Carbon dioxide removal
Taking carbon back out
Cutting emissions is necessary and not sufficient. Meeting climate targets also means removing CO₂ that is already in the atmosphere — and keeping it out. Here is how that is done, how the methods differ, and how a removal becomes a credit you can defend.
Why removal exists
Emissions cuts alone cannot close the gap
Some emissions are extremely hard to eliminate — cement chemistry, long-haul aviation, parts of heavy industry and agriculture. Even on an aggressive decarbonisation path, a residual remains. And the carbon already released is not withdrawn by cutting future emissions; it stays in the atmosphere, warming, for centuries.
Carbon dioxide removal addresses both. It is the counterweight to residual emissions, and the only mechanism that reduces the existing stock of atmospheric CO₂. This is the distinction that matters and that the market still blurs: an avoidance offset prevents a future emission; a removal takes carbon out of the air. Only one of them can be a net negative.
The methods, compared
Six ways to remove a tonne
They are not interchangeable. Durability, cost and how provable the tonne is vary by an order of magnitude — and those three axes are what a serious buyer trades off.
| Method | How it stores carbon | Durability | Cost / tonne | Verifiability | Scale today |
|---|---|---|---|---|---|
| Biochar carbon removalours | Biomass residue is pyrolysed; carbon is locked in a stable aromatic form and stored in soil or materials. | Several centuries (CORC200+) | €100–200 | High — physical, measurable per batch | Deployable today |
| Direct air capture (DACCS) | CO₂ is chemically filtered from ambient air and injected into geological storage. | 1,000+ years | €400–1,000+ | High — metered at injection | Early, energy-hungry |
| BECCS | Biomass is burned for energy and the resulting CO₂ is captured and stored geologically. | 1,000+ years | €100–300 | High — metered at capture | Limited by biomass supply |
| Afforestation & reforestation | Trees are planted or forests restored; carbon is stored in living biomass and soil. | Decades — reversible | €5–50 | Moderate — modelled, remote-sensed | Large, land-constrained |
| Soil carbon sequestration | Farming practices increase organic carbon held in agricultural soils. | Years to decades — reversible | €10–50 | Low to moderate — high sampling variance | Very large, hard to prove |
| Enhanced rock weathering | Crushed silicate rock is spread on land; weathering converts CO₂ mostly into dissolved bicarbonate carried to the ocean, and to a lesser extent into solid carbonate. | 10,000+ years | €100–300 | Developing — indirect measurement | Early |
Cost and durability are indicative ranges drawn from public market data and registry methodologies, not quotes. Prices vary widely by project, volume and delivery date; verifiability reflects how directly the stored carbon can be physically measured.
Where biochar wins
Durable, physical, and available now
- You can hold the carbon in your hand. Storage is a physical material that can be weighed, sampled and analysed — not a model of what a forest might do.
- Centuries of durability, today. No geological storage infrastructure required, and no waiting for a technology to mature.
- It solves a second problem. The feedstock is fire-risk residue, and the product improves the soil it returns to.
Where biochar is not the answer
The honest limits
- Biomass is finite. Biochar scales with genuinely surplus residue. It cannot absorb global emissions, and any supplier whose growth depends on new harvesting has stopped doing removal.
- Centuries, not geological time. For storage measured in tens of thousands of years, mineralisation and geological injection are the stronger claim.
- Quality varies enormously."Biochar" covers material made well and material made badly. Without batch-level analysis, the word alone guarantees nothing.
A serious removal portfolio uses several methods. We would rather tell you where ours fits than pretend it is the whole answer.
How a tonne becomes a credit
Measurement, certification, issuance, retirement
01
Measure
The removal is quantified from physical measurements — batch mass, carbon fraction, permanence — net of lifecycle emissions.
02
Certify
An accredited third party audits the evidence against a published methodology (EBC, C-Sink, Puro.earth; in the EU, the CRCF).
03
Issue
The registry issues serialised units — one per certified tonne — recorded so the same tonne cannot be sold twice.
04
Retire
The buyer retires the unit against their claim. Retirement is permanent and public: the tonne is spent.
Most of the voluntary market's credibility problems live in step one. If the measurement is modelled rather than physical, everything downstream inherits that uncertainty — which is why we built our own measurement stack, and why we publish exactly how we count a tonne.
Removal you can put on the record
Durable, physically measured, and traceable to the batch it came from.