How Eion's Enhanced Rock Weathering Works

Earth’s surface, its rocks, soils and sediments, naturally absorb carbon dioxide from the air. More specifically, atmospheric carbon dioxide reacts with alkaline minerals on Earth’s surface to create carbonates that remove and securely store carbon dioxide. This process, called carbon mineralization, occurs naturally over hundreds to thousands of years and removes about 0.3 metric tons of carbon a year. There are many ways to accelerate this reaction and enhanced rock weathering is one of them.

Photo courtesy Eion

Enhanced rock weathering is a type of carbon mineralization that occurs on Earth’s surface. It is a process by which certain types of rocks - silicates - are ground into a fine powder and spread on areas like agricultural fields to increase the rate of carbon dioxide absorption.  

Eion’s technique calls for the application of pulverized olivine, a type of silicate rock that weathers very quickly, to farmland. Olivine pulls carbon out of the atmosphere at a faster rate than natural carbon mineralization. When the rock weathers and the stored carbon makes its way to the ocean, it is stored permanently as carbonates on the seafloor. 

In short, all rocks naturally absorb carbon dioxide from the air and break down (or weather) over time. Once a rock is broken down it will naturally move down slope due to gravity. Enhanced rock weathering is simply kickstarting the natural process of weathering by applying minerals to soil that speed up the natural carbon absorption, removal, and sequestration process. 

Measuring ERW

While enhanced rock weathering has been understood for a long time as a way to clean up carbon dioxide from the atmosphere, it has also been very difficult to measure. 

Eion uses a patented direct measurement process to measure and verify total carbon removal. 

The process looks for certain elements that stay put during the process of weathering. With these stable elements in place, it becomes easy to confirm the amount of olivine weathered and the carbon dioxide absorbed in the process. Eion samples soil before and after applying olivine, and because farmers already test their soil before planting and after harvesting, the sampling process integrates easily into growing cycles. 


Most of us are familiar with the use of fertilizers that farmers often use to help increase crop yields and profitability. Eion’s olivine product, which they’ve named CarbonLock - helps pull carbon dioxide from the air and also offers an easy alternative to existing soil enhancers:

  1. Olivine has been available and approved for agricultural input since the 1940’s and can be used as a near 1-1 replacement for aglime, a common soil additive made from limestone
  2. Olivine makes soil less acidic
  3. Improves soil structure and helps restore degraded lands.
  4. Strengthens the soil’s ability to cycle nitrogen leading to less nitrogen runoff in waterways and less use of fertilizers which are often fossil fuel based. 

At Tomorrow’s Air we love enhanced rock weathering for its climate benefits: it permanently and verifiably removes carbon dioxide from the atmosphere while also improving soil and reducing ocean acidification.

Photo courtesy Eion

Another reason to love Eion though is their commitment to communities. The team at Eion - with roots in agronomy and chemistry - is dedicated to helping agricultural communities as much as our climate. Eion’s enhanced rock weathering olivine product supports healthier soils which improve crop yields and in turn, profitability for farmers. Eion’s projects also help create jobs and boost local economies. Through their focus on local communities and crop health, Eion is turning enhanced rock weathering into a scalable climate solution that improves soil health and puts people to work. 

Support the expansion of Eion’s enhanced rock weathering when you join Tomorrow’s Air today.

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