…civilization’s survival dilemma in the 21st century is best described by a concept from population ecology—overshoot. This refers to the situation w… - Richard Heinberg

For a population of field mice in overshoot, the critical resource might consist of small plants whose unusually robust growth has been triggered by high levels of rainfall. For humanity currently, the critical resource is fossil energy. Temporary energy abundance has led to many good things (for some of us, anyway): more food, more people, more commercial products, more knowledge, more comfort, and more convenience. But we are about to become victims of our own success.

Global human population has doubled three times in the past 200 years, surging from 1 billion in 1820 to 2 billion in 1927, to 4 billion in 1974, to 8 billion today. Its highest rate of growth was in the 1960s, at over 2 percent per year; that rate is now down to 1.1 percent. If growth continues at the current rate, we’ll have about 18 billion people on Earth by the end of this century. All of this would be fine if we lived on a planet that was itself expanding, doubling its available quantities of minerals, forests, fisheries, and soil every quarter-century, and doubling its ability to absorb industrial wastes. But we don’t. It is essentially the same beautiful but finite planet that was spinning through space long before the origin of humans.

Most environmental dilemmas have to do with limits (usually limits to either resources or to waste sinks). And most environmental solutions have to do with reining in our wants and ambitions in some way. Cleverness may help at the margins—as when chemists identify a relatively harmless substance that can substitute for a toxic one. But without self-limits on population and consumption, no amount of cleverness can halt humanity’s accelerating march toward collapse. Economist William Stanley Jevons got an inkling of this stark reality in 1865, when he published his observation that making coal usage more efficient led to increased coal mining (and depletion), not conservation. Too often, we outsmart ourselves by thinking we’re doing something to save resources and reduce pollution, when in fact we’re just paving the way for more of the same.
Another intelligence-resistant problem is deciding what’s a good life or a good death. These are arguably the most important personal questions with which any of us will ever grapple, but intelligence doesn’t always help with answers. It’s true that smart people sometimes avoid a lot of problems that plague less-smart people (such as falling prey to obvious scams and rip-offs). But they just as often end up burdening themselves and others around them with even bigger problems brought on by the unforeseen consequences of their own cleverness—as when a smart investor or inventor accumulates a huge fortune, over which their heirs fight bitterly, to the point that family dynamics are poisoned for generations to come.
Finally, there is the uber-problem that should be at the top of all our minds—the long-term survival of humanity. We naturally want our species to stick around. And we like to think that our intelligence improves our prospects in that regard. But, so far, the evidence points in the opposite direction.

It’s sad when loved ones die, and few of us look forward to our own demise; hence the perennial quest for an elixir of eternal life, or at least a cure for cancer. But if nobody died, the planet would quickly fill with humans and empty of all the things that feed and provision us. Death clears space for new life; it is the non-negotiable price of admission to the great banquet of existence.