Desalting the seas provides a new, fresh source of clean water right where we increasingly need it. Two of the most commonly used desalination technologies that extract fresh water from salty water are thermal desalination and membrane technologies. Reverse osmosis is an example of a membrane technology for desalination. John Tonner concedes that desalination processes which actually remove salt from water DO exist - though they are not widely used. Electrodialysis is one example.
Thermal desalination is the technology most often used to get fresh water from sea water.
Major thermal desalination plants are currently operating in several nations along the Persian Gulf, and in the Caribbean. In contrast to distillation technologies, membrane processes are most commonly used to get fresh water from brackish water, or to remove contaminants other than salt from polluted water. Several communities in Florida use membrane technology to get fresh water from brackish groundwater. One role chemistry may play in the future of desalination is in keeping the machinery clean. And that is limited by our ability to avoid those salts and minerals from sticking inside our machines. . .