资源环境科技发展态势分析平台

During the first decade of the twenty-first century, the Earth's surface warmed more slowly than climate models simulated(1). This surface-warming hiatus is attributed by some studies to model errors in external forcing(2-4), while others point to heat rearrangements in the ocean(5-10) caused by internal variability, the timing of which cannot be predicted by the models(1). However, observational analyses disagree about which ocean region is responsible(11-16). Here we show that the hiatus could also have been caused by internal variability in the top-of-atmosphere energy imbalance. Energy budgeting for the ocean surface layer over a 100-member historical ensemble reveals that hiatuses are caused by energy-flux deviations as small as 0.08 W m(-2), which can originate at the top of the atmosphere, in the ocean, or both. Budgeting with existing observations cannot constrain the origin of the recent hiatus, because the uncertainty in observations dwarfs the small flux deviations that could cause a hiatus. The sensitivity of these flux deviations to the observational dataset and to energy budget choices helps explain why previous studies conflict, and suggests that the origin of the recent hiatus may never be identified.