The Fundamentals

Frequently Asked Questions

There's a lot to learn (and unlearn) about carbon removal.Here's a good place to start.

What is Carbon Dioxide Removal (CDR)?

Think of Carbon Dioxide Removal as climate clean-up duty. It's a set of natural and technological methods that suck CO₂ out of the atmosphere and stash it away for a very long time (we're talking decades to millennia). Nature does it with forests and healthy soils, while tech gets in the game with machines like Direct Air Capture (DAC), ocean-based removal methods, and turning CO₂ into rock.

The goal? Lower the amount of CO₂ in the sky and put the brakes on climate change.

Why does CDR matter for climate?

Imagine the atmosphere as an overstuffed closet—we've crammed way too much CO₂ in there, and it’s bursting at the seams. Even if we stop emitting today (spoiler: we won’t), the leftover carbon keeps heating the planet. CDR is how we clean up that old mess—pulling legacy carbon out and locking it away. It also helps us cancel out emissions from things like air travel and cement-making, which are really hard to clean up.

Bonus: CDR doesn't just get us to net-zero; it lets us go net-negative, which is like not only stopping the damage but starting to fix it.

What does the science say about CDR?

Short answer: CDR is non-negotiable if we want to keep living comfortably on Earth. All serious scientific roadmaps and assessments now include it. Every scenario that avoids climate catastrophe uses CDR to mop up emissions that are just too stubborn to eliminate.
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As the IPCC’s 2022 Sixth Assessment Report put it:

“CDR is required to achieve global and national targets of net zero CO₂ and greenhouse gas (GHG) emissions. CDR cannot substitute for immediate and deep emissions reductions, but it is part of all modeled scenarios that limit global warming to 2°C or lower by 2100. ”

By 2035, we might need to be removing 4.5 billion tonnes of CO₂ a year. By 2050, close to 6 billion. That’s a lot of carbon. So, better start now—because building these systems takes time and investment. Like solar and wind before it, early investment pays off.

Can we just remove carbon instead of cutting emissions?

Absolutely not!!! That’s like mopping your floor while the faucet is still gushing water. We need to both stop the emissions and clean up the mess. CDR is a tag-team partner to emissions reductions, not a replacement.

Also: tech takes time to scale. Just like early solar panels cost a fortune, early CDR isn't cheap—but give it time and support, and we can make it better, faster, cheaper.

How do we actually remove CO₂ from the air?

There’s no one magic trick. Instead, we have a whole toolbox:

‍Nature-based: Planting forests, restoring wetlands, improving organic content of soil.

‍Engineered: Fancy machines (like DAC) that suck CO₂ from the air and stash it. Some even turn it into rock.

‍BiCRS (Biomass Carbon Removal and Storage): Turning plant waste into biochar, or burying it so it doesn’t rot and release CO₂.

‍Ocean-based: Boosting the ocean’s natural carbon sponge powers using methods like ocean alkalinity enhancement or growing seaweed.

Is this stuff really happening, or just sci-fi hype?

It’s happening. Like, right now. In the real world. Here's a snapshot:

‍Direct Air Capture: Climeworks just opened a mega-plant in Iceland in 2024. Texas is getting one too, via Occidental. As of early 2025, 27 DAC plants are operational globally, with more than 130 in development. In total, over 100 DAC companies worldwide are working to scale the technology across a range of climates and use cases.

‍Biochar: One of the fastest-growing segments of the CDR market. Thousands of biochar producers now operate globally, ranging from small-scale farms to industrial operations. Biochar is made by heating organic waste in low-oxygen environments and produces a carbon-rich solid that resists decomposition and enhances soil health.

‍BECCS: Microsoft signed a deal to store millions of tonnes in Louisiana. Other BECCS projects are in development across the U.S., Europe, and Asia, integrating biomass power generation with carbon capture and long-term storage.

‍Ocean-based: Nearly 50 field trials have launched since 2020, including ocean alkalinity enhancement, macroalgae cultivation, and electrochemical CO₂ removal. Companies like Planetary Technologies and Captura are leading some of the most promising pilot projects.

‍Mineralization: Mineralization converts captured CO₂ into solid carbonate minerals using natural or accelerated chemical reactions. It offers one of the most permanent storage options and is already being applied in underground storage and building materials like concrete.

And who is paying for this? By early 2025, over 6 million tonnes of durable CO₂ removals had been purchased, with a record-breaking 1 million in Q1 alone. The CDR market experienced significant growth in 2024, with total purchased volumes reaching nearly 8 million tonnes—a 78% increase from the previous year.

Additionally, 318,600 tonnes of durable CDR were delivered in 2024, marking a 120% increase from 2023, though the delivery-to-booking ratio remains low at 4.4%, reflecting the early stage of the industry's development.

Is CDR the same as Carbon Capture and Storage (CCS)?

This is a common point of confusion, and for good reason—both deal with carbon dioxide, and both involve storage. But they’re actually doing two very different jobs.

‍Carbon Dioxide Removal (CDR) pulls CO₂ directly from the atmosphere. This includes natural techniques like restoring forests and soils, and engineered approaches like Direct Air Capture (DAC), BECCS, and ocean-based removal. CDR reduces the total concentration of CO₂ already in the air, delivering what are called negative emissions.

‍Carbon Capture and Storage (CCS), on the other hand, captures CO₂ at the source—like a power plant or cement factory—before it’s released into the air. It helps prevent new emissions but doesn't reduce the carbon that’s already accumulated in the atmosphere.

‍Key difference? CDR is about cleaning up the atmosphere. CCS is about keeping things from getting worse. But CDR is essential to not just slowing the climate crisis—but beginning to reverse it.

Where does the carbon go after it’s removed?

There's no point in pulling down CO2 if it's going to just go right back up again. Different forms of CDR entail different kinds of storage:
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‍Forests & Soils: Stored organically in plants and dirt. But it can be reversed by fire or bad land management.

‍Biochar: Stable material buried in soil—lasts centuries.

‍Enhanced Weathering: Ground-up rock reacts with CO₂ and locks it in. Simple chemistry, big impact.

‍Mineralization: Turns CO₂ into literal rock. Extremely durable, and pretty much stays that way forever.

‍Ocean Storage: Transforms CO₂ into bicarbonate. Stays put in the sea for centuries. Or stored in organic material that sinks so deep in the ocean that it doesn't decompose.

‍Geologic Storage: Injects CO₂ underground, into ancient rock vaults. Monitored, verified, very secure.

Matching the right storage method to the removal type is key. And yes, we monitor this stuff to make sure it stays put.

What does it mean to 'buy' carbon dioxide removal?

Purchasing carbon dioxide removal is akin to hiring a cleanup crew for the atmosphere. The emphasis remains on permanence—ensuring that the removed CO₂ remains securely stored and does not re-enter the atmosphere. Transparency, verification, and long-term monitoring are crucial to validate the effectiveness of these efforts. Here’s how it works:

1. You buy a carbon removal credit, typically representing one tonne of CO₂ that has been verifiably removed and securely stored.

2. Your investment supports the project responsible for the removal, facilitating its growth and technological advancement.

In 2024, the CDR market experienced significant growth, with total purchased volumes reaching nearly 8 million tonnes—a 78% increase from the previous year. However, the market remains concentrated, with over 75% of purchases attributed to Microsoft, Google, and Frontier buyers. Microsoft alone accounted for 64% of total purchased volume in 2024.

Governments are also beginning to engage more actively. In the U.S., for example, the Inflation Reduction Act provides financial incentives for carbon removal, and the EU is building out a certification framework.

Is CDR dangerous, or is it the same thing as geoengineering?

This is a common concern—and a fair one. But let’s break it down:

‍No, CDR is not the same as geoengineering. CDR deals with removing carbon dioxide that’s already in the air. Geoengineering, by contrast, usually refers to large-scale interventions aimed at altering the Earth’s climate—like injecting aerosols into the atmosphere to reflect sunlight. That’s a very different approach, with very different risks and ethical considerations.

Most CDR approaches work with natural systems (like planting trees or enhancing soil carbon) or use targeted technologies (like mineralization or DAC) to capture and safely store CO₂. CDR doesn’t manipulate planetary systems in the same way geoengineering proposals do.

Of course, CDR must be done carefully—especially at scale. Land use trade-offs, water demands, and energy requirements all need to be considered. That’s why transparency, local engagement, environmental assessments, and long-term monitoring are critical for any serious CDR deployment.

Bottom line: when done responsibly, CDR is a necessary and increasingly viable part of solving the climate crisis. It’s not a climate shortcut—it’s part of the climate toolkit.

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