A major study shows that the climate crisis has brought the world to the brink of multiple “catastrophic” tipping points.
The study shows that five critical tipping points may have already passed due to human-caused global warming of 1.1°C.
These include the collapse of the Greenland ice sheet, which eventually led to a sharp rise in sea levels, the cessation of the main current in the North Atlantic, the cessation of the rains on which billions of people depend for food, and the sudden melting of carbon. – rich permafrost.
The analysis showed that at 1.5 degrees Celsius of heating, the minimum increase currently projected, four out of five tipping points move from possible to probable.
Also at 1.5°C, five additional tipping points become possible, including changes to vast boreal forests and the loss of nearly all mountain glaciers.
In total, scientists have found evidence for 16 tipping points, the last six of which require a global temperature of at least two degrees Celsius, according to scientists.
Turning points are applied on time scales ranging from a few years to centuries.
The scientists concluded that “the Earth could have left the ‘safe’ climatic state of ‘greater than one degree Celsius of global warming’ as all human civilization has evolved at temperatures below that level.
Getting past one point of no return often excites others, creating cascading chains. But this is still being studied, which means that the current analysis may pose minimal risk.
Professor Johan Rockström, director of the Potsdam Institute for Climate Impact Research, who was part of the research team, said: “The world is moving towards global warming of 2-3°C. points that will have catastrophic consequences for people around the world … in order to maintain habitable conditions on earth and create stable societies, we must do everything possible to prevent the critical points from crossing.”
Dr David Armstrong McKay of the University of Exeter, lead author of the study, added: “The study really highlights why the Paris Agreement’s 1.5°C target is so important and worth fighting for.”
Recent studies have shown signs of destabilization in the Amazon rainforest, the loss of which would have “profound” consequences for global climate and biodiversity, as well as for the Greenland ice sheet and Gulf Stream currents, which scientists call the Amoka circulation.
A recent report by the Intergovernmental Panel on Climate Change states that the risk of climate tipping points becomes high with global warming of 2°C.
In this analysis, published in the journal Science, scientists evaluated more than 200 previous studies of past tipping points, climate monitoring, and modeling studies.
The term “tipping point” is used when a temperature threshold is exceeded, resulting in an unstoppable change in the climate system, even if global warming stops.
Nine global tipping points have been identified: the collapse of Greenland, West Antarctica and two parts of the East Antarctic ice sheet, the partial and complete collapse of Amok, the death of the Amazon, the collapse of permafrost and the disappearance of the winter sea. ice in the Arctic.
The Amazon tipping point estimate did not take into account the effects of deforestation.
“The combination of global warming and deforestation could cause this to happen much sooner,” Armstrong McKay explained.
Seven other tipping points will have major regional impacts, including the loss of tropical coral reefs and the reversal of monsoons in West Africa. Other potential tipping points still being studied include loss of oxygen to the ocean and major shifts in the Indian summer monsoons.
Scientists define critical point crossing as “possible” when the minimum temperature is exceeded and “probable” after evaluating the central threshold.
“The review is a timely update on the potential elements of an Earth upheaval, and the threat of events turning into further warming is real,” said Professor Niklas Burs from the Technical University of Munich.
He added that more research is needed to narrow down critical temperature thresholds, with current estimates remaining highly uncertain.