ScenarioMIP experiment names

[matthew-mizielinski]

ScenarioMIP are currently working with the following nomenclature for their experiments:

High (H)
Medium (M)
Medium-Low (ML)
Low (L)
Very Low (VL)
Low Overshoot (LOS)

Concentration driven variant for models that also ran the emission driven variant
High, Concentration driven (HC)
Medium, Concentration driven (MC)
Low, Concentration driven (LC)

Extensions branching from the scenario indicated by the first letter(s)

H-ext
H-ext-OS
M-ext
ML-ext
L-ext
VL-ext
LOS-ext

How should this best be translated to the form needed for the CVs

[matthew-mizielinski]

A simple extrapolation from CMIP6 names would give

Emissions driven

• esm-ssp-high
• esm-ssp-med
• esm-ssp-low
• esm-ssp-vlow
• esm-ssp-low-os

Concentration driven;

• ssp-high
• ssp-med
• ssp-low

Extensions

• esm-ssp-high-ext
• esm-ssp-high-os-ext
• esm-ssp-med-ext
• esm-ssp-low-ext
• esm-ssp-vlow-ext
• esm-ssp-low-os-ext

Note the addition of the overshoot to the high scenario within the extensions list.

Questions that come to mind;

1. I've assumed that "ssp" is still relevant here; it stood for shared socioeconomic pathway. Is this still the right nomenclature? (noting that in CMIP5 to CMIP6 we changed from rcp to ssp)
2. Can/should we swap the high, med, low, vlow terms for something more quantitative? Note that ssp585 represented SSP5 (fossil fueled development) with an 8.5 W m-2 forcing pathway.
3. Do we need to separate the extensions from the core experiments or can these be combined? In CMIP6 we had options on the end date for an experiment. Removing these extensions would likely require the definition of a high overshoot experiment separately.

@taylor13, let me know your thoughts on the above. I think an initial answer might be useful

@CMIP-IPO, If there is any other information that can be shared on the nature of the different scenarios that might help with naming let me know.

[matthew-mizielinski]

Found https://wcrp-cmip.org/wp-content/uploads/2024/04/24-04-15_ScenarioMIP-CMIP7-proposal_final.pdf via the experiment airtable

[eleanororourke]

ScenarioMIP are currently finalising their protocol and should be able to get the version they circulate to their SSC to provide the up to date information.

[johndunne13]

My understanding is that the "SSP" terminology will NOT be taken forward in CMIP7 due to severe pushback from some nations in AR6

[matthew-mizielinski]

My understanding is that the "SSP" terminology will NOT be taken forward in CMIP7 due to severe pushback from some nations in AR6

Is there a replacement term/acronym from their discussions that we could use in its place?

[eleanororourke]

@claudiatebaldi could you review Matt's suggestions and questions above?

[taylor13]

In the past, we could easily distinguish between the CMIP3, CMIP5, and CMIP6 "scenario runs" because they were named differently. I'm worried that generic "high" "med", and "low" would likely be used in the future for different scenarios, which might not be that comparable to the previous phase.

[johndunne13]

Agreed, just not sure what ScenarioMIP will advise as of yet.

[johndunne13]

I have not heard anything, but it would probably be good for the ipo to reach out to scenarioMIP to let them know that this needs to be on their radar.On Sep 24, 2024, at 12:28 PM, Matthew Mizielinski ***@***.***> wrote: My understanding is that the "SSP" terminology will NOT be taken forward in CMIP7 due to severe pushback from some nations in AR6 Is there a replacement term/acronym from their discussions that we could use in its place? —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you commented.Message ID: ***@***.***>

[taylor13]

How about simply "scenario-high", etc. And to address my concern above, simply include a 7 (for CMIP7) somewhere: "scenario7-high" or "scenario-high7" or "scenario-high-7". We would like not to confuse "7" as identifying the scenario but associated with a CMIP phase. For that reason, I might choose the last option: "scenario-high-7".

[matthew-mizielinski]

I'm happy with ssp -> scenario and if we think we need my preference from these is to use scenario7 (otherwise this might be interpreted as "high scenario number 7")

Including the number and omitting the explicit extensions (assuming that they are dealt with as options for end year) this would give

Emissions driven

• esm-scenario7-high
• esm-scenario7-med
• esm-scenario7-low
• esm-scenario7-vlow
• esm-scenario7-low-os

Concentration driven;

• scenario7-high
• scenario7-med
• scenario7-low

Extensions

• esm-scenario7-high-os

[taylor13]

I'm fine with the 7 attached to scenario: "scenario7". We can think of it as a shorthand for "scenarioMIP7" (although to my knowledge scenarioMIP hasn't ever numbered its phases).

[claudiatebaldi]

Hi. First my apologies but I have never received any notification that this discussion was going on. I need to first say that we are in the process of revising the paper and one of the issues is the naming of the low scenarios, which may change slightly. We need to send the whole thing to the SSC in the next few days and we will make a final decision shortly thereafter. I will forward the proposal to add that "scenario7" to the labeling. John is right that we want to stay away from having ssp anywhere near these scenarios' labeling. And as for the question about having a more quantitative labeling, given the switch to emission driven is anybody's guess what the outcomes will be, so we opted for this qualitative nomenclature. Will be back asap with a reaction about that "scenario7". THanks for your patience and thanks Eleanor for alerting me to this.

[claudiatebaldi]

SSC = Scientific Steering Committee of ScenarioMIP

[claudiatebaldi]

Also, a couple of details: The Medium-Low (ML) scenario is missing from your list
ScenarioMIP will provide concentration input for all six scenarios (the three specified will have high and medium priority for ESMs that ran the emission-driven versions, as a means to compare outcomes vis-a-vis the role of an active carbon cycle in the whole uncertainty range that will come out of this) so the version without "esm" would apply to all six scenarios.

[claudiatebaldi]

A few more consideration/suggestion from Detlef van Vuuren:

Completely up to the climate guys, but as esm is to some degree the default, one could have expected esm (earth system model?) to have the default short name, and the concentration-driven scenarios being given the longer names. As also esms can run concentration driven… would the naming not be nicer to just add “cd” (concentration-driven) and “ed” (emission-driven) in front of all scenarios.
Maybe it is me – but why “scenario7” and not “scen7” (just saves a lot of unnecessary typing).

[taylor13]

Hi Claudia and all,

I think "scen7" would be fine if that's what's preferred. Anyone else have an opinion?

For consistency across CMIP, the approximately two dozen simulations that were emission-driven in CMIP6 were all prefixed with "esm-" (for example, "esm-piControl" and "esm-ssp585"). For the sake of users who have gotten used to this convention, I think we should continue it.

thanks for thinking about this and providing your input and feedback,
Karl

[johndunne13]

The Strategic Ensemble Design Task Team and CMIP Panel both discussed the somewhat confusing "esm" designation for CO2 emissions forcing (particularly as ESMs become more comprehensive may run with emissions of additional forcings such as methane), but in the end decided to retain this designation in the current phase to avoid further confusion and defer the renaming until a clear need arose..

…

On Mon, Sep 30, 2024 at 11:14 AM taylor13 ***@***.***> wrote: Hi Claudia and all, I think "scen7" would be fine if that's what's preferred. Anyone else have an opinion? For consistency across CMIP, the approximately two dozen simulations that were emission-driven in CMIP6 were all prefixed with "esm-" (for example, "esm-piControl" and "esm-ssp585"). For the sake of users who have gotten used to this convention, I think we should continue it. thanks for thinking about this and providing your input and feedback, Karl — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGUJAMSL4P5C6H747N5DS6TZZFTELAVCNFSM6AAAAABOCXLGDCVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTANZZHE2TKNI> . You are receiving this because you commented.Message ID: ***@***.***>