Subsea Desalination to Address Water Shortages

One of today’s major challenges, which will only intensify as the world’s population grows, is ensuring there is enough water for humans and animals to survive. God has provided ways to obtain the water needed for crop growth, maintaining healthy animals, and even for space travel. Our space probes have detected vast amounts of water on other planets in our solar system, and even on the Moon. While these discoveries are promising for the distant future, when humans live elsewhere, the more immediate challenge is securing sufficient water on Earth. A potential new solution is subsea desalination.

The 1798 poem “The Rime of the Ancient Mariner” by Samuel Taylor Coleridge describes a sailor stranded at sea who laments, “Water, water everywhere and not a drop to drink.” Today, various desalination methods are used to remove salt from seawater and produce drinking water. These include boiling seawater and condensing the vapor, flash distillation utilizing temperature and pressure, and reverse osmosis with extremely tiny membranes that allow only water molecules to pass through. These methods often require a lot of energy and specialized materials. Subsea desalination requires far less energy from fossil fuels and can be deployed anywhere with an ocean depth of at least 1,600 feet (500 meters).

Subsea desalination uses the immense pressure found deep in the ocean to generate the necessary energy. At a depth of 1600 feet, the pressure reaches approximately 102,400 pounds per square foot, enough to push water through membranes, leaving the salt behind. The clean water can then be piped to shore. This water will contain very few bacteria and other microorganisms and will be free of algae, river runoff, and the effects of storms and seasonal temperature changes. Very little chemical addition would be needed, and coastal cities like Los Angeles and San Francisco could benefit most from subsea desalination.

Everywhere we look, we see that God has provided Earth and our solar system with abundant resources to meet our most basic needs. And He has created humans in His image with the creativity and intelligence to find those resources.

— John N. Clayton © 2025

Reference: Scientific American for October 2025, pages 10-12, and scientificamerican.com