Microsoft has entered a five-year agreement with climate tech firm Carba to purchase 44,000 carbon removal credits, with deliveries starting in 2025. This long-term deal underscores Microsoft’s continued investment in durable carbon removal solutions as part of its broader climate goals.
Carba, based in Minnesota, uses a patented pyrolysis reactor to convert biogenic waste into stable biochar. This carbon-rich material will be buried in landfills under low-oxygen conditions, significantly reducing the risk of carbon re-release into the atmosphere. The process is energy-efficient, thanks to Carba’s autothermal technology, and offers potential environmental co-benefits for surrounding communities.
This agreement not only supports Microsoft’s carbon reduction portfolio but also serves as a real-world testbed for the effectiveness and scalability of biochar as a climate solution. The project builds on Carba’s growing momentum, including a $7 million grant from the U.S. Department of Energy under the Carbon Negative Shot initiative, which supports promising carbon-negative technologies.
“By co-locating biomass supply chain delivery, pyrolysis, and end-use & storage, Carba’s biochar burial offers the potential to become a scalable and cost-effective climate solution,” said Brian Marrs, Senior Director for Energy & Carbon Removal at Microsoft.
