[2] His work on tipping elements in the Earth System has led Barnosky to work for clearer efforts in climate policy to make possible the two-degree target for increase in average temperature rise.
[3] Barnosky stresses that climate change is a major cause of displacement[4] and the cause of the current mass extinction.
A key concern is the concept of "tipping point"Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds.
Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence.
The plausibility of a planetary-scale 'tipping point' highlights the need to improve biological forecasting by detecting early warning signs of critical transitions on global as well as local scales, and by detecting feedbacks that promote such transitions.