The single biggest thing holding back carbon removal? Cost. Direct air capture runs $400–1,000 per ton. Enhanced weathering is cheaper but slower. Biochar sits in a sweet spot — and a Minnesota startup just made it sweeter.
Carba, co-founded by University of Minnesota Distinguished McKnight Professor Paul Dauenhauer, has developed a proprietary process that converts plant-based waste into biochar stable enough to lock carbon underground for over 1,000 years. Their target: $100–200 per ton of CO₂ removed.
Why This Matters
Most biochar companies pyrolyze biomass. That’s not new. What Carba brings is a university-backed engineering approach to cost reduction at scale. The partnership with the University of Minnesota isn’t just a branding exercise — it’s serious process engineering aimed at making biochar CDR economically competitive with avoided emissions.
NPR’s Climate Cast featured Carba this week, with Dauenhauer explaining the approach: take agricultural and forestry waste that would otherwise decompose and release CO₂, convert it into a carbon-rich solid, and bury it. The carbon stays put for millennia.
The $100/ton Question
At $200/ton, Carba is already selling carbon removal credits to buyers. Their roadmap targets $100/ton — a price point that could unlock demand far beyond the current pool of corporate early-movers like Microsoft and Shopify.
For context: Boeing just locked in 40,000 tons of biochar credits. The biochar market is projected to grow from $877 million in 2025 to $3.6 billion by 2035.
The CDI Angle
CDI has several biochar companies in its portfolio — from SYNCRAFT’s power-generating pyrolysis to Happy Ground’s tropical biochar in Thailand. The pathway works. The question has always been whether the economics can scale. Carba’s university-backed engineering approach is exactly the kind of innovation that could answer it.
Bottom line: $100/ton biochar CDR isn’t science fiction. It’s a Minnesota lab working on it right now.
Sources: MPR News / NPR Climate Cast, Carba