🤔 My two cents on the ongoing biochar permanence debate 🤔

🔥 The topic that keeps giving… how permanent is biochar?

📄 A paper recently appeared challenging that soil-applied biochar can be permanent for 1,000s of years. It generated lively discussions and several folks asked me for my take.

🧪 First things first: I am not a scientist, and this is a matter that needs to be settled 100% by science. However, the latest paper is explicitly a policy commentary. So allow me to weigh in.

My main observations:

⚖️ The debate is not on whether BCR represents a durable CDR pathway – everyone here agrees on this – but just on whether the permanence is 100s or 1,000s of years.

📚 The scientific “divide” is actually smaller than outsiders think. Many authors appear on papers across the argumentative spectrum. The debate is around the fringes.

🔄 One side says “there is no evidence of inertinite decay under soil conditions”, the other says “absence of evidence is not evidence of absence”.

⏳ We will not be able to empirically “solve” this debate, as it would require experiments over decades (or more), which we simply do not have.

📌 Importantly, the latest paper does not provide any evidence that the inertinite fraction of biochar decays under soil conditions. It merely argues that nothing is ever 100% inert in a philosophical sense. That is valid scientific caution, but it is not evidence of decay.

Now, let’s move to policy:

🧭 Policy makers must make decisions with imperfect data based on best available science.

🎯 The difference between 100s and 1,000s of years is basically irrelevant outside of niche CDR circles.

📆 Climate policy is built around short to medium-term horizons (5–25 years), not millennial timescales.

🇪🇺 Let’s take the example of the EU CRCF, arguably the most advanced and relevant regulation, which just finalised a permanent CDR methodology for BCR.

🔬 This represents a years-long process, led by a highly capable scientific team, who reviewed hundreds of studies (including basically all those quoted in the latest paper), conducted dozens of workshops, reviewed all existing BCR standards, and interviewed the leading BCR scientists.

🛡️ Their conclusion? Inertinite measurement represents a rigorous approach to determine the exact percentage of permanent CDR. Further – to account for any potential inaccuracies – a 2.5% conservatism factor is applied. Plus additioal deductions based on sampling variance.

✅ There you have it.

💬 My take: it is healthy for scientists to keep poking holes in each other’s arguments. However, I personally do not see any policy implications from the latest paper. Policy makers seem well aware of the strengths and weaknesses of inertinite benchmarking, and are developing policy accordingly.

🚀 I am glad the CRCF is moving forward and that policy makers are focused on creating the conditions necessary to scale BCR in Europe.

👉 Over to you. Whether you agree or disagree with me – please do weigh in.

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