The World Without Us

The word “Anthropocene” does not appear in The World Without Us, but the concept deeply informs the book’s premise. The term was introduced into mainstream environmental discourse in a 2002 essay by the Dutch meteorologist and atmospheric chemist Paul J. Crutzen to denote a proposed new geological epoch, the “Age of Man” (Crutzen, Paul J. “Geology of mankind.” Nature, 2002). Beginning with the Industrial Revolution in the late 18th century, Crutzen observed, human actions have had increasingly profound impacts on the biophysical environment. Humans have always altered their environment, but Crutzen and colleagues argued in a subsequent article that the industrial revolution ushered in a qualitatively different form of environmental impact:

Preindustrial societies […] did not have the numbers, social and economic organisation, or technologies needed to equal or dominate the great forces of Nature in magnitude or rate. Their impacts remained largely local and transitory, well within the bounds of the natural variability of the environment (Steffen, Will, et al. “The Anthropocene: Are Humans Now Overwhelming the Great Forces of Nature?” Ambio, 2007).

Since industrialization, however, and especially since the post-World War II “Great Acceleration” of human enterprise, humans have increased our population, resource consumption, habitat destruction, and greenhouse-gas emissions so explosively as to alter the functioning of fundamental Earth systems, making humanity itself a “force of nature.” The most dramatic manifestation of this dynamic is anthropogenic climate change due to the burning of fossil fuels; as Weisman puts it, “[B]y tapping the Carboniferous Formation and spewing it up into the sky, we’ve become a volcano that hasn’t stopped erupting since the 1700s” (40). Many scientists today agree that these transformations have shifted Earth out of the relatively stable Holocene epoch into a less stable “planetary terra incognita.”

This new terrain is proving to be less hospitable for humans in many ways. Climate variability has become more extreme and less predictable, with one record-breaking heat wave, drought, wildfire, or storm after another disrupting thousands or millions of lives. The Anthropocene also coincides with the planet’s sixth mass extinction event, with species on every land mass and in every ocean disappearing at a rate estimated to be 100 to 1,000 times higher than natural background extinction rates. Synthetic toxins have infiltrated the food webs of creatures great and small, as Weisman demonstrates. Present-day agricultural processes convert more atmospheric nitrogen into reactive forms than all of Earth’s terrestrial processes combined; one consequence is that nutrient pollution has fouled half of the world’s lakes and created hundreds of hypoxic “dead zones” in the oceans. In 2005 the World Bank estimated that human actions have destroyed around 60% of the “ecosystem services” that humans rely on; draining wetlands, for example, eliminates their capacity to purify water, buffer storm surge, absorb carbon dioxide, and perform other beneficial functions (Reid, Walter V. et al. Ecosystems and Human Well-Being: a Synthesis. Island Press, 2005). Complex Earth systems respond to change unpredictably, and when certain thresholds or “tipping points” are crossed, they can change very abruptly. The impacts of human activity could thus be catastrophic and irreversible, greatly reducing human well-being and potentially leading to the sudden human extinction that Weisman posits.

Geological epochs are defined by distinctive “signatures” in the fossil record, and scientists have proposed various markers of the Anthropocene. Geologists in future millennia—or the visiting extraterrestrial scientists Weisman imagines—would discover, for example, a massive shift in faunal composition, with domesticated livestock outnumbering wild species. One marker Weisman discusses at length is changes in soil composition due to agricultural practices, such as ploughing and grazing, and the introduction of trace elements, such as radionuclides from nuclear tests. Another is the now-global distribution of microplastics, which according to a 2020 report from the Anthropocene Working Group, are “forming a near-ubiquitous and unambiguous marker of Anthropocene strata” (Syvitski, Jaia, et al. “Extraordinary human energy consumption and resultant geological impacts beginning around 1950 CE initiated the proposed Anthropocene Epoch.” Communications Earth & Environment, 2020). Throughout The World Without Us, Weisman explores which of humanity’s environmental legacies would likely leave stratigraphic markers and which would fade away without a trace.