The World Without Us

Megafauna are animals large enough to be seen with the naked eye. Outside of technical scientific literature, however, this term is most commonly used to describe very large animals (i.e., comparable to or larger than humans) such as bears, lions, or elephants, which are often referred to as “charismatic megafauna.” The latter are Weisman’s primary concern in The World Without Us, as when he discusses the Pleistocene extinction of mammoths, giant sloths, dire wolves, and more in the Americas.

A nurdle is a very small plastic pellet, usually less than 0.2 inches in diameter or length, that is the raw material from which plastic products are manufactured. When ocean-borne plastic detritus is eroded by wave action and the like, it eventually disintegrates into nurdles, which are small enough for tiny marine organisms to consume. Since plastic is such a new creation, scientists do not yet know the long-term ecological impacts of microplastics permeating the marine food web.

POPs is an acronym for “persistent organic pollutants,” manufactured chemicals that biodegrade extremely slowly, if at all. This stability was considered a boon when the substances were initially developed for commercial or industrial use, but as many have since proven to have harmful health effects, their persistence in the environment has become cause for concern. Weisman devotes particular attention to PCBs, which were banned in the 1970s but continue to show up in the bodies of people and animals living in the world’s polar regions, where most of them drifted over time.

Rewilding is an ecological restoration strategy that seeks to reestablish natural processes by reducing human influences on ecosystems with the goal of making those ecosystems resilient, self-regulating, and self-sustaining. The term was coined in 1990 by members of the grassroots environmental network Earth First! and refined in a 1998 academic paper by conservation biologists Michael Soulé and Reed Noss, who advocated reintroducing large predators into protected areas of wild land connected by habitat corridors that would allow wildlife to move through the landscape.

Transhumanism is a theory and movement involving the evolution of humanity beyond its current biological limitations; it often imagines a fusing of humans with technology that would allow for greatly enhanced intelligence and extended—possibly quasi-immortal—lifespans. Weisman describes this a kind of extinction, noting that transhumanism is sometimes also referred to as “posthumanism.” He presents it as a complement and counterpart to Les Knight and other advocates of voluntary extinction—an initially intriguing idea that nevertheless contains serious flaws, not the least of which is its underestimation of humans’ intrinsic worth.