Our understanding of Arctic sea ice variability is constrained by the relatively short time span of satellite observations (available only since 1979) and the uncertainties in model simulations, which stem from model biases and natural climate variability. Evaluating model performance in historical simulations is essential, as the reliability of future projections depends on how accurately models can replicate past climate changes.

In a recent study, Elena Bianco et al. examine changes and variability in Arctic sea ice using 29 CMIP6* historical simulations spanning 1850–2014, compared against available observational data. By analyzing a broad subset of CMIP models and their ensemble members, they highlight the range of simulated sea ice variability across models, considering differences in model sensitivity and the uncertainty arising from internal climate variability. The authors also investigate whether state-of-the-art climate models are capable of simulating the sea ice response to low-frequency hemispheric and global climate variability.