tl;dr: resources tend to last longer if you use less of them
Sometimes resources can seem so plentiful that it is just unfathomable to think that they could ever be exhausted. It may also seem that the problem of running out is not a possibility within any of our lifetimes. Technically, the sun will eventually die, but we are looking at another 7 to 8 billion years before that event happens. Similarly, I don’t think anyone is exactly worried about a sand shortage, and for good reason. There is an abundance of that resource and we’re not being ridiculous in our sand consumption (unfortunately, there are some exceptions to this, as well). Yeah, Timmy, I'm talking about that extra sandcastle you built on your vacation. Not cool, buddy.
For a long time on the North American continent, there existed a species of bird, ectopistes migratorius. The common name of this bird was the passenger pigeon. Stories exist as late as the 1870s of flocks of passenger pigeons so large that they completely darkened the sky. It would take several hours for an entire flock to pass by. Hunting these tasty avians was as simple as pointing a shotgun in the sky and pulling the trigger. Americans did not just utilize that simple hunting technique to harvest these birds. No, we got very efficient and utilized nets, fire, sulfur, poison, and the demolition of entire forests holding resting broods. Eventually, the flocks dwindled and the very last passenger pigeon, a female named Martha, died at the Cincinnati Zoo on September 1, 1914.
What once numbered in the billions and thrived for millions of years before European settlers arrived, disappeared completely in the relative blink of an eye. This bird was, for all intents and purposes, sand with wings. The pigeon census was just too high for any one person to be concerned with the damage that they could inflict on the overall population. In fact, the immense concentrated numbers of individual pigeons are what allowed them to thrive for most of their time on this planet. This concept is called predator satiation. You can see this practice today in schools of sardines. But you better hurry up, because at the rate that we’re screwing up commercialized fishing, we’ll probably be writing about the long-lost sardine in about a century or so.
There is another resource that seems to be vast in quantity. For many, it is a substance that just cannot ever disappear. Yet, these annoying science people are starting to really get vocal with their alarm bells about it. That resource is freshwater. Freshwater represents only 2.5% of the entire planet’s worth of water, yet we consume it like it's actually 97.5% of all the water on this planet. Sadly, this is just not the case, no matter how plentiful it might seem to many of you. Of the 2.5% of the freshwater on this planet, only 31.3% of this is available for consumption (ground, surface, and other). A big chunk of other is ground ice and permafrost, which is not as accessible. Perhaps this vast quantity of fresh water isn't quite so abundant as we had initially thought it to be?
To make matters even worse, Americans consume a lot of water on a daily basis. In fairness, we need that water for really important stuff! Our yards, designed on an archaic concept of European manors, need to be watered! Our snazzy oversized SUVs need to be sparkling! Our teeth get way whiter when the water is running while we are brushing! Our household water usage looks something like this:
20 to 40 gallons of water for one shower
25 gallons per washing machine load
20 gallons per day from kitchen sink for preparing food and washing dishes
15 gallons per day for washing hands, shaving, and brushing teeth
The intent of this information is not to make you feel like crap. It's to emphasize that sustainability is an examination of consumption, not just climate change. Climate change will severely impact our freshwater resources. We must consider adjusting our daily consumption to preserve these endangered sources of freshwater. Examining how the largest consumers of water like agriculture and industry use this precious resource is critical. The reality is that all sectors have to tackle their usage simultaneously. Change is challenging. It may seem that a lot of the changes that are recommended for sustainability purposes really make life a lot more inconvenient. My question is if living without these inconveniences is worth a very near future where people have to move, wars are fought, and rationing exists because of freshwater shortages? If you conclude that having the nicest yard in the neighborhood is worth that, then I suppose not only will freshwater go the way of the passenger pigeon, but humans as well.