I would venture two objections: The first is more of a detail: you write that biomass not converted into biochar would be a "waste". But organic material, wether originating in forest or fields, is not a waste in nature, it is feed for milllions of microorganisms. It also comes with nutrients which are all but lost in the biochar process. So I would argue that large scale biochar applications is something that needs to be considered carefully. .The second objection is about the energy need. You write. "And energy-hungry CDR must add its own energy, not take it from a grid that is not yet decarbonized. " Already that is a tall order, but even when CDR is made with decarbonized energy it is a huge problem if it is energy-hungry as the future will be short in affordable energy.
I would venture two objections: The first is more of a detail: you write that biomass not converted into biochar would be a "waste". But organic material, wether originating in forest or fields, is not a waste in nature, it is feed for milllions of microorganisms. It also comes with nutrients which are all but lost in the biochar process. So I would argue that large scale biochar applications is something that needs to be considered carefully. .The second objection is about the energy need. You write. "And energy-hungry CDR must add its own energy, not take it from a grid that is not yet decarbonized. " Already that is a tall order, but even when CDR is made with decarbonized energy it is a huge problem if it is energy-hungry as the future will be short in affordable energy.