Per-SSP β values (post-2024 forecast)
| SSP | 2100 ppm | β (full) | β post-2024 | β=1 forward year |
|---|---|---|---|---|
| SSP1-1.9 | 374.6 | −1.526 | −6.517 | — |
| SSP1-2.6 | 478.4 | −3.122 | −24.319 | — |
| SSP2-4.5 | 654.1 | +1.213 | −1.610 | 2029 |
| SSP3-7.0 | 962.5 | +2.138 | +0.828 | 2039 |
| SSP5-8.5 | 1031.4 | +2.076 | +0.621 | 2038 |
σ_cross over 5 SSP-fan post-2024 β = 9.438 (median β = −1.610). σ_cross over 9 statistical-fan post-2024 β = 0.399 (median β = +0.020). The SSP fan has 24× the cross-shadow dispersion of the rate-perturbation fan, reflecting much wider end-of-century divergence.
Climate Mitigation Atlas — \(\beta\) by observable × emissions pathway
Each cell's colour is one number — the rate exponent \(\beta\). Green = stoppable (returns to rest). Orange = super-rate. Red = locked-in.
Click any cell for the full reading: \(\beta\), cross-model dispersion, theorem anchor, and the source code on GitHub.
How to read this chart · what the SSPs mean
The axes
- Rows: 8 climate observables — what is changing.
- Columns: 5 emissions pathways from "very aggressive mitigation" (left) to "no mitigation" (right).
- Cell colour: the rate exponent \(\beta\). Below 1 is stoppable; above 1 is locked-in.
- Cell label: the actual \(\beta\) value cross-model median.
The five emissions pathways (SSPs)
- SSP1-1.9 — ~1.5°C. Aggressive net-zero by mid-century. Paris lower bound.
- SSP1-2.6 — ~2°C. Moderate mitigation. Net-zero by ~2070.
- SSP2-4.5 — ~2.7°C. Current policies, middle-of-the-road.
- SSP3-7.0 — ~3.6°C. Regional rivalry, fragmented action.
- SSP5-8.5 — ~5°C. Continued fossil-fuel growth, no mitigation.
SSPs (Shared Socioeconomic Pathways) are the IPCC's standard set of emissions futures. The number after the dash is the radiative forcing in 2100 (W/m²).
Best mitigation pathway
SSP1-2.6 — deepest sub-rate β post-2024
SSP1-2.6 produces the deepest sub-rate post-2024 β = −24.319 (sub-rate by Law IV, finite-time return per Theorem 1). SSP1-1.9 also clean sub-rate (β = −6.517). SSP3-7.0 and SSP5-8.5 cross β=1 in 2038–2039 — supercritical thereafter. The framework's reading agrees with IPCC assessment that aggressive mitigation pathways meaningfully change the CO₂ trajectory.
Source: scenario_fan_co2.py + co2_atmospheric_trajectory_v2.py