The geological record shows that abrupt changes in the Earth system can occur on timescales short enough to challenge the capacity of human societies to adapt to environmental pressures. In many cases, abrupt changes arise from slow changes in one component of the Earth system that eventually pass a critical threshold, or tipping point, after which impacts cascade through coupled climate–ecological–social systems. The chance of detecting abrupt changes and tipping points increases with the length of observations. The geological record provides the only long-term information we have on the conditions and processes that can drive physical, ecological and social systems into new states or organizational structures that may be irreversible within human time frames. Here, we use well-documented abrupt changes of the past 30 kyr to illustrate how their impacts cascade through the Earth system. We review useful indicators of upcoming abrupt changes, or early warning signals, and provide a perspective on the contributions of palaeoclimate science to the understanding of abrupt changes in the Earth system.

地质记录表明，地球系统的突然变化可以在足够短的时间尺度内发生，以挑战人类社会适应环境压力的能力。在许多情况下，突然变化源于地球系统一个组成部分的缓慢变化，最终超过临界阈值或临界点，之后影响通过耦合的气候-生态-社会系统级联。检测突变和临界点的机会随着观察时间的延长而增加。地质记录提供了我们拥有的关于条件和过程的唯一长期信息，这些条件和过程可以推动物理、生态和社会系统进入在人类时间框架内可能无法逆转的新状态或组织结构。这里，我们使用有据可查的过去 30 kyr 的突然变化来说明它们的影响如何通过地球系统级联。我们回顾了即将发生的突变或早期预警信号的有用指标，并提供了古气候科学对理解地球系统突变的贡献的观点。