A new research by the Potsdam Institute for Climate Impact Research (PIK) in Germany has said that if the global temperatures rises beyond 1.5 degree Celsius above pre-industrial levels, then it may trigger multiple climate tipping points. The study, published in Science, says that even at current levels of global heating, the world is already at risk of passing five dangerous climate tipping points, and risks increase with each tenth of a degree of further warming.
The international research team gathered evidence for tipping points, their temperature thresholds, timescales, and impacts from a comprehensive review of over 200 papers published since 2008 when climate tipping points were first rigorously defined. They have increased the list of potential tipping points from nine to sixteen, reported AFP.
This research, published ahead of a major conference "Tipping Points: from climate crisis to positive transformation" at the University of Exeter (12-14th September), concludes that human emissions have already pushed Earth into the tipping points danger zone. Five of the sixteen tipping points may be triggered at today's temperatures - the Greenland and West Antarctic ice sheets, widespread abrupt permafrost thaw, collapse of convection in the Labrador Sea, and massive die-off of tropical coral reefs.
"We can see signs of destabilisation already in parts of the West Antarctic and Greenland ice sheets, in permafrost regions, the Amazon rainforest, and potentially the Atlantic overturning circulation as well," said the lead author of the study, Davi Armstrong McKay from Stockholm Resilience Centre, University of Exeter, and the Earth Commission.
Mr Mckay added, "The chance of crossing tipping points can be reduced by rapidly cutting greenhouse gas emissions."
"The world is already at risk of some tipping points. As global temperatures rise further, more tipping points become possible." he further said. "The chance of crossing tipping points can be reduced by rapidly cutting greenhouse gas emissions, starting immediately."
Additionally, the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) had earlier stated that risks of triggering climate tipping points become high by around 2°C above preindustrial temperatures and very high by 2.5-4°C.
This new analysis indicates that Earth may have already left a 'safe' climate state when temperatures exceeded approximately 1°C warming. A conclusion of the research is therefore that even the United Nations' Paris Agreement goal to limit warming to well-below 2°C and preferably 1.5°C is not enough to fully avoid dangerous climate change. According to the assessment, tipping point likelihood increases markedly in the 'Paris range' of 1.5-2°C warming, with even higher risks beyond 2°C.
The study provides strong scientific support for the Paris Agreement and associated efforts to limit global warming to 1.5°C, because it shows that the risk of tipping points escalates beyond this level. To have a 50% chance of achieving 1.5°C and thus limiting tipping point risks, global greenhouse gas emissions must be cut by half by 2030, reaching net-zero by 2050.
