Why some ecosystems collapse suddenly—and others don’t

(Press-News.org) A new study published in the journal One Earth reveals that the way ecosystems collapse—abruptly or gradually—may depend on internal complexity, much like how magnetic materials behave under stress.

The study, led by Professor John Dearing at the University of Southampton with colleagues from Rothamsted Research, Bangor University, and Edinburgh University, challenges the prevailing assumption that climate tipping points always happen suddenly. Instead, it shows that some large-scale Earth systems may be experiencing gradual collapses that are easy to miss, with profound implications for climate policy and planetary resilience.

"Some systems snap. Others sag," said Professor Simon Willcock of Rothamsted Research, one of the study team. "Our findings suggest that the classic model of abrupt tipping—like a lake suddenly turning green from algae—may not apply to some of Earth’s most important systems, such as forests, ice sheets, or ocean currents."

To investigate, the researchers turned to an unlikely source: magnetic materials. In the lab, magnets can be pushed between alternative states using external fields. These stress-responses mirror how ecosystems shift under environmental pressure. The team found that materials with simpler, homogeneous structures showed abrupt, irreversible changes—akin to ‘hard’ tipping points. But more complex materials exhibited ‘soft’ tipping, where changes occurred incrementally as internal components realigned.

This analogy helps explain why large, diverse systems—like rainforests or ocean circulation—may appear stable even as they quietly reorganise under stress.

Key insights from the study:

Complex systems reorganise gradually under stress, masking early signs of collapse. Faster climate change increases the risk of abrupt transitions, even in systems that would otherwise change gradually. Systems that change gradually may be more easily restored—if action is taken early enough. Viewing ecosystems at the wrong scale may cause policymakers to miss vital warning signs. The authors warn that inaction could be fatal, as delayed responses allow stress to accumulate unnoticed—like frogs unaware that the water is boiling.

"Our work suggests we may already be crossing tipping points without realising," said Dearing. "For too long, we’ve treated tipping points as dramatic collapses. These findings show that some systems may slide into collapse silently. That makes them even more dangerous. Slowing the rate of climate change is essential—not only to avoid catastrophic collapse, but to buy time for systems to adapt and recover."

“Slow changes can be deceptive,” said co-author Professor Roy Thompson.  “Laboratory observations of tipping points in magnetic materials give us a safe, controlled way to understand what we can’t test directly in ecosystems and in the global climate system, without relying on computer models.”

The study underscores the importance of scale, complexity, and timing in both modelling and managing global change. It calls for more nuanced definitions of tipping points, investment in high-resolution monitoring, and urgent action to reduce the pace of environmental stressors.

“This work flips the script on climate risk,” said Willcock. Not all tipping points are abrupt. Some are slow and silent—and we may already be inside them.  If we wait for ecosystems to scream, we’ll have waited too long. The real danger is in systems that whisper while they fall apart.”

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