Climate 'tipping points' can be reversed – but only if we act quickly © Getty Images

Climate ‘tipping points’ can be reversed, suggests new research – but only if we act urgently

The more extreme the warming, the less time we would have to prevent tipping points, new research suggests.

Acting quickly to curb global warming could help avert the devastating consequences of climate change and avoid going past the point of no return, research has suggested.

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It is thought that climate change has several “tipping points” – thresholds for change which, when reached, result in a process that is difficult to reverse. Consequences would include abrupt changes such as the dieback of the Amazon rainforest or melting of major ice sheets.

However, in a new study published in the journal Nature, UK scientists say these thresholds could be “temporarily exceeded” without causing irreversible damage, provided swift action is taken. They add that the time available to act would depend on the level of global warming and the timescale involved in each tipping point.

“The more extreme the warming, the less time we would have to prevent tipping points,” said Dr Paul Ritchie, of the University of Exeter’s Global Systems Institute and the Department of Mathematics. “This is especially true for fast-onset tipping points like Amazon forest dieback and disruption to monsoons, where irreversible change could take place in a matter of decades.

“Slow-onset tipping points take place over a timescale of many centuries and – depending on the level of warming – this would give us more time to act.”

In 2015, global leaders formed the Paris Agreement, with an aim to keep global warming below 1.5°C above pre-industrial levels. But researchers say current rates of warming make it almost inevitable that this level will be exceeded.

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“Ideally, we will not cross tipping point thresholds, but this gives hope we may be able to pull back from danger if needed,” said Dr Chris Huntingford, of the UK Centre for Ecology and Hydrology (UKCEH).

Commenting on the findings, Professor Hannah Cloke, a natural hazards researcher at the University of Reading who was not involved in the study, said: “Taking action to slow and reverse global warming can only be a good thing.

“Although this study is encouraging in suggesting we can avoid irreversible damage to the planet, we should not look at climate tipping points like a see saw. By definition, once a tipping point is surpassed there is no coming back.

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“What this research does confirm is that by acting quickly to curb global warming we can give ourselves more time to change course and avoid surpassing the point of no return.”

Reader Q&A: Do we really know what climate change will do to our planet?

Asked by: Jennifer Cowsill, via email

There is no doubt that greenhouse gas emissions caused by humans are changing our climate, resulting in a progressive rise in global average temperatures. The scientific consensus on this is comparable to the scientific consensus that smoking causes lung cancer.

Our climate is a hugely intricate system of interlinking processes, so forecasting exactly how this temperature increase will play out across the globe is a complex task. Scientists base their predictions on powerful computer models that combine our understanding of climatic processes with past climate data.

Many large-scale trends can now be calculated with a high degree of certainty: for instance, warmer temperatures will cause seawater to expand and glaciers to melt, resulting in higher sea levels and flooding. More localised predictions are often subject to greater uncertainty.

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