Parameter Registry

Every numerical parameter with value, uncertainty range, distribution, source, and expert-judgment flag.

4 flagged parameter(s) require enhanced monitoring P-DAM-001: Damage coefficient estimates vary 10× across literature; expert judgment required for selection P-ECO-002: Discount rate is an ethical/intergenerational equity parameter, not empirically identified. Nordhaus (1.5%) vs Stern (0.1%) drives SCC difference of ~10×. P-UNC-002: De-duplication factor is poorly constrained empirically; expert judgment with high uncertainty P-FIN-001: Climate risk premium methodology varies widely; no consensus market-derived estimate exists
JSON
ID Name Value Range Distribution Source type Models Rank Flag
P-CLM-001 Transient Climate Response (TCR)
Global mean surface temperature rise per doubling of atmospheric CO₂ under trans… 		1.8 °C per CO₂ doubling 1.0–2.5
CI66%: 1.2–2.4 		normal empirical ClimateModelService
MonteCarloEngine		 1
P-CLM-002 Remaining 1.5°C carbon budget (2020 reference, 67% probability)
Total CO₂ emissions permissible from 2020 while staying within 1.5°C with 67% li… 		400.0 GtCO₂ 200.0–650.0
CI66%: 300.0–550.0 		normal empirical ClimateModelService 2
P-CLM-003 Global baseline emissions (2025)
Current annual global GHG emissions under reference/current-policies scenario. 		57.4 GtCO₂e/yr 54.0–61.0
CI90%: 55.0–59.5 		normal empirical ClimateModelService
GapAccountingEngine
MonteCarloEngine		 2
P-DAM-001 DICE-2023 damage coefficient (α)
Quadratic damage coefficient in Nordhaus DICE-2023 model. Controls rate of GDP l… 		0.00267 dimensionless (fract 0.001–0.01
CI66%: 0.0018–0.006 		lognormal calibrated DamageModelService 1
P-DAM-002 Model-to-model AAL uncertainty band
Coefficient of variation in annualised average loss across major catastrophe mod… 		0.4 CV (dimensionless) 0.25–0.65
CI80%: 0.3–0.55 		uniform empirical CatastropheModel
DamageModelService		 3
P-ECO-001 Cobb-Douglas capital income share (α)
Capital's share of national income in the standard Cobb-Douglas production funct… 		0.35 dimensionless 0.25–0.45
CI90%: 0.3–0.4 		normal empirical EconomicModelService
DSGEModel		 4
P-ECO-002 Pure rate of time preference (ρ) — Nordhaus
Discount rate applied to future utility in the Nordhaus DICE social welfare func… 		0.015 fraction per year 0.001–0.04
CI%: 0.001–0.03 		expert_elicited expert EconomicModelService 1
P-ECO-003 Global clean energy investment gap (2025–2035, cumulative)
Additional annual clean energy investment required above current policy scenario… 		4.2 $tn/yr 2.5–6.5
CI80%: 3.0–5.8 		triangular literature FinancialStressService
FiscalModelService		 2
P-UNC-001 Monte Carlo sample size (N)
Number of parameter draws used in CE Monte Carlo simulation. 		2000 samples 500–10000 deterministic calibrated MonteCarloEngine 6
P-UNC-002 Abatement portfolio de-duplication factor (δ)
Fraction of gross portfolio abatement discarded to account for double-counting a… 		0.22 fraction 0.1–0.35
CI80%: 0.15–0.3 		triangular expert GapAccountingEngine 3
P-UNC-003 Technology abatement potential (2050, gross)
Sum of abatement potential across all breakthrough and mature technologies in th… 		29.0 GtCO₂e/yr 18.0–45.0
CI90%: 21.0–39.0 		normal literature GapAccountingEngine
MonteCarloEngine		 1
P-FIN-001 Climate risk premium on WACC — high physical risk scenario
Additional basis points added to WACC for high physical climate risk exposure se… 		150 basis points 0–300
CI80%: 50–250 		triangular expert FinancialStressService 3
P-ADP-001 Early warning system BCR
Benefit-cost ratio of multi-hazard early warning system investment vs. loss redu… 		8.4 dimensionless ($ ben 4.0–16.0
CI80%: 6.0–12.0 		lognormal empirical AdaptationService 4
P-ADP-002 Coastal flood defense cost (sea wall, per km)
Unit cost of coastal flood defence infrastructure (engineered sea walls and surg… 		10.0 $mn per km 3.0–50.0
CI80%: 5.0–25.0 		lognormal empirical AdaptationService 5