I believe that this earth is a closed system. Nothing can be depleted or destroyed to the point where it is not recoverable. Everything alters their state subject to the manipulation that it is subjected to, but that altered state either makes it usable or unusable. If unusable, appropriate manipulation can be brought to bear on it that will recover it into a usable state once again.
Therefore, our ability to deplete natural resources is in fact only limited to our inability to recover what we’ve altered. I disagree with the premise that the earth will be incapable of sustaining life in years to come because it will be over populated. It can never be over populated but it can be, and is abused. It’s our abuse of the resources at our disposal that leads to the massive disparity in quality of life between nations and geographical locations.
The greater our ability to responsibly balance how we consume, the greater will be our ability to restore and sustain the availability of resources that we have at our disposal. Even the conception and birth of a baby is a result of resources in some form or another being consumed. The mother, through the nourishment that she provides her body, influences the quality of foetal life, as well as the subsequent birth. Just because it is all a result of extremely complex chemical reactions does not imply that something is being created out of nothing.
What exists, exists. How we manipulate that will determine how many beautiful or disgusting permutations of the combination of our resources can yield subject to our limited intellectual and physical abilities. The more we grow to understand this world and everything it contains, the greater our ability to influence its form and function. But we must never forget that we are nothing but manipulators of what already exists, and therefore we should not delude ourselves about our capabilities.
This realisation, for me, further establishes my views about the atheist philosophies compared to that of the theists, who are now more fashionably called creationists. Man has never, and will never create something out of nothing. Nor are we able to truly grasp what nothing is, because it will always be thought of in the context of the absence of something. And as we know, the absence of one thing creates a condition in which something else is manifested. Think about it. All we do all day is alter the state of things. Things that already exist.
The search for the beginning of creation will never end, because every single time we think we arrived at the smallest particle known to man, we fail to conclusively answer a simple question. What causes that particle to assume the characteristics and properties that it does? There is always more, and the only thing that limits how much we understand of how much more there is, is our limited knowledge and our limited abilities to delve deeper than we already have.