Add scripts to modify "Low" and "Very Low" ScenarioMIP/SSP scenarios

[measrainsey]

This PR adds my scripts that I developed during the ScenarioMIP submission, to modify the "Low" and "Very Low" scenarios.

This PR is associated with the following:

• The branch ssp-dev
• The PR: Collect pieces for SSP 2024/ScenarioMIP #235
• The issue: Collect pieces for SSP 2024/ScenarioMIP workflows #234

The changes made to the "Low" (SSP1 & SSP2) scenarios were:

• Removed growth_activity_lo and initial_activity_lo for bof_steel
• Changed growth_activity_up for dri_gas_steel, dri_h2_steel, eaf_steel from 0.02 to 0.075
• Changed initial_activity_up for dri_gas_steel and dri_h2_steel from 0.1 to 1
• Added balance equalities

The changes made to the "Very Low" (SSP1 & LED) scenarios were:

• The same changes made to the "Low" scenarios above
• Disallow the revival of loil_rc and biomass_rc in residential & commercial sector by changing the bound_activity_up
• Set the UE share of gas in transportation to 0.05 and the UE share of electricity in transportation to 0.9 (starting in 2035)
• Replace the tax_emission from 2080 onwards

I've uploaded the UE shares Excel files I use to message_ix_models/data/ue-shares, but please let me know if that would be a problem.

How to review

TBD

PR checklist

TBD

[khaeru]

Hi @measrainsey — @glatterf42 and I were just discussing the various SSP-related branches, issues, and PRs.

What I'd suggest here:

• Let's merge this branch into ssp-dev, as-is.
• Then, ssp-dev can serve its purpose as being the "single point of reference" for @OFR-IIASA and others, containing all SSP-related code in message-ix-models.
• That does not mean that this code will next get merged to main as-is. Per the description of Transport improvements for 2024-W36 #225, we can later choose how/whether to clean up, rearrange, etc. the code.
• It also does not preclude you making a further branch from ssp-dev, or commits directly to ssp-dev, to improve the scripts for the "Low" and "Very Low" scenarios, as we probably will need to do while preparing the next round of submissions.

We can imagine that perhaps @ywpratama @yiyi1991 and @macflo8 have similar code or scripts. It would be better to collect these on the same, single branch, rather than have them sit separately on multiple branches; in the latter case we won't achieve our goal of having that single point of reference.

[measrainsey]

hi @khaeru and @glatterf42 -- that works for me, thanks! would you like to go ahead and do the merging, or should i? (or should i open up this PR for review and we go through the process of review, approve, merge)?

[khaeru]

Please just go ahead! The usual process only applies for PRs into main. For other target branches, as long as "All checks have passed" you can merge.

[yiyi1991]

Reclarrify here that my examinations on the M scenario (multiple alternative NPi_forever pathways) were not making more sense than the original version so no specific updates from my side (and sorry for not being able to reply earlier).