Peak oil has had the most attention. No one knows whether we are at peak oil now, or within another decade or so, but it does not have an infinite horizon. Peak does not mean that we run completely out. It means that we can no longer extract at an increasing rate. After hitting peak, the annual draw of any virgin material cannot support continued growth in its use. Indeed, assuming two percent annual growth in use, even iron ore will hit a peak within 50 years.
Another key to understanding the nature of shortage is yield on energy. After rich natural sources of materials are worked out, subsequent ones are more dispersed, so it takes more energy and technology to get them. That is, it takes more energy to obtain energy. This is obvious today in the deep drilling for oil, hydrofracking for natural gas, and so on.
The same is true of minerals; they take energy to obtain. Basic physics: the more dispersed any source is, the more energy it takes to concentrate it into useable form. Improved technology can improve this return, but it cannot beat nature’s basic physics. And all known sources of fossil fuel alternatives have energy yields far below the 100/1 or higher of the first Spindletop oil gusher.
Water is another impending shortage, water we can use, that is. Fresh water is scarce in many places around the world. The Colorado is not the only river nearly tapped out. How climate may affect this is not precisely predictable, but in most places we can use water far more frugally and still maintain quality of life. But we may not be able to maintain lush golf courses in the middle of deserts. And to maintain supplies of fresh water, we had best be careful with toxins. Don’t dump them in rivers or pump them into the ground to contaminate water tables.