As we are entering yet another hot summer (the current heatwave in Paris is no fun at all), sustainability efforts are becoming paradoxically contentious. If many food companies are reducing their efforts, that is not stopping tech and finance giants from investing in a new agriculture technology: Enhanced Rock Weathering or ERW. But is it the breakthrough we need, or a risky bet on uncertain chemistry?
Food production is responsible for about one-quarter (26% to be exact) of global greenhouse gas emissions. Beyond emissions attributed to livestock and the use of alternative nitrogen-based fertilisers, ERW is emerging and making waves.
1 – How does Enhanced rock weathering work?
ERW is a pretty straightforward technique: it aims to accelerate an already existing natural geological process to sequester CO₂ into the soil. Finely crushed rocks are spread on farmland, and when it rains, through a chemical reaction, the CO₂ contained in the rainwater is converted into carbonates. These then flow into rivers and oceans, eventually forming solid carbonates, “stocking” carbon for millennia.
It has then obvious, and meaningful climate benefits: a 2020 research paper concluded that ERW could remove up to 2 gigatonnes of CO₂ per year from the atmosphere. To compare, global emissions reached approximately 37.4 gigatonnes in 2024. So, ERW could be a significant contributor to efforts to become climate-neutral (by compensating for emissions that won’t be easy to reduce).
ERW also has benefits for farming, notably:
- Helping to fight soil acidification, one of the consequences of intensive farming,
- Improving soil health
2 – Increased venture appetite and big tech involvement
While ERW’s principles have been known for quite some time, there has been a boom in the number of deals and partnerships announced in recent months:
- Terradot (US, basalt): after having raised $54M for its Series A last December, it announced a few months ago a deal with Microsoft, where the tech giant will buy 12,000 tonnes of ERW carbon credits. The startup is focused on Brazil for its operation, a country often mentioned as one of the most well-suited to benefit from ERW.
- Mati (US, basalt), which just received the XPrize and its $50M prize.
- Eion (US, olivine) signed another deal with Microsoft for 8,000 tons of CO₂ removal and signed a $33M contract for carbon removal in March.
More than food companies, current announced partnerships are mostly involving large tech companies (Microsoft, Alphabet, and Meta), and also financial institutions such as JPMorgan and Stripe.
ERW has yet to be refined to reduce costs and increase efficiency by exploring:
- New types of rocks
- Geographical optimisation to adapt the process to temperatures and soil types
- Ways to better measure and verify the reality of the carbon stored (through sensors, AI modelling, or manual measurements)
- Revenue-sharing models through carbon credits to support farmers financially for their sustainability efforts.
As with many carbon reduction and carbon removal technologies, the latter point is probably the most important. No matter the cost or the potential, without an easy way to audit them, carbon credits can’t be seriously trusted.
3 – What’s next?
While there is a real appetite for this new approach to improve soil health and reduce emissions, it also comes with multiple challenges (particularly cost and trust). Beyond the research mentioned above, doubts have been expressed regarding the real potential of the ERW, especially the speed at which the chemical process will occur and the duration for which CO₂ will be stored.
In the context of a decline in AgriFoodTech funding and a somewhat diminished appetite for sustainability projects, the current hype around Enhanced Rock Weathering shouldn’t be ignored.
If you’re exploring how carbon removal fits into your roadmap or wondering what these partnerships with Microsoft and other tech giants mean for the future of agriculture, we’re here to help.
