Microsoft and nature-based carbon removal startup Chestnut Carbon announced today a 15-year offtake agreement, with Chestnut providing Microsoft with potentially more than 3 million tons of nature based credits from its U.S.-based afforestation project.

The deal includes the removal of 362,000 tons of carbon in its first phase, and up to 2.7 million tons in subsequent phases, which would mark one of the largest-ever nature-based carbon removal offtake agreements globally.

Launched in 2022 by energy sector-focused alternative asset manager Kimmeridge, Chestnut develops afforestation projects in the U.S., buying and restoring marginal crop and pasture lands to plant native species and develop biodiverse ecosystems. The company uses proprietary technology and data sets to identify optimal land for its projects, and to monitor and measure carbon sequestration. Chestnut has 20,000 acres of land under ownership, and plans to add another 500,000 acres by 2030, with a capacity of 100 million tons of carbon removal.

Ben Dell, CEO of Chestnut and Managing Partner of Kimmeridge said:

“We’re pleased to be working with Microsoft on its commendable journey to offset emissions through high-quality nature-based solutions. When launching Chestnut in 2022, we were guided by a strong belief that these solutions are the most attractive, scalable and cost-effective means for sustainability-minded organizations. We are actively building out our platform to meet demand from the most discerning customers and look forward to announcing additional blue-chip partnerships in the near future.”

The agreement marks a further expansion of Microsoft’s portfolio of carbon removal deals, forming part of the company’s initiative to become carbon negative by 2030, and to remove all of its historical emissions by 2050, and follows another large-scale nature-based credit deal by the company announced earlier this month with Brazilian reforestation-focused startup Mombak. Microsoft’s carbon removal portfolio spans a range of technologies and approaches, including direct air capture (DAC), ocean-based carbon removal, and biochar-based agreements.

Brian Marrs, Senior Director of Energy & Carbon Removal at Microsoft, said:

“Microsoft’s 15-year purchase agreement with Chestnut Carbon for afforestation-based carbon removal credits is a positive step towards Microsoft’s carbon negative goals. We are excited to collaborate with Chestnut and its Sustainable Restoration Project for high-quality, nature-based solutions located in the United States.”