Desalination

Being sustainable lets us believe in an endless continuance. If people lived sustainably upon Earth then we’d expect things to remain roughly the same for a very many lifetimes. Just as we saw happened for the dinosaurs; at least according to dinosaur fossils. However we know energy or rather its potential doesn’t get recharged and we haven’t a replacement yet. This prevents us from living truly sustainably.

The same concern can be said for other resources such as water. Most people live within ready access to water but of course we know that all water is not equal. We drink potable water. And we sail upon ocean water however we’d never drink it! To make it potable we utilize desalination plants. Seems we’re relying upon these plants a lot. Worldwide we have well over 18000 of them pumping out over 86.8 million cubic metres of potable water every day. This is a recent phenomenon as their construction began only in 1955. What’s its energy cost. One reference puts the plants’ average power draw at 3 kWh per m3. This calculates to 3.4e17 J per year of energy dedicated to providing us with water. At least half of this energy for desalination comes from fossil fuels. And of course there’s a waste stream. The effluent from a desalination plant gets discarded nearby usually to a negative effect upon the ecosystem. Yes indeed we see from this that our use of the Earth’s water resources isn’t sustainable either.

About 1% of our human population relies upon water from desalination plants. They have no other ready source of potable water. This percentage continues to increase. How do we affect a sustainable, endless continuance when we our reliance upon artificial means grows? And the ready supplies of energy get consumed? What does this makes you think about sustainability and our future?
water