Improvement of CDR and Carbon Management variables

[amerfort]

Here is my proposal of how we can improve the variable structure of the Emi|CO2|CDR variable family as well as the Carbon Management family for better clarity and to add future carbon flows from additional methods (i.e. ocean alkalinity enhancement, biochar, carbon fibres, plastics, non-energy hydrocarbon flows)

See overview of existing and proposed variables here

Emi|CO2|CDR

• add plus notation for clarity
• report CDR from afforestation, not just net-negative land use change
• add OAE
• Discussion: I propose to split it into ocean CO2 uptake and positive calcination emissions. BUT reporting positive calcination emissions under CDR is misleading. Any better ideas?
• add biochar
• add materials
• Discussion: Where and how do we report emissions caused by impernanence?

Carbon Management

• Discuss whether we want to name it "Carbon Management|Materials" or "Carbon Management|Feedstocks"
• add split in management of CO2 flows under Carbon Management|Carbon Capture and Hydrocarbon flows Carbon Management|Materials
• add split of materials into Plastics and Carbon Fibres: Carbon Management|Materials|Plastics, Carbon Management|Materials|Carbon Fibres
• improve naming from Carbon Management|Storage/Usage zu Carbon Management|Carbon Capture|Storage/Usage
• add plus notation for clarity
• Discussion: Should Carbon Management|Carbon Capture|+|DAC contain emissions from fuel combustion for heat generation? If yes, it is consistent with the sectoral summation. But then it potentially contains fossil carbon that is not reported under Carbon Management|Carbon Capture|+|Fossil. Should we then just keep one summation with plusses? (either over sectors or over CO2 origin?)
• Take care about infamous capture_valve so summations finally add up

[mellamoSimon]

moin y'all. thank you, Anne, for this!
wouldn't we end up double-counting removals in Emi|CO2|CDR if we add up the proposed variables? as in Emi|CO2|CDR|+|DACCS (Mt CO2/yr) and Emi|CO2|CDR|+|Materials (Mt CO2/yr) . We could have those variables but I don't think they are necessarily additive. Or am I missing something?

thanks!

[mellamoSimon]

Hey, I updated my knowledge on this and now I want to take back what I said; here DACCS is actually DACCS, so stored carbon (and not in plastics). I do still have some doubts but I'll move the discussion to our mattermost channel :)

[orichters]

Maybe it is worth checking also the values after being converted to AR6 reporting. Currently, they fail the summation checks:

Carbon Sequestration|CCS >                                                    Carbon Management|Storage >
   + Carbon Sequestration|CCS|Biomass                                            + Carbon Management|Storage|+|Biomass|Pe2Se + Carbon Management|Storage|Industry Energy|+|Biomass
   + Carbon Sequestration|CCS|Fossil                                             + Carbon Management|Storage|+|Fossil|Pe2Se + Carbon Management|Storage|Industry Energy|+|Fossil
   + Carbon Sequestration|Direct Air Capture                                     + Emi|CO2|CDR|DACCS
   + Carbon Sequestration|CCS|Industrial Processes                               + Carbon Management|Storage|+|Industry Process
Relative difference between 1% and 41.4%, absolute difference up to 652.98 Mt CO2/yr.

Carbon Sequestration|CCS|Fossil <>                                            Carbon Management|Storage|+|Fossil|Pe2Se + Carbon Management|Storage|Industry Energy|+|Fossil <>
   + Carbon Sequestration|CCS|Fossil|Energy                                      +
   + Carbon Sequestration|CCS|Fossil|Industrial Processes                        + Carbon Management|Storage|+|Industry Process
Relative difference between -5397.4% and 100%, absolute difference up to 1605.14 Mt CO2/yr.

If you have questions about the notation, let me know.