What is Direct Air Capture (DAC)?

Direct air capture has become one of the most closely watched technologies in the carbon removal space, championed by climate tech investors, featured in corporate net-zero roadmaps, and increasingly present in high-permanence carbon credit portfolios. Unlike most carbon reduction methods, DAC doesn't target a specific emissions source at all, it pulls CO₂ straight out of the open air, anywhere on the planet.

For anyone working in carbon markets, climate finance, or emissions management, DAC is worth understanding on its own terms. It represents a genuinely different category of carbon removal, with its own cost structure, permanence profile, and role in a diversified credit portfolio.

This article breaks down what direct air capture actually is, how it works, and why it's attracting so much attention in carbon markets despite still being an early-stage, relatively expensive technology.

What Is Direct Air Capture, Exactly?

Direct air capture, or DAC, is a technology that extracts carbon dioxide directly from ambient air, rather than from a concentrated emissions source like a factory or power plant. Once captured, the CO₂ is either permanently stored underground, typically in deep geological formations, or used in various industrial applications. When DAC is paired with permanent geological storage, the full process is sometimes referred to as DACCS, direct air carbon capture and storage.

The defining feature of DAC is that it works regardless of where emissions originally came from. It doesn't need to be installed at a smokestack or industrial facility, it can operate anywhere, pulling CO₂ from the same atmosphere everyone shares. This makes DAC a true carbon removal technology, actively reducing the total concentration of CO₂ in the atmosphere, rather than simply preventing new emissions from being added.

How Direct Air Capture Actually Works

DAC systems generally rely on one of two core approaches:

• Liquid solvent systems: Air is passed through a chemical solution, typically an alkaline solvent, that binds with CO₂ molecules. The CO₂ is later separated from the solvent through a heating process, releasing a concentrated stream of CO₂ for storage or use.
• Solid sorbent systems: Air passes over solid filter material coated with chemical sorbents that capture CO₂. The sorbent is then heated to release the captured CO₂, and the material is reused for the next capture cycle.

In both approaches, large volumes of air need to be moved through the system to capture even relatively small amounts of CO₂, since atmospheric concentrations are far more dilute than the concentrated exhaust streams targeted by traditional point-source carbon capture. This is one of the central engineering and cost challenges facing DAC at scale.

Why DAC Requires So Much Energy

Because atmospheric CO₂ is so diluted, roughly 420 parts per million, compared to the much higher concentrations found in industrial flue gas, DAC systems need to process enormous volumes of air to capture meaningful amounts of carbon. This drives significant energy demand, both for moving air through the system and for the heating process used to release captured CO₂ from the solvent or sorbent.

This energy intensity is central to ongoing debates about DAC's near-term viability. If the electricity powering a DAC facility comes from fossil fuel sources, the net climate benefit is significantly reduced. This is why most credible DAC projects are built around renewable or low-carbon power sources, and why facility location, often chosen for access to abundant clean energy or waste heat, plays such an important role in project design.

DAC vs. Carbon Capture and Storage (CCS): The Key Distinction

DAC is often mentioned alongside carbon capture and storage, but the two technologies serve fundamentally different purposes. CCS captures CO₂ at a concentrated point source, an industrial facility already emitting it, before it reaches the atmosphere. DAC, by contrast, extracts CO₂ that's already dispersed in ambient air, regardless of its original source or how long ago it was emitted.

This distinction matters for how each technology fits into a broader climate strategy. CCS reduces emissions at the source, essentially preventing future atmospheric increase from a specific facility. DAC actively removes existing atmospheric carbon, making it relevant even for addressing historical emissions that have already accumulated over decades. Both technologies can generate carbon credits, but they represent genuinely different categories of climate impact.

Why DAC Credits Are Gaining Attention in Carbon Markets

DAC credits are increasingly sought after by buyers specifically prioritising high-permanence, high-integrity carbon removal. Because captured CO₂ is typically stored in stable geological formations, the risk of reversal is extremely low compared to many nature-based sequestration methods, which can be affected by fire, disease, or land-use change.

This durability is a major reason DAC credits generally trade at a significant premium compared to most other carbon credit categories. Buyers building diversified removal portfolios often include a smaller allocation of DAC credits specifically for their permanence characteristics, even at higher cost per tonne, alongside larger volumes of more affordable nature-based credits.

Sourcing DAC-Linked Carbon Credits

For companies looking to include DAC-based credits in an offset portfolio, sourcing through a reliable carbon offset platform makes it easier to review project documentation, storage verification, and certification standards before purchasing. Given how technically complex and capital-intensive DAC projects are, that due diligence step matters considerably.

Buyers comparing DAC credits against other removal categories, biochar, forestry, blue carbon, or CCS, often use a carbon market exchange platform to evaluate options side by side, weighing permanence, cost, and portfolio diversification before allocating offset budgets.

Pricing and Market Trends for DAC

DAC remains one of the more expensive carbon removal categories on a per-tonne basis, reflecting the technology's early-stage maturity, high energy demand, and significant capital costs for facility construction. That said, costs have been trending downward as more DAC facilities come online and the technology scales.

Teams tracking how DAC pricing compares to other removal categories can benefit from carbon market intelligence tools that surface pricing trends across project types. Access to real time global carbon credit pricing is especially useful here, since DAC remains a smaller, less liquid segment of the market, making up-to-date data more valuable for buyers trying to time purchases or benchmark project costs.

Challenges Facing DAC at Scale

DAC's biggest hurdle remains cost. Current per-tonne capture costs are substantially higher than most nature-based and even many engineered alternatives, and building out the infrastructure needed for meaningful global scale will require sustained investment over years, not months. There are also legitimate questions about whether DAC's high energy demand makes it the most efficient use of limited clean energy capacity compared to other decarbonization priorities.

Despite these challenges, DAC continues to attract significant investment, partly because it's one of the few technologies capable of addressing legacy atmospheric carbon that's already accumulated, a role nature-based and point-source methods can't fully replicate.

The Bottom Line

Direct air capture occupies a distinct and increasingly important niche in the carbon removal landscape. It's expensive and energy-intensive today, but it offers a genuinely unique capability: removing carbon from the atmosphere regardless of source or timing, with very strong permanence once stored. For anyone building a diversified removal portfolio or evaluating high-integrity carbon credits, understanding where DAC fits, and what it costs to get there, is an increasingly essential part of the picture.