Carbon Removal: Include negative emissions from regrowth of timber plantations?

[flohump]

The following question came up in the ScenarioMIP land sub-group:
Should Carbon Removal include negative emissions from regrowth of timber plantations?
Timber plantations will be harvested after the end of the rotation period. Thus, all carbon sequestred during growth will be eventually released gain.

The question is if this is in line with the definition of Carbon Removal here:
https://github.com/IAMconsortium/common-definitions/blob/main/definitions/variable/emissions/carbon-removal.yaml#L23
Gross removals of carbon dioxide (CO2) from atmospheric origin or biomass through deliberate human activities
https://github.com/IAMconsortium/common-definitions/blob/main/definitions/variable/emissions/tag_land-removal-options.yaml
includes Forest Management: description: improved forest management

Forestry is certainly a "deliberate human activitiy". But the goal is timber production and not carbon sequestration.
Therefore, I would argue that negative emissions from regrowth of timber plantations should not be included in Carbon Removal.

Does anyone agree or disagree with this @IAMconsortium/common-definitions-land @IAMconsortium/common-definitions-emissions @jkikstra @MathijsHarmsenPBL @strefler

[kanishkan91]

Hello, Thanks for the question. I'm adding my two cents here - In my opinion, while the goal of timber plantations is indeed not carbon removal, under reforestation scenarios (carbon price scenarios for example0 we would get an increase in both plantations and reduction in harvests of older forests. Thus the same plantations would be sequestering carbon by design (this time by adjusting rotations and increasing plantations). Therefore the intent matters less and can change based on the forestry response to a scenario? Also, this gets a bit more complicated when thinking beyond the forestry sector. Recently, with the increase in CCUS applications (underground storage), there has also been an increase in enhanced oil recovery using CCUS in oil fields. So, even though the CCS is technically being used to recover some oil, in reality it still remains CCS. I think the same logic can be extended to the forestry sector? Thus,

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On Wed, Nov 27, 2024 at 11:01 AM Florian Humpenöder < ***@***.***> wrote: The following question came up in the ScenarioMIP land sub-group: Should Carbon Removal include negative emissions from regrowth of timber plantations? Timber plantations will be harvested after the end of the rotation period. Thus, all carbon sequestred during growth will be eventually released gain. The question is if this is in line with the definition of Carbon Removal here: https://github.com/IAMconsortium/common-definitions/blob/main/definitions/variable/emissions/carbon-removal.yaml#L23 Gross removals of carbon dioxide (CO2) from atmospheric origin or biomass through deliberate human activities https://github.com/IAMconsortium/common-definitions/blob/main/definitions/variable/emissions/tag_land-removal-options.yaml includes Forest Management: description: improved forest management Forestry is certainly a "deliberate human activitiy". But the goal is timber production and not carbon sequestration. Therefore, I would argue that negative emissions from regrowth of timber plantations should not be included in Carbon Removal. Does anyone agree or disagree with this @IAMconsortium/common-definitions-land <https://github.com/orgs/IAMconsortium/teams/common-definitions-land> @IAMconsortium/common-definitions-emissions <https://github.com/orgs/IAMconsortium/teams/common-definitions-emissions> @jkikstra <https://github.com/jkikstra> @MathijsHarmsenPBL <https://github.com/MathijsHarmsenPBL> @strefler <https://github.com/strefler> — Reply to this email directly, view it on GitHub <#222>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AI4CLJTHK2JFUNE7GJM6LPD2CXUEFAVCNFSM6AAAAABSTGC7TKVHI2DSMVQWIX3LMV43ASLTON2WKOZSGY4TSMBVGA2TSNY> . You are receiving this because you are on a team that was mentioned.Message ID: ***@***.***>

[kanishkan91]

Hello, Thanks for the question. I'm adding my two cents here - In my opinion, while the goal of timber plantations is indeed not carbon removal, under reforestation scenarios (carbon price scenarios for example0 we would get an increase in both plantations and reduction in harvests of older forests. Thus the same plantations would be sequestering carbon by design (this time by adjusting rotations and increasing plantations). Therefore the intent matters less and can change based on the forestry response to a scenario? Also, this gets a bit more complicated when thinking beyond the forestry sector. Recently, with the increase in CCUS applications (underground storage), there has also been an increase in enhanced oil recovery using CCUS in oil fields. So, even though the CCS is technically being used to recover some oil, in reality it still remains CCS. I think the same logic can be extended to the forestry sector? Thus, I think calling this carbon removal is fine. (Sorry about the duplicate email. Last one got cut off by mistake) On Wed, Nov 27, 2024 at 1:02 PM Kanishka Narayan ***@***.***> wrote:

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Hello, Thanks for the question. I'm adding my two cents here - In my opinion, while the goal of timber plantations is indeed not carbon removal, under reforestation scenarios (carbon price scenarios for example0 we would get an increase in both plantations and reduction in harvests of older forests. Thus the same plantations would be sequestering carbon by design (this time by adjusting rotations and increasing plantations). Therefore the intent matters less and can change based on the forestry response to a scenario? Also, this gets a bit more complicated when thinking beyond the forestry sector. Recently, with the increase in CCUS applications (underground storage), there has also been an increase in enhanced oil recovery using CCUS in oil fields. So, even though the CCS is technically being used to recover some oil, in reality it still remains CCS. I think the same logic can be extended to the forestry sector? Thus, On Wed, Nov 27, 2024 at 11:01 AM Florian Humpenöder < ***@***.***> wrote: > The following question came up in the ScenarioMIP land sub-group: > Should Carbon Removal include negative emissions from regrowth of timber > plantations? > Timber plantations will be harvested after the end of the rotation > period. Thus, all carbon sequestred during growth will be eventually > released gain. > > The question is if this is in line with the definition of Carbon Removal > here: > > https://github.com/IAMconsortium/common-definitions/blob/main/definitions/variable/emissions/carbon-removal.yaml#L23 > Gross removals of carbon dioxide (CO2) from atmospheric origin or biomass > through deliberate human activities > > https://github.com/IAMconsortium/common-definitions/blob/main/definitions/variable/emissions/tag_land-removal-options.yaml > includes Forest Management: description: improved forest management > > Forestry is certainly a "deliberate human activitiy". But the goal is > timber production and not carbon sequestration. > Therefore, I would argue that negative emissions from regrowth of timber > plantations should not be included in Carbon Removal. > > Does anyone agree or disagree with this > @IAMconsortium/common-definitions-land > <https://github.com/orgs/IAMconsortium/teams/common-definitions-land> > @IAMconsortium/common-definitions-emissions > <https://github.com/orgs/IAMconsortium/teams/common-definitions-emissions> > @jkikstra <https://github.com/jkikstra> @MathijsHarmsenPBL > <https://github.com/MathijsHarmsenPBL> @strefler > <https://github.com/strefler> > > — > Reply to this email directly, view it on GitHub > <#222>, or > unsubscribe > <https://github.com/notifications/unsubscribe-auth/AI4CLJTHK2JFUNE7GJM6LPD2CXUEFAVCNFSM6AAAAABSTGC7TKVHI2DSMVQWIX3LMV43ASLTON2WKOZSGY4TSMBVGA2TSNY> > . > You are receiving this because you are on a team that was mentioned.Message > ID: ***@***.***> >

[gidden]

Hi @flohump - my 2 cents:

The broader question you raise is how we deal with non-permanent/non-durable carbon removal. The case where release occurs in the same modelling time period is trivial (no removal, only release, or net zero emissions). The case where n+1 time periods elapse before rerelease is more complicated. I see two options:

1. Models keep track of these non-permanent processes internally and only report the final state (so in the case above, do not report the removal)
2. Models report removals in the time period they occur and emissions in the time period they occur such that the cumulative total nets to 0

In the @IAMconsortium/common-definitions-emissions group, we have two separate classes of variables: Carbon Removal and Carbon Capture. To date, we have only identified land-based variables in Carbon Removal and not Carbon Capture (the latter is more focused on engineering-based approaches).

So I see four possible implementations:

1. We add land-related variables to Carbon Capture where then models would report "Gross Removals" from plantations as Carbon Capture, re-emission during harvest as Carbon Capture|Leakage, and net removals as Carbon Removal
2. We add additional Carbon Removal negative variables corresponding to re-release (such that adding all Carbon Removal terms gets the total inter-temporal carbon removed from the atmosphere as represented in the model)
3. Models report "Gross Removals" under Carbon Removal and re-emissions under the respective AFOLU Emissions variables such that balances net out.
4. We only report net-removals

cc @jayfuhrman @strefler @tscheypidi

[flohump]

@gidden Thanks for your reply and your suggestions!
This discusssion is related to #224 @merfort

Carbon Capture does not make sense for negative emissions from regrowth of vegetation.
I think it makes sense to keep Carbon Removal as is, which is clearly defined as deliberate human activities.
But what's missing in the template is a place for reporting (non-permament) gross CO2 removals, such as regrowth of natural forest after harvest or regrowth of timber plantations.
This would allow to better understand net CO2 AFOLU emissions . With Carbon Removal alone this is not possible because it is only a subset of gross CO2 emissions (and definied positivly).