Alt Carbon

About

Alt Carbon is an India-based CDR startup founded in 2023 by brothers Shrey and Sparsh Agarwal that deploys Enhanced Rock Weathering by spreading waste basalt rock dust on tea, rice, and bamboo farms in the Darjeeling/Rajmahal region. The company raised a $12M seed round in May 2025 and has secured agreements with Frontier, NextGen (South Pole/Mitsubishi), and MOL Group, with credits issued via Isometric.

Registry Activity

Independently verified by carbon-credit registries:

Isometric

• 3 projects · Rock Weathering · 9,566 tCO₂ issued · 50 retired · first issued 2025-11-14  ↗

Data from Puro.earth and CarbonPlan OffsetsDB (Verra, Gold Standard, ACR, CAR, ART, Cercarbono, Isometric). Refreshed monthly.

Registry Memberships

• Isometric
• Cdrjobsearth

History

• 2026-10-12 — news mention: NULIFE GreenTech: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-09-25 — news mention: Carbon Removal India Alliance: 🇮🇳 India’s Top Carbon Removal Suppliers 🇮🇳 As durable c (source)
• 2026-09-06 — news mention: NULIFE GreenTech: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-09-06 — news mention: Frontier Climate: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-08-30 — news mention: NULIFE GreenTech: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-08-29 — news mention: Frontier Climate: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-08-15 — refresh: coresignal
• 2026-08-13 — news mention: Graphyte: Midway through the year and happy to report that the Frontier portfolio has removed 30,600 (source)
• 2026-08-01 — news mention: NULIFE GreenTech: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-07-30 — news mention: Graphyte: Midway through the year and happy to report that the Frontier portfolio has removed 30,600 (source)
• 2026-07-25 — news mention: NULIFE GreenTech: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-07-24 — news mention: Frontier Climate: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-07-22 — news mention: Charm Industrial: Midway through the year and happy to report that the Frontier portfolio has remove (source)
• 2026-06-06 — news mention: 9,566 tonnes. One enhanced rock weathering operator in India just delivered the largest ERW credit b (source)
• 2026-06-06 — news mention: 9,566 tonnes. One enhanced rock weathering operator in India just delivered the largest ERW credit b (source)
• 2026-06-04 — news mention: Alt Carbon Makes The World’s Largest ERW Issuance With Nearly 10,000t Of Removed CO2 (source)
• 2026-05-21 — news mention: The supplier set is wider than people think. Lithos, UNDO, Terradot, InPlanet, and Alt Carbon do cro (source)
• 2026-05-21 — news mention: Foundation Opens Consultation On CCS EACs Methodology The Cynthia and George Mitchell Foundation ha (source)
• 2026-05-18 — news mention: Dr. Sambuddha Misra: Drinking Tea to Save Coral Reefs? The Mechanics of Enhanced Rock Weathering in (source)
• 2026-05-18 — news mention: Take: Dr. Sambuddha Misra: Drinking Tea to Save Coral Reefs? The Mechanics of Enhanced Rock Weatheri (source)
• 2026-05-18 — news mention: The AI Boom Needs Carbon Removal The CEO of Climeworks argues in Heatmap News that carbon removal s (source)
• 2026-05-01 — refresh: screenshot
• 2026-05-01 — refresh: coresignal, screenshot
• 2026-04-19 — reclassified: pathway=Enhanced Weathering focus=supplier liveliness=🟢 Active (source)
• 2026-04-19 — refresh: coresignal, screenshot
• 2026-04-19 — reclassified: pathway=Enhanced Weathering focus=supplier liveliness=🟢 Active (source)
• 2026-04-18 — reclassified: pathway=Enhanced Weathering focus=supplier liveliness=🟢 Active (source)
• 2026-04-18 — backfilled from V1 (source)