Mafinga, Tanzania, March 2025. atmosfair retires the first carbon credits from the biochar project in Tanzania, which we use to permanently remove carbon dioxide from the air. These are the first negative emissions worldwide that Carbon Standard International (CSI) has certified according to the new ‘Global Biochar C-Sink’ standard. The standard not only takes into account the amount of carbon that is sequestered in the soil, but also ecological and social aspects.

Since the beginning of 2024, we have been using our pyrolysis plant in the town of Mafinga to produce biochar from wood waste generated by sawmills in the region. Employees from our Tanzanian partner company Dark Earth Carbon (DEC) transport these sawmill residues to the pyrolysis plant. ‘Our machines process 8,000 tonnes of these plant residues into 2,000 tonnes of charcoal every year. Farmers use this charcoal to improve their fields. The charcoal retains water and nutrients in the soil, which increases yields,’ explains atmosfair project manager Anna Seefried.

Creating value for wood waste

The CO₂ credits meet the criteria of the ‘Global Biochar C-Sink’ standard for industrially produced biochar for the first time. It checks whether the residual biomass used is environmentally and socially compatible. We comply with this standard by only using wood residues that have no other use and have previously been incinerated. The operators of the sawmills receive an additional income if we buy this unused wood waste from them.

We only work with sawmills that source their wood from sustainably managed forests. The owners of these forests must draw up land utilisation plans in which they record in detail the quantities of wood they intend to harvest in a given period. The local forestry authority must approve these plans and inspectors from the Tanzanian government regularly check whether the land use plans are being adhered to. DEC inspectors also check whether the forestry meets our requirements.

In the pyrolysis plant, we heat the wood to up to 600 degrees Celsius so that gases escape from the wood and pure carbon remains. We will be building a second plant in the same region this year, more than doubling our biochar production capacity in Tanzania.

In Tanzania, many soils are washed out by heavy rainfall and can be significantly improved with biochar, which increases crop yields. And we bind carbon in the soil in the long term, which the trees previously draw from the atmosphere.