In a significant boost for India’s growing carbon removal sector, climate-tech startup Alt Carbon has entered into a multi-year agreement with Microsoft to deliver 36,920 tonnes of carbon dioxide removal (CDR) credits through its enhanced rock weathering (ERW) project in Darjeeling.
The agreement marks Microsoft’s first carbon removal purchase based on enhanced rock weathering technology in Asia, highlighting the increasing global interest in scalable, science-backed climate solutions emerging from the region.
The deal also includes provisions for Microsoft to purchase additional carbon removal credits in the future, subject to successful project delivery and independent verification milestones.
Strengthening Carbon Removal Capacity in South Asia
Founded in 2023 by brothers Shrey Agarwal and Sparsh Agarwal, Alt Carbon is focused on building large-scale carbon dioxide removal infrastructure across South Asia. The startup aims to remove 5 million metric tonnes of CO₂ by 2030 using innovative carbon removal technologies.
At the core of the company’s approach is enhanced rock weathering, a process that accelerates a natural geological mechanism for carbon sequestration.
The method involves sourcing basalt rock dust from mines and applying it to agricultural land. When exposed to rainwater, the basalt undergoes a chemical reaction that captures atmospheric carbon dioxide and converts it into stable bicarbonate ions. These ions are stored in the soil before gradually making their way through river systems to the ocean, where they can remain locked away as calcium carbonate for thousands of years.
This approach is increasingly being viewed as one of the most promising long-term carbon removal technologies capable of supporting global net-zero ambitions.
Darjeeling Revival Project Combines Climate Action with Agricultural Benefits
The carbon credits purchased by Microsoft will be generated through Alt Carbon’s Darjeeling Revival Project (DRP), an initiative designed to transform Darjeeling’s historic tea-growing region into a hub for large-scale carbon removal.
Beyond capturing carbon, the project aims to improve agricultural productivity and environmental resilience across tea estates and surrounding farming communities.
According to the company, the application of basalt rock dust can help:
- Improve soil health and fertility
- Balance soil pH levels
- Increase crop productivity
- Enhance long-term agricultural sustainability
By combining climate action with rural economic development, the project demonstrates how carbon removal initiatives can deliver broader environmental and social benefits.
Commenting on the partnership, Shrey Agarwal, CEO and Co-Founder of Alt Carbon, said:
“Our deal with Microsoft is built upon years of work building high-integrity carbon removal infrastructure in India. From laboratory capabilities to field operations and farmer networks, we have focused on advancing the science of rock weathering globally.”
He added:
“Climate Change remains one of the most significant civilizational challenges we face & India can be a global leader in tech based carbon removal.”
Microsoft Continues Strategic Carbon Removal Investments
The agreement comes at a time when the carbon removal market is evolving rapidly.
Earlier this year, reports suggested that Microsoft was reviewing the pace of its carbon removal procurement strategy. However, the technology giant reaffirmed its commitment to carbon removal as a key component of its broader sustainability roadmap.
Microsoft remains the world’s largest buyer of carbon removal credits. According to industry platform CDR.fyi, the company accounted for approximately 90% of global carbon removal credit purchases in 2025, underscoring its influence in scaling emerging climate technologies.
The latest agreement with Alt Carbon signals continued confidence in high-quality carbon removal projects that offer measurable, durable and scientifically verified climate benefits.
Building Trust Through Scientific Verification
A key focus of the partnership is ensuring transparency and environmental integrity throughout the carbon removal process.
Phil Goodman, Program Director, Carbon Removal at Microsoft, said:
“Our contract with Alt Carbon for high-quality carbon removal uses field deployments to collect primary and secondary quantification methods for carbon quantification, while using a high standard to safeguard against environmental impacts. We are encouraged by Alt’s efforts to build durable carbon removal capacity in India given their past success in delivering carbon credits.”
The agreement reflects a growing trend among corporate climate leaders to prioritise carbon removal solutions that combine rigorous scientific validation with long-term environmental impact.
India Emerging as a Carbon Removal Innovation Hub
As countries and corporations intensify efforts to meet net-zero targets, demand for permanent carbon removal solutions is expected to rise significantly over the coming decade.
India’s vast agricultural landscape, mineral resources and growing climate-tech ecosystem position the country as a potentially important player in the global carbon removal market.
The Alt Carbon-Microsoft partnership not only strengthens India’s role in climate innovation but also demonstrates how local startups can contribute to solving global environmental challenges while creating value for farming communities and regional economies.
With carbon removal becoming an increasingly critical pillar of climate action, collaborations like this could help accelerate the development of scalable, high-integrity solutions capable of supporting long-term global decarbonisation efforts.
