Human activity may trigger the greatest extinction event since the dinosaurs
New research synthesizes decades of environmental data and expert workshops to argue that human activity is driving biodiversity loss at a pace that rivals the most dramatic extinction events in Earth’s history. While the study stops short of labeling today’s declines as a true mass extinction, it emphasizes that current rates are unprecedented in the era of Homo sapiens and could escalate if protected ecosystems and species aren’t safeguarded.
Where we stand in the long arc of extinction
Researchers trace human impact back roughly 130,000 years, noting how the first waves of large animal losses—mammoths, giant ground sloths and other megafauna—foreshadow modern trends. As humans spread across continents and islands, vulnerable species disappeared one by one, a pattern that has continued with more recent victims like the Tasmanian tiger and Steller’s sea cow. The team’s comparison with fossil records aims to place today’s losses on a broader timeline while highlighting the unique force of human-driven change.
Head-to-head with dinosaurs: how today differs from the past
Compared with the asteroid-induced mass extinction that wiped out the dinosaurs, today’s extinction pulse is not yet on the same scale or speed. The researchers find that the dinosaur event resulted in the loss of an extremely large proportion of species within a short window, something clearly beyond the reach of current biodiversity losses. Yet the pace of contemporary decline is rapid and highly consequential, signaling a potential trajectory toward a mass extinction if trends continue unchecked.
What makes today’s losses potentially dangerous?
Explaining the contemporary risk, the study highlights that this era is characterized by accelerated species loss across multiple continents, particularly among mammals. While the Eocene–Oligocene extinction event—about 34 million years ago—also saw widespread declines, it unfolded over millions of years and occurred before humans manipulated a global climate through industrial activity. The contrast underscores a central point: the present pace is driven largely by human actions that intensify habitat destruction, climate change, pollution, and overexploitation, rather than natural climate cycles alone.
Lessons from major historical climate shifts
Looking at the Eocene–Oligocene transition offers a valuable, albeit imperfect, benchmark. That event was associated with global cooling and the formation of Antarctic ice sheets, yet it lacks the present-day human signature. The researchers argue that while the ancient episode demonstrates how climate shifts can reshape life, the current crisis is distinctly linked to anthropogenic impacts. This insight strengthens the call to reduce environmental harm now, rather than later, to avoid crossing a threshold into an irretrievable loss of biodiversity.
What the research adds to our understanding
The study emphasizes the complexity of comparing the present to the deep past. Gaps in the fossil record, unknown species, and extinctions not captured in existing data all cloud direct comparisons. Despite these uncertainties, the consensus among palaeobiologists and ecologists is that human-driven change has become a dominant force shaping Earth’s biological future. The overarching message is clear: the trajectory of biodiversity loss is controllable, and action taken today could alter the course of the planet’s ecological history.
Dr. Jack Hatfield, from the Leverhulme Centre for Anthropocene Biodiversity, articulates the core takeaway: the current pace of change is without precedent in the last 66 million years, but it is not irrevocable. “It’s a complex, nuanced story, but the message is clear — our species has become a defining force in Earth’s history, and we still have the power to decide how that story ends,” he says. The researchers publish their findings in Global Change Biology, inviting policymakers, scientists, and the public to engage with strategies that reduce harm and preserve biodiversity for future generations.
