Ocean acidification is likely to impact all stages of the ocean carbonate pump. We show divergent responses of CaCO₃ export throughout this century in earth system models, with anomalies by 2100 ranging from −74 % to +23 % under a high-emission scenario. While we confirm the limited impact of carbonate pump anomalies on 21st century ocean carbon uptake and acidification, we highlight a potentially abrupt shift in CaCO₃ dissolution from deep to subsurface waters beyond 2100.