Humankind is using water at an unsustainable rate, according to a recent article in Science Magazine. The article states humans use 10,700 cubic kilometers of water each year, or roughly 20 times the amount of water that flows down the Mississippi River. The amount is 18% higher than previous estimates and it seems to be getting worse. The culprits primarily seem to be over irrigation and damming rivers, both of which significantly raise the amount of water lost to evaporation.
According to a University of Michigan page I found, humans are currently using 54% of available runoff, putting stress on natural ecosystems. Given that global population is growing at 1.1% per year, it’s not hard to see that the whole house of cards will come tumbling down if we don’t do something about it.
So, what can be done?
About 70% of the fresh water on Earth is held frozen in polar ice caps. On the surface, the solution seems easy: tap into this mammoth repository of fresh water. Unfortunately that “solution” carries many negative consequences. First off, the polar caps are already being depleted at an alarming rate. Accelerating that doesn’t seem to be in our best interests. Secondly, the ice caps are not a sustainable source. Once they’re gone, they’re gone. Humanity needs a renewable source of water.
How about the Sun? Well, maybe not the Sun, exactly, but what fuels it. The Sun burns using a nuclear fusion reaction and, it just so happens, we’re on the cusp of creating for the first time a fusion reactor that creates more power than it uses to sustain the reaction. Once it can be perfected, things that were previously limited by the cost of power will no longer be so. What, exactly, does this have to do with our water shortage?
San Diego is about to turn on the nation’s largest desalination plant, a privately funded facility that will pull fresh water from sea water and supply 7% of the city’s water. Another similar plant is in the works in Huntington Beach. If everything sounds great and like desalination will solve all our water worries, it won’t – at least not yet. The problem with desalination is that it’s expensive – currently about twice that of standard water purifying methods – with much of the expense coming from the power required for the process. See where I’m going with this? If fusion brings power costs down to a fraction of today’s value, then mass desalination can become a plausible solution to our water woes.
UPDATE: Tomer D Tamarkin, who is responsible for the web site Fusion4Freedom, brought up to me another reason power helps with water issues: water movement. Simply having enough fresh water is one issue, but getting it to where it’s needed is another. It takes power to do that.