Tokyo, Oct. 26 (Jiji Press)–A Japanese government study has found that global warming intensified six major heavy rain events that happened in the country in August or September this year, highlighting growing risks of disasters. The science ministry and the Japan Meteorological Agency’s Meteorological Research Institute on Friday announced the results of the study, in which the degree of global warming impact on the rain events was analyzed using a computer. The amount of rain was about 20 pct more compared with a scenario assuming that global warming did not occur in and after 1850, according to the study. All five events led to the issuance of the highest Level 5 emergency warnings, causing landslides, river flooding or flooding of houses above or below floor level. Three of the six events occurred in August, hitting the eastern prefecture of Chiba, the central prefectures of Toyama and Ishikawa, and Fukui Prefecture, also central Japan, respectively. Of the other three events that happened in September, the Tokai central region was hit by heavy rain from a weather front, eastern and western Japan regions were struck by a typhoon, and the northern part of Tokyo’s Izu Islands and the southern part of the Kanto eastern region were damaged by a different typhoon. Compared with the scenario assuming no global warming, temperatures were 1.3-1.6 degrees Celsius higher, while the amount of atmospheric water vapor and that of rainfall increased by 9.5-11.4 pct and by 15.7-22.9 pct, respectively. The increase in rainfall was about twice that in the amount of atmospheric water vapor because water vapor not only turns directly into rain but also helps strengthen the development of cumulonimbus clouds by generating updrafts. The increase in rainfall was the largest in the event in Fukui, at 22.9 pct, followed by the downpour in Chiba and the incident in the Izu Islands and Kanto, both at 22.8 pct. END [Copyright The Jiji Press, Ltd.]
