A Hydraulic-Thermodynamic Framework for Forest-Climate Coupling

Current climate models treat forests as passive carbon reservoirs, parameterizing their surface properties but largely missing their active role as planetary hydraulic infrastructure. We propose, for the first time, a framework integrating three previously independent mechanisms into a single physical chain. The three pillars are: (1) the Aerosol Baseline, where intact forests contribute to the preindustrial CCN reference state over continents; (2) the Stomata-Cumulus Pump, where groundwater availability acts as a binary gate for vertical energy export; and (3) the Tradewind Engine, where condensation-driven pressure gradients sustain horizontal atmospheric circulation. Using Convergent Cross-Mapping (CCM) rather than Granger causality, we find evidence for biotic-atmosphere coupling (ρ = 0.72) between forest-derived aerosols and regional precipitation. A preliminary Planetary Hydraulic Health Index (PHHI) suggests critical stress in the Maritime Continent (Borneo: 48% of baseline wind force remaining), while the Amazon and Congo basins appear marginally stable (95–98%). This framework identifies additional mechanisms consistent with the anomalous 2023–2025 warming, complementing established explanations.