T. M. Lenton, V. N. Livina, V. Dakos, E.N. van Nes, M. Scheffer Detection and early warning of climate tipping points.
Full article (Open Access) at Royal Society, doi:10.1098/rsta.2011.0304
Abstract
A suite of ‘tipping elements’ in the climate system have been identified that may pass a tipping point under human-induced climate change. Recent climate changes add to the collective concern that these pose a significant risk to societies. Here we address how tipping points can be detected, and whether any useful early warnings can be provided before a tipping point is reached. We classify tipping points into those that involve approaching (and/or passing) a bifurcation point, those that are purely noise-induced (with no change in the underlying potential), and those that depend on rate of forcing. We review the methods that are being developed for tipping point detection and early warning, and recent critiques, in an effort to identify robust approaches. These methods are quite generic and could equally apply to tipping points in other dynamical systems. Finally we focus on applying the methods to climate time-series data that runs up to the present. The methods are able to pick up known historical climate anomalies. Furthermore, our analysis of recent sea surface temperature data suggests that a new climate state is beginning to emerge. We attempt to identify its location and what might be the underlying mechanism.