Arca to deliver 300,000 tonnes of carbon removal to Microsoft

Arca has announced an agreement to supply Microsoft with nearly 300,000 tonnes of durable carbon dioxide removal (CDR) over the next ten years.

The arrangement will see Arca deliver CDR using its industrial mineralization pathway, a process which makes use of existing industrial infrastructure and repurposes alkaline waste streams to capture and store atmospheric CO2 permanently as stable carbonate minerals.

Arca's approach involves the repurposing of mining byproducts, such as mine tailings and waste rock. These materials accelerate the process of carbon mineralization, which converts gaseous CO2 into a solid mineral form. This process enables measurable, independently verified, and highly durable removals of atmospheric carbon dioxide. In addition to the environmental benefits, the company states mineralization can make mine waste safer and generate employment for local communities.

Industrial mineralization is gaining attention as a potential contribution to global carbon removal targets. The process is described as having the potential for scalability and requiring minimal additional energy, land, or water resources compared to other forms of carbon removal. The use of abundant historical industrial byproducts already found at the surface is seen as a particular advantage.

Government endorsement

The agreement has received support from the Canadian government, with The Honourable Tim Hodgson, Minister of Energy and Natural Resources, highlighting its dual impact on economic and environmental objectives. He said:

"The next generation of clean growth will be built by Canada's first-class innovation ecosystem - companies like Arca, which are turning Canadian ingenuity into global leadership. Carbon removal technologies are not only strategic tools we can use to tackle climate change, they create good jobs and position Canada at the forefront of the global opportunity of a low-carbon economy."

Arca previously completed its first full-scale mineralization demonstration project at an active mine site in 2025. The demonstration proved, in practice, that Arca's technology can be deployed at scale and integrated with the operations of active mining sites. The company continues to expand its portfolio and is aiming to advance from pilot projects to reaching million-tonne operations in the future. The long-term commitment with Microsoft is expected to accelerate this progress.

Science foundation and feedstocks

Dr. Greg Dipple, Co-Founder and Head of Science at Arca, explained that the company's work is founded on substantial scientific research and industry collaboration. He said:

"Arca was built on the foundation of more than 20 years of academic research, dozens of field trials and collaborations with more than 30 mining companies around the world."

The key aspects of Arca's approach with industrial mineralization include access to large volumes of suitable industrial waste, lowered environmental footprint, and the geological durability of the storage. The process removes CO2 for millennia with robust measurement, reporting, and verification (MRV) systems to ensure transparency. According to Arca, other benefits include reducing industrial environmental risks, creating local jobs, and potentially converting waste liabilities into valuable resources.

Industry perspective and validation

Paul Needham, Chief Executive Officer at Arca, elaborated on the environmental potential of utilising mine tailings as a tool for carbon removal. He said:

"We have a unique opportunity to utilize one form of waste (mine tailings) to neutralize another (excess atmospheric CO2). The result is less waste and a healthier environment."

He also described the agreement with Microsoft as an important validation of industrial mineralization as a plausible route for achieving climate targets. Needham stated:

"This agreement with Microsoft validates Industrial Mineralization as a viable pathway for durable carbon removal with the potential to scale and meaningfully contribute to global climate goals."

Microsoft's interest in CDR comes as the company seeks to meet its own long-term climate goals. Phil Goodman, Director of Microsoft's Carbon Dioxide Removal Programme, noted the importance of scalable and permanent solutions for carbon removal. He commented:

"This offtake agreement diversifies Microsoft's carbon removal portfolio into a pathway that combines scalability and permanence. Arca brings notable scientific expertise and has proven they can sequester carbon through their demonstration project, giving us confidence to enter into a multi-year agreement. We are pleased to support Arca in advancing industrial mineralization."

The agreement between Arca and Microsoft reflects a broader trend of corporate commitments to long-duration, permanent carbon removal technologies, as both companies and governments increase their focus on achieving net zero objectives by mid-century.