Possible tipping elements in the climate system.
Interactions of climate tipping points (bottom) with associated tipping points in the socioeconomic system (top) on different time scales. [1]

A tipping point in the climate system is a threshold that, when exceeded, can lead to large changes in the state of the system. Potential tipping points have been identified in the physical climate system, in impacted ecosystems, and sometimes in both.[2] For instance, feedback from the global carbon cycle is a driver for the transition between glacial and interglacial periods, with orbital forcing providing the initial trigger.[3] Earth's geologic temperature record includes many more examples of geologically rapid transitions between different climate states.[4]

Climate tipping points are of particular interest in reference to concerns about global warming in the modern era. Possible tipping point behaviour has been identified for the global mean surface temperature by studying self-reinforcing feedbacks and the past behavior of Earth's climate system. Self-reinforcing feedbacks in the carbon cycle and planetary reflectivity could trigger a cascading set of tipping points that lead the world into a hothouse climate state.[5][6]

Large-scale components of the Earth system that may pass a tipping point have been referred to as tipping elements.[7] Tipping elements are found in the Greenland and Antarctic ice sheets, possibly causing tens of meters of sea level rise. These tipping points are not always abrupt. For example, at some level of temperature rise the melt of a large part of the Greenland ice sheet and/or West Antarctic Ice Sheet will become inevitable; but the ice sheet itself may persist for many centuries.[8] Some tipping elements, like the collapse of ecosystems, are irreversible.[2]