Reconciling global tipping point theories: insight from magnetic experiments

Driven by a combination of global warming and unsustainable resource management, global tipping elements represent existential threats to Earth’s systems and communities. However, tipping point theory is still developing. Here, we reconcile alternative theories through a comparison of mathematical tipping point models and empirical experiments on micromagnet systems. We show how discontinuous change in spatially complex ecosystem models and multidomain magnetic materials represents common generic stress-response behaviour in systems that organise spatially when placed under stress. Such systems show ‘soft’ incremental rather than ‘hard’ abrupt change and may represent the majority of ecological, landscape and social-ecological systems. The findings emphasize how the classic fold bifurcation model should be restricted to describing simple systems. We explore the effects of stress magnitude and rate on ‘soft’ and ‘hard’ systems and draw insight for global tipping elements: scale-dependence, abrupt versus incremental change, reversibility, early warning signals, and positive social-economic tipping points.