El Niño/Southern Oscillation (ENSO) sea surface temperature (SST) variability increased after 1960, influenced by more frequent strong El Niño and La Niña events. Whether such changes are linked to anthropogenic warming, however, is largely unknown. In this Perspective, we consider anthropogenic impacts on ENSO variability in several commonly used modelling designs, which collectively suggest a greenhouse warming-related effect on post-1960 ENSO SST variability. Specifically, a comparison of simulated ENSO SST variability between 1901–1960 and 1961–2020 indicates that more than three quarters of climate models produce an amplitude increase in post-1960 ENSO SST variability, translating into more frequent strong El Niño and La Niña events. Multiple large ensemble experiments further confirm that the simulated post-1960 ENSO amplitude increase (approximately 10%) is not solely due to internal variability. Moreover, multicentury-long simulations under a constant pre-industrial CO₂ level suggest that the observed post-1960 ENSO variability is high, sitting in the highest 2.5 and 10 percentiles for eastern Pacific and central Pacific ENSO, respectively. Improvement in model ENSO physics, identification of consistent future and historical change in additional ENSO characteristics and single-forcing large-ensemble experiments are further needed to ascertain climate change impacts on the ENSO.

厄尔尼诺/南方涛动 (ENSO) 海面温度 (SST) 变率在 1960 年后增加，受到更频繁的强烈厄尔尼诺和拉尼娜事件的影响。然而，这些变化是否与人为变暖有关，在很大程度上是未知的。在本《观点》中，我们在几种常用的建模设计中考虑了人为对 ENSO 变率的影响，这些设计共同表明温室效应对 1960 年后 ENSO SST 变率的影响。具体而言，对 1901-1960 年和 1961-2020 年期间模拟的 ENSO SST 变率的比较表明，超过四分之三的气候模型产生了 1960 年后 ENSO SST 变率的振幅增加，转化为更频繁的强厄尔尼诺和拉尼娜事件。多个大型集合实验进一步证实，模拟的 1960 年后 ENSO 振幅增加（约 10%）不仅仅是由于内部变率。此外，在持续的工业化前 CO2 条件下长达多个世纪的模拟₂水平表明观察到的 1960 年后 ENSO 变率很高，分别位于东太平洋和中太平洋 ENSO 的最高 2.5 和 10 个百分位数。还需要改进 ENSO 物理模型、确定其他 ENSO 特征的一致未来和历史变化以及单一强迫大型集合实验，以确定气候变化对 ENSO 的影响。