The Role of Internal Variability in Regional Climate Change

Abstract

Abstract. Disentangling the effects of internal variability and anthropogenic forcing on regional climate change remains a key challenge with far-reaching implications. Due to its largely unpredictable nature on timescales longer than a decade, internal climate variability limits the accuracy of climate model projections, introduces challenges in attributing past climate changes, and complicates climate model evaluation. Here, we highlight recent advances in climate modeling and physical understanding that have led to novel insights on these key issues. In particular, we synthesize new findings from Large Ensemble simulations with Earth System Models, Observational Large Ensembles, and “dynamical adjustment” methodologies, with a focus on European climate.