One other important point that Scolnikov glosses over:
The best indicator of how much fresh water we can sustainably use is the rate at which freshwater resources are replenished by precipitation (any freshwater sources, like lakes, rivers, or aquifers, are just buffers we can draw from, but ultimately are refilled from precipitation, or via channels passing precipitation water back to the ocean)
Well, unhappily it isn't as easy as that. Aquifers don't fill up like a swimming pool. It takes minimally hundreds of thousands and in most cases millions of years for an aquifer to recharge. We are rapidly using them up, not just in this country but in every highly populated country that I am aware of. The Ogallala Aquifer is mainland US's largest, and it is drawing down at alarming rates. See "Ground Water Depletion in the High Plains Aquifer" geology.com and "Time, Water Running Out for America's Biggest Aquifer" aolnews.com for example. But that is just the largest example. Aquifers all over the world are being drawn down, and while more powerful pumps can continue to get water from them, at some point the water becomes more and more salt- and mineral-laden, making it harder to use either for agriculture or for human consumption.
And, as he notes, water is also different from oil in that there are no substitutes for it. I have come to have a greater appreciation of that fact over the past couple of years as I have read more and more about the utter uniqueness of the molecule H2O. |
