I argued that the human race should have known it was in trouble, [...] given how insane our way of life had become. Minor quit blowing into his harm… - James Howard Kunstler

It has been estimated that the world human population stood at about one billion around the early 1800s, which was roughly about when the industrial adventure began to gain traction. It has been inferred from this that a billion people is about the limit that the planet Earth can support when it is run on a nonindustrial basis. World population is now past six and a half billion, having more than doubled since my childhood in the 1950s. The mid-twentieth century was a time of rising anxiety over the “population explosion.” The marvelous technological victory over food shortages, including the “green revolution” in crop yields, accelerated that already robust leap in world population that had begun with modernity. Dramatic improvements in sanitation and medicine extended lives. Industry sopped up expanding populations and reassigned them from rural lands to work in the burgeoning cities. The perceived ability of the world to accommodate these newcomers and latecomers in a wholly new disposition of social and economic arrangements seemed [to] be the final nail in the coffin of Thomas Robert Malthus, the much-abused author of the 1798 [groundbreaking work] An Essay on the Principle of Population as It Affects the Future Improvement of Society.

[Everything, and not just] all human enterprise can tend toward diminishing returns and unsustainability, but some modes have far more long-term prospects than others and some are socially suicidal, even in the short term. Many civilizations, from the Sumerians to the Maya, have faltered when overinvestments in the scale and complexity of food production produced ruinous diminishing returns. On American farms in the early 1800s, the balance between calories expended and calories produced as [the] food was about even. This occurred as tools reached a high stage of refinement but before machines replaced human labor and traditional knowledge. It implies a distinction between tools and machines, between work done with tools and work done by machines. Production improved while entropy was kept to a minimum. Under the current industrial farming system, it takes sixteen calories of “input” to produce one calorie of grain, and seventy calories of input to produce one calorie of meat. A hundred years ago, just before the introduction of… fossil fuel-based technologies, more than 30 percent of the American population was engaged in farming. Now the figure is 1.6 percent. The issue is not moral, academic, or aesthetic. […] It’s a matter of those ratios being made possible only because cheap oil and automation made up for so much human labor. We did what we did in the twentieth century because we could. Of course, not all farm labor amounts to slavery or serfdom. Depending on how farming is organized, it can result in a very satisfactory way of life and rewarding social relations. Agriculture in the United States was organized very differently in Pennsylvania and South Carolina 150 years ago, and not simply because of climatic differences.
Farmers had quickly become addicted to a new debt system of annual operation, mortgaging their farms to raise cash to pay for new machinery and fertilizer—literally betting the farm on a good crop. With prices chronically depressed, mortgages could not be paid off. Farm foreclosures soared in the mid-1920s. Another unanticipated consequence of mechanized farming was the destruction of [the] soil. The tractor and its implements were machines that no one had previously experienced before, and it was some time before farmers noticed the insidious effects of soil compaction, rutting, and erosion that occurred. This would combine a few years later with an extended drought to produce the additional hardship of the .

The belief that “market economics” will automatically deliver a replacement for fossil fuels is a type of magical thinking like that of the cargo cults of the South Pacific.
This age-old tendency of humans to believe in magical deliverance and to wish for happy outcomes has been aggravated by the very technological triumphs that the oil age brought into existence. Technology itself has become a… supernatural force, one that has demonstrably delivered all kinds of miracles within the memory of many people now living […]. There's no question that technology has prolonged life spans, relieved misery, and made everyday life luxurious for a substantial lucky minority. […] A hopeful public, including leaders in business and politics, views the growing problem of oil depletion as a very straightforward engineering problem of exactly the kind that technology and human ingenuity have so successfully solved before, and it, therefore, seems reasonable to assume that the combination will prevail again. There are, however, several defects in this belief.
One is that we tend to confuse and conflate energy and technology. They go hand in hand, but they are not the same thing. The oil endowment was an extraordinary and singular occurrence of geology, allowing us to use [a fraction of] the stored energy of millions of years of sunlight. Once it's gone it will be gone forever. Technology is just the hardware and programming for running that fuel, …not the fuel itself. And technology is… bound to the laws of physics and thermodynamics […]. All of this is to say that much of our existing technology simply won't work without petroleum, and without the petroleum "platform" to work off, we may lack the tools to get beyond the current level of fossil-fuel-based technology. Another way of putting it is that we have an extremely narrow window of opportunity to make that happen. In the meantime, here are the problems with the various alternative fuels, based on what we know now.