So I was a bit surprised to read this at the end of one report about yesterday's flood:
Kei Yoshimura, a hydrologist at the University of Tokyo’s Atmosphere and Ocean Research Institute, said the magnitude of the Kinugawa River flooding on Thursday was “something that takes place only once in 100 years.”This is one of those cases of over-caution on the matter of attribution to individual events. If Kei had wanted to paint the "bigger picture" he might of cited this 2007 paper about increased rainfall intensity in his country:
He added that it was too early to conclude the flooding was linked to climate change, saying the heavy rainfall happened to occur along that river.
“It’s my view that the effect of climate change on this particular incident is zero, or unknown at this point,” he said.
This paper explores features of long-term changes in precipitation in Japan based on recent studies using daily data from 51 stations since 1901, partly updated for the present article. We show that heavy daily precipitation ( 200 mm and 100 mm) has significantly increased during the last century as weak to moderate precipitation ( 1 mm to 10 mm) has decreased. New analysis using hourly precipitation records at over 600 stations on the AMeDAS network has shown an increase in very intense hourly and six-hourly precipitations ( 100 mm/h and 300 mm/6h) during the last 28 years.Or he might have referred to the worldwide trend, as discussed here in a 2012 paper:
Based on the discussions above, we can make the following conclusions. First, the large increase in global average precipitation intensity increase derived from the GPCP data, with the top 10% heavy precipitation increased by about 108% for each degree Kelvin increase in global mean temperature and the bottom 30%–60% bins decreased by about 20% K 1, is credible. Increases in heavy precipitation can lead to more and worse floods and mudslides, while decreases of light and moderate precipitation can increase the risk of droughts. The 100-year linear trend (1906–2005) of global temperature is 0.74 C 0.18 C, and is expected to increase even faster [Solomon et al., 2007]. This implies that the global top 10% heavy precipitation had already increased by about 80% and will continue increase at a faster rate. Meanwhile there are corresponding increases in the risk of droughts. It follows that the increasing occurrence and severity of floods, mudslides, as well as shortage of water resources has been and would increasingly be one of the worst hazards to the global ecosystem as the result of global warming.The lesson: this key damaging aspect of climate change is already happening.
And, second lesson: ANDREW BOLT - YOU ARE WRONG AND A FOOL FOR NOT ACKNOWLEDGING CLIMATE CHANGE HAS LONG BEEN PREDICTED TO INCREASE BOTH FLOOD AND DROUGHT.