Cmip7 Emissions Variables List (v0)

[jkikstra]

Implementing the variable list from here [sheet: IAMC variables]

General context documented under #151 (currently bit outdated).

Should address:

Minimum:

• CDR under "Emissions|*" CDR under the Emissions|CO2|* : is it clear enough where to report removals from different methods ? #145
  • check consistency with Refactor list of carbon-removal variables #172
• High-level (CO2) variables; components Product Use and Fossil Fuel Fires Changes in Emissions Reporting (high-level) for climate-assessment (FaIR, MAGICC) since AR6 #165
• Burning variables Burning variables emissions: overlap in definitions in Peat / Other Land #167 and Emi|CH4/N2O|Agriculture|Waste Burning  #64
  • Update descriptions
• Add "Gross Emissions|CO2|AFOLU" IAMC-to-CMIP7: emissions mapping and harmonization for SSP/ScenarioMIP  #151
• Supply + Demand = Total Emissions|{Level-2 Species}|Energy: add "Demand" and "Supply" as components. #173
• merge check: are "level" 1/2/3 components defined consistently between 'component' and the actual variables?

Optional / can leave for future versions:

• How to best add a "CMIP7-harmonization" tag for a specific list of emissions variables #185
• Additional minor gases to include in template? (e.g. montreal, Halon, etc.) #166
• Definition: Emissions|Kyoto Gases - which GWP version? #144
• Labelling default climate-assessment variables #187
• Labelling IPCC sectors in emissions variables #186
• Question about sectors under Final Energy|Transportation, and consistency with Emission sectors. #184 (now domestic aviation would be calculated by adding/subtracting other variables see here [sheet: IAMC variables])
• add tier levels (Update LU emissions #179)
• create a 'diff' with the AR6 database template
• update synfuels guidelines (Emissions Accounting of Synthetic Fuels / (short-term) CCU #49)
• national GHG inventories (Allowing emissions reporting both for IAM definitions and National Inventories definitions (CO2|AFOLU) #146)
• consider changing the hierarchy by placing Fires outside of AFOLU (Fires Emissions: changing hierarchy #200)
• clarify HWP reporting (PR/issue tbd)
• provide clarity on which sector-species combinations are expected to be zero / not required [e.g. BC|Agriculture] (Emissions: combinations of sector-species: do we need more tags? #202)
• consider adding CDR methods not only in top-level descriptions, but also to lower-level variable descriptions (PR/issue tbd)
• reconsider reporting unit for NO2 (NOx / NO2 - NOx may be a bit ambiguous) (PR/issue tbd)

[jkikstra]

@danielhuppmann @phackstock apologies for not fully finishing this today. But probably it's already clear where this should go (just the burning variable definitions are left to do for a v0, I think).

So might be ready for a first review?

Feel free to change things, I don't have anything changed locally right now.

[danielhuppmann]

Thanks @jkikstra! A few clarifying questions and corrections inline.

The main issue, for me, is that that the formulations "net of" or "not accounting for" is inherently ambiguous (should the activity be not counted or the emissions from that activity?)...

I suggest to revert to shorter variable description, and the add a "notes" attribute with a clear guide on how to compute it, like this example

common-definitions/definitions/variable/energy/secondary-energy-electricity.yaml

Line 17 in 88ad6f3

notes: This variable should be computed as yearly average additions between the previous

[tmkhsgw]

Hi, thank you for your great work! I just let you know Land group would like to have the following variables as gross emissions subcategories for AFOLU (as tier3). Units should be Mt CO2/yr. Thank you.

Gross Emissions|CO2|AFOLU|Deforestation:
description: Gross emissions of CO2 from deforestation
Gross Emissions|CO2|AFOLU|Other Land:
description: Gross emissions of CO2 from forest management
Gross Emissions|CO2|AFOLU|Forest Management:
description: Gross emissions of CO2 from other land-use change

[jkikstra]

Hi, thank you for your great work! I just let you know Land group would like to have the following variables as gross emissions subcategories for AFOLU (as tier3). Units should be Mt CO2/yr. Thank you.

Gross Emissions|CO2|AFOLU|Deforestation: description: Gross emissions of CO2 from deforestation Gross Emissions|CO2|AFOLU|Other Land: description: Gross emissions of CO2 from forest management Gross Emissions|CO2|AFOLU|Forest Management: description: Gross emissions of CO2 from other land-use change

Added (with minor corrections) here: 3dc5809

[jkikstra]

Feedback from the IAMC SWG Data - Emissions group meeting, which will be discussed a bit more.

Major:

• Should we report Fires separate from AFOLU? Two reasons were brought up by @shinichirofujimoriKU :
  • Fires are not clearly just anthropogenic, but a mix with also some emissions from natural fires.
  • Fires are gridded separately (from agriculture)
    Upon reflection: I think this is probably a good suggestion.
    Note on harmonization (for SCMs and ESMs): peat fires and deforestation & degradation are represented in the GCB, and are also the ones that should be included in AFOLU-like forcing (but not other fires!) following the guidance of Van Marle et al. (2017) "Climate models should not use the CO2 emissions (or nitrogen emissions if the nitrogen cycle is included in the model), as forcing because in general these emissions are not net emissions to the atmosphere, but a return pathway of previously sequestered carbon just as respiration is. The exceptions are CO2 emissions from deforestation and peat fires.".
• Can we add a signpost for national accounting vs scientific model reporting? (@gidden offered to come with a suggestion)

Minor:

• Can it be clarified a bit more cleanly how Harvested Wood Products (HWP) should be reported? Maybe have a look at Chapter 12 of Volume 4 of the 2019 refinement of the reporting guidelines and report on a preferred suggested way?

[gidden]

Can we add a signpost for national accounting vs scientific model reporting? (@gidden offered to come with a suggestion)

Simple suggestion is to use [tags] like [model] or [nghgi]

[jkikstra]

nghgi

Do we need an extra variable?

[jkikstra]

I just noticed that tier level are currently missing from the emission reporting @jkikstra I think it would be useful to have tier level based on this definition from @danielhuppmann Tier-1: Must-have Tier-2: Important for sensible analysis Tier-3: Nice-to-have

P.S. in the presentation that the SWG Data leads were giving now, they put
Tier 1: Basic variables, keep number as small as possible
Tier 2: Standard reporting
Tier 3: Detailed reporting, enabling in-depth analysis

[gidden]

nghgi

Do we need an extra variable?

The use case here is that teams would be required to report "LULUCF [model]" and can optionally report in addition "LULUCF [nghgi]"

[jkikstra]

On nghgi:
Suggestion coming from discussion between @gidden @jayfuhrman and me:

1. add extra AFOLU NGHGI variable (and make clear it is NOT a component of totals)
2. add a note to the model/scientific AFOLU variable that this is model/scientific accounting, and NOT NGHGI-aligned

This way, we don't break post-processing scripts, but still add the extra reporting detail option.

[jkikstra]

for fires: we try discussing between @shinichirofujimoriKU and @gidden and the CMIP7 fires emissions people for an extra discussion

[jkikstra]

@IAMconsortium/common-definitions-emissions ping to check before we merge?

[znichollscr]

• Should we report Fires separate from AFOLU?

Another reason is that we can maybe harmonise better if we do this. There are biomass burning emissions from GFED, so if we report separately, we can think about whether we want to do something more sophisticated than just harmonising to GCP at the global level

[jkikstra]

• Should we report Fires separate from AFOLU?

Another reason is that we can maybe harmonise better if we do this. There are biomass burning emissions from GFED, so if we report separately, we can think about whether we want to do something more sophisticated than just harmonising to GCP at the global level

I think in principle this can be done anywhere where it would be reported, but sure.

Just for everyone @IAMconsortium/common-definitions-emissions (e.g. @strefler ) - since @danielhuppmann wants to send out the new variable template today, I would really like to merge this in before.
Then we can update after.
I think that the current state of the template (+comment) is better than not merging this in before.

And so we'll make a new PR directly afterwards then, to continue discussions?

[znichollscr]

Last thoughts, looks super nice thanks!

[jkikstra]

My suggestion for now:
we take what we have (with final polishing fixes), and leave the changes to Fires reporting for a new PR (see #200).

Thumbs up from people for that?

[strefler]

Looks to me like all the removal options are missing as subcategories. Not a showstopper though, can add them later, just need to ensure consistency with the carbon management variables

[jkikstra]

That's right, thanks - I'll note it down for future refinement.

[strefler]

great, thanks! Let's merge this and leave other updates for later PRs

[danielhuppmann]

Thank you @jkikstra

Merging as is so that ScenarioMIP-SSP-submission can proceed, but this will require more discussion in several variables and a harmonization of descriptions.