Defining the Anthropocene

The Anthropocene epoch – though formally rejected by geologists – remains a widely used concept, both within and beyond academia. And rightly so, argue scientists in a new article published in Nature Reviews Earth & Environment.

“The science of the Anthropocene is multi-faceted and sophisticated. Yet the patterns that emerge are often astonishingly simple: human activity accelerated in all sorts of ways at roughly the same time,” write three of the articles’ lead authors, Jan Zalasiewicz, Colin Waters and Martin J. Head, all from the University of Leicester, in The Conversation.

But the widespread use of the term, alongside its formal rejection, has led to diverse and sometimes incompatible definitions of what the Anthropocene actually means.

“The Anthropocene is perhaps best and most clearly understood in its original meaning: as representing an epoch characterised by the human-driven departure from the Holocene epoch,” explains Centre science director Magnus Nyström, co-author of the article.

For 12,000 years, Earth has been in a relatively stable state known as the Holocene. But in the 1950s, the planet began to move away from this state. This shift has been described as the Great Acceleration – an unprecedented increase in the exploitation of geological and biological resources to support a rapidly growing, though highly unequal, human population.

“The proposal to date the start of the Anthropocene to 1952, when the first thermonuclear weapons test was conducted by the United States over the Enewetak Atoll in the Marshall Islands, acts as a tragic reminder of the highly unjust impacts of planetary change,” says Centre researcher Victor Galaz, co-author of the article, and also author of a new book in Swedish that explores the ecological and human dimensions of nuclear testing in the Pacific after World War II.

A proposal to include the Anthropocene epoch in the official Geological Time Scale was rejected in 2024. The authors argue that the decision should be reconsidered.