India Turns 100,000 Tons of Farm Waste Into Carbon Solution

Cotton farmers across India have a problem every harvest season: what to do with leftover stalks that clutter their fields. Many have resorted to burning them, releasing harmful smoke into the air and worsening climate change.

Varaha, a climate technology company, found a better way. The startup collects those unwanted stalks from smallholder farms in Maharashtra and transforms them into biochar, a charcoal-like material that traps carbon dioxide for hundreds of years.

Here's how it works. Varaha heats the cotton stalks in special reactors using a process called pyrolysis, which means heating with very little oxygen. Instead of releasing carbon dioxide into the atmosphere through burning, the process locks the carbon into a stable form that farmers can return to their soil to improve its health.

Microsoft just signed a deal to help Varaha build 18 new reactors across India's cotton-growing regions. The tech giant will purchase carbon credits representing the removal of over 100,000 tons of carbon dioxide over three years. Each reactor costs about $1.1 million to set up and will run for 15 years, potentially removing more than 2 million tons of carbon dioxide total.

The partnership builds on a similar agreement Varaha made with Google last year. Both tech companies are scrambling to offset rising emissions from their growing networks of data centers and AI computing needs.

The Ripple Effect

Varaha has already brought 40,000 farmers into the program across Gujarat, Rajasthan, and Maharashtra. Instead of losing money dealing with crop waste, these farmers now earn income selling their stalks. They also get cleaner air in their communities since the stalks aren't burned in open fields.

The biochar they receive back improves their soil quality, helping future crops grow better. Phil Goodman, who directs carbon removal programs at Microsoft, says the project creates "improved soils, cleaner air, and shared economic opportunity" for farming communities.

Varaha currently operates seven reactors and plans to deliver its first carbon credits to Microsoft by late 2026 or early 2027. The company isn't stopping with biochar either. It's also running projects on enhanced rock weathering, tree planting, and regenerative farming practices across India.

The timing matters. Technology companies worldwide are struggling to meet climate goals while building the massive infrastructure needed for artificial intelligence. Microsoft ranks among the world's largest purchasers of carbon credits as it tries to balance growth with environmental responsibility.

What started as a farm waste problem is becoming a climate solution that pays farmers, cleans the air, and removes carbon at the same time.