#12 Enhanced Weathering
#12 Enhanced Weathering
Accelerating nature's carbon capture process
Read time: 3 minutes
In this week’s issue you will learn about how spreading some crushed rocks on the ground can help us capture CO2: Enhanced Weathering
“Idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100.“ - Nature Climate Change
Top Enhanced Weathering News 🗞️
World’s first methodology: Puro.earth has launched the first enhanced rock weathering carbon crediting methodology. Helping such projects monetize their carbon removal activities.
Money raising: German-Brazilian startup InPlanet just has raised $1.3 million to use enhanced rock weathering in tropical countries where the technology has the highest potential impact.
EU project: The EU is funding a project to implement new technologies in mine wastes to reduce CO2 emissions through enhanced weathering.
Let’s dive in 🧠
Enhanced weathering is about accelerating the natural process through which the Earth regulates atmospheric levels of CO2.
Weathering just means breaking down rocks via chemical, biological, or physical processes. Ex: Rain, wind, plants, etc.
How does this natural process work?
CO2 in the atmosphere mixes with the water in the rain forming carbonic acid.
When the drops reach the Earth’s surface the carbonic acid reacts with the rocks.
Continuous rainfall dissolves the rocks into smaller components (chemical weathering).
The components eventually get transported into the ocean by rivers and groundwater.
Once there, they react with the CO2 in the ocean and make very stable formations such as shells, corals, rocks, etc.
The issue with this process is that it takes thousands of years.
We have accelerated the natural process of putting CO2 in the atmosphere way too much in the last few decades.
So we also need to accelerate the speed of removing it.
And of course we have to stop emitting even more.
How does the enhanced process work?
By spreading finely ground powder of rocks on beaches and fields.
Rocks rich in calcium, magnesium and iron, which react very well with CO2.
A mineral called olivine or rocks such as volcanic basalt are great examples since they are far more reactive and help capture CO2 much faster than average rocks.
Spreading powder of such rocks not only helps capture CO2 in decades instead of thousands of years.
It also helps:
Lower ocean acidification rates.
Fertilize by providing nutrients to plants in fields.
These rocks are really abundant in nature but getting them can be expensive and energy intensive. We can also use rocks with similar properties that come from industrial processes’ waste or old mines.
Btw, enhanced weathering has the most potential in tropical regions since it rains a lot there, which is key for the process.
Cons
Cost: Using waste rocks would be cheap (around $10 per tonne) but there’s not that much waste to be used. Freshly mined rocks would cost $50 to $200 per tonne.
Logistics: Getting the rocks, crushing them, transporting them and spreading them in the right places requires lots of players coordinating at a massive scale.
Impact: Measuring the carbon being removed is not easy. Plus, we don’t know the exact effects each type of rock would have on each type of soil, which is a big deal for agriculture.
Top Enhanced Weathering Companies 💰
Vesta: They’re adding a carbon-removing sand made of crushed olivine to eroding coastal systems. It reduces ocean acidity and removes carbon dioxide permanently.
Lithos: They spread basalt on croplands and use software to maximize CO₂ removal while boosting crop growth.
InPlanet: They spread rock powder on agricultural land in the tropics to capture CO2 and regenerate tropical soils. This way they contribute to more sustainable farming.
❗Extreme knowledge area❗
Just in case that wasn’t enough here are some additional resources:
How they do it at Vesta: This is the most famous enhanced weathering project so check out this video to know about their pilot project.
The chemistry behind: This simple video goes into the details of the chemistry of this whole carbon cycle.
That’s it for today, 1 climate tech topic in under 5 minutes.
Next week… Tidal Power! 🤯
If you enjoyed today’s issue, the best compliment you could pay me would be to share it with one person who you think would benefit from it :)
Txs for the article.
We are organizing a conference on the 24th of May.
There are other companies active.
Ambient greensand undo
Accelerated MCi in Australia and Paebbl in the Netherlands
Thank you for the article. Here are three more suggestions:
Two publicly funded research projects PyMiCCS https://cdrterra.de/consortia/pymiccs and BAM https://www.fet-bam.eu/
There is also the non-profit project of the Carbon Drawdown Initiative https://www.carbon-drawdown.de/ who just started a huge enhanced weathering MRV project in a greenhouse in Germany.