Parametric regional GHG cap (AR6 GWP) + trade self-sufficiency floor (+ NZB grid) - #4
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…e-in; soil-C carry-forward cap_apr26_reg (module 56 GHG-policy realization): - Continuous parametric regional cap: a config-driven, time-flexible cap trajectory (s56_emis_cap_parametric switch + start/target year and start/endpoint value scalars in input.gms; m_linear_time_interpol in preloop.gms). The cap is free before s56_emis_cap_start_year, ramps linearly from s56_emis_cap_start_value to s56_emis_cap_target by s56_emis_cap_target_year, and is held at the target for all later years (works for any horizon, incl. runs to 2100). No cs3 columns / capscen56 set entries needed. It is applied to the region(s) selected via policy_countries56 (config-driven region mask p56_cap_region, no hard-coded region — mirrors the existing country->region price-share machinery). With s56_emis_cap_parametric=0 (default) the cs3 path is used unchanged. - GWP basis switched AR5 -> AR6 (CH4 28->27, N2O 265->273) so the capped quantity uses the same GWP100 basis as the magpie4 GWP100AR6|Land reporting. 57_maccs/on_aug22: - Optional linear fade-in of the prescribed s57_maxmac steps (s57_maxmac_fadein/_start/_end). Gated: fadein=0 reproduces the flat baseline. 59_som (cellpool_jan23, static_jan19): - Carry the soil-C stock forward to the next timestep (as done for the above-ground pools), fixing soil-C telescoping under the cap (= PR magpiemodel#904). config/default.cfg: - Defaults for the new switches: the parametric cap (s56_emis_cap_parametric + start_year/start_value/target_year/target) and the MACC fade-in (s57_maxmac_fadein/_start/_end). scripts/start: NZB run setups using the parametric cap / no-cap reference runs (parametric +-200 extension, lever corners, baseline variants, reference runs). Parametric runs select the capped region via policy_countries56 (e.g. "BRA").
…into cap-parametric-ar6gwp
…t curve Young secondary forest on other land (youngsecdf) took its wood yield from the FRA-calibrated secdforest growing stock while its carbon followed the uncalibrated curve, letting the optimiser extract calibrated-level wood at near-zero booked carbon under any land-CO2 incentive. Add a dedicated im_growing_stock_ysf derived from the uncalibrated curve and feed it to the youngsecdf term of q35_prod_other, so wood yield and carbon are consistent. Addresses the PR magpiemodel#876 other-land wood-harvest known limitation.
Generalize the BRA-only forced wood/woodfuel self-sufficiency switch into a region-selectable lever: s21_force_wood_selfsuff (default off) + policy_countries21 country selector with a superregion mask (a superregion is forced only if all its countries are selected via supreg/i_to_iso), replacing the hard-coded sameas(h,"BRA") guard. Mirrors policy_countries56. Suppresses wood-harvest trade leakage when a region's land-use emissions are constrained. Also drop the unused ov56_emis_co2eq output block in cap_apr26_reg/postsolve.
One start script -> 49 SLURM jobs on the PIK HPC, all cap_apr26_reg / nocc /
AR6 GWP / forced BRA wood self-sufficiency, indexed on achieved reported
GWP100AR6|Land BRA AFOLU 2050:
Fam C conservation {WDPA, 30by30, HalfEarth} x cap ladder (cap alone)
Fam A BRA capped + RoW 2C price; global context {A/R + 2nd-gen bioenergy}
toggled on/off together
Fam B cap + BRA 1.5C price driving price-induced A/R + price-driven MACC
anchor NPI only
Tier-switchable (light/medium) via 2 lines; horizon via c_timesteps.
Family A ('BRA does not act alone') now applies the 2C context (price +
price-induced A/R + 2nd-gen bioenergy demand) to the REST OF WORLD only:
BRA stays capped/unpriced with BASELINE bioenergy demand (NPi2025; in NZB
BRA's bioenergy comes from MACRO). Implemented via scen_countries60=BRA so
the region split mirrors policy_countries56. Collapses to one gA_RoW2C
ladder ('context-off' == Family C HalfEarth). Adds NZB_FAMILIES env switch
to re-run a subset (e.g. NZB_FAMILIES=A) without touching C/B/anchor.
Replace the wood-only s21_force_wood_selfsuff pin with a general, region- and commodity-flexible minimum self-sufficiency FLOOR. - New equation q21_min_selfsuff: superregional production >= i21_min_selfsuff * demand -- a one-sided lower bound (raises self-sufficiency where it binds, does not cap the upper side; unlike the old two-sided i21_trade_bal_reduction pin). - i21_min_selfsuff = s21_forcesuff_value * f21_self_suff for the commodities in forcesuff21 and the regions in policy_countries21, from sm_fix_SSP2 onward. Anchored to the time-constant input f21_self_suff, so it freezes each commodity's 2025 export/import intensity -- no baseline run needed. - New switches: s21_force_selfsuff (on/off), forcesuff21 (subset of k_trade, empty by default), s21_forcesuff_value (fraction of the 2025 self-sufficiency held). - Removes s21_force_wood_selfsuff; wood/woodfuel self-sufficiency is now obtained by listing them in forcesuff21 (floor == pin for wood under a cap, since the binding side is always the lower bound). - nzb_hpc_grid.R updated to the new switch. Empty forcesuff21 / s21_force_selfsuff = 0 reproduces develop behaviour bit-for-bit. codeCheck-clean; compiles (gams main.gms action=c).
scripts/start/nzb_export_grid.R -- one start script for the 61-run NZB export grid
(each start_run -> one SLURM job). 7 families, indexed by achieved reported
GWP100AR6|Land BRA AFOLU 2050:
gC_wdpa / gC_30by30 / gC_half : conservation, cap alone + forced 1.5C MACC
gA_RoW2C : RoW at 2C, BRA capped/unpriced (WDPA), baseline BRA bioenergy
gB_price : cap + BRA 1.5C CO2 price (price-driven A/R + MACC), WDPA
gF_freeze: gC_wdpa + forcesuff21 = all BRA f21_self_suff>1 (export freeze)
g0_npi : NPI-only anchor
All: cap_apr26_reg, nocc, AR6 GWP, c56_cap_policy=all, s21_force_selfsuff=1 (BRA),
forest NPI, 5year2050. Reported ladder {-1000,-500,-250,-100,-50,0,50,100,250,500}
(cap target = reported + 50 nominal; dashboard re-indexes on achieved). BRA price
trimmed to its <= -63 window. NZB_FAMILIES env for subset re-runs.
…ciency Consolidate the NZB start scripts to one portable example (scripts/start/nzb_export_grid.R) and remove the exploratory ones; strip HPC/SLURM/site-specific wording from the keeper so it runs anywhere. Add cane/cassava/molasses to the common forcesuff21 self-sufficiency floor so no run shows spurious raw-sugar imports (a processing-hub artifact at f21~1.0).
flohump
marked this pull request as ready for review
July 3, 2026 14:47
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Summary
Adds the modelling machinery used for the Net-Zero Brazil (NZB) regional AFOLU-cap
analysis, on top of
emis_cap_reg. Everything sits behind new switches that default tocurrent behaviour, so
emis_cap_reg/develop runs are bit-preserved unless a switch isturned on (all new mechanisms gated at
sm_fix_SSP2).What's in it
Module 56 (
cap_apr26_reg) — parametric regional cap + AR6 GWPTime-flexible linear cap ramp (
s56_emis_cap_parametric=1): free beforestart_year,linear
start_value→targetbytarget_year, held after — viam_linear_time_interpolin
preloop.gms. Region-general: applied to the regions selected bypolicy_countries56(mask
p56_cap_region, no hard-coded region); supersedes the discrete cs3 ladder forcontinuous cap sweeps. AR6 GWP100 baked into
p56_gwp(CH₄=27, N₂O=273) so theconstrained quantity matches the
GWP100AR6|Landreporting basis.Module 21 (
selfsuff_reduced) — minimum self-sufficiency floorNew one-sided lower bound
q21_min_selfsuff:Σ vm_prod_reg ≥ i21_min_selfsuff · Σ vm_supply, anchored at the 2025f21_self_suffratio ("freeze at 2025", no baseline runneeded). Region mask
policy_countries21, commodity subsetforcesuff21, scaled bys21_forcesuff_value. Keeps a tight regional cap from cutting the region's exports (tradeleakage) and prevents spurious raw-feedstock imports.
Module 57 (MACC) — temporal fade-in
s57_maxmac_fadeinlinearly fades forced MAC-curve abatement betweens57_maxmac_fadein_start/_end(default 2025→2050) for a 1.5 °C-aligned path.Modules 14 / 35 / 59 — supporting fixes
youngsecdfharvestable growing stock taken from the uncalibrated secondary-forest curve(resolves a wood-yield/carbon inconsistency; also a candidate for upstream
develop);soil-C carry-forward in
postsolve.config + start script
config/default.cfgregisters all new switches, each defaulting to current behaviour(
s56_emis_cap_parametric=0,s21_force_selfsuff=0,forcesuff21="",s57_maxmac_fadein=0).scripts/start/nzb_export_grid.Ris one portable example thatlaunches the 61-run NZB comparison grid (7 policy families × a reported-AFOLU cap ladder)
and documents how the switches combine.
Testing
codeCheckclean;gams main.gms action=ccompiles.emis_cap_regbaseline reproduced.Status
Draft — opening for review of the mechanism/config surface before finalising.