Enhanced Rock Weathering: how it works

Enhanced rock weathering accelerates one of nature’s best ways of removing greenhouse gases.

It requires certain types of rock reacting with rainwater. The outcome: carbon dioxide is turned into a stable bicarbonate, and it does not return to the atmosphere as a planet-heating gas.

This phenomenon has happened forever. It plays out over million-year arcs. But nature’s timing does not help us mitigate climate change in the present.

Flux’s role is to speed up nature’s process through technological interventions.

First, we crush rock and spread it on fields so that the reaction of rainwater, groundwater, air, and minerals happens as quickly as possible.
Second, we measure the carbon removed, so that the process generates scientifically validated credits that trade in the carbon markets and finance more enhanced rock weathering — and more carbon removal.
Our rock powder also adds nutrients to the soil. Enhanced rock weathering is growing rapidly because of this double benefit for people and planet: it helps crops grow while removing greenhouse gases.

Natural Removal

Rainwater absorbs carbon dioxide from the atmosphere. It falls on silicate rocks that contain elements like calcium and magnesium. A chemical reaction forms bicarbonates that draw down atmospheric CO2. While not rocks themselves, these bicarbonates are similarly stable. The atmospheric carbon that they help remove is not re-released.

The natural carbon cycle removes and stores carbon over arcs of 100,000 years.

Our Intervention

Step 1:

We crush the silicate rocks to a powder. This exposes more surface area to natural weathering, allowing more bicarbonates to form.

Step 2:

We spread the rock powder on fields. Wet, acidic topsoil is an ideal environment for weathering to happen. Exposed to groundwater and rainwater, the formation of bicarbonates accelerates. The rock powder also adds nutrients to soil.

Step 3:

Using a combination of soil and pore water samples, we measure the carbon drawdown. We rely on fieldwork at each site as well as earth science models.

Natural Storage

Water systems carry the dissolved bicarbonates through the groundwater to streams, rivers and seas. They eventually settle at the bottom of the ocean, which ensures that the carbon removal is permanent.