The 1.5 degree target is a core element of climate protection - at least on paper. A research team is now predicting that 1.5 degrees would be reached in just eight years. With consequences that can no longer be reversed. "For people all over the world," as they write in their appeal.
Four tipping points for the global climate could be reached by 2030. This is the result of an analysis by an international group of climate researchers. Two of these tipping points concern the Greenland Ice Sheet and the West Antarctic Ice Sheet, respectively. Crossing the threshold could lead to dynamics that will allow the ice sheets to continue to melt even if the temperature on Earth does not increase any further, reports the team led by David Armstrong McKay and Timothy Lenton from the University of Exeter (UK) in the journal "Science".
Lenton is one of the researchers who first identified tipping points for the global climate in 2008. They defined tipping points as "a critical threshold at which a minute perturbation can qualitatively change the state or evolution of a system". For example, when a glacier loses altitude as it melts, its surface moves into lower, warmer layers of air, which accelerates melting. Beyond the tipping point, feedback processes can ensure that development becomes unstoppable.
In the case of ocean currents like the Gulf Stream, changes can have a huge impact on climate. The researchers estimate that when global warming reaches an average of 1.5 degrees Celsius compared to the pre-industrial era, four tipping points will be reached: the Greenland and West Antarctic ice sheets, the dying of tropical coral reefs and the thawing of the permafrost. Based on developments in recent years, they predict that 1.5 degrees will be reached as early as 2030.
"This puts the Earth right on course to surpass several dangerous thresholds that would have catastrophic consequences for people around the world," co-author Johan Rockstrom of the Potsdam Institute for Climate Impact Research is quoted as saying in a statement from his institute. "In order to maintain good living conditions on earth, to protect people from increasing extremes and to enable stable societies, we must do everything we can to prevent tipping points from being exceeded - every tenth of a degree counts."