Dr. Sambuddha Misra: Drinking Tea to Save Coral Reefs? The Mechanics of Enhanced Rock Weathering in Darjeeling | S5E5

In this episode, we sit down with Dr. Sambuddha Misra, a chemical oceanographer, associate professor of earth sciences at the Indian Institute of Science, and the chief scientist at Alt Carbon. Dr. Misra has spent two decades studying how chemical weathering shapes the planet's climate over millions of years, and is now actively applying that science to draw down atmospheric carbon at scale.

Alt Carbon's Darjeeling Revival Project is spreading finely crushed basalt, a byproduct of the Indian construction industry, across tens of thousands of acres of Himalayan tea estates. We explore the surprisingly elegant chain of geochemistry that removes CO2 from the air, supplies crucial micronutrients to degraded agricultural soils, and ultimately pushes alkalinity into the Bay of Bengal to buffer against ocean acidification.

Some topics we cover:

• The Geochemistry of Accelerated Weathering: The literal mechanics of how crushed basalt, rainwater, and atmospheric CO2 interact to compress a million-year geological process into a single commercial cycle.

• Agricultural Yields and the Human Element: Why the physical application of basalt is done entirely by hand, and how this process is driving incredible crop yield increases in degraded soils.

• Measurement Bottlenecks and the Reality of Scaling: The grueling structural reality of verifying commercial carbon credits. Dr. Misra breaks down the exact science of tracking elements in open soil profiles, and why scaling this project will require inventing entirely new measurement technologies.

Mentioned in This Episode:

• Alt Carbon: ⁠altcarbon.com⁠

  • The Darjeeling Revival Project: ⁠⁠⁠altcarbon.com⁠⁠⁠

• Isometric Registry: ⁠isometric.com⁠

  Indian Institute of Science: ⁠https://iisc.ac.in/⁠

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Thanks as always to our Producer, Emily Pokou.