The Slow Exhale

The multi-decade rebound phase between roughly 2060 and 2090 during which the ocean releases stored CO₂ as atmospheric concentrations fall. Net atmospheric decline is slower than gross removal during this phase because the ocean is exhaling carbon back into the air to maintain equilibrium with the falling atmospheric concentration. The phase ends when atmosphere and ocean re-equilibrate at lower concentrations, after which removal again dominates the net arithmetic.