CARBONICA: A Multi-Parameter Earth System Science Framework for Real-Time Quantification of Global Carbon Cycle Dynamics, Sink Saturation, and Planetary Self-Regulation Thresholds

CARBONICA (Carbon Accounting and Regulatory Budget Observatory for Networked Integrated Carbon Assessment) is a physically rigorous eight-parameter Earth system science framework for real-time quantification of global carbon cycle dynamics, natural sink capacity, and the critical threshold at which Earth's self-regulating biogeochemical systems approach irreversible saturation. The framework integrates eight governing parameters into the Planetary Carbon Saturation Index (PCSI): (1) Net Primary Productivity (NPP), (2) Oceanic Carbon Sink Strength (S_ocean), (3) Atmospheric CO₂ Growth Rate (G_atm), (4) Permafrost Thaw Flux (F_perma), (5) Carbon Buffer Capacity / Revelle Factor (β), (6) Soil Carbon Residence Time (τ_soil), (7) Anthropogenic Emission Factor (E_anth), and (8) Photosynthetic Quantum Yield (Φ_q). CARBONICA was validated against a 65-year observational baseline (1960–2025) spanning the Keeling Curve (NOAA Mauna Loa), GLODAP ocean carbon database, MODIS NPP satellite time series, GTN-P permafrost monitoring network, SOCAT surface ocean CO₂ atlas, FLUXNET eddy covariance network, and the Global Carbon Project annual budget. Validation performance: r² = 0.947 against the prospective 2001–2025 Keeling Curve test period. Key results: The PCSI has risen from 0.31 (1960) to 0.78 (2025) at an accelerating rate of 0.012 units/year — three times the 1960–1990 rate. Permafrost thaw flux F_perma has reached 1.71 ± 0.40 PgC/yr (2025), constituting 4.3% of global emissions. The Revelle Factor has increased from 9.1 (pre-industrial) to 12.4 (2025), indicating a 36% reduction in ocean buffer capacity. Photosynthetic quantum yield Φ_q is declining at −0.9%/decade globally. Under SSP3-7.0, the PCSI is projected to reach the critical 0.90 threshold between 2047 and 2053. Achieving anthropogenic net-zero emissions by 2050 would not prevent PCSI exceeding 0.85 by 2055, because autonomous permafrost and soil carbon feedbacks will contribute 2.5–4.0 PgC/yr through 2060 — implying the effective remaining carbon budget for 1.5°C is 15–25 PgC smaller than the IPCC AR6 estimate. Repository: github.com/gitdeeper9/carbonica | gitlab.com/gitdeeper9/carbonica Dashboard: carbonica.netlify.app Package: pip install carbonica Submitted to: Nature Climate Change (Springer Nature), March 2026