It found that heatwaves that smash previous records by roughly 5C would become two to seven times more likely in the next three decades and three to 21 times more likely from 2051-2080, unless carbon emissions are immediately slashed. Such extreme heatwaves are all but impossible without global heating. The vulnerability of North America, Europe and China was striking, said Erich Fischer, at ETH Zurich in Switzerland, who led the research. “Here we see the largest jumps in record-shattering events. This is really quite worrying,” he added. “Many places have by far not seen anything close to what’s possible, even in present-day conditions, because only looking at the past record is really dangerous.”
The study also showed that record-shattering events could come in sharp bursts, rather than gradually becoming more frequent. “That is really concerning,” Fischer said: “Planning for heatwaves that get 0.1C more intense every two or three years would still be very worrying, but it would be much easier to prepare for.” The new research, published in the journal Nature Climate Change, concluded: “Record-shattering extremes are [currently] very rare but their expected probability increases rapidly in the coming three decades.” It found the rate of global heating was critical in increasing the risk, rather than simply the global temperature reached. This indicates that sharp cuts in emissions are needed as soon as possible, rather than emissions continuing and being sucked back out of the atmosphere at a later date. The scientists used a scenario in which carbon emissions are not reduced, which some experts have argued is unrealistic, given that some climate action is being taken. However, global emissions are not yet falling, bar the blip caused by the coronavirus pandemic, and the researchers argue the scenario remains relevant until CO2 emissions are consistently falling.