Warm and wet anomalies persist across the pan-Arctic after carbon dioxide removal

Abstract The pan-Arctic region is experiencing rapid climate change under global warming, with Arctic amplification occurring at a rate 2–3 times faster than the global average. This study investigates Pan-Arctic climate responses to carbon dioxide removal (CDR) using nine CMIP6 models from the CDR Model Intercomparison Project (CDRMIP) and also analyzes two ScenarioMIP pathways, SSP126 and SSP534-over, which feature declining CO ₂ concentrations. Our results reveal significant hysteresis and asymmetric responses in both temperature and precipitation during CO ₂ increase and decrease phases. The multi-model mean shows that when CO ₂ concentrations return to pre-industrial levels, the pan-Arctic region retains a warming of approximately 1.5 °C and increased precipitation of about 0.1 mm d −1 compared to initial conditions. Notably, temperature and precipitation changes in the pan-Arctic at peak CO ₂ are approximately twice the global average. We identify substantial inter-model uncertainties, primarily driven by divergent representations of Atlantic meridional overturning circulation (AMOC) responses and associated North Atlantic cooling patterns in the ramp-up period. Two models (CESM2 and NorESM2-LM) simulate particularly strong AMOC weakening during the ramp-up phase, resulting in reduced warming and wetting trends across the pan-Arctic. A similar persistence of warmer and wetter conditions is also found under the SSP126 and SSP534-over scenarios. These findings highlight the irreversible nature of Arctic climate change even under aggressive CDR scenarios and emphasize the need for improved representation of Arctic processes in climate models to reduce uncertainties in climate projection and mitigation strategy design.