It is highly likely that western Japan will post the worst shortage of sunlight for August after the end of World War II. How should we face the current climate change, in which extreme weather has become the new normal? Time has come for farmers to think of drastic measures to prepare for disasters beyond expectations which have now turned into nothing out of the ordinary.
According to the Meteorological Agency, sunlight hours in early August in both the Sea of Japan and the Pacific sides of western Japan were only 20 percent of an average August. If this trend continues throughout the month, the region is likely to break the worst record set after the agency began compiling the data in 1946.
Instead of summer heat, western Japan is experiencing long rains like in the rainy season. Many worry about the impact of the weather on rice fields. This year, beginning with the heavy snowfall in February, rice-growing regions are hit by frequent weather extremes, including tornadoes, hailstorms, typhoons, heavy rains, heat waves and shortage of sunlight.
Putting together two typhoons, long rains and shortage of sunlight hours marked in western Japan, the agency named the weather “the August 2014 heavy rain.” The worst rainfall record was broken every time a rain fell, and shortage of sunlight hours worsened. Compared with an average summer, the Pacific high was too weak to push the rain front northward, and wet air continued to flow into the front which stalled over Japan.
This was because the prevailing westerlies – the middle-latitude wind belts in the Northern Hemisphere – have been meandering significantly southward near western Japan, bringing in cold air and blocking the Pacific high from extending. While eastern Japan was covered by high pressure systems which brought heat waves of more than 35 degrees Celcius for several days, western Japan which was affected by the westerlies suffered from long rain and lack of sunlight. In the Asakita and Asaminami wards of Hiroshima city, which were hit by large-scale mudslides a week ago, 86 people were reported dead or missing, and rescue workers are still searching eagerly for missing victims.
The unusual weather is expected to continue until the end of the month. The agency says sunlight hours in western Japan maintain worse-than-average levels and predicts troughs will bring more clouds. There is high possibility that sunlight hours will break the worst record since the compiling of data began in 1946, which was marked in August 1980 with the Sea of Japan side receiving only 41 percent of an average August sunshine and the Pacific side 57 percent.
Extreme weather is not an issue only of Japan. The prevailing westerlies are influencing climate conditions around the world. According to the agency’s press release on global anomalous weather patterns reported between Aug. 13 and 19, monthly rainfall in Jilin Province in China was less than 20 mm, while more than 30 people were killed by heavy rain and flood in the southern provinces of Guizhou and Jiangxi. Weather disasters were also reported in other areas, with more than 100 people dead in the western part of Nepal due to landslides caused by heavy rainfall and more than 90 deaths in northern India.
Extreme weather events on a global level directly link to agricultural damages. As for Japan, measures against rice blasts should be taken immediately mainly in the western regions. With risks rising for further damages on rice crops, five prefectures – Yamaguchi, Tottori, Fukuoka, Saga and Oita – have issued warnings to prevent the spread of the disease. It was the first time in 21 years for Yamaguchi to issue the warning.
Makeshift measures would not be enough to prepare for climate changes. In view of frequent occurrence of disasters beyond expectations, comprehensive package of measures should be taken, such as using rice paddies as dams by temporarily storing rainwater, a method adopted in areas along the Chikusa River in Hyogo Prefecture. Other measures include building greenhouses strong enough to withstand strong typhoons and heavy snowfalls and developing weather-resistant rice varieties.
(Aug. 28, 2014)