In this review paper, we explore latest results concerning a few key tipping elements of the Earth system in the ocean, cryosphere, and land realms, namely the Atlantic overturning circulation and the subpolar gyre system, the marine ecosystems, the permafrost, the Greenland and Antarctic ice sheets, and in terrestrial resource use systems. All these different tipping elements share common characteristics related to their nonlinear nature. They can also interact with each other leading to synergies that can lead to cascading tipping points. Even if the probability of each tipping event is low, they can happen relatively rapidly, involve multiple variables, and have large societal impacts. Therefore, adaptation measures and management in general should extend their focus beyond slow and continuous changes, into abrupt, nonlinear, possibly cascading, high impact phenomena. Remote sensing observations are found to be decisive in the understanding and determination of early warning signals of many tipping elements. Nevertheless, considerable research still remains to properly incorporate these data in the current generation of coupled Earth system models. This is a key prerequisite to correctly develop robust decadal prediction systems that may help to assess the risk of crossing thresholds potentially crucial for society. The prediction of tipping points remains difficult, notably due to stochastic resonance, i.e. the interaction between natural variability and anthropogenic forcing, asking for large ensembles of predictions to correctly assess the risks. Furthermore, evaluating the proximity to crucial thresholds using process-based understanding of each system remains a key aspect to be developed for an improved assessment of such risks. This paper finally proposes a few research avenues concerning the use of remote sensing data and the need for combining different sources of data, and having long and precise-enough time series of the key variables needed to monitor Earth system tipping elements.

中文翻译：

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来自太空的物理、生物和社会生态系统几个关键临界点的早期预警

在这篇综述论文中，我们探讨了地球系统在海洋、冰冻圈和陆地领域的一些关键倾斜要素的最新结果，即大西洋翻转环流和次极地环流系统、海洋生态系统、永久冻土、格陵兰和南极冰盖，以及陆地资源利用系统。所有这些不同的倾翻元件都具有与其非线性特性相关的共同特征。它们还可以相互交互，从而产生协同效应，从而导致级联临界点。即使每个倾覆事件的概率很低，它们也可能发生得相对较快，涉及多个变量，并具有很大的社会影响。因此，适应措施和管理一般应将重点从缓慢和持续的变化扩展到突然的、非线性的、可能的级联、高冲击现象。遥感观测对许多倾覆要素的预警信号的理解和确定具有决定性作用。尽管如此，仍需进行大量研究以将这些数据正确地纳入当前一代耦合地球系统模型中。这是正确开发强大的十年预测系统的关键先决条件，该系统可能有助于评估跨越对社会可能至关重要的阈值的风险。临界点的预测仍然很困难，特别是由于随机共振，即自然变率和人为强迫之间的相互作用，需要大量的预测来正确评估风险。此外，使用对每个系统的基于过程的理解来评估与关键阈值的接近程度仍然是改进此类风险评估的一个关键方面。本文最后提出了一些研究途径，涉及遥感数据的使用和组合不同数据源的需要，以及具有监测地球系统倾斜要素所需的关键变量的足够长且足够精确的时间序列。