledge of nuclear physics could produce in the coming years, risking a war more horrifying than the one that had just concluded.
Oppenheimer, and many of his fellow atomic scientists, would spend much of the postwar period arguing for international cooperation, scientific openness, and nuclear restriction. But there was another cadre of scientists, exemplified by a former colleague turned rival, Edward Teller, that sought to answer the threat of nuclear annihilation with new technology — including even bigger bombs.
As the urgency of the nuclear question declined with the end of the Cold War, the scientific community took up a new threat to global civilization: climate change. While the conflict mapped out in Oppenheimer was over nuclear weapons, the clash of visions, which ended up burying Oppenheimer and elevating Teller, also maps out to the great debate over global warming: Should we reach international agreements to cooperatively reduce carbon emissions or should we throw our — and specifically America’s — great resources into a headlong rush of technological development? Should we massively overhaul our energy system or make the sun a little less bright?
Oppenheimer’s dream of international cooperation to prevent a nuclear arms race was born even before the Manhattan Project culminated with the Trinity test. Oppenheimer and Danish physicist Niels Bohr “believed that an agreement between the wartime allies based upon the sharing of information, including the existence of the Manhattan Project, could prevent the surfacing of a nuclear-armed world,” writes Marco Borghi in a Wilson Institute working paper.
Oppenheimer even suggested that the Soviets be informed of the Manhattan Project’s efforts and, according to Martin Sherwin and Kai Bird’s American Prometheus, had “assumed that such forthright discussions were taking place at that very moment” at the conference in Potsdam where, Oppenheimer “was later appalled to learn” that Harry Truman had only vaguely mentioned the bomb to Joseph Stalin, scotching the first opportunity for international nuclear cooperation.
Oppenheimer continued to take up the cause of international cooperation, working as the lead advisor for Dean Acheson and David Lilienthal on their 1946 nuclear control proposal, which would never get accepted by the United Nations and, namely, the Soviet Union after it was amended by Truman’s appointed U.N. representative Bernard Baruch to be more favorable to the United States.
In view of the next 50 years of nuclear history — further proliferation, the development of thermonuclear weapons that could be mounted on missiles that were likely impossible to shoot down — the proposals Oppenheimer developed seem utopian: The U.N. would "bring under its complete control world supplies of uranium and thorium," including all mining, and would control all nuclear reactors. This scheme would also make the construction of new weapons impossible, lest other nations build their own.
By the end of 1946, the Baruch proposal had died along with any prospect of international control of nuclear power, all the while the Soviets were working intensely to disrupt America’s nuclear monopoly — with the help of information ferried out of Los Alamos — by successfully testing a weapon before the end of the decade.
With the failure of international arms control and the beginning of the arms race, Oppenheimer’s vision of a post-Trinity world would come to shambles. For Teller, however, it was a great opportunity.
While Oppenheimer planned to stave off nuclear annihilation through international cooperation, Teller was trying to build a bigger deterrent.
Since the early stages of the Manhattan Project, Teller had been dreaming of a fusion weapon many times more powerful than the first atomic bombs, what was then called the “Super.” When the atomic bomb was completed, he would again push for the creation of a thermonuclear bomb, but the efforts stalled thanks to technical and theoretical issues with Teller’s proposed design.
Nolan captures Teller’s early comprehension of just how powerful nuclear weapons can be. In a scene that’s pulled straight from accounts of the Trinity blast, most of the scientists who view the test are either in bunkers wearing welding goggles or following instructions to lie down, facing away from the blast. Not so for Teller. He lathers sunscreen on his face, straps on a pair of dark goggles, and views the explosion straight on, even pursing his lips as the explosion lights up the desert night brighter than the sun.
And it was that power — the sun’s — that Teller wanted to harness in pursuit of his “Super,” where a bomb’s power would be derived from fusing together hydrogen atoms, creating helium — and a great deal of energy. It would even use a fission bomb to help ignite the process.
Oppenheimer and several scientific luminaries, including Manhattan Project scientists Enrico Fermi and Isidor Rabi, opposed the bomb, issuing in their official report on their positions advising the Atomic Energy Commission in 1949 statements that the hydrogen bomb was infeasible, strategically useless, and potentially a weapon of “genocide.”
But by 1950, thanks in part to Teller and the advocacy of Lewis Strauss, a financier turned government official and the approximate villain of Nolan’s film, Harry Truman would sign off on a hydrogen bomb project, resulting in the 1952 “Ivy Mike” test where a bomb using a design from Teller and mathematician Stan Ulam would vaporize the Pacific Island Elugelab with a blast about 700 times more powerful than the one that destroyed Hiroshima.
The success of the project re-ignited doubts around Oppenheimer’s well-known left-wing political associations in the years before the war and, thanks to scheming by Strauss, he was denied a renewed security clearance.
While several Manhattan Project scientists testified on his behalf, Teller did not, saying, “I thoroughly disagreed with him in numerous issues and his actions frankly appeared to me confused and complicated.”
It was the end of Oppenheimer’s public career. The New Deal Democrat had been eclipsed by Teller, who would become the scientific avatar of the Reagan Republicans.
For the next few decades, Teller would stay close to politicians, the military, and the media, exercising a great deal of influence over arms policy for several decades from the Lawrence Livermore National Laboratory, which he helped found, and his academic perch at the University of California.
He pooh-poohed the dangers of radiation, supported the building of more and bigger bombs that could be delivered by longer and longer range missiles, and opposed prohibitions on testing. When Dwight Eisenhower was considering a negotiated nuclear test ban, Teller faced off against future Nobel laureate and Manhattan Project alumnus Hans Bethe over whether nuclear tests could be hidden from detection by conducting them underground in a massive hole; the eventual 1963 test ban treaty would exempt underground testing.
As the Cold War settled into a nuclear standoff with both the United States and the Soviet Union possessing enough missiles and nuclear weapons to wipe out the other, Teller didn’t look to treaties, limitations, and cooperation to solve the problem of nuclear brinksmanship, but instead to space: He wanted to neutralize the threat of a Soviet first strike using x-ray lasers from space powered by nuclear explosions (he was again opposed by Bethe and the x-ray lasers never came to fruition).
He also notoriously dreamed up Project Plowshare, the civilian nuclear project which would get close to nuking out a new harbor in Northern Alaska and actually did attempt to extract gas in New Mexico and Colorado using nuclear explosions.
Yet, in perhaps the strangest turn of all, Teller also became something of a key figure in the history of climate change research, both in his relatively early awareness of the problem and the conceptual gigantism he brought to proposing to solve it.
While publicly skeptical of climate change later in his life, Teller was starting to think about climate change, decades before James Hansen’s seminal 1988 Congressional testimony.
The researcher and climate litigator Benajmin Franta made the startling archival discovery that Teller had given a speech at an oil industry event in 1959 where he warned “energy resources will run short as we use more and more of the fossil fuels,” and, after explaining the greenhouse effect, he said that “it has been calculated that a temperature rise corresponding to a 10 percent increase in carbon dioxide will be sufficient to melt the icecap and submerge New York … I think that this chemical contamination is more serious than most people tend to believe.”
Teller was also engaged with issues around energy and other “peaceful” uses of nuclear power. In response to concerns about the dangers of nuclear reactors, he in the 1960s began advocating putting them underground, and by the early 1990s proposed running said underground nuclear reactors automatically in order to avoid the human error he blamed for the disasters at Chernobyl and Three Mile Island.
While Teller was always happy to find some collaborators to almost throw off an ingenious-if-extreme solution to a problem, there is a strain of “Tellerism,” both institutionally and conceptually, that persists to this day in climate science and energy policy.
Nuclear science and climate science had long been intertwined, Stanford historian Paul Edwards writes, including that the “earliest global climate models relied on numerical methods very similar to those developed by nuclear weapons designers for solving the fluid dynamics equations needed to analyze shock waves produced in nuclear explosions.”
Where Teller comes in is in the role that Lawrence Livermore played in both its energy research and climate modeling. “With the Cold War over and research on nuclear weapons in decline, the national laboratories faced a quandary: What would justify their continued existence?” Edwards writes. The answer in many cases would be climate change, due to these labs’ ample collection of computing power, “expertise in numerical modeling of fluid dynamics, and their skills in managing very large data sets.”
One of those labs was Livermore, the institution founded by Teller, a leading center of climate and energy modeling and research since the late 1980s. “[Teller] was very enthusiastic about weather control,” early climate modeler Cecil “Chuck” Leith told Edwards in an oral history.
The Department of Energy writ large, which inherited much of the responsibilities of the Atomic Energy Commission, is now one of the lead agencies on climate change policy and energy research.
Which brings us to fusion.
It was Teller’s Lawrence Livermore National Laboratory that earlier this year successfully got more power out of a controlled fusion reaction than it put in — and it was Energy Secretary Jennifer Granholm who announced it, calling it the “holy grail” of clean energy development.
Teller’s journey with fusion is familiar to its history: early cautious optimism followed by a realization that it would likely not be achieved soon. As early as 1958, he said in a speech that he had been discussing “controlled fusion” at Los Alamos and that “thermonuclear energy generation is possible,” although he admitted that “the problem is not quite easy” and by 1987 had given up on seeing it realized during his lifetime.
Still, what controlled fusion we do have at Livermore’s National Ignition Facility owes something to Teller and the technology he pioneered in the hydrogen bomb, according to physicist NJ Fisch.
While fusion is one infamous technological fix for the problem of clean and cheap energy production, Teller and the Livermore cadres were also a major influence on the development of solar geoengineering, the idea that global warming could be averted not by reducing the emissions of greenhouse gas into the atmosphere, but by making the sun less intense.
In a mildly trolling column for the Wall Street Journal in January 1998, Teller professed agnosticism on climate change (despite giving that speech to oil executives three decades prior) but proposed an alternative policy that would be “far less burdensome than even a system of market-allocated emissions permits”: solar geoengineering with “fine particles.”
The op-ed placed in the conservative pages of the Wall Street Journal was almost certainly an effort to oppose the recently signed Kyoto Protocol, but the ideas have persisted among thinkers and scientists whose engagement with environmental issues went far beyond their own opinion about Al Gore and by extension the environmental movement as a whole (Teller’s feelings about both were negative).
But his proposal would be familiar to the climate debates of today: particle emissions that would scatter sunlight and thus lower atmospheric temperatures. If climate change had to be addressed, Teller argued, “let us play to our uniquely American strengths in innovation and technology to offset any global warming by the least costly means possible.”
A paper he wrote with two colleagues that was an early call for spraying sulfates in the stratosphere also proposed “deploying electrically-conducting sheeting, either in the stratosphere or in low Earth orbit.” These were “literally diaphanous shattering screens,” that could scatter enough sunlight in order to reduce global warming — one calculation Teller made concludes that 46 million square miles, or about 1 percent of the surface area of the Earth, of these screens would be necessary.
The climate scientist and Livermore alumnus Ken Caldeira has attributed his own initial interest in solar geoengineering to Lowell Wood, a Livermore researcher and Teller protégé. While often seen as a centrist or even a right wing idea in order to avoid the more restrictionist policies on carbon emissions, solar geoengineering has sparked some interest on the left, including in socialist science fiction author Kim Stanley Robinson’s The Ministry for the Future, which envisions India unilaterally pumping sulfates into the atmosphere in response to a devastating heat wave.
The White House even quietly released a congressionally-mandated report on solar geoengineering earlier this spring, outlining avenues for further research.
While the more than 30 years since the creation of the Intergovernmental Panel on Climate Change and the beginnings of Kyoto Protocol have emphasized international cooperation on both science and policymaking through agreed upon goals in emissions reductions, the technological temptation is always present.
And here we can perhaps see that the split between the moralized scientists and their pleas for addressing the problems of the arms race through scientific openness and international cooperation and those of the hawkish technicians, who wanted to press the United States’ technical advantage in order to win the nuclear standoff and ultimately the Cold War through deterrence.
With the IPCC and the United Nations Climate Conference, through which emerged the Kyoto Protocol and the Paris Agreement, we see a version of what the postwar scientists wanted applied to the problem of climate change. Nations come together and agree on targets for controlling something that may benefit any one of them but risks global calamity. The process is informed by scientists working with substantial resources across national borders who play a major role in formulating and verifying the policy mechanisms used to achieve these goals.
But for almost as long as climate change has been an issue of international concern, the Tellerian path has been tempting. While Teller’s dreams of massive sun-scattering sheets, nuclear earth engineering, and automated underground reactors are unlikely to be realized soon, if at all, you can be sure there are scientists and engineers looking straight into the light. And they may one day drag us into it, whether we want to or not.
Editor’s note: An earlier version of this article misstated the name of a climate modeler. It’s been corrected. We regret the error.
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Plus, Google and Amazon report on what hyperscaling has done to their emissions.
There’s an interesting new report out today from the progressive think tank Groundwork Collaborative that makes a case for how Democrats can harness the artificial intelligence and data center boom to help the power grid — while also cutting costs for electricity customers.
But first, some news. We’ve known for some time now that artificial intelligence is transforming America’s biggest technology companies, turning them into major energy consumers and even quasi-industrial firms. Now we have even more evidence that it’s driving up their carbon emissions, too.
Google and Amazon released their annual sustainability reports yesterday, and both show huge surges in their energy use and climate pollution. Google’s greenhouse gas pollution grew by 18% last year, its largest year-over-year jump on record, and its energy use leapt by 37%. The company’s energy use rose by more than a quarter last year; it now uses roughly 3.5 times as much energy as it did before the pandemic.
Amazon’s climate pollution, meanwhile, increased by more than 16%, surging by the equivalent of more than 10 million metric tons of carbon dioxide. Emissions from its purchased electricity increased 34% since last year. If you feel like you’re seeing more Rivian-made Amazon delivery vans on the road, you’re not wrong: The company claims it deployed an additional 21,000 last year.
What’s driving this surge? The AI boom, of course. “Our AI infrastructure buildout is currently accelerating faster than the grid is decarbonizing,” Kate Brandt, Google’s chief sustainability officer, said in a statement.
What to do about it? That’s what Groundwork’s report is about.
“How do we bring down costs now? How do we bring down costs in the long term? And how can we make those two things mutually reinforcing?” Grayson Flood, the report’s author and a former policy adviser to Representative Alexandria Ocasio-Cortez, told me. “We wanted to be pretty direct about addressing what we see as a broken incentive structure within the system, particularly for interregional transmission.”
The report outlines a few novel ideas about how to lower prices immediately, in part to get through a coming multi-year “crunch,” during which the power grid in some regions will be maximally constrained while utilities work to bring new power plants online:
The report also imagines several policy ideas to help build out the grid. One of them is a Grid Trust Fund, a new federal bank account funded through an excise tax on data centers and other large electricity loads.
The government has often turned to funds like these to support infrastructure that creates a natural monopoly at national scale, Flood said. “The interstate highway is the most notorious example, but you can look at airports, you can look at seaports — they have these types of trust funds. There’s a lot of precedent for this in the tax code, and they tend to be financed with excise taxes on some sort of corresponding usage of the infrastructure.”
Under his scheme, the new excise tax would fall on big power users like data centers or crypto miners that don’t generate many permanent local jobs — in other words, aluminum smelters, steel mills, and semiconductor fabs would be exempt from it. But even just taxing electricity for large loads at 1 or 1.5 cents per kilowatt-hour, he said, could throw off more than $100 billion in a decade. That money could then be used to fund new transmission projects, technical assistance for utilities, ratepayer relief, or economic development.
That trust fund would be partly overseen by a National Power Authority, a new government corporation modeled on the Tennessee Valley Authority or the Energy Department’s existing power marketing administrations. This authority would have limited powers and would be partly inspired by Texas’ successful effort to centrally plan transmission lines in order to expand its electricity market.
The new authority would plan and develop interregional transmission, linking far-flung regions of the country to create new power markets. It would also have the power to build new 24/7 zero-carbon electricity power plants with high up-front capital costs, such as new geothermal projects, offshore wind farms, or nuclear plants.
“People talk about the power grid as a platform,” Flood said. But “right now, the grid is not functioning as a backbone and platform, it’s functioning as a bottleneck.”
The goal of the report, he said, is to ask: “How do we build [the power grid] as a backbone to support the growth of private markets, whether that’s in renewable energy generation, or an AI data center, or a new hospital that’s showing up?”
It’s an interesting document. Many energy wonks have proposed plans to shift some of the costs of expanding the electricity system out of the ratebase — that is, out of customers’ power bills — and onto the tax base, which is funded in a more progressive way. (I recently argued for a national, publicly funded grid buildout in The New York Times.) The new Groundwork report, in essence, tries to reframe those ideas for an era of populist politics — and one in which Americans are suspicious of data centers, as Heatmap’s polling has shown.
In its fusion of populist and pro-growth attitudes, this new set of proposals reminds me of New York City Mayor Zohran Mamdani’s attempt to freeze the rent for some tenants while passing major supply-side reforms allowing new housing construction. That effort has won Mamdani praise from many housing advocates in New York (even as some remain dubious about his de facto rent freeze). Whether that kind of politics works at a national level remains to be seen.
The bill is part of a package now sitting on Governor Mikie Sherrill’s desk.
Data center politics are continuing to evolve rapidly, and almost always in the direction of increasing costs and restrictions for data center development.
In New Jersey, which has become ground zero for the political backlash to high electricity prices, a gaggle of bills relating to data centers and electricity prices just hit the desk of newly elected Governor Mikie Sherrill, including a large load tariff bill, a water and energy reporting bill, and a bill to scale back tax credits available to data center projects.
All of these pieces of legislation are consistent with national and local trends (federal regulators are encouraging regional electricity markets to come up with large load tariffs, for example), with tax credits getting an especially close look in statehouses across the country.
Thirty-eight states have “ dedicated tax incentives for data centers,” according to an April study by the National Conference on State Legislatures. These often include exemptions from sales taxes for data center equipment like servers and routers, or property tax abatements for newly constructed data centers.
In Virginia, which last year elected Sherrill’s former House colleague Abigail Spanberger as governor, the sales tax exemption has become a hot issue of political contestation, as powerful Virginia State Senator Louise Lucas has come out in opposition to it. A budget deal recently reached in the state’s General Assembly included a tax on data center electricity consumption, while the data center tax exemption question will be kicked to a working group for now, according to the Virginia Mercury.
The New Jersey bill currently on the governor’s desk targets a tax credit program called Next New Jersey, which has some $500 million to disburse for tax credits. Half of that has been allocated for a CoreWeave data center project on the site of an existing laboratory, State Senator Joseph Cryan told me. The remaining $250 million would be used to bolster a number of existing state programs.
“The reason for eliminating it was, frankly, because people are outraged over the amount of money CoreWeave got,” Cryan said.
CoreWeave did not respond to a request for comment. A Sherill spokesperson didn’t comment on the record about when or whether the bills would be signed.
New Jersey and Virginia’s examination of tax credits comes after another state with a Democratic governor, Illinois, paused tax incentives for data centers that had been worth almost $1 billion in the first five years of this decade.
The turn against tax incentives for data centers comes as the public is increasingly wary of the latter and their perceived effect on electricity prices. This turn in sentiment has forced governors — like, say, Indiana Governor Mike Braun — to pivot away from their typical cheerleading for new businesses.
“States are very focused on attracting industries of the future, attracting jobs for their residents, attracting business,” Justin Balik, a former economic development official in New Jersey and vice president for states at the climate group Evergreen Action, told me. But, he asked, “Does the economic development strategy for a state reflect its other policy priorities?”
New Jersey itself is an example of how quickly the politics of economic development can turn. When the bill establishing the Next New Jersey program passed in 2024, then-Governor Phil Murphy trumpeted the bill for “capitalizing on this moment to ensure we establish ourselves as a frontrunner in generative AI innovation.”
“AI has already started to revolutionize our everyday lives, and New Jersey is capitalizing on this moment to ensure we establish ourselves as a frontrunner in generative AI innovation,” Murphy said in a statement typical of the more boosterist era of, uhhh, two years ago. “AI will be a transformative industry that will change lives and grow our economy and New Jersey is ready to take the lead.”
That was in July 2024. Now it’s July 2026. Electricity bills in New Jersey have gone up from $108 per month in May 2024 to $140 this past May, according to the Heatmap-MIT Electricity Price Hub, while rates have gone up some 38%. And while it’s often difficult to attribute electricity rate hikes directly to data center development — or even determine whether data centers raise rates at all — New Jersey, which is part of the PJM Interconnection electricity market, is almost certainly seeing hikes due to data center construction. PJM has struggled to bring on new generation or adequate transmission, and its own market monitor said in March that “data center load growth is the primary reason for recent and expected capacity market conditions, including total forecast load growth, the tight supply and demand balance, and high prices.”
The conditions have forced lawmakers to reconsider their typical bias toward economic development, Balik told me. “I think we’re seeing a moment where there’s a reckoning with the energy affordability conversation,” he said, “Where folks are rightly saying, hey, we care about clean energy in some cases, and in a lot of cases we care about energy affordability. Does our economic development strategy match those priorities, or are these two things at odds with each other?”
Cryan, the state senator, put it more bluntly: “The reason for doing it was to show the public that we hear their outrage and can do something about it,” he said. “The governor and the legislature have heard the voices of the people of New Jersey.”
What the heck is “surficial mineralization”?
According to one of the world’s leading carbon removal buyers, the sector’s future lies in piles of industrial waste.
When Frontier, the Stripe-led coalition of carbon removal supporters, announced its latest $915 million funding commitment, it took the opportunity to lay out the five technologies it views as most promising. I was familiar with four of them — ocean alkalinity enhancement, biomass carbon removal and storage, enhanced rock weathering, and direct air capture. Heatmap has covered them all. But the name on the very top of the list stumped me: surficial mineralization.
It sounds technical, and like all methods of carbon removal, it is — sort of. The idea is to take advantage of the tailings ponds and slag heaps left behind by the mining and steelmaking industries. These piles of calcium- or magnesium-rich debris naturally capture and store carbon from the air — not enough to change the trajectory of our warming planet without any human intervention, but managed well, they could one day capture carbon at a significant scale.
How significant, exactly? While there’s been very little action in the space to date, Frontier says surficial mineralization has the potential to remove over 10 gigatons of carbon from the atmosphere per year — as much or more than any other pathway — at an eventual cost of $80 to $120 per ton. That would put it among the cheapest approaches on Frontier’s list, in part because those heaps of industrial waste alone could absorb anywhere from a gigaton to 4 gigatons of carbon before there’s a need to mine rocks solely for carbon removal purposes.
“The beauty of surficial mineralization is twofold,” Hannah Bebbington Valori, who heads the Frontier coalition, told me. “One, we are working with an abundant source of highly reactive rock, and so there is a significant opportunity for carbon dioxide drawdown. And two, it is carbonating in place, and so sufficient mineralization technologies can be considered closed system approaches, and have generally more straightforward measurement reporting and verification infrastructure.”
At a chemical level, the process resembles other carbon removal pathways Frontier champions, such as enhanced rock weathering and ocean alkalinity enhancement. All three rely on alkaline minerals reacting with moisture and ambient carbon dioxide to form stable carbonate compounds that permanently lock away the gas. The difference is exactly where this reaction takes place: While surficial mineralization contains it to waste piles at industrial sites, the other approaches disperse the reaction across open, difficult-to-monitor systems such as farmland soils and the ocean.
That makes measurement, reporting, and verification — known as MRV — far more challenging and expensive for ocean- and soil-based systems, as scientists must track carbon uptake across ecologically complex environments where countless biological and chemical processes are unfolding simultaneously. These intersecting processes makes it difficult to demonstrate that human intervention was responsible for any given ton of carbon removed, as opposed to natural variability. MRV for these pathways thus relies heavily on modeling, which can never provide the same level of certainty as direct measurement.
Surficial mineralization, however, can be measured much more directly. On-site sensors continuously monitor CO2 concentrations above mine tailings or steel slag, providing a real-time signal of how quickly and to what degree the materials are drawing down carbon. Scientists can then validate these measurements in the lab by comparing physical samples of the material taken before and after the reaction, quantifying exactly how much solid carbonate formed as a result of various engineered interventions. The primary tool for this is X-ray diffraction — a well-established geological technique that identifies a sample’s mineral composition like a chemical fingerprint, making it possible to directly measure how much carbon the material locked away.
Don’t mistake the relative simplicity of the MRV framework for evidence that surficial mineralization is a proven carbon removal pathway — the reality is far from it. While mineralization may look simpler than, say, direct air capture, which typically uses giant fans and specialized sorbents to pull CO2 from the air, there are very few companies working in this space today. All are extremely early stage, and the time and capital required to secure feedstock partnerships, gain site access, and acquire necessary industrial equipment remain significant barriers to getting these projects off the ground.
Why is this heavy equipment needed in the first place? Because these waste piles won’t do much carbon capture work if they’re simply left untouched. That’s because the minerals at the pile’s surface will begin to slowly carbonate, eventually becoming fully saturated and acting as a seal that blocks carbon from reaching the reactive minerals below. As yet there’s no consensus on how to most quickly and cost-effectively break through this natural process to maximize carbon uptake — companies are testing a range of approaches, from crushing and spreading material to maximize air exposure (similar to enhanced rock weathering) to actively churning piles of waste to constantly reveal fresh reactive surfaces.
“Understanding exactly what is the best system to use to maximize your carbon removal efficiency and minimize your cost — this is what we need real-world deployment to do, and to understand,” Bebbington Valori told me.
One of the seed-stage startups Frontier has supported with a small pre-purchase agreement, Arca, spun out of the University of British Columbia to commercialize its approach to carbon removal from mine tailings. The company’s focus is ultramafic waste — magnesium- and iron-rich rock that locks away carbon dioxide as stable magnesium carbonate. “My pathway for interest on that was knowing that there was already about 2 billion tons of ultramafic mine waste sitting on the surface of the Earth in Canada alone,” Greg Dipple, Arca’s co-founder and head of science, told me.
Arca proposes to increase the surface area available for carbon capture in two ways. The first is by using customized robots to continuously till and churn tailings piles, constantly exposing fresh feedstock to the air to maximize carbon uptake before the next layer of tailings is deposited on top. That strategy, Dipple told me, “can give us a five- to 10-fold increase in the rate of CO2 capture” at active mine sites.
It successfully demonstrated this approach in an 18-month pilot project with Australian mining giant BHP at an active mine in the country's Northern Goldfields region where Arca says it increased the tailings’ mineralization rate by an order of magnitude. But the startup plans to push the efficacy of its tech further through what it calls “mineral activation.” This technique uses industrial-scale microwaves to heat the minerals rapidly enough to drive off the water that’s chemically bound within their crystal structure. This essentially blows apart the minerals from the inside out, exposing fresh magnesium-rich surfaces primed to react with carbon dioxide. The expected result is faster mineralization and more carbon captured per ton of mine tailings — but the startup has yet to test it in the field.
“Essentially we’re making microwave popcorn out of silicate minerals,” Dipple explained. “The microwaves cause the release of that water in the same way that when you make popcorn, you’re essentially boiling the water out of the center of the kernel, and that’s what blows the kernel up and creates this high surface area.” The idea is to eventually integrate this step into the mine’s tailings processing stream, with minerals moving through the giant microwave before they’re deposited at the storage facility.
Dipple told me that mineral activation will be a core part of Arca’s future projects, including those intended to fulfill the company’s 10-year carbon removal offtake agreement with Microsoft. Signed last October, the deal calls for Arca to deliver nearly 300,000 metric tons of carbon removal to the software giant.
While no other startup in the space has landed an offtake agreement of that scale, several have secured early backing from Frontier through pre-purchase agreements. One of them, Karbonetiq, is working to capture carbon from steel slag, the calcium-rich byproduct of steel production that accumulates in large piles at processing sites. Like the magnesium-rich minerals in mine tailings, calcium compounds in steel slag naturally react with moisture and carbon dioxide to form a stable calcium carbonate — a.k.a. limestone — permanently locking up the CO2.
Unlike mine tailings however, slag doesn’t begin as a fine powder. Instead, the molten byproducts poured off from high-temperature steel furnaces cool into chunks the size of large rocks, leaving only their outer surfaces exposed to the air and able to react with CO2. Karbonetiq’s strategy is essentially to crush and disperse those rocks to increase their reactive surface area. As the company’s commercial vice president, Luke Rondel, explained, “We crush [the slag] down so you get smaller particle sizes. We then spread that out in a field of material, and we till that material with a tractor and plow, which is just turning over new surfaces.”
Each pathway has its advantages — while Arca’s magnesium-rich mine tailings are the most abundant feedstock, Rondel told me that the calcium-based reactions in slag happen significantly faster. For its part, Frontier hopes to test and evaluate a range of approaches at its new Surficial Mineralization Hub in Quebec, which it announced at the end of April. Located at a former asbestos mine, the hub will give participating startups access to “10,000 tons of serpentinite tailings and space for pilot scale testing,” Bebbington Valori told me, as well as local labs with specialized equipment.
This should eliminate some of the hurdles facing the nascent sector, chief among them being access to the right kinds of reactive rocks. Small startups “really need to either partner with large academic labs or with large mining companies to get access to that feedstock,” Bebbington Valori told me — a difficult and expensive proposition for a company that’s just getting off the ground.
While Frontier has yet to announce the cohort of participating startups, both Arca and Karbonetiq told me they hope to test their technology there, with the latter planning what would be one of its first mine tailings pilots through the program. Ultimately the goal is to generate the proof points needed to give both the startups and Frontier a clearer roadmap for which approaches can realistically scale — and what kind of support they’ll need to get there.
It certainly won’t be a straightforward process — bringing new technology into old-school industries never is — and the economics will only start to pencil if their operations reach meaningful scale. In theory, mining companies could benefit from hosting surficial mineralization projects, whether through site access fees, outsourcing elements of waste management, or even critical minerals recovery. Miners could even develop and scale the technology themselves, if they so desire. But the sector has historically been reluctant to adopt new tech. “The classic quote is, in mining you always want to be No. 2, you don’t want to be the first one,” Dipple told me. “You don’t want to put up a $2 billion plant that doesn’t work.”
So like nearly everything in the carbon removal space, early execution is falling to the startups that aren’t afraid of a little risk. “They’re watching for sure,” Dipple said of the mining industry at large. “But they want to be No. 2. We’re going to have to be No. 1.”