🌋 Turning Volcanic Rock Into a Carbon Sink

About this simulation

Silicate rocks like basalt and olivine naturally react with dissolved CO₂ in rainwater, releasing calcium and magnesium ions that combine with carbon to form solid carbonate minerals — mineral carbonation. This locks the carbon away for tens of thousands of years. In nature this weathering takes millennia; enhanced weathering speeds it up by crushing rock into fine grains and spreading it where rain and CO₂ reach it constantly, most often over farmland.

How it works

• Green CO₂ molecules drift down from the atmosphere layer and dissolve onto exposed rock grains.
• Each grain accumulates a carbonation progress value; as it rises the grain's surface whitens into a chalky carbonate crust.
• Grain size controls surface area — finer crushed rock reacts far faster than coarse gravel.
• Temperature and rainfall both accelerate the underlying dissolution reaction, roughly following how real weathering rates respond to heat and moisture.
• Rock type sets the baseline reaction rate: olivine weathers fastest, basalt is the practical middle ground used at scale, granite is a slow control for comparison.

Controls

• Rock type — switch between olivine, basalt and granite feedstocks.
• Grain size — from coarse gravel to fine crushed powder.
• Temperature / Rainfall — environmental conditions driving the reaction.
• Simulation speed — compress the (otherwise very slow) weathering timeline.
• ↺ Reset rock pile — spread a fresh, unreacted batch of rock. Drag to rotate, scroll to zoom.

Did you know?

A single tonne of finely crushed basalt can theoretically absorb up to roughly 0.3 tonnes of CO₂ as it fully weathers — and because the carbon ends up locked in solid minerals rather than a gas reservoir, enhanced weathering is considered one of the more durable, low-risk forms of carbon dioxide removal.