A new study concludes it may still be possible to temporarily exceed the environmental “tipping points” that would signal a drastic deepening of the climate crisis—but only with rapid action to address those impacts and drive down the greenhouse gas emissions at the root of the problem.
The research has one expert warning that the natural world is a “delicate balance of systems”, and it’s still difficult to identify the precise points when key tipping points—like the dieback of the Amazon rainforest, or melting of major ice sheets—will occur.
“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,” the London Evening Standard explains. The new study in the journal Nature says those thresholds “could be ‘temporarily exceeded’ without causing irreversible damage, provided swift action is taken.”
The UK scientists behind the study “add the time available to act would depend on the level of global warming and the time scale involved in each tipping point,” the Standard says.
“The more extreme the warming, the less time we would have to prevent tipping points,” said lead author Dr. Paul Ritchie of the University of Exeter’s Global Systems Institute.
“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,” he added. “Slow-onset tipping points take place over a time scale of many centuries and—depending on the level of warming—this would give us more time to act.”
While the 1.5°C target in the 2015 Paris Agreement was meant to give humanity a two-in-three chance of averting those impacts, countries are still far off track with their Paris commitments. And the Standard says researchers consider it “almost inevitable” that future emissions will exceed the limit.
Scientists commenting on the study stressed that it mustn’t be seen as diminishing the urgency of faster, deeper carbon cuts.
“Ideally, we will not cross tipping point thresholds, but this gives hope we may be able to pull back from danger if needed,” Dr. Chris Huntingford of the UK Centre for Ecology and Hydrology told the Standard.
“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,” cautioned University of Reading natural hazards researcher Prof. Hannah Cloke. “By definition, once a tipping point is surpassed, there is no coming back. 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.”
The study “clearly shows another important aspect of the agency by humans,” added Valerio Lucarini, professor of statistical mechanics at the University of Reading. It also demonstrates that “a rapid realignment of climate policies towards more sustainable levels can avoid irreversible changes in the climate system.”
But “the natural world is a delicate balance of systems, and dramatically altering one can cause others to fall like a house of cards,” Lucarini said. “Research to estimate where these tipping points lie is improving all the time, but it remains difficult to pinpoint them.”