Home SCIENCE Climate ‘points of no return’ may be much closer than we thought

Climate ‘points of no return’ may be much closer than we thought


A new study has warned that irreversible climate “tipping points” are more numerous and closer to being triggered than previously thought. (Image credit: Shutterstock)

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Climate tipping points, the “points of no return” beyond which key components of Earth’s climate will begin to break down irreversibly, could be triggered by temperatures much lower than scientists previously thought, with some tipping points inflection potentially reached. There are also many more potential tipping points than scientists previously identified, according to a new study.

In climatology, a turning point is defined as an increase in the temperature beyond which a localized climate system, or “tipping element,” such as the Amazon rainforest or the Greenland ice sheet, begins to shrink irreversibly. Once a tipping point has been reached, that tipping element will experience runaway effects that will essentially doom it forever, even if global temperatures recede below the tipping point.

The idea of ​​climate tipping points first emerged in a 2008 article published in the journal PNASwhen the researchers identified nine key tipping elements that could reach such a threshold due to climate change. In the new study, published September 9 in the journal SciencesA team of researchers re-evaluated data from more than 200 articles on the topic of tipping points published since 2008. They found that there are now 16 major tipping points, almost all of which could reach the point of no return if global warming it continues beyond 2.7 degrees Fahrenheit (1.5 degrees Celsius) above pre-industrial levels.

Land It has already warmed more than 2 degrees F (1.1 C) above pre-industrial levels and, if current warming trends continue, is on track to reach 3.6 to 5.4 F (2 to 3 C). ) above pre-industrial levels, the study authors said in a statements.

“This puts the Earth on a path to cross multiple dangerous tipping points that will be disastrous for people around the world,” study co-author Johan Rockström, director of the Potsdam Institute for Climate Impact Research in New York, said in the statement. Germany.

Related: Is climate change making the weather worse?

Tipping points could be triggered much sooner than expected, according to the new study. (Image credit: Shutterstock)

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When the researchers conducted their reassessment, they removed two of the original nine turning points due to insufficient evidence, but then identified nine new ones that had been previously overlooked, bringing the total to 16, they reported in the study.

“Since I first assessed climate tipping points in 2008, the list has grown and our assessment of the risk they represent has increased dramatically,” said co-author Tim Lenton, director of the Institute for Global Systems at the University of Exeter at the UK and leading author of the original 2008 turning points document, said in the statement.

In the new study, the researchers calculated the exact temperature at which each tipping element is likely to pass its point of no return. Their analysis revealed that five tipping elements: the Greenland and West Antarctic ice sheets; arctic permafrost; tropical coral reefs; and a key ocean current in the Labrador Sea, are in the “danger zone,” meaning they are rapidly approaching their tipping points.

Two of these danger zone tipping points, the Greenland and West Antarctic ice sheets, are already beyond their potential lower tipping points of 1.4 F (0.8 C) and 1.8 F(1 C) above pre-industrial times, respectively, suggesting that these two systems may already be beyond saving, the researchers wrote.

The other 11 tipping points are listed as “likely” or “possible” if warming continues beyond 2.7 F.

The activation of climatic tipping points will increase the severity and frequency of extreme events such as wildfires. (Image credit: Shutterstock)

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Previous estimates, such as the Sixth Assessment Report of the United Nations Intergovernmental Panel on Climate Change, published in three parts in 2021 and 2022, suggested that most major tipping points would be reached only if the Earth warmed by more than 3.6 F, which would give humanity more time to prepare mitigation and adaptation strategies. But according to the new study, those tipping points may be closer than expected.

One explanation for this accelerated timeline is that researchers now fully understand the interconnectedness of the tipping points. Better climate models now show that the fall of one tipping point could increase the probability of the collapse of another. For example, if the Arctic permafrost melts due to rising temperatures, it will release more carbon into the atmosphere. This will further increase surface temperatures on land and in the oceans, accelerating the melting of major ice sheets and stressing coral reefs. In other words, turning points stack up like dominoes; as soon as one falls, the others could quickly follow.

Related: Could climate change cause humans to go extinct?

Therefore, it is imperative to drastically reduce our greenhouse gases emissions immediately before this irreversible chain reaction begins, the researchers warned.

“To maintain habitable conditions on Earth, protect people from rising extremes, and enable stable societies, we must do everything we can to avoid crossing tipping points,” Rockström said. “Every tenth of a degree counts.”

The researchers warn that we must quickly reduce our greenhouse gas emissions. (Image credit: Shutterstock)

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But this will not be an easy task. To have just a 50% chance of limiting global warming to 2.7 F, greenhouse gas emissions would have to be cut in half by 2030 and reach net zero by 2050, the researchers said in the statement.

Given little progress in combating climate change, this goal may seem unattainable. In fact, in a way, we seem to be going backwards; In June, a ruling by the US Supreme Court. severely limited the federal government’s ability to regulate greenhouse gas emissions.

However, the study authors argue that it might still be possible to achieve such drastic changes through a different kind of tipping point: a social one. This is a theoretical threshold in public opinion that, once passed, will force governments and large corporations to take drastic climate action, the scientists said in the statement.

The only problem is that this social tipping point must be reached long before the climatic tipping points are passed; otherwise it will be too little too late.

Originally published on Live Science.



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