Pick up a copy of Jared Diamond’s “Collapse”. I read another great book on the same subject, but can’t find it in my library and don’t remember the name or author, unfortunately. The lessons of the two were similar. Both took a number of case points of civilizations that either died out or survived serious artifacts of their own existence.
The simplest examples were due to deforestation, for the Anasazi, the Fertile Crescent, and Easter Island and others, but there were other growth-limiting factors. Deforestation is a great example simply because things seem to be going great right up to the point where the last trees disappear.
Diamond gives several illuminating examples of cultures facing the same issues but which survived., and makes the point that these civilizations faced a choice: to continue business as usual (and perish) or to make a dramatic cultural change, revising values, and giving up part of the collective cultural identity, to survive.
Malthus was wrong in a few key details, but his essential point was correct: if population growth is exponential but resource growth is not, the result is calamity. He was wrong about resource growth, which he posited was linear (and had been at that time). Fortunately, technology rescued everyone by making existing land more productive plus making more land arable, and converting unproductive land to arable land at higher rates. (Malthus’s point was a key inspiration to Darwin, btw, giving him the idea of competition for survival, leading to “survival of the fittest.”)
Decades ago, Carl Sagan wisely pointed out that the population problem is really a poverty problem. Wealthy, educated populations have low growth rates, for the obvious reasons: people don’t multiply so much because multiplication is fun, they do because sex is fun and sex leads to multiplication. Furthermore, in the poorest and densest populations, having many sons is the best retirement plan – not so much the case for wealthier societies.
There was a great TED talk projecting global population growth and demographics in this century, where the guy had a bunch of color-coded storage bins, each representing a billion in population. I wish I could find it and cite it. I really hope the guy is right! He says that while the global population will continue to grow, thanks to technology, the biggest growth will be in what I’ll inaccurately call a “middle class”, and that the subsequent population growth of this majority will dramatically slow down. [I described that poorly, as it hardly makes sense as I put it. Hopefully someone can clarify this.] In any case, it projects a significant reduction in population growth rate, to an overall peak (no overall growth), IIRC, around 2100.
But the pessimist in me believes that technology is inherently destabilizing in the long run, as advances exceed our ability to predict the results of the advances, and that the long-term (in terms of thousands or tens of thousands of years) forecast for the human race is dim. Or, more accurately, it’ll be too easy for a small group to destroy the planet, so unless we can get our eggs out of one basket, we’re doomed.
I try not to let my inner pessimist out much, or give it too much reign. I’m hopeful that there’s something I’m missing here. I’m not particularly optimistic that we’ll be able to spread from this solar system, and I have doubts whether a Solar population could survive without significant support from an Earth population.
And then there’s the LONG term thing: even if we’re doomed, some may survive, to start another cycle. Maybe the best way to find extraterrestrial civilization is to look for 10K-year cycles in EM radiation! (jk)