An intense exploration of the fundamental transformations that led to the modern world. Historian Smil begins with population transitions before moving on to agriculture, energy, economics, and environments. All premodern societies had high birth and death rates and slow population growth. Improved food production in the 18th century and sanitary and medical advances reduced death rates, but birth rates remained high until entire societies felt secure. The result was a period of hyperbolic growth after World War II that peaked in the 1960s. Today, except for Pakistan, Yemen, Bolivia, and sub-Saharan Africa, population growth is low, and some nations, such as Japan and Russia, are shrinking. Though modern agriculture has become massively efficient, it depends far more on fossil fuel and chemicals than sunlight and rain. Smil maintains that the greatest economic impact on human life is the gasoline-fueled internal combustion engine. By 1929, it provided 88% of America’s mechanical power. “Electrification,” writes the author, “has…been partially a transition within a transition (from direct uses to an indirect exploitation of fossil fuels)” and is “perhaps the most important of all transformative processes originating from technical innovations: ‘electric’ might be the single most important adjective used to describe the functioning of modern societies.” Readers will encounter the usual bad news about the environment—e.g., the burning of fossil fuels provided 91% of Earth’s energy in 1992; by 2017, it was…91%)—but Smil’s focus on facts and recent history situates him in a moderate position between catastrophists and those who tout a future of “general and unstoppable improvement.” The author mostly (but not entirely) avoids turgid academic prose, and he isn’t shy about delivering information, often overwhelming readers with facts, statistics, and analyses. The result is an expert portrait of spectacular technical and economic advances that many in the 21st century enjoy but which exclude large segments of the population and are creating problems that may or may not be solvable. Ingenious, insightful, and disturbing.