Global warming raised chance of extreme heat during Japan summer by 240 times: study
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Global warming caused by human activities raised the probability of record high temperatures across Japan this summer by 240 times compared to the expected chances in the absence of global warming, a Japanese research team announced on Sept. 6.
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The group used a method called "event attribution" to quantitively analyze how global warming has affected extreme weather phenomena. According to the researchers, the probability of high temperatures in Japan between late June and early July this year was about "once in five years." This took into account the effects of global warming and the La Nina phenomenon triggered by lower-than-normal sea surface temperatures off the coast of Peru, which lasts for about a year.
In contrast, the results of analysis presuming no global warming showed that extreme heat would occur as rarely as "once in 1,200 years" even if the same La Nina phenomenon occurred.
JMA statistics showed that the average temperatures in late June were 4 degrees Celsius higher than normal years in east Japan, and 3.2 C higher in west Japan. In the eastern Japan city of Isesaki, Gunma Prefecture, the mercury hit 40.2 C on June 25 -- the first time in the country that the temperature has exceeded 40 C in that month.
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