Standard names: *mass_flux_of_carbon_into_carbon_dioxide_removal_pool_from_biomass*

[ckoven]

Proposer's name Charles Koven

Date November 6, 2024

For each term please try to give the following:

- Term mass_flux_of_carbon_into_carbon_dioxide_removal_pool_from_biomass

- Description Flux of carbon from biomass that is intentionally stored in long-term reservoirs as a carbon dioxide removal process. This is most closely related to the variable mass_flux_of_carbon_into_forestry_and_agricultural_products_due_to_crop_harvesting, which represents the flux to product pools. For the purpose of simulations that include intentional carbon dioxide removal from biomass (e.g., biomass energy with carbon capture and storage (BECCS)), it is necessary to be able to separate the fluxes to long-term (e.g. geologic storage) pools from shorter- and medium-term product pools.

- Units [kgC m-2 s-1]

[github-actions[bot]]

Thank you for your proposal. These terms will be added to the cfeditor (http://cfeditor.ceda.ac.uk/proposals/1) shortly. Your proposal will then be reviewed and commented on by the community and Standard Names moderator.

[JonathanGregory]

Dear Charles @ckoven

Thanks for the proposal. I think it would be easier to understand if the order were changed to mass_flux_of_carbon_from_biomass_into_carbon_dioxide_removal_pool. Would thet be OK? Also, not being familiar with these terms, I don't find the meaning of "carbon dioxide removal pool" obvious, whereas I would understand "geological storage". What other "removal" stores are included, and what's their common or defining property, I wonder?

The units should be SI i.e. kg m-2 s-1.

Best wishes

Jonathan

[ckoven]

Dear @JonathanGregory Yes, that name would be fine. Given that some other schemes aside from geologic sequestration have been proposed for long-duration biomass carbon removal (e.g., "wood vaults", which are essentially landfills, see https://link.springer.com/article/10.1186/s13021-022-00202-0), I had thought it might be best to be general to any proposed long-duration CDR, rather than specifically geologic storage. I think the key feature of the storage is the timescale, i.e. that it can be considered indefinite for the purposes of a simulation. But also ok if the decision is to just call it "geologic storage", as that gets at the essential feature of the timescale.

[taylor13]

I also, think we should brain storm a replacement phrase for "carbon_dioxide_removal_pool". To be sure what we're talking about: Is it removal of biomass material that might decay (or burn) and increase atmospheric CO2? Does it only cover "managed" removal and not, say, natural burial of organic material into environments where decay will not occur? Is all the carbon in biomass subject to decay into CO2, or is some of the carbon tied up in chemical compounds protected from being a potential CO2 source? To my ear, the use of "flux" to describe something like the harvesting of trees seems a little odd. Maybe a term like "rate of removal" could be substituted?

[taylor13]

Just read this in an announcement:

Carbon accounting for carbon dioxide removal
In a perspective paper, researchers evaluated a range of carbon dioxide removal methods, 
including Direct Air Capture and Storage, Biomass Carbon Removal and Storage, and a 
mineralization-based approach.

does the proposed standard name only cover the 2nd of the 3 processes mentioned?

[ckoven]

Thanks @taylor13 -- yes I think we should be clear that this is only intentional removal of carbon from biomass into pools that are considered indefinite-storage for the purposes of the simulation. So this would exclude natural burial (which there is already a flux mass_flux_of_carbon_into_litter_from_vegetation for), and exclude transfer into pools that have a decay term (which is I believe what variable mass_flux_of_carbon_into_forestry_and_agricultural_products_due_to_crop_harvesting already represents). It would thus exclude approaches where the source of the carbon is not harvested biomass (e.g. DACCS, and enhanced weathering, which is I think what is meant by "mineralization-based approaches" above?). So, given these ambiguities I do think it may make sense to just specify geological storage as the end point to this. I had suggested mass_flux to be consistent with other carbon flows that are already accounted for.

[JonathanGregory]

Dear Charles

I agree that mass_flux should be used for consistency with other standard names. It's an area-average, I presume. Thanks for explaining about the storage. I imagine that into_geological_storage would be generally understood, and I think into_indefinite_storage (a phrase you've just used) would also make sense.

Best wishes

Jonathan

[ckoven]

Hi All, two things related to this:

(1) It sounds like the consensus here is that the variable info is the following:

• Term mass_flux_of_carbon_from_biomass_into_geological_storage

• Description Flux of carbon from biomass that is intentionally stored in long-term geological reservoirs as a carbon dioxide removal process. This is most closely related to the variable mass_flux_of_carbon_into_forestry_and_agricultural_products_due_to_crop_harvesting, which represents the flux to product pools. For the purpose of simulations that include intentional carbon dioxide removal from biomass (e.g., biomass energy with carbon capture and storage (BECCS)), it is necessary to be able to separate the fluxes to indefinitely long-term (i.e., geologic storage) pools from shorter- and medium-term cycling product pools.

• Units [kg m-2 s-1]

(2) I've subsequently come to realize that there also needs to be the corresponding carbon stock variable for the geological storage pool, so that we can confirm carbon conservation. Thus, I'd also like to add the following variable:

• Term carbon_mass_content_of_geological_storage

• Description Carbon mass per unit area that has been removed from the environment and stored in geological reservoirs, carbon dioxide removal processes.

• Units [kg m-2]