In beginning any discussion of water access, it is important to ask: how much water does Earth actually have? There are 326,000,000,000,000,000,000 (326 million trillion) gallons of water on Earth, enough for each human being on Earth to have a 46.5 billion gallon share. Of all of the water on Earth, though, only 2.5% is fresh water. Additionally, only 0.3% of all fresh water is readily accessible in lakes and rivers; the remaining 99.7% of freshwater is locked up in ice, snow, and groundwater. It is also important to consider that not all fresh water is drinkable. The United States Environmental Protection Agency defines fresh water as water containing less than 500 ppm salt, which is not necessarily drinkable. This water simply has lower average salinity than seawater. Wastewater constitutes another considerable portion of freshwater that is not available for human consumption. All things considered, humanity is left with about 0.008% of Earth’s water supply to use for drinking and sanitation.
With this tiny fraction of water in mind, it is perhaps not surprising then that water scarcity is already an issue for around 40% of the planet’s population. Water-starved countries like Haiti, Bangladesh, and Yemen struggle to survive. For the other 60% of the global population, which typically lives in developed countries with advanced water infrastructure, excessive water use per capita is common. The average American uses more than 100 gallons of water per day, while the UN assessment places average human need at only 6 to 13 gallons of water per day. The Water Resources Database estimates that there would have to be the equivalent of three Earths to supply the area needed to sustain a global standard of living equivalent to that of the average European or North American.
The graphic above represents the world if each country’s size were determined by its water usage. Countries like India, the United States, and China account for an astonishing 33% percent of humanity’s water usage while parts of Central and Southern Africa are barely visible on this map. Breaking down each country’s use, almost 70% of all fresh water used on Earth is devoted to irrigation, 20% is used in industry, and 10% is dedicated to domestic use. With such a small domestic water sector, 780 million people lack access to clean drinking water, which is more than 2.5 times the total population of the United States. An astonishing 2.5 billion lack access to adequate sanitation, and as a result, every year, 3.4 million people die from water-related illnesses – the rough equivalent of the population of Los Angeles dying each year.
These numbers are both shocking and likely to be exacerbated by population growth. Currently, the human population grows globally by about 77 million people per year. Most of this growth occurs in low-income or developing countries. This population growth has put a massive strain on useable water resources, as water is required to fulfill both drinking needs and agricultural needs. In addition to population growth, population distribution is also placing strain on water resources. The world population is slowly shifting from rural locations to urban centers, with 56% of the world’s population projected to live in urban areas by 2020. Urban populations place higher demands on water supplies than rural populations, and often do so at the expense of nearby rural communities.
Given all this information, it appears that humanity may soon reach a tipping point where human actions threaten global access to fresh water. Staving off a global freshwater crisis is one of the major challenges confronting the human race in the 21st Century. Without significant and proactive change to the way that we consume and view our water supply, the effects of this crisis could become irreversible.