Across the world, developed nations have locked themselves into unsustainable, energy-intensive lifestyles. As environmental collapse threatens, the journalist Noah Gallagher Shannon explores the lessons in sustainability that can be learned from looking “at smaller, perhaps even less prosperous nations” such as Uruguay. “The task of shrinking our societal footprint is the most urgent problem of our era — and perhaps the most intractable,” writes Shannon, who explains that the problem of reducing our footprints further “isn’t that we don’t have models of sustainable living; it’s that few exist without poverty.” Tracing Uruguay’s sustainability, Shannon shows how a relatively small population size and concentration (about half of the country’s 3.5 million people live in Montevideo, the capital) had long provided the country with a collective sense of purpose. He also shows how in such a tight-knit country, the inequalities reach a rapid boil, quoting a slogan of a Marxist-Leninist...