Human population growth has followed the trajectory of a typical invasive species, says a study published Wednesday in the journal Nature, and that suggests there may be a looming global population “crash.”
“The question is: Have we overshot Earth’s carrying capacity today?” said Elizabeth Hadly, a professor in environmental biology at Stanford University and senior author of the paper, in a press statement.
“Because humans respond as any other invasive species,” Hadly continued, “the implication is that we are headed for a crash before we stabilize our global population size.”
The study examined 1,147 archaeological sites via radiocarbon dating to understand the patterns of human population growth in South America. As a successfully invasive species, upon arrival “humans spread rapidly throughout the continent,” the study authors note.
Once humans reached the continent’s carrying capacity—meaning its resources couldn’t support further population growth—”consistent with over-exploitation of their resources,” the study found that humans’ population growth halted and the species “remained at low population sizes for 8,000 years.”