One of the many misconceptions among environmentalists is that clean drinking water is increasingly scarce, and that we will run out of it soon if we do not drastically change our ways. There is merit to this argument, but it fails to consider the age we live in, and the sustainable solutions we already wield.
Drought is becoming exceedingly common and severe in many highly-populates regions of world, including areas in developed countries like the Southwest United States. It is true that regional water resources are strained, in part due to climate change and as well as from unsustainable human practices.
These issues are not new, however. For hundreds of years, ancient civilizations across North Africa, the Mediterranean, and the Near East used aqueducts and channels to carry water for dozens of miles. Today, cities like Phoenix and Los Angeles are supplied via modern day aqueducts which carry freshwater hundreds of miles through inhospitable desert.
Freshwater rivers are available in each continent, and long-distance water transport is very cheap on the macroeconomic scale, with large-diameter pipelines typically costing $2 million per mile, less than the cost of roads, rails, or runways. To the best of my knowledge, there is no practical limit to how far these pipelines and channels can carry water.
This is an important thing to note. If we have water available somewhere on Earth, we can take it where we need it, and on the large scale, at no substantial cost. The next thing to note is just as important: we have more than enough water for the global population to consume as much as Americans do, even if none of that water is recycled.
It is estimated that the United States uses nearly 150 trillion gallons of water anually, or enough water to fill the Grand Canyon once every 7 years. This is a little over 450,000 gallons per capita each year. If all 7.7 billion people used this much water per capita, we would require over 3.5 quadrillion gallons. Can this demand be met? How much freshwater is there on the Earth?
According to the US Geological Survey, there are around 332,500,000 cubic miles of water on Earth, which is equivalent to just over 366 quintillion gallons, or 366 billion billion gallons. Also, according to the USGS, 21,830 cubic miles of freshwater in surface lakes, and 2.53 million cubic miles fresh groundwater.
With American levels of consumption, the world’s surface freshwater would only last 7 years, however, with all fresh groundwater at humanity’s disposal, the hypothetical level of freshwater consumption could last as long as 820 years.
We can see that it may be wise to maintain rivers and resort to the use of ground water almost exclusively, pumping it out of the ground where we find it, and piping it where we wish to utilize it. I recognize that not all ground water will be accessible, but if even one-tenth of it was, we’d have enough water to last us at least a half-century at American levels of usage, without reducing water usage or recycling, allowing us plenty of time to implement sustainable solutions.
The City of Phoenix in Arizona was once lauded as the world’s least sustainable city, a poster child for suburban sprawl and the bourgeois American dream, and yet today it recycles 90% of its wastewater and puts more water in the ground than it takes out. Phoenix has prepared itself with 100 years of climate change-proof freshwater supply.
Why freshwater isn’t necessarily scarce: what if we could just take water from the ocean and turn it into freshwater? Meet desalination. Desalination plants can produce a gallon of freshwater using a meager 1 to 1.3 watt-hours of electricity.
Hypothetically, let’s say all the freshwater in the United States were to disappear; the US would require a one-time investment of roughly $570 billion for desalination plants, and 150 billion KWh each year of electricity. At current electricity prices, 150 billion KWh is worth about $19 billion. Now obviously it’s not quite that simple since without water you’re going to have a hard time employing thousands of people to build plants, etc.
Since the oceans are available to the overwhelming majority of humanity, over the next few decades the entire world could consume as much water as Americans do without sucking lakes and rivers dry. The primary concern of environmentalists would then become preventing desalination plants from causing ecological damage, but I’m sure we humans can engineer our way out of that problem too.
Thank you for coming this far and I hope you enjoyed reading and learned something worth knowing.