Direct air capture (DAC) is exactly what it sounds like: industrial machines that strip CO2 directly out of ambient air, anywhere on Earth. It produces the most verifiable, most durable — and most expensive — carbon credits money can buy.
How the machines work
Air is only about 0.04% CO2, which makes capturing it thermodynamically hard. DAC plants push large volumes of air across chemical media that bind CO2 — liquid solvents (potassium hydroxide loops) or solid sorbents (amine-coated filters). Once saturated, the media is heated, releasing concentrated CO2, and the cycle repeats. The captured CO2 is then either stored permanently — injected into deep geological formations or mineralized into basalt rock, where it effectively becomes stone — or used in products. Only durable storage earns removal credits.
Why DAC credits are the gold standard
Three properties set DAC apart. Measurability: the plant meters exactly how many tonnes it captured and stored — no baselines, no counterfactuals, no satellite estimates. Additionality: nobody builds a DAC plant by accident; without credit revenue the tonnes don’t happen. Permanence: geological and mineral storage lasts millennia, versus decades for forests. In a market scarred by integrity scandals, that certainty commands a premium.
The price problem
That premium is steep: DAC credits trade at $500+ per tonne in 2026, versus $6 for average REDD+ and $22 for reforestation. The costs are real — energy is the killer, since heating sorbents takes serious power, which must itself be low-carbon for the math to work. Current plants are also small: global DAC capacity is measured in the tens of thousands of tonnes per year, a rounding error against gigatonne-scale emissions.
Who’s buying and why
Frontier buyers — big tech firms and coalitions making advance market commitments — buy DAC not because it’s the cheapest tonne today but to fund the cost curve down, the way early solar buyers did. Science-based net-zero rules requiring durable removals for residual emissions give corporates a structural reason to start building DAC positions now, before 2030 deadlines collide with scarce supply.
Will costs fall?
The industry’s roadmap targets $100–200 per tonne as plants scale, sorbents improve, and cheap clean energy is co-located. Skeptics note DAC has missed cost targets before; optimists note every energy technology looked absurd at kilotonne scale. Either way, most credible net-zero models need some DAC by mid-century — the question is how much, how soon.
Buyer’s note
Verify storage type (geological/mineralized, not enhanced oil recovery), delivery timeline (many DAC purchases are forward agreements), and third-party measurement. With those boxes ticked, a DAC tonne is the closest thing carbon markets have to a certainty.
Related reading: Biochar Carbon Credits · Carbon Credit Permanence Explained
