Water is recognized worldwide as a global risk. The remaining water resources on Earth are the river outflows that flow into all oceans from the global water cycle. This river outflow is estimated at approximately 40,000 km3 per year. Of this 40,000 km3, the world’s population utilizes approximately 10%. In 1995, the world’s annual water withdrawals were 3,800 km3, and are expected to reach 4,300-5,200 km3 by 2025. According to the United Nations, the population of water-scarce urban areas is expected to increase to 1.7-2.4 billion by 2050. Meanwhile, in 2018, Cape Town, South Africa, was hit by a water shortage. The dam that supplied the city with water dried up. This emergency situation meant that only 50 liters of water per day—enough for food and drinking—was supplied. A cultured lifestyle requires 65 liters of water per person for bathing, 60 liters for toileting, 50 liters for laundry, 55 liters for cooking, and 10 liters for other uses. While two to three liters per day are sufficient for survival, a cultured lifestyle requires 200 to 300 liters.
Water resources are not limited to daily life and agriculture. Water shortages affect many sectors. In Brazil, hydroelectric power accounts for nearly 70% of the country’s energy mix. However, Brazil is currently experiencing its first water shortage in 100 years. A lack of electricity stagnates economic activity. To compensate, thermal power plants are used. The use of liquefied natural gas (LNG) as an alternative fuel is increasing. Currently, Brazil imports 500,000 tons more LNG per month than usual. Brazil’s 500,000-ton increase in imports has also contributed to rising global LNG prices. The water shortage in the distant country of Brazil has reached a level that even Japan cannot ignore.
Merely lamenting and worrying about water shortages is no fun. As more people seek solutions to water shortages and clean water, that demand becomes a business opportunity. Humanity’s water issues are addressed in both the long and short term. In the long term, some countries are beginning to take measures to adapt to water shortages, such as making effective use of groundwater and developing integrated water and sewage plans. In the agricultural sector, measures include improving varieties that are resistant to drought and water shortages, irrigation, and strengthening climate observation systems. In India, where the water-hungry automobile industry has expanded, there are moves to build rainwater storage facilities on factory grounds. There are also moves to build dams in suitable locations. This shows that humanity is not without measures.
