Investigation for Resolution
After our visit to Professor. Taikan Oki, we realize solving water problems cannot solely dependent on the efforts of societies and companies. It is also important to raise the awareness of consumers’.
However, in Japan we take it for granted that we have enough water and feel the water problem is too far away from us.
To make people realize the importance of water, we planned a menu and calculated the quantity of the water consumed to make our meals with the calculator (*1) from Ministry of the Environment.
Then, we made a menu which shows the quantity of the water consumed in making it.
Because producing food such as meat and wheat needs much water, it has a lot of virtual water. Moreover, seasoning such as olive oil and drink also has much virtual water. So, we use more water than we expected.
Compared to Western style meals such as steak and hamburger, Japanese style meals such as miso soup and nimono, food cooked in seasoned broth, do not use meat well. Japanese style meals have less virtual water than Western style. Because a lot of water is required when producing animal feed such as corn., the menu using meal have a lot of virtual water. Especially, cattle eat much grain so that beef has much virtual water.
Therefore, dishes using beef are likely to have a lot of virtual water. Moreover, ingredients of Japanese style meals are more likely to be able to be produced in Japan than those of Western style meals and we import less virtual water.
However, the food self-sufficiency rate on a calorie basis of Japan is low, 38% (*2) and we depend on imports for plenty of food.
In particular, the beef self-sufficiency rate on a calorie basis is 36% (*2) and it is only 10% (*2) in taking into consideration self-sufficiency ratio for feeding. We compensate for the lack by importing much food and thus import a lot of virtual water.
To summarize, low food self-sufficiency rate on a calorie basis means that we consume water resources all over the world as virtual water.
Besides our meals, we use much water to live for baths, toilets, laundry and so on.
The graph shows that 150～250L per capita is used a day in developed countries. But “mizu kiki hontou no hanashi [water crisis true story]”, written by Professor. Taikan Oki, says that
"2～3L of drink water is enough for us to keep living as people."
That is, water problems are not only whether we live or die but also whether we can live a life that meets certain basic standards.
*1:Ministry of the Environment. (n.d.) . Kaso-sui keisanki [The calculator of virtual water]
*2:Ministry of Agriculture, Forestry and Fisheries. (2018). Heisei 29 nendo syokuryou zikyu hyou [The table of the food self-sufficiency rate in 2018]
*3:Japan Water Research Center. (2017). Suidou no kokusaihikaku ni kansuru kenkyu [Research about International Comparison of Water Service]
・Oki, T. (2012). Mizu kiki honto no hanashi [water scarcity true story].Tokyo: Shintyo sensho
The original graph made on the basis of the data (*3) from Japan Water Research Center