Microsoft signs ‘world’s largest’ biochar carbon removal purchase

Microsoft has agreed to purchase 1.24 million tonnes of carbon removal credits from Exomad Green over 10 years in a landmark deal for the biochar removal sector.

Biochar carbon removal company Exomad Green will deliver 1.24 million credits to Microsoft over a 10-year period as part of the agreement. This is the largest biochar carbon removal deal in history by volume, and among the largest across all forms of durable carbon dioxide removals, according to the firm.

The deal has made Exomad Green the top global supplier of carbon dioxide removals, according to benchmarking platform cdr.fyi. Microsoft was already the largest buyer, and has now purchased 21,617,120 tonnes of CDR credits, data from the platform shows.

As part of the agreement Exomad Green will verify every tonne of carbon removed and sold as a credit through Carbonfuture MRV+, an independent digital Monitoring, Reporting, and Verification (dMRV) system for durable carbon removal. The contractual obligation aims to ensure that every tonne of CO2 removed is tracked from carbon capture to credit issuance, enabling third-party verification and certification and contributing to the integrity of the market.

“Today’s historic deal is testament to the relationship we have formed between Microsoft and Exomad Green, powered by Carbonfuture’s dMRV”, commented Diego Justiniano, CEO of Exomad Green. “Microsoft has shown true climate leadership and commitment by seizing the immediate potential of biochar as a carbon removal solution that is measurable and scalable, while demonstrating significant co-benefits across communities and in improving soil quality.”

Biochar carbon removals

Biochar carbon removals, now the most popular type of carbon removal credit, sold at an average of US$150 per tonne (according to cdr.fyi), involves heating biomass – in this case forestry residues – in the absence of oxygen. The resulting biochar is then added to the soil, where it improves soil health and stores carbon for hundreds of years.

Exomad Green says this model delivers co-benefits to local communities, including soil health enhancement to increase agricultural productivity, reductions in local air pollution, and decreased urban fire risk due to lower incidence of sawmill residue incineration.

Brian Marrs, Senior Director of Energy and Carbon Removal at Microsoft, added: “Microsoft is pleased to build on our relationship with Exomad Green and Carbonfuture to deliver high-quality, high-impact, and high-integrity durable CDR through biochar. We value Exomad Green’s commitment to high standards for biomass sustainability and traceability through its establishment of a new Forest Monitoring Center and recognise biochar’s significant co-benefits for community and soil quality in addition to its carbon removal potential.”

Microsoft had already bought 32,000 tonnes of biochar carbon removal credits from Exomad Green in December 2023.