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 … - Richard Heinberg

Agriculture enabled population growth and social complexity, but it gradually robbed soils of nutrients. Sailing ships guided with clocks and navigational charts could increase the scope of trade, but building wooden ships (and making charcoal for forging steel) was leading to the deforestation of whole continents. A reckoning with limits seemed to be in store. Then a miracle happened. People who lived in some key centers of global trade started using fossil fuels—energy sources capable of delivering power in previously unimaginable and seemingly endless quantities. Coal, oil, and natural gas enabled the development of transport technologies (steamships, railroads, cars, trucks, and airplanes) that overcame prior limits to the speed of travel and trade, so that products and resources that were abundant in one place could be transported to places where they were scarce. Fossil fuels could be used to increase the rates of resource extraction via powered mining machinery, and to process lower grades of ores as more concentrated ores were depleted. They could be fashioned into plastics and chemicals to substitute for some natural materials that were getting scarce, such as hardwoods and whale oil. And they could be made into artificial fertilizers, which could replace soil nutrients lost due to unsustainable agricultural practices. All these developments together enabled population growth at rates that far outstripped historic trends: human numbers expanded from one billion to eight billion in a mere two centuries. We were, in effect, stretching existing constraints on population and consumption to the point that it was difficult for many people to see that boundaries still existed at all.

Prior to the widespread use of coal, oil, and natural gas, agrarian societies saw cyclical periods of rise and fall. But the scale of expansion since the dawn of the fossil-fueled industrial revolution, beginning roughly at the start of the 19th century, has been unprecedented. Energy usage per capita has grown 800 percent, as has population. Meanwhile, the contours of society have been transformed: for the first time in human history, most people now live in cities.

Climate change is a wicked problem… [and] there is no way to solve it without sacrificing something that society currently holds dear, and without thereby generating more problems. For example, shrinking the economy would reduce carbon emissions, but it would throw a lot of people out of work (in effect, we did trial runs during the financial crash of 2008 and the COVID pandemic of 2020; both times, carbon emissions plunged, yet everyone was eager to “get back to normal”). Building vast amounts of low-carbon energy-producing and energy-using infrastructure would also reduce emissions, but that would require tens of trillions of dollars of investment as well as enormous quantities of depleting, non-renewable minerals—the mining of which would generate pollution and destroy wildlife habitat.