Reliability of future global warming projections depends on how well climate models reproduce the observed climate change over the twentieth century. In this regard, deviations of the model-simulated climate change from observations, such as a recent “pause” in global warming, have received considerable attention. Such decadal mismatches between model-simulated and observed climate trends are common throughout the twentieth century, and their causes are still poorly understood. Here we show that the discrepancies between the observed and simulated climate variability on decadal and longer timescale have a coherent structure suggestive of a pronounced Global Multidecadal Oscillation. Surface temperature anomalies associated with this variability originate in the North Atlantic and spread out to the Pacific and Southern oceans and Antarctica, with Arctic following suit in about 25–35 years. While climate models exhibit various levels of decadal climate variability and some regional similarities to observations, none of the model simulations considered match the observed signal in terms of its magnitude, spatial patterns and their sequential time development. These results highlight a substantial degree of uncertainty in our interpretation of the observed climate change using current generation of climate models.

未来全球变暖预测的可靠性取决于气候模型如何很好地再现了二十世纪观测到的气候变化。在这方面，模型模拟的气候变化与观测值的偏差，例如最近全球变暖的“暂停”，已引起了相当大的关注。在整个二十世纪，模型模拟和观测到的气候趋势之间的年代际失配现象十分普遍，其成因仍知之甚少。在这里，我们表明，观测到的和模拟的气候变化在年代际和更长的时间尺度上的差异具有一致的结构，表明全球多年代际振荡明显。与这种变化有关的地表温度异常起源于北大西洋，并扩展到太平洋和南部海洋以及南极洲，在大约25-35年的时间里与北极公司接suit而至。尽管气候模型表现出不同的年代际气候变化水平，并且与观测值在某些地区相似，但考虑到的模型模拟均未在其大小，空间模式及其连续时间发展方面与观测到的信号相匹配。这些结果凸显了我们在使用当前气候模型生成的观测到的气候变化的解释中存在很大程度的不确定性。