The calculation is complicated. To decide if a non-renewable resource is unsustainable depends on how much of it there is, the changing rate of its use, and the number of people expected in the future. It also hinges on whether the non-renewable will remain non-renewable, that a substitute for the non-renewable will not be discovered, and that the effect caused by use of the non-renewable will always be desired. We must know all these things, else the point at which we run out of the non-renewable will be unknown. If we do not know all these things, it is wrong to claim use of a resource is “unsustainable.”
Ah, problems with limited information and an inability to predict the future duly noted. But, how does this relate to the Catholic Church, you may ask?
People. The Church’s concern is with people and their relationship to the Divine — something any fair-minded observer of the environmental sustainability movement will admit is incompatible with its goal of “minimal impact” on Pure Nature. In the New Manicheanism of environmentalism, people are the problem of evil. All would be right with Nature if it weren’t for dirty, rotten, filthy, wasteful people. Ptui!
It’s somewhat shocking then to learn that the Pontifical Academy for Science (PAS) has used the term “sustainable population” unironically. By doing so, it accepts the false premise that people and nature are separate with opposing interests, and it calls into question the PAS’s dedication to the idea of just Who Is the Author of Life. Whose side are they on anyway?!
This is where Malthus is usually invoked. But Briggs is helpful in explaining how we get Malthus wrong:
It is not that more people are encroaching upon more food sources, it is that more food leads to more people. Plentiful, cheap, and nutritious food caused, or rather allowed, the increase. Think: if there is not enough food, there cannot be an increase in population! It follows there cannot be “too many” people.
Briggs further explains there cannot be too many people in either the scientific or eschatological sense. He quotes Father Schall:
The root of the “sustainability mission,” I suspect, is the practical denial of eternal life. “Sustainability” is an alternative to lost transcendence. It is what happens when suddenly no future but the present one exists. The only “future” of mankind is an on-going planet orbiting down the ages. It always does the exact same, boring thing. This view is actually a form of despair. Our end is the preservation of the race down the ages, not personal eternal life.