Analysis of a global warming hiatus

After a spike in global-mean temperature associated with the 1998 El Niño, the climate system experienced several years of reduced warming, and perhaps even slight cooling. This period, variously termed the ‘hiatus’, ‘pause’ or ‘slowdown’, should have come as no surprise given our understanding of El Niño and natural climate variability. However, soon after the recognition of the reduced warming, it appeared that models and observations were diverging, raising the question of whether the models were missing important processes. Although global warming has since recommenced, the hiatus sparked an enormous research effort. Iselin Medhaug et al. synthesize the literature and reassess the model and observational evidence. Their assessment reconciles the apparent contradictions between models and data and obviates the need to revise our understanding of the underlying physics of climate systems. The hiatus was an episode of natural variability after all.