The estimated total annual freshwater consumption by humans is 24,000 cubic kilometers per year.
What are the estimation?
The total annual freshwater consumption by humans can be estimated by considering the consumption of blue, green, and grey water.
Blue water: Blue water is freshwater that is withdrawn from surface or groundwater sources for human use. This includes water used for drinking, irrigation, industry, and power generation. The global consumption of blue water is estimated to be 4,000 cubic kilometers (km³) per year.
Green water: Green water is water that is stored in the soil and used by plants for growth. This water is not directly withdrawn from surface or groundwater sources, but it is still a valuable source of freshwater for humans. The global consumption of green water is estimated to be 15,000 km³ per year.
Grey water: Grey water is wastewater that is generated from human activities, such as washing clothes, bathing, and cooking. This water is not directly used for human consumption, but it can be treated and reused for purposes such as irrigation. The global consumption of grey water is estimated to be 5,000 km³ per year.
Total consumption: The total annual freshwater consumption by humans can be estimated by summing the consumption of blue, green, and grey water:
Total consumption = Blue water + Green water + Grey water
Total consumption = 4,000 km³ + 15,000 km³ + 5,000 km³
Total consumption = 24,000 km³
Therefore, the estimated total annual freshwater consumption by humans is 24,000 cubic kilometers per year.