A cheap method to remove salt from seawater will have enormous geopolitical ramifications. From the Reuters article “Pentagon weapons-makers finds method for cheap, clean water” by David Alexander (here):
A defense contractor better known for building jet fighters and lethal missiles says it has found a way to slash the amount of energy needed to remove salt from seawater, potentially making it vastly cheaper to produce clean water at a time when scarcity has become a global security issue.
The process, officials and engineers at Lockheed Martin Corp say, would enable filter manufacturers to produce thin carbon membranes with regular holes about a nanometer in size that are large enough to allow water to pass through but small enough to block the molecules of salt in seawater. A nanometer is a billionth of a meter.
Because the sheets of pure carbon known as graphene are so thin - just one atom in thickness - it takes much less energy to push the seawater through the filter with the force required to separate the salt from the water, they said….
…. Access to clean drinking water is increasingly seen as a major global security issue. Competition for water is likely to lead to instability and potential state failure in countries important to the United States, according to a U.S. intelligence community report last year.
"Between now and 2040, fresh water availability will not keep up with demand absent more effective management of water resources," the report said. "Water problems will hinder the ability of key countries to produce food and generate electricity."
About 780 million people around the world do not have access to clean drinking water, the United Nations reported last year….