Humanity must avoid ‘tipping point’ for climate change

Humans must avoid reaching a ‘point of no return’ that will lead to ecological disasters such as deforestation and irreversible climate change, a ground-breaking study has found.

Research led by the University of Reading combined maths with climate science to look at how the Earth teeters between its current warm climate and entering a ‘snowball’ state, which it is last believed to have entered millions of years ago.

Analysing how random events and human action could combine to form a ‘tipping point’ for natural states, academics have said the study offers insight into how the Earth’s climate, landscape and ecosystems, such as rainforests, could potentially be changed or destroyed entirely.

Valerio Lucarini, professor of statistical Mechanics at the University of Reading and lead author of the study, said: ‘Changes in climate or catastrophic declines in natural features like forests all happen in a fashion similar to a journey in a mountain region. These states are like two valleys divided by a mountain pass, which must be crossed in order to move between them.

‘Pinpointing this dividing line has allowed us to better understand when we are likely to see transitions in the natural world. This helps outline a safe operating space, enabling us to tailor our behaviour to remain within this and to realise when a transition could occur.

‘Cutting down trees, damaging ecosystems or altering the climate could all cause us to stray too close to a tipping point, risking dramatic and irreversible change.’

The study, published in Physical Review Letters, builds on previous research by the same authors which identified the tipping point between two competing states.

The Earth is believed to have flip-flopped several times between a warm and snowball state around 650 million years ago, prior to the start of life as we know it.

The team behind the research used random fluctuations to simulate the run-up to such a tipping point, thereby finding out what sparks a transition from one state to another.

The research is particularly relevant for ecosystems such as the Amazonian rainforest, which often experiences fluctuations caused by incidents such as fires, drought and deforestation but is able to regenerate itself.

By better understanding the point at which ecosystems like forests move from potential recovery into irreparable decline, we will be better able to act to protect them, the academics say.

The team behind the study now hopes to test its research against real-world climate transitions such as the start and end of monsoon seasons across the world.

Professor Lucarini added: ‘Crossing a tipping point relies on a combination of random events that accumulate to produce the transition.

‘Human action might be insignificant when the tipping point is far away, but could be the final straw as we approach it. Understanding this context is crucial to judging when we might topple into a new state.’

Last week research from the Universities of Bristol and Texas found that Earth could take millions of years to recover from the mass extinctions currently being caused by climate change.]

Photo credit – NASA