f the overpopulation alarmists of the 1970s had really wanted, above all, to protect the environment, they should have promoted the development of dense, energy-efficient communities.

The evidence is clear, and has been for some time, that density is good for the environment. As UC Berkeley researchers argued in a 2014 paper, “population-dense cities contribute less greenhouse-gas emissions per person than other areas of the country,” and “the average carbon footprint of households living in the center of large, population-dense urban cities is about 50 percent below average, while households in distant suburbs are up to twice the average.”

But the people worried about other people don’t have a pro-density history; quite the opposite.

As the urban planner Greg Morrow detailed in his 2013 dissertation, overpopulation activists fought for the very legal frameworks that would keep cities low-density and worsen suburban sprawl. Morrow noted that in the early 1970s, the UCLA professor Fred Abraham, then-president of ZPG of Los Angeles, argued that “we need fewer people here—a quality of life, not a quantity of life. We must request a moratorium on growth and recognize that growth should be stopped.” Morrow added that “the Sierra Club (L. Douglas DeNike) agreed and suggested ‘limiting residential housing is one approach to lower birth rates’ and recommended ‘a freeze on zoning to limit new residential construction.’”