JustMIP ES by RahelMA · Pull Request #2437 · remindmodel/remind

RahelMA · 2026-08-24T11:49:40Z

Purpose of this PR

Concept of standard permit trading:

Permit allocation is distributed via a certain rule e.g., POPint, CandC
The trading permits are connected to regional emissions as a quantity constraint here.
Quantity restricted permit trade scenarios run under cm_emiscen = 6 or 4

This PR introduces the 41_emicapregi realization JustMIP that allows for limited emission trading that relaxes the regional budget allocations in 45_carbonprice/functionalFormRegi.
With these central main differences compared to regular permit trading scenarios:

Initial permit allocation is generously distributed to all regions! Trade restriction is only linked to the trading volume as 1% of global GDP and trade volume in valued in regional carbon prices.

q41_globalPermitTradeCap(t,regi)$(t.val gt 2025) ..
    sum(regi2,
        (vm_Xport(t,regi2,"perm") + vm_Mport(t,regi2,"perm"))*(1/sm_c_2_co2)
        * (pm_taxCO2eq(t,regi2))
    )
    =l=
    0.01 * p41_gdpGlob(t);

Trading permits are NOT linked to emission quantities but relax the regional carbon budget in FunktionalFormRegi.
Emission trading is now also allowed under a policy run cm_emiscen = 9 if cm_permTradingJustMip = 1. Emission permit are consistently treated in GtCO2eq. This still requires adjustments in remind2 for the correct unit output.

Changes in the configs

File comparison: /p/projects/rd3mod/github/repos/remindmodel/remind/develop/config/scenario_config_JustMIP.csv -> config/scenario_config_JustMIP.csv
Columns deleted: -
Columns added:   c_budgetscen, c_edgeTransportIter, c_magpieIter, cm_33_maxFeShare, cm_budgetCO2from2020RegiShare, cm_CPslopeAdjustment, cm_nash_autoconverge, cm_peakBudgYrRegi, cm_permitTradeFinalYr, cm_permitTradeRatio, cm_permittradescen, cm_permTradingJustMip, cm_taxCO2_IncAfterPeakBudgYr, cm_taxCO2_lowerBound_nr, cm_taxCO2_lowerBound_path_gdx_ref, cm_taxCO2_Shape, cm_useInputGdxForCarbonPrice, emicapregi, jpn_goes_wild
Renamed columns: -
Renamed rows:    -

Changes in the rows:
+ SSP1_800f_es1 was added.
+ SSP1_800f_es1_noTrading was added.
~ SSP2_dls1:
    start: 0 -> 1
    path_gdx_ref: SSP2-NPi2025-CES -> SSP2-NPi2025
    path_gdx_refpolicycost: Reference_SSP2_800f -> NA
    description: was changed (default: REMIND run with default settings)
    path_gdx_carbonprice: NA -> Reference_SSP2_800f
+ SSP2_dls1_800 was added.
~ SSP1_dls1:
    start: 0 -> 1
    path_gdx_ref: SSP2-NPi2025-CES -> SSP2-NPi2025
    path_gdx_refpolicycost: Reference_SSP1_800f -> NA
    description: was changed (default: REMIND run with default settings)
    path_gdx_carbonprice: NA -> Reference_SSP1_800f
+ SSP1_dls1_800 was added.
- SSP2-NPi2025-CES was deleted.

$allwarnings
NULL

File comparison: /p/projects/rd3mod/github/repos/remindmodel/remind/develop/config/scenario_config_magpie_JustMIP.csv -> config/scenario_config_magpie_JustMIP.csv
Columns deleted: -
Columns added:   path_mif_ghgprice_land
Renamed columns: -
Renamed rows:    -

Changes in the rows:
~ SSP2-NPi2025:
    start: 1 -> 0
~ SSP1-NPi2025:
    start: 1 -> 0
~ Reference_SSP1_800f:
    start: 1 -> 0
~ Reference_SSP2_800f:
    start: 1 -> 0
+ SSP1_800f_es1_noTrading was added.
+ SSP1_800f_es1_Trading_refRef was added.
+ SSP2_dls1_800 was added.
+ SSP1_dls1_800 was added.
- SSP2-NPi2025-CES was deleted.

$allwarnings
NULL

Scenarios including and excluding trade:
/p/projects/elevate/WP5.4/Tests_Rahel/CO2eqWP/compScen-Submission_V1_ES-2026-08-02_06.19.43-REMIND-MAgPIE.pdf

Trade

Strong trade price increase seems to motivate regions to change trading strategies

</style>

		pm_pvp perm	pm_pvp good	price in $/tCO2
2030	perm	0.00042	0.00464	90.25291
2035	perm	0.00043	0.00365	117.6696
2040	perm	0.00043	0.00279	153.3952
2045	perm	0.00043	0.00209	203.9378
2050	perm	0.00042	0.00156	271.848
2055	perm	0.00042	0.00119	355.5936
2060	perm	0.00043	0.00079	540.2535
2070	perm	0.00043	0.00058	738.1596
2080	perm	0.00043	0.00034	1246.955
2090	perm	0.00043	0.00022	1950.41
2100	perm	0.00043	0.00015	2867.72

Type of change

Indicate the items relevant for your PR by replacing ◻️ with ☑️.
Do not delete any lines. This makes it easier to understand which areas are affected by your changes and which are not.

Parts concerned

☑️ GAMS Code
◻️ R-scripts
◻️ Documentation (GAMS incode documentation, comments, tutorials)
◻️ Input data / CES parameters
◻️ Tests, CI/CD (continuous integration/deployment)
☑️ Configuration (switches in main.gms, default.cfg, and scenario_config*.csv files)
◻️ Other (please give a description)

Impact

◻️ Bug fix
◻️ Refactoring
◻️ New feature
◻️ Change of parameter values or input data (including CES parameters)
☑️ Minor change (default scenarios show only small differences)
◻️ Fundamental change of results of default scenarios

Checklist

Do not delete any line. Leave unfinished elements unchecked so others know how far along you are.
In the end all checkboxes must be ticked before you can merge.

I executed the automated model tests (make test) after my final commit and all tests pass (FAIL 0)
I adjusted the reporting in remind2 if and where it was needed
I adjusted the madrat packages (mrremind and other packages involved) for input data generation if and where it was needed
My code follows the coding etiquette
I explained my changes within the PR, particularly in hard-to-understand areas
I checked that the in-code documentation is up-to-date
I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
I updated the CHANGELOG.md correctly (added, changed, fixed, removed, input data/calibration)

Further information (optional)

Runs with these changes are here:
Comparison of results (what changes by this PR?):

…to JustmipDefault

VerenaHof · 2026-08-28T13:19:34Z

 if (c_ccsinjecratescen eq 6, s_ccsinjecrate = s_ccsinjecrate *   0.44 ); !! Intermediate estimate
 pm_ccsinjecrate(regi) = s_ccsinjecrate;

+if (jpn_goes_wild = 1, 


Delete jpn_goes_wild, instead adjust in config file c_ccsinjecrateRegi for JPN

Thank you, I switched to c_ccsinjecrateRegi!

VerenaHof · 2026-08-28T13:26:32Z

      - sum(se2fe(enty,enty2,te),     !! subtract bunker emissions if cm_bunkerscen is eq 3 or 6
        pm_emifac(ttot2,regi,enty,enty2,te,"co2")
-        * vm_demFeSector.l(ttot2,regi,enty,enty2,"trans","other"))$(c_budgetscen eq 3 OR c_budgetscen eq 6))
+        * vm_demFeSector.l(ttot2,regi,enty,enty2,"trans","other"))$(c_budgetscen eq 3 OR c_budgetscen eq 6))!! subtract net trade of permits if cm_emiscen is eq 6 or 4


If this applies to cm_emiscen eq 4, please adjust it in the line above, where eq 3 is still written

VerenaHof · 2026-08-28T13:31:17Z

+      - sum(se2fe(enty,enty2,te),     !! subtract bunker emissions if cm_bunkerscen is eq 3 or 6
+        pm_emifac(ttot2,regi,enty,enty2,te,"co2")
+        * vm_demFeSector.l(ttot2,regi,enty,enty2,"trans","other"))$(c_budgetscen eq 3 OR c_budgetscen eq 6)
+      + (vm_Xport.l(ttot2,regi,"perm") - vm_Mport.l(ttot2,regi,"perm"))*(1/sm_c_2_co2))!! subtract net trade of permits (units from CO2 to C)


Adjust vm_Xport and vm_Mport to GtC instead of conversion

Changed perm trading to GtC

VerenaHof · 2026-08-28T13:39:36Z

    p33_EW_maxShareOfCropland(regi)$(regi_groupExt(ext_regi, regi)) = f33_EW_maxShareOfCropland(ext_regi);
  );

+if (jpn_goes_wild = 1, 


See comment above regarding jpn_goes_wild, should be adjusted via config cm_33_EW_maxShareOfCropland JPN 0.5

VerenaHof · 2026-08-28T13:40:29Z

+*** In later iterations, recalculate allocation from market emissions
+
+!! Set bounds for permit allocation
+vm_perm.lo(t,regi) = -10;


Please explain logic and values for this and following line

VerenaHof · 2026-08-28T13:41:47Z

+pm_emicapglob(t) = 100;
+pm_shPerm(t,regi) = 1;
+vm_perm.fx(t,regi) = 0;


Please add further explanation for values

tabeado · 2026-08-28T14:09:00Z

+*' * (0): no numeric lower bound for the carbon price
+*' * (any number > 0): numeric lower bound for the carbon price in $ per t CO2eq
+
+parameter


remove switch also here please :)

tabeado · 2026-08-28T14:11:06Z

    );
 );

+*RM* Permit price growth reflects the carbon price trajectory


interesting that you made this choice! let's talk about whether it is necessary and/or wanted? Also in combination with the othre changes you make to the intertemporal budget equation of regions?

tabeado · 2026-08-28T14:12:31Z


 *AJS* starting policy runs from permit prices that are all zero doesnot work. start from 49$ price path instead
-if((cm_emiscen ne 1) and (cm_emiscen ne 9) and (smax(t,pm_pvp(t,"perm"))) eq 0,
+if((cm_emiscen ne 1 or (cm_emiscen ne 9 and cm_permTradingJustMip eq 0)) and (smax(t,pm_pvp(t,"perm"))) eq 0,


this now means that it is active when cm_emiscen = 9 and cm_permTradingJustMIP = 1
Just checking that this is what you want?

Yes! it should be off with cm_emiscen = 9 and cm_permTradingJustMIP = 0 as in the initial setting...

tabeado · 2026-08-28T14:14:57Z

  !! "Very low" is for now <1 USD/t CO2 in 2100, tbd
  else
    if ((abs(p80_regionalBudget_absDev_iter(iteration,regi)) gt abs(cm_budgetCO2_absDevTol)) 
         AND (pm_taxCO2eq("2100",regi) gt (1 * sm_DptCO2_2_TDpGtC)), 


the problem may also be the combination with the lower bound on carbon prices? I will have a look

If we keep the cm_taxCO2_lowerBound_nr switch, we will have to adjust the code here independent of JustMIP

This was my code with cm_taxCO2_lowerBound_nr existing - might help for testing now

!! If the deviation is negative, i.e. budget is too low and would require a decrease of the Carbon Price => only "not converged" if the carbon price is not already very low, !! "Very low" is for now <1 USD/t CO2 in 2100, tbd else if (cm_taxCO2_lowerBound_nr eq 0, if ((abs(p80_regionalBudget_absDev_iter(iteration,regi)) gt pm_regionalBudget_absDevTol(regi)) AND (pm_taxCO2eq("2100",regi) gt (1 * sm_DptCO2_2_TDpGtC)), s80_bool = 0; p80_messageShow("regiBudget") = YES; ); else !! if there is a lower bound that is equal to cm_taxCO2_lowerBound_nr, then this should be the defining lower carbon price bound if ((abs(p80_regionalBudget_absDev_iter(iteration,regi)) gt pm_regionalBudget_absDevTol(regi)) AND (pm_taxCO2eq("2100",regi) gt (1.01 * cm_taxCO2_lowerBound_nr * sm_DptCO2_2_TDpGtC)), s80_bool = 0; p80_messageShow("regiBudget") = YES; ); ); !! if there is a lower carbon price bound set through cm_taxCO2_lowerBound_nr

tabeado · 2026-09-01T13:31:59Z

 *'
+
+parameter
+  cm_taxCO2_lowerBound_nr "switch to set a numeric lower bound for the carbon price"


this switch is in the main.gms but no longer in the code in functionalFormRegi/postsolve

tabeado · 2026-09-02T09:12:30Z

  pm_taxCO2eq(t,regi) = max(pm_taxCO2eq(t,regi), p45_taxCO2eq_path_gdx_ref(t,regi));
  display pm_taxCO2eq;
 );



add here:

if(cm_taxCO2_lowerBound_nr ne 0, loop(regi, loop(t, pm_taxCO2eq(t,regi) = max(pm_taxCO2eq(t,regi), cm_taxCO2_lowerBound_nr * sm_DptCO2_2_TDpGtC); display pm_taxCO2eq; ); ); );

tabeado · 2026-09-02T09:15:19Z

replace with:

!! Set the peakBudgYr value plus predefined increase thereafter (the only currently tested version is post-increase slope = 0) (necessary because initial shape & thus all following are taken from the anchor trajectory) !! if the rescaled carbon price in the peak year is lower than 1.5 times the carbon price in the start year, then have a no increase after the peak budget year. if(sum(ttot$(ttot.val eq p45_peakBudgYr_regi(regi)), p45_taxCO2eq_anchorRegi(ttot,regi)) le (1.5 * sum(ttot2$(ttot2.val eq s45_YearBeforeStartYear), p45_taxCO2eq_anchorRegi(ttot2,regi))), p45_taxCO2eq_anchorRegi(ttot3,regi)$(ttot3.val gt p45_peakBudgYr_regi(regi)) = sum(ttot4$(ttot4.val eq p45_peakBudgYr_regi(regi)), p45_taxCO2eq_anchorRegi(ttot4,regi)); !! CO2 tax in peak budget year else p45_taxCO2eq_anchorRegi(ttot,regi)$(ttot.val gt p45_peakBudgYr_regi(regi)) = sum(ttot2$(ttot2.val eq p45_peakBudgYr_regi(regi)), p45_taxCO2eq_anchorRegi(ttot2,regi)) !! CO2 tax in peak budget year + (ttot.val - p45_peakBudgYr_regi(regi)) * cm_taxCO2_IncAfterPeakBudgYr * sm_DptCO2_2_TDpGtC); !! increase by cm_taxCO2inc_after_peakBudgYr per year !! B4.4a: Calculate the slope for a linear connection between the last carbon price from input data and the price in the Peak Bud

…to JustmipDefault

rahelMA and others added 13 commits July 15, 2026 11:43

dafault JUSTMIP changes

0772996

Merge branch 'remindmodel:develop' into JustmipDefault

2ffa576

incl Tabeas changes

f3da494

bugfix

cad2637

configs

dbf4739

limited trade with market clearing

ec0b4a3

JUSTMIP ES realization

8383967

Merge branch 'remindmodel:develop' into JustmipDefault

2563c59

add description

54a6e48

Merge branch 'JustmipDefault' of https://github.com/RahelMA/remind in…

b471543

…to JustmipDefault

switch for JUSTMip trading

9a63520

documentation

1c7d06a

cleaning configs plus DLS

890c761

RahelMA requested review from LaviniaBaumstark, VerenaHof and tabeado August 25, 2026 08:01

Merge branch 'develop' into JustmipDefault

09cb659

VerenaHof reviewed Aug 28, 2026

View reviewed changes

tabeado reviewed Aug 28, 2026

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Merge branch 'remindmodel:develop' into JustmipDefault

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tabeado reviewed Sep 1, 2026

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tabeado reviewed Sep 2, 2026

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Merge branch 'remindmodel:develop' into JustmipDefault

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tabeado reviewed Sep 2, 2026

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rahelMA and others added 3 commits September 2, 2026 15:31

unit change

ce788a3

functionalFormRegi postsolve adjustments

96a3834

Merge branch 'JustmipDefault' of https://github.com/RahelMA/remind in…

95996f2

…to JustmipDefault

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tabeado Sep 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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RahelMA commented Aug 24, 2026 •

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