6 Things to Know About Direct Air Capture

People around the globe are increasingly feeling the effects of climate change through more severe storms, extreme heat, wildfires and flooding. This underscores the urgent need to slash greenhouse gas (GHG) emissions, such as by switching to electric vehicles, deploying renewable power and reducing deforestation. At the same time, the most authoritative climate science indicates that such efforts alone will not be enough to prevent the worst impacts of climate change.

While reducing GHG emissions should always take priority, meeting global climate goals will also require carbon dioxide removal (CDR) — systems that remove carbon directly from the air. Carbon removal is needed not only to balance out residual emissions that cannot be or are not eliminated in the coming years, but also to reduce the concentration of carbon dioxide in the atmosphere to safe levels. Carbon removal can take numerous forms, including natural solutions (like growing trees) and technological solutions that accelerate or mimic natural carbon removal processes.

Direct air capture (DAC) with sequestration is one carbon removal method that is already being developed, and in some cases deployed, today. DAC is theoretically highly scalable and can be coupled with permanent CO2 storage. It's also relatively easy to quantify the amount of CO2 captured. Thanks to this, DAC is already seeing significant interest and investment — though how rapidly it can scale remains uncertain.

Here we answer some key questions about DAC and its future potential.

1) What Is Direct Air Capture?

Direct air capture is a suite of technologies that use chemical reactions to pull carbon dioxide out of the air. When air moves over certain chemicals, they selectively react with and trap CO2, allowing the other components of air to pass through. Today's leading DAC systems often remove CO2 using liquid solvents or solid sorbents. These are materials composed of common chemicals that are already used in other applications today, from soap to water filtration.

Once carbon dioxide is captured from the atmosphere, most DAC systems apply heat to release it from the solvent or sorbent. This regenerates the material so it can be used again. Other types of DAC systems use electrochemical processes, which could reduce energy needs and potentially costs by using only electricity — instead of electricity and heat — to fuel the process.

Captured CO2 can be injected deep underground for sequestration in certain geologic formations. It can also be used in products, though the amount of carbon dioxide stored and how long it stays there varies. Materials like concrete can sequester CO2 for centuries, while products like beverages or synthetic fuel quickly re-release carbon into the atmosphere.

In some cases — jet fuel, for example — products produced with captured CO2 could still be a favorable substitute for more emissions-intensive fossil fuels. However, to maximize the climate benefit of direct air capture, most of the CO2 would need to be permanently stored rather than used and re-released.

2) What Is the Status of DAC Development and Deployment?

DAC has seen a surge in interest and investment over the past several years. This is in part due to the growing recognition that carbon removal will be needed to meet national and global climate goals. The United States has provided significant policy support to help launch DAC technologies. Other countries, like Canada, the U.K. and Japan, are beginning to follow suit.

As of early 2025, there were around 150 DAC companies globally, up from just a few less than ten years ago. And around three dozen DAC plants were operational, with many more in development.

The largest DAC facility in operation as of August 2025 was the Mammoth project in Iceland, operated by the Swiss company Climeworks. It can capture up to 36,000 tonnes of CO2 each year (tCO2/yr) that can then be sequestered through mineralization underground. Another DAC facility, known as Stratos, is set to come online in late 2025 in west Texas. It will capture 500,000 tCO2/yr once fully operational — equivalent to taking more than 116,000 gas-powered cars off the road each year.

Two other large-scale DAC projects are in earlier stages of construction in south Texas and Louisiana. These were supported by the U.S. Department of Energy's (DOE) Regional DAC Hubs program and are meant to capture 1 million tCO2/yr when complete. As of August 2025, DOE was reviewing whether to continue funding these projects.

DAC is also gaining traction in Kenya, where — similar to Iceland — there is abundant geothermal energy to power DAC plants and suitable geology to store CO2.

These facilities are the first to test real-world demonstration and deployment of DAC with sequestration, moving beyond the lab and small-scale pilots. The challenges encountered in real-world application are already providing key learnings to improve efficiency and performance of future projects.

3) What Policies and Investments are Supporting DAC Development?

The United States has been a leader in enacting policies to support DAC. From 2021-2024, the U.S. government provided unprecedented funding for every stage of DAC development. This included millions of dollars in research funding through DOE, as well as billions of dollars in the Bipartisan Infrastructure law for four large-scale demonstration projects (known as DAC "hubs") and infrastructure for CO2 transport and sequestration. As of August 2025, much of this funding was under review or frozen, including for the DAC hubs, creating uncertainty about the future of DAC and broader CDR demonstration and deployment in the U.S.

The 45Q tax credit, which was expanded in the 2022 Inflation Reduction Act, provides up to $180 per tonne of CO2 captured through DAC and stored permanently. This has not been significantly changed since the passage of the IRA.

As the U.S. federal government steps back its CDR policy support, states have the opportunity to step in. California has introduced several policies to support and govern CDR, including its Low-Carbon Fuel Standard, which provides a roughly $50/tCO2 credit for DAC projects. Other states, like Massachusetts, New York and Colorado, are beginning to follow suit.

Countries outside the U.S. are also enacting supportive policies. Canada provides an investment tax credit for DAC and has announced a $10 million purchasing program for all types of CDR. Japan added DAC as a compliance option in its emissions-trading scheme. The EU supports DAC through broader research and innovation programs and is also considering policy that would support CDR broadly, including integration of permanent CDR into the EU emissions-trading scheme and an EU purchasing program for carbon removal credits.

Private investment in carbon removal and DAC is increasing, with 8 million tonnes of durable carbon removal — including DAC with sequestration (DACS) — purchased in 2024. Microsoft has purchased more than 80% of all carbon removal credits to date, including significant DACS purchases. Other companies, such as those in the Frontier advance market commitment, have committed over a billion dollars to carbon removal, including DACS, by 2030.

At the international level, Article 6 of the Paris Agreement enables countries to buy and sell carbon removal credits to help meet their climate goals. Some are already using this option; for example, Switzerland and Norway agreed to sell each other credits generated from DACS and bioenergy with carbon capture and sequestration, laying the groundwork for longer-term cooperation. Sweden is exploring cooperation with several countries.

4) What are the Concerns Associated with Scaling Direct Air Capture?

The IPCC has made it clear that carbon removal is needed to help meet global climate goals. But countries must ensure that efforts to ramp up DAC and other types of CDR do not take the place of rapid and deep emissions cuts. Policy measures, like setting separate targets for emissions reductions and carbon removal, can help address this risk by providing transparency around the role that each will play in meeting broader climate goals.

At the same time, CDR technologies, including DAC, are still in development, with few examples of large-scale deployment to date. The pace at which they will scale up remains highly uncertain. This means countries and companies must plan to use CDR only to balance out the most difficult to abate emissions sources — not those that are feasible to eliminate with existing technologies.

Concerns around DAC are present at the local level as well. Communities, especially those that already host fossil fuel infrastructure, may be worried about adding first-of-a-kind technologies without full understanding of the potential local impacts. Some community groups have expressed a preference for investments in renewable energy solutions rather than DAC.

There are also concerns that CO2 captured through DAC could be used to prolong fossil fuel production through a process known as "enhanced oil recovery." While enhanced oil recovery permanently sequesters the injected CO2, it also produces fossil fuels, which reduces the climate benefit of carbon removal and can cause negative impacts to the local environment and nearby communities. Some jurisdictions, like the state of California, have already prohibited enhanced oil recovery for CDR projects.

Although not linked to a DAC project, incidents such as the 2020 CO2 pipeline rupture in Mississippi have fueled some doubts around the safety of CO2 transportation. Strong regulation is needed to ensure the safety of CO2 transportation via pipelines.

Geologic CO2 storage has been demonstrated safely at million-tonne volumes. Expanding to multi-million or billion-tonne scales is largely untested and will require rigorous monitoring to ensure safety.

5) What Are the Main Resource Impacts of DAC?

Energy

Scaling up today's DAC systems would require nontrivial amounts of energy. Reaching 8 million tonnes per year of DAC in the U.S. by 2030 would use the equivalent of 0.4% of the country's current electricity generation (assuming each tonne of CO2 requires 2,000 kWh at scale). This energy needs to be zero or very low carbon to maximize the efficiency of direct air capture — otherwise, more CO2 emissions will be produced using the energy than would be captured from the air in the process.

That said, energy needs vary across DAC approaches. Some DAC technologies just use electricity, while others use electricity and heat. Liquid solvent systems based on strong base chemistry (such as potassium hydroxide) often require higher heat — around 900 degrees C (1,652 degrees F) — to release captured CO2. Solid sorbent systems require temperatures around 80-120 degrees C (176-248 degrees F). This means that solid sorbent systems can use renewable energy (such as geothermal) or in some cases waste heat sources, while solvent systems requiring higher quality heat may rely on natural gas with carbon capture and storage.

Powering DAC at scale will require renewable energy capacity to expand beyond what is already needed to decarbonize power production and electrify sectors like buildings and transport. This will come with its own impacts, such as those related to expanded mining activities for rare earth metals. And it may create competition for clean electrons as electricity demand increases due to data centers and AI.

Learning through deployment could help optimize existing systems to reduce energy needs, while research and development funding will help develop entirely new systems with lower energy requirements.

Land

The land area needed for large-scale DAC deployment depends on the type of system and the energy resource powering it. If renewables are used, they will be the largest portion of a system's land footprint. However, even DAC powered with renewables requires a smaller amount of land per tonne of CO2 removed than some other CDR approaches, like reforestation.

To capture half a million tonnes of CO2 — the scale of the largest DAC facility under construction today — 0.3-33 square kilometers would be needed for the plant and the energy resource. Capturing a similar amount of CO2 from forests would require an estimated 690 square kilometers. If DAC can be integrated into existing infrastructure (for example, to use waste heat from nuclear plants or data centers), it would take up less land area.

Another benefit of direct air capture is its siting flexibility. DAC can theoretically be sited anywhere with clean energy and close to geologic storage or an option for CO2 utilization. It does not require arable land, which can minimize impacts on food production or other land uses.

Water

Water usage associated with direct air capture depends on the system type as well as local temperature and humidity.

For a solvent DAC system, capturing one tonne of CO2 can require 1-7 tonnes of water for plausible siting locations in the U.S. This is comparable to the amounts of water required to produce a tonne of cement or steel. Water losses come mainly through evaporation, so the relative humidity and temperature of the plant's location are the main determinants of the level of water loss, with higher losses in hot and dry environments.

Solid sorbent DAC systems vary widely in terms of water usage, depending on the sorbent regeneration method. A system that uses steam condensation to regenerate the sorbent may result in water losses to the environment — a typical plant may use 1.6 tonnes of water per tonne of CO2 captured. Other systems regenerate the sorbent using indirect heating, causing minimal water losses. These indirect heating systems can actually be net water producers, yielding an estimated 0.8-2 tonnes of water per tonne of CO2 captured.

Other DAC systems based on "moisture-swing" technologies use changes in humidity to release captured CO2 and can also produce water as part of the process.

Because resource usage is linked to community impacts, people living near DAC plants or parts of the DAC supply chain will also be impacted. Water use may not be significant in absolute terms, but can have significant impacts locally.

6) How Much Does Direct Air Capture Cost?

Despite its benefits and flexibility, direct air capture generally costs more per tonne of CO2 removed than many other climate solutions, including natural approaches like growing trees. This is largely due to the energy needed to separate carbon dioxide from ambient air.

In 2024, purchase prices for DAC on the voluntary market ranged from as little as $100/tCO2 to as much as $2,000/tCO2, with the average over the past several years around $490/tCO2. These are generally purchases of tonnes to be delivered in the future, over a specified timeframe, and the price will vary depending on many factors (including the technology, energy source, volume and timeframe for delivery of credits, and more). The price may be lower than the total cost of removal for projects that receive policy support. For comparison, most reforestation costs less than $50/tonne of CO2 removed.

DAC companies are working to lower costs per tonne of removal over time, with some aiming for $250-$400 by the end of the decade and others setting long-term goals closer to $100/tCO2.

Reducing DAC costs will require increased deployment to enable learning and optimization, as well as more robust policies to support its scale-up and drive long-term demand. At a billion-tonne scale, one recent study estimated that DAC costs could be in the range of $385-$530/tCO2.

Unlike other climate technologies that reduce emissions while providing a consumer good or service, DAC mainly provides a public good of atmospheric clean-up. This means opportunities for direct revenue are limited. Captured CO2 can be sold for use in products, from CO2-mineralized concrete to carbon fiber, but these markets typically don't provide enough revenue to offset the cost of capture. Greater policy support will be needed to drive both supply and demand for CDR, including DAC, and deploy these technologies at the level required.

Direct Air Capture: An Important Part of a Climate Solution Portfolio

Climate models have made it clear that carbon dioxide removal will likely need to happen on a multi-billion-tonne scale by mid-century alongside deep emissions reductions. This will require a portfolio of different CDR approaches — including direct air capture. Investing in DAC now will help reduce future costs, while supportive policies will be needed to ensure that novel technologies like DAC are scaled responsibly and sustainably.

Editor's note: This article was originally published in January 2021. It was last updated in September 2025 to reflect the latest developments.

Thanks to Noah McQueen, Max Pisciotta and Liz Bridgwater, who co-authored earlier versions of this article.