Depleting and climate-changing coal, oil, and natural gas have brought about dramatic human population growth, along with immense profits and unprece… - Richard Heinberg

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.

Our core ecological problem is not climate change. It is overshoot, of which global warming is a symptom. Overshoot is a systemic issue. Over the past century-and-a-half, enormous amounts of cheap energy from fossil fuels enabled the rapid growth of resource extraction, manufacturing, and consumption; and these in turn led to population increase, pollution, and loss of natural habitat and hence biodiversity. The human system expanded dramatically, overshooting Earth’s long-term carrying capacity for humans while upsetting the ecological systems we depend on for our survival. Until we understand and address this systemic imbalance, symptomatic treatment (doing what we can to reverse pollution dilemmas like climate change, trying to save threatened species, and hoping to feed a burgeoning population with genetically modified crops) will constitute an endlessly frustrating round of stopgap measures that are ultimately destined to fail.

If we do nothing, we still get to a post-carbon future, but it will be bleak. However, if we plan the transition, we can have a world that supports robust communities of healthy, creative people and ecosystems with millions of other species.