Is biochar a carbon dioxide removal?

Biochar is commonly presented as a carbon dioxide removal (CDR) technology with great potential to contribute to climate change mitigation and co-benefits thanks to its soil conditioning properties, among others. We discuss the relevance of classifying biochar as a carbon dioxide removal and argue that in most cases its use will rather reduce CO2 emissions. The reason is that biochar is mostly a way of processing biomass into a more permanent matrix for carbon storage, independently of carbon removals that may have occurred previously into various types of biomass. It is therefore misleading to attribute carbon removal processes to biochar except in some very specific cases (e.g., purpose-grown tree plantations). Making a distinction between CDR and emission reductions is important to prevent the misallocation of resources available for mitigation activities and provides more certainty to biochar business models that could be misled by unrealistic expectations over (inflated) carbon-related revenues. As biochar has the potential to play a significant role, not only for mitigation but also for adaptation to climate change with increasing resilience of agriculture and forestry, we argue that policies should fully recognise the combined adaptation and mitigation benefits of biochar and act accordingly to create the right conditions for deploying it at scale (e.g., by supporting its use as a replacement for chemical fertilisers).