According to a new paper by scientists from a dozen institutions, the world’s average temperature will surpass 1.5°C above preindustrial times within the next several years—much faster than most existing forecasts. The study goes on to say that without extreme action by the international community, temperatures will reach 2°C above preindustrial levels before 2050—also faster than most predictions.
“The 1.5 limit is deader than a doornail,” Hansen told a press conference to introduce the paper. He said he and his co-authors expect temperatures to consistently hit or exceed that level during the 2020s, then rise rapidly over the next two to three decades afterward. “The 2-degree limit is also dead, unless we take purposeful actions to reduce Earth’s energy imbalance,” he said.