Scrubbing the Sky: Engineering Carbon Removal at Scale
In direct air capture, one form of engineered carbon removal, air is pulled through modular fans and sorbents that concentrate CO₂. Oxygen is vented while the captured CO₂ is compressed, piped and injected into underground formations where it mineralizes into solid carbonate minerals (CO₃²⁻), such as calcite or magnesite. Direct air capture can turn dilute atmospheric CO₂ into durable, climate-safe mineral storage.
When it comes to stabilizing our climate, just cutting emissions isn’t going to cut it. The science is clear: we need to couple carbon dioxide reduction with active removal. Enter engineered carbon removal. Using technology paired with advanced chemistry to capture and lock away carbon can potentially offer scalable, durable solutions that nature alone can’t deliver. From direct air capture plants to systems that scrub CO₂ from oceans, innovators are racing to make removal cheaper, cleaner, and faster. With the right breakthroughs, engineered carbon removal could become one of the defining climate technologies of our time.
The Path We’re On
What can’t be reduced must be removed
Many climate solutions work indirectly. We change how we generate power, how we grow food, or how we move people. The intention: a meaningful reduction in emissions. These efforts are essential, but they all share a limitation: none of them directly address the excess carbon dioxide that has already accumulated in the atmosphere.
Engineered carbon removal is different. It offers something rare in climate mitigation: a direct control knob. Instead of reducing the flow of new emissions, engineered carbon dioxide removal (CDR) pulls CO₂ out of the air itself and locks it away long term.
Of course, nature already does this, and always has. Forests, soils, and oceans naturally absorb vast volumes of CO₂. Mineralization gradually converts carbon into stable rock, where it remains for millennia.
Engineered carbon removal is designed to complement these natural processes. It refers to human-made technologies that actively capture CO₂ from the atmosphere and store it in forms intended to prevent re-release for centuries or longer. Rather than relying on ecological recovery or slow geologic processes alone, engineered CDR aims to deliver deliberate, measurable, and durable carbon removal on demand.
All of these CDR systems are critical to climate stabilization, yet each approach has distinct advantages and limitations. In the case of engineered CDR, the primary benefits are durability and control. Captured carbon can be stored with high degrees of confidence, and removals can be directly measured, tracked, and verified.
The barriers, however, are significant. The concentration of carbon dioxide in the atmosphere is extremely low (roughly 0.04%), which means removing meaningful quantities requires processing enormous volumes of air. As a result, today’s engineered CDR systems are energy-intensive, capital-heavy, and costly to deploy at scale. Infrastructure requirements (from clean power to transport and storage) further constrain rapid expansion.
Perhaps most importantly, engineered CDR often only makes commercial sense in markets that assign a clear value to carbon. Overcoming these technical and economic barriers — and ensuring carbon removal is properly valued — will be essential if engineered solutions are to move beyond pilots and early adopters.
For companies in hard-to-abate sectors such as cement, steel, chemicals, and heavy transport, in the future engineered CDR offers a critical complement. Some emissions cannot be cost-effectively eliminated through electrification, efficiency, or fuel switching alone. In these cases, engineered carbon removal provides a pathway to address residual emissions through high-confidence carbon capture and storage — enabling credible progress toward carbon-neutrality goals.
The scale of this challenge is immense. To remain aligned with a 1.5°C pathway, the world will need to remove between 5 and 16 gigatons of CO₂ per year by mid-century — an all-hands-on-deck effort requiring contributions from every form of carbon removal. Engineered CDR can be a central part of this portfolio.
Another pathway to engineered CDR: seawater
Although many engineered CDR approaches focus on capturing CO₂ from air, we can also extract carbon dioxide from water. The atmosphere and the world’s oceans exist in chemical equilibrium. Because surface waters continuously exchange CO₂ with the atmosphere, extracting dissolved CO₂ from seawater can indirectly pull additional carbon out of the air. This concept underpins emerging “direct ocean capture” technologies, which use electrochemical or other processes to extract CO₂ from seawater before storing it permanently or reusing it.
A New Way Forward
Human-made solutions to a human-made problem
We already know how to remove carbon dioxide from the atmosphere. The chemistry works. The physics works. The question isn’t whether it’s possible — it’s whether it can be done cost-effectively and at scale. Today, engineered carbon removal can cost hundreds of dollars per ton, limiting deployment to small pilots, buyers with deep pockets, and voluntary markets.
Meeting global carbon removal goals will depend on making engineered solutions cheaper, cleaner, and easier to deploy. Two breakthroughs stand out as particularly urgent: one focused on capturing CO₂ more efficiently, the other on storing it permanently. And beyond these near-term challenges, innovators are exploring a more radical frontier: integrating carbon removal passively into the systems that already move our air and water. Together, these ideas encapsulate what we see as the core innovation challenges for engineered carbon removal.
Innovation Imperatives
Create low-cost, permanent, scalable CO₂ sequestration methods
Carbon sequestration is critical to engineered CDR. After all, capturing carbon is only half the battle; it then needs to go somewhere, and stay there long-term. Today, that’s largely done by compressing captured CO₂ into a dense, fluid-like form and injecting it deep into the earth. However, geologic sequestration remains expensive and geographically limited. New approaches, including mineralization, advanced well designs, and novel storage media, aim to cut costs while enhancing permanence and scalability. Reliable, low-cost sequestration methods will be essential to making engineered carbon removal not only effective, but economically sustainable at a gigaton scale.
Maximize energy efficiency in direct air capture
DAC is a process by which machines chemically capture CO₂ directly from ambient air, which is then stored underground (geologic storage) or used in products, such as synthetic fuels or building materials. Current DAC systems require large amounts of energy, limiting scalability and driving up costs. Innovations in sorbent materials, process design, and heat integration aim to cut energy use in order to drive down costs and minimize the energy infrastructure required to power engineered carbon removal. Optimizing efficiency would make DAC far more deployable, enabling large-scale carbon removal while minimizing demands on clean energy resources.
Moonshots
Build engineered carbon removal into existing air and water flows
Passive removal envisions embedding carbon capture directly into the systems that already move massive volumes of air and water. By leveraging existing flows — through ship exhaust streams, HVAC ventilation, or industrial cooling loops — these technologies could capture CO₂ continuously without the need for dedicated fans or energy-intensive air handling. Though still experimental, integrating capture into everyday infrastructure could dramatically reduce costs and open new pathways to scale carbon removal seamlessly across the built environment.
The most viable solutions will:
To achieve widespread adoption, innovations must dramatically reduce the cost of both carbon capture and long-term storage. High costs remain one of the primary barriers to scale. Affordable solutions will be essential to unlock broader deployment across industries, geographies, and markets — and move engineered CDR from pilots to gigaton-scale impact. In some cases, carbon removal may also scale when embedded within economically valuable activities — for example, when industrial processes or materials permanently store carbon as part of production, or reuse it.
Engineered CDR is only as climate-positive as the energy it uses. Solutions must prioritize energy efficiency (which should positively impact cost) and rely on low-carbon or renewable energy sources to avoid offsetting their own climate benefits.
Scalable CDR technologies will need to fit into existing energy, industrial, and transportation systems. Leveraging current infrastructure can accelerate deployment and reduce costs.
As these technologies scale, they must avoid causing land, water, and ecological impacts. That means preventing competition with food systems, protecting biodiversity, and considering cumulative environmental effects.
