In 2024, Climeworks’ Mammoth plant in Iceland — the world’s largest direct air capture facility, designed to remove 36,000 metric tons of CO₂ per year — captured 105 tons. Total. For the year. That’s less than the annual tailpipe emissions of a dozen long-haul trucks. It’s roughly one-thousandth of the plant’s stated design capacity. In mid-2025, Climeworks began laying off at least 10 percent of its approximately 500 employees. The company had raised over $800 million in equity and subsidies. JPMorgan Chase paid roughly $800 per ton for Climeworks removal credits in 2023. The co-CEO told reporters the operating cost was “closer to the $1,000 per ton mark than the $100 per ton mark.” The DOE’s target — the threshold at which direct air capture becomes economically viable for climate-scale deployment — is $100 per ton.
Meanwhile, in West Texas, Occidental Petroleum’s subsidiary 1PointFive is constructing Stratos, a direct air capture plant designed to remove 500,000 tons of CO₂ annually — nearly 14 times Mammoth’s design capacity. Construction of the first two “trains” finished in December 2024. Operations are expected to begin in 2025–2026, with full capacity by mid-2026. The facility cost $1.3 billion, up from original estimates of $800 million. It will be powered partly by a dedicated 145-megawatt solar installation. It will run on natural gas for the high-temperature heat the process requires. The captured CO₂ will be injected underground and earn 45Q tax credits. Occidental will continue selling hydrocarbons.
These two data points — Mammoth’s 105 tons and Stratos’s $1.3 billion construction cost — frame the honest state of direct air capture in 2026. The technology works. The physics is real. The scale, cost, and energy requirements are somewhere between daunting and disqualifying, depending on how much optimism you’re willing to extend and over what timeframe.
How it works
CO₂ constitutes roughly 422 parts per million of the atmosphere — 0.04 percent of the air around you. Direct air capture means extracting a trace gas from a mixture that is 99.96 percent other stuff. The dilution problem dictates the scale: processing enough air to capture meaningful quantities of CO₂ requires moving enormous volumes through chemical systems, which requires enormous amounts of energy.
Two approaches dominate. Liquid solvent systems — the Carbon Engineering technology that Occidental acquired and uses at Stratos — pass air through large contactors where it meets an alkaline solution, typically potassium hydroxide. The CO₂ reacts with the solution, forms calcium carbonate pellets through subsequent processing, and those pellets are heated in a kiln to roughly 900 degrees Celsius to release pure CO₂ gas. The high-temperature step is the cost driver: that kiln needs fuel, and at Stratos, the fuel is natural gas.
Solid sorbent systems — Climeworks’ approach — use porous materials coated with amine compounds that bind CO₂ from air at ambient temperature. When the sorbent is saturated, a temperature-vacuum swing cycle heats it to 80–120 degrees Celsius and reduces pressure to release the CO₂. The sorbent is then cooled and returned to capture mode. Lower regeneration temperatures make solid sorbent systems more compatible with renewable heat and waste heat, which is why Climeworks located in Iceland — geothermal energy provides the heat and electricity at near-zero carbon intensity.
Heirloom Carbon takes a third approach: accelerated mineralization. Limestone naturally absorbs CO₂ from the air, but the process takes years. Heirloom speeds it to days by spreading crushed limestone on trays exposed to air, then heating the saturated limestone to release concentrated CO₂. The company is developing two facilities in Louisiana with a combined capacity of 320,000 tons per year.
In every case, the captured CO₂ must then be compressed, transported, and either injected underground for permanent geological storage or mineralized into rock. The energy requirements for the full chain — capture, concentration, compression, injection — run between 2,000 and 3,000 kilowatt-hours per ton for the most mature systems. Newer electrochemical approaches are targeting 700 to 1,000 kWh per ton. Even with clean energy, life-cycle analyses show that DAC systems re-emit roughly 10 percent of the CO₂ they capture through embedded emissions in materials, equipment fabrication, and operational overhead.
The scale problem
Global CO₂ emissions are approximately 40 billion tons per year. DAC, across all companies, all technologies, and all years of operation combined, has removed less than 20,000 tons to date. That’s 0.00005 percent of annual emissions. IPCC pathways for holding global temperature increases to 1.5 degrees suggest the world may need to remove 5 to 10 gigatons of CO₂ annually by mid-century. One gigaton is a billion metric tons. Reaching one gigaton per year of DAC would require thousands of Mammoth-scale plants or dozens of Stratos-scale plants, consuming hundreds of terawatt-hours of energy annually — roughly equivalent to doubling the electricity consumption of a mid-sized industrial country.
The IEA’s net-zero roadmap calls for about 32 million tons of DAC removal per year by 2030, rising to gigatons by 2050. Current global capacity is measured in thousands of tons. The gap between where DAC is and where it needs to be is not a gap that the current trajectory closes. Mammoth was designed for 36,000 tons and delivered 105 in its first year. Stratos is designed for 500,000 tons and hasn’t started operations. If Stratos works at design capacity — a significant if, given that Carbon Engineering’s pilot in British Columbia handled 1 ton per day — it will represent an 873 percent increase in global DAC capacity from a single facility. But 500,000 tons is still one-eightieth of the 2030 IEA target, which is itself a fraction of what’s needed by 2050.
What’s actually happening in the market
The money is real even if the tonnage isn’t. The DOE allocated $3.5 billion for DAC Hubs — large-scale facilities designed to remove 1 million tons per year each. Project Cypress in Louisiana (Climeworks, Heirloom, Battelle) and Stratos in Texas have both received initial awards. Microsoft signed a 3.3-million-ton purchase agreement with Stockholm Exergi for bioenergy carbon capture. Microsoft’s DAC deals with 1PointFive are reported at $200 to $300 per ton — multi-year, multi-hundred-thousand-ton contracts that provide the revenue certainty developers need to secure construction financing. Climeworks sells credits at $600 to $800 per ton. Heirloom is targeting below $100 per ton at scale but currently prices credits significantly higher during its pilot phase.
The investment thesis has shifted from “can this technology work?” to “can it work economically at the energy cost the process requires?” Energy is the dominant cost driver. A process that needs 2,000 kWh per ton of CO₂ captured is, fundamentally, an energy project that happens to produce carbon removal as its output. The plants that will determine whether DAC reaches viability are the ones that solve the energy integration problem — co-locating with cheap, abundant, low-carbon energy sources and locking in long-term power contracts at rates that make the per-ton math work.
The Occidental problem
Occidental Petroleum acquiring Carbon Engineering in 2023 and building Stratos raises a question that the industry can’t avoid: is a DAC plant owned by an oil company and powered partly by natural gas a climate solution or a license extension? The captured CO₂ can be permanently stored underground, but it can also be used for enhanced oil recovery — injecting CO₂ into depleted wells to extract more crude. Occidental earns 45Q tax credits for the stored CO₂ while continuing to produce and sell the hydrocarbons whose combustion put the CO₂ in the atmosphere in the first place. The facility’s net climate impact depends on whether the stored carbon exceeds the emissions from the natural gas burned to power the process and the oil extracted using the captured CO₂ — a calculation that critics argue is unlikely to come out positive.
The counterargument is that waiting for perfectly clean DAC means waiting while atmospheric CO₂ concentrations continue to rise. Stratos, imperfect as it is, would demonstrate whether liquid-solvent DAC can operate at commercial scale — a question nobody has answered yet. If it works, future iterations can be powered by renewables. If it doesn’t, the industry learns where the engineering breaks. The question of whether an oil company should be building carbon removal infrastructure or whether its involvement contaminates the enterprise is a political judgment, not a technical one. The technical question is simpler: does the plant capture more CO₂ over its lifetime than the full supply chain emits? That number doesn’t exist yet because the plant isn’t operating yet.
Where this sits
Direct air capture is a technology that is simultaneously necessary and insufficient. Necessary because IPCC pathways for climate stabilization include gigatons of carbon removal — the world has emitted too much already for emission reduction alone to hold temperatures. Insufficient because the current cost, energy intensity, and scale are orders of magnitude away from what climate models require, and the trajectory from Mammoth’s 105 tons to the gigatons needed is not a line anyone can draw with confidence.
The honest framing: DAC is in the position that solar photovoltaics occupied in the early 2000s — expensive, small-scale, and dependent on subsidies, but on a learning curve that has the potential to drive costs down dramatically if manufacturing scale materializes and the technology iterates. Solar costs fell 99 percent over four decades. Whether DAC follows a similar trajectory depends on whether the energy integration problem is solvable, whether the modular manufacturing approach (Climeworks’ container design, Heirloom’s tray-based system) enables factory-style cost reduction, and whether the market for carbon removal credits generates enough revenue to sustain the industry through the expensive early decades.
The DOE’s $100-per-ton target is the benchmark. Climeworks is at roughly $1,000. The next generation aims for $300 to $350 by 2030. Heirloom is targeting below $100 at scale. The gap is closing, but it’s closing from a starting point that is ten times the target, at a deployment scale that is one-ten-thousandth of what climate models need. The math is brutal. The alternative — a world with no carbon removal capability when the IPCC says gigatons are required — is worse.
We cover direct air capture alongside fusion energy, space-based solar power, and the full landscape of civilization-scale moonshot technologies across our Moonshot 2169 course — including why the technology that may determine whether the planet’s thermostat stabilizes captured 105 tons in its first year, and what has to change before it captures a billion.