Cheap fresh water at scale
Two-thirds of the planet is water we can't drink. Can we make the ocean drinkable for everyone?
What makes this fascinating
An ocean we can't drink — Most of Earth's water is salt; cheap desalination could quench growing shortages.
It takes a lot of energy — Reverse osmosis is the leading method but remains energy-intensive.
The brine problem — Disposing of the concentrated salt waste without harming ecosystems is an open challenge.
Frequently asked questions
- Why can't we just desalinate the ocean cheaply?
- Desalination works but is energy-hungry and costly, and it produces concentrated brine that's hard to dispose of. Making fresh water from seawater cheaply and sustainably at global scale is still unsolved.
- What is the main method of desalination?
- Reverse osmosis, which forces seawater through membranes that block salt, is the dominant technology — efficient compared to older methods but still energy-intensive.
- Why does cheap fresh water matter?
- Two-thirds of the planet faces water stress at least part of the year; abundant, affordable fresh water would transform agriculture, health, and stability worldwide.
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