{ "model_id": "ce-solution-scale", "version": "3.7.0", "generated": "2026-06-30", "epistemic_status": "Illustrative / scenario accounting \u2014 not a predictive IAM", "comparable_to": [ "UNEP Emissions Gap Report", "IEA NZE scenario accounting", "NGFS Phase 5 scenarios (2024)" ], "not_comparable_to": [ "DICE", "PAGE", "MESSAGE-GLOBIOM", "GCAM" ], "assumptions": [ { "id": "BASELINE_EMISSIONS", "label": "2025 baseline GHG emissions", "value": 57.0, "unit": "GtCO2e/yr", "source": "UNEP Emissions Gap Report 2024", "source_year": 2024, "observed_year": 2023, "uncertainty": "\u00b12\u20133 GtCO2e/yr (5th\u201395th pct)", "last_reviewed": "2025-01", "notes": "2023 observed; used as 2025 anchor with flat projection assumption." }, { "id": "BUDGET_1P5", "label": "Remaining 1.5\u00b0C carbon budget", "value": 250.0, "unit": "GtCO2", "probability_threshold": "67%", "source": "IPCC AR6 WG1 Table SPM.2", "cross_reference": "Global Carbon Project 2024 (~235 GtCO2 at 50% probability from Jan 2025)", "source_year": 2021, "reference_date": "2020 (AR6 base); adjusted to 2025 via GCB 2024 drawdown accounting", "uncertainty": "\u00b1220 GtCO2 (likely range per AR6)", "last_reviewed": "2026-05", "notes": "CE uses 67% probability threshold; GCB 2024 figure uses 50% threshold \u2014 different thresholds, both consistent with AR6 range." }, { "id": "BUDGET_2C", "label": "Remaining 2\u00b0C carbon budget", "value": 1150.0, "unit": "GtCO2", "probability_threshold": "67%", "source": "IPCC AR6 WG1 Table SPM.2", "source_year": 2021, "uncertainty": "\u00b1300 GtCO2 (likely range per AR6)", "last_reviewed": "2026-05" }, { "id": "COMMITTED_INFRA", "label": "Committed emissions from existing infrastructure", "value": 680.0, "unit": "GtCO2", "source_primary": "Tong et al. 2019 (Nature 572, 373\u2013377)", "source_primary_estimate": "658 GtCO2 from 2018 asset base", "source_cross_ref": [ "IEA World Energy Outlook 2022", "Carbon Brief committed emissions analysis 2022", "Global Registry of Fossil Fuels 2022" ], "scope": "Operating infrastructure only; excludes planned/permitted assets", "uncertainty": "\u00b150\u2013100 GtCO2 depending on asset-life assumptions", "last_reviewed": "2026-05", "notes": "CE ~680 Gt reflects ~2025 asset base; consistent with Tong (2019) range after accounting for new capacity added 2018\u20132025." }, { "id": "DEDUP_FACTOR", "label": "Technology cross-overlap de-duplication factor (\u03b4)", "value": 0.22, "unit": "fraction", "interpretation": "22% cross-technology abatement overlap assumed (raised from 15% in v3.4.0 to account for livestock/land-use/food-system bilateral overlaps)", "source": "IPCC AR6 WG3 sector decomposition; Luderer et al. 2018; Rogelj et al. 2015; CE v3.4.0 recalibration", "uncertainty": "\u00b15 ppt (sensitivity range 12\u201332%)", "last_reviewed": "2026-05", "notes": "Raised from 0.15 to 0.22 in v3.4.0. Applied as (1-\u03b4) multiplier to stacked portfolio total before comparing against gap." }, { "id": "CCS_INJECTION_CEILING", "label": "Practical annual CO2 geological injection ceiling by 2050", "value": 9.0, "unit": "GtCO2/yr", "ipcc_scenario_range": "4\u201315 GtCO2/yr (IPCC AR6 WG3 Chapter 12 C1 pathway spread)", "source": "IPCC AR6 WG3 Chapter 12", "source_year": 2022, "important_note": "Physical total geological storage volume is vast (8,000\u201355,000 GtCO2; not a constraint). The binding limit is annual injection infrastructure, verified site development, and monitoring capacity.", "last_reviewed": "2026-05" }, { "id": "BECCS_BIOMASS_FLOOR", "label": "BECCS sustainable biomass \u2014 conservative no-regrets floor", "value": 4.5, "unit": "EJ/yr", "interpretation": "Zero food/land-conflict estimate only", "ipcc_full_range": "50\u2013250 EJ/yr total sustainable bioenergy (IPCC AR6 WG3 Ch.7; wide, heavily sustainability-constrained)", "source": "IPCC AR6 WG3 Chapter 7", "source_year": 2022, "last_reviewed": "2026-05", "notes": "CE uses floor figure to flag constraint risk; actual BECCS deployment assumes 5 Gt/yr (base) which requires ~30\u201335 EJ/yr biomass \u2014 flagged as an aspirational ceiling, not a no-regrets estimate." }, { "id": "SECTOR_WEIGHTS", "label": "Sector abatement share weights", "value": { "energy": 0.38, "industry": 0.24, "transport": 0.16, "buildings": 0.09, "agriculture": 0.08, "land_use": 0.05 }, "unit": "fraction", "source": "IPCC AR6 WG3 Chapter 6", "source_year": 2022, "uncertainty": "\u00b15 ppt per sector", "last_reviewed": "2026-05", "notes": "'energy' = electricity generation + heat production (not disaggregated further). CDR is embedded within sector totals per IPCC AR6 WG3 C1\u2013C3 pathway accounting, not reported as a stand-alone sector here. 'agriculture' = non-LULUCF agriculture; 'land_use' = LULUCF (forestry, soil carbon). These six weights sum to 1.0 and are the constants used in the model's sector decomposition: G_t^j = w_j \u00d7 G_t." }, { "id": "MC_CORR_ELEC", "label": "Monte Carlo technology co-variance \u2014 electricity group (\u03c1_elec)", "value": 0.21, "unit": "correlation coefficient", "group": [ "solar_pv", "onshore_wind", "offshore_wind", "perovskite", "enhanced_geothermal" ], "source": "CE calibration; IPCC AR6 scenario spread for electricity technologies", "last_reviewed": "2026-05" }, { "id": "MC_CORR_CDR", "label": "Monte Carlo technology co-variance \u2014 CDR group (\u03c1_CDR)", "value": 0.25, "unit": "correlation coefficient", "group": [ "dac", "beccs", "enhanced_weathering", "ocean_iron_fertilisation" ], "source": "CE calibration; IPCC AR6 CDR scenario spread", "last_reviewed": "2026-05" } ], "scenario_probabilities": { "optimistic": 0.25, "base": 0.5, "pessimistic": 0.25, "framing": "User-adjustable decision weights per NGFS Phase 5 (2024) guidance; not calibrated probability estimates", "source": "NGFS Phase 5 scenario framework 2024" }, "reproducibility": { "computation": "Client-side JavaScript; all parameters visible in page source", "methodology_endpoint": "/models/ce-solution-scale/methodology.txt", "csv_export": "Available via Download CSV button on model page", "version_history": "Available via Version History panel on model page" } }