More Stabilizing Radiative Feedbacks in CO 2 Removal Scenarios

Recent studies show that global mean surface temperature exhibits a transient hysteresis during removal, where temperatures remain elevated after concentrations return to pre‐industrial levels. This is largely attributed to ocean thermal inertia rather than an irreversible climate response; however, the role of radiative feedbacks remains unclear. Here, using a fully coupled Earth System Model, we find that radiative feedbacks are nearly identical for increase and subsequent removal up to 3 times pre‐industrial concentrations. However, at 4× and higher forcings, feedbacks become more stabilizing during removal. Through a hierarchy of experiments we show that this is driven by low‐level clouds in the North Atlantic, linked to warmer sea‐surface temperatures from an overshoot of Atlantic Meridional Overturning Circulation (AMOC) strength during removal. These results suggest that AMOC‐mediated feedbacks contribute to the transient temperature hysteresis in future removal scenarios by keeping the removal phase warmer.