Mar 13, 2023Liked by Mitch Rubin

I agree that biochar's permanence makes it strait forward for issuing carbon credits. But I am surprised that you didn't mention composting. Unlike biochar, where the the majority of the nitrogen in the feedstock is vaporized during production (as NOX), compost preserves - recycles nitrogen, reducing the need for producing chemical fertilizer - avoiding GHG production. And the humics in compost can rival the recalcitrance of biochar.

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Tip of the hat, and thank you for penning the Raising the Flag on Carbon Credit article. It's the best call to action for getting Soil Carbon Credits right. We are a climate action startup focusing on inset carbon and decarbonization of its supply chain (through eliminating agrochemical emissions).


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Jan 13, 2023·edited Jan 13, 2023

Thank your for this article, with which I mostly agree. However, I'd be happy if you could share your views on the following:

It's interesting that you mention ERW as an alternative to soil carbon credits, yet scientific studies on the quantification of ERW-impacts vary widely and are mostly based on theoretical evaluations. While ERW is potentially more permanent: if we are talking about scientific evidence, it actually even worse, at least in the context of carbon credits. Or am I mistaken?

You also mention that ERW falls outside the FLAG Guidance for carbon sinks. Why ist that? Isn't it a case of on-farm carbon sequestration and thus eligible for FLAG accounting?

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Interesting read, Mitch! I hadn’t realized how similar the sampling for MRV is to the soil sampling I’ve done for contaminated sites when trying to characterize large areas. I can vouch for the high effort, high expense claim there. Curious to dig into some of those technologies potentially making that better!

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It's about flows rather than stocks. The benefit comes from pumping more into the soil than is released. It has been likened to a basin which has a drain and a spigot. The spigot must flow more than the drain to gain height in the basin. However, you can never turn the spigot off or it all promptly drains away.

Worse perhaps, as the height in the basin gets higher the pressure on the drain increases and the rate of drainage does too.

What isn't known precisely is how closely the analogy applies to soil carbon. Is there increasing carbon loss as soil carbon increases? It seems possible since soil life would be increasing.

It isn't clear what a truly useful payment system would look like, but I suspect that isn't the objective. The goal is dependency, and it doesn't much matter how that is achieved.

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