Human activity leading Earth into a new geological epoch

Has rapid human activity driven Earth into a new geological epoch? According to an international group of geoscientists, the evidence for a new geological epoch which marks the impact of human activity on Earth is now overwhelming.

The Anthropocene, which is argued to start in the mid-20th Century, is marked by the spread of materials such as aluminium, concrete, plastic, fly ash and fallout from nuclear testing across the planet.

It is coincident with elevated greenhouse gas emissions and unprecedented trans-global species invasions.

"Humans have long affected the environment, but recently there has been a rapid global spread of novel materials including aluminium, concrete and plastics, which are leaving their mark in sediments," said Dr Colin Waters from the British Geological Survey.

Fossil-fuel combustion has dispersed fly ash particles worldwide, pretty well coincident with the peak distribution of the "bomb spike" of radionuclides generated by atmospheric testing of nuclear weapons.

"All of this shows that there is an underlying reality to the Anthropocene concept," commented Jan Zalasiewicz from University of Leicester.

Is the Anthropocene world different from the stable Holocene Epoch of the last 11,700 years that allowed human civilisation to develop?

The Holocene Epoch has been a time during which human societies advanced by gradually domesticating the land to increase food production, built urban settlements and became proficient at developing the water, mineral and energy resources of the planet.

The proposed Anthropocene Epoch, however, is marked as a time of rapid environmental change brought on by the impact of a surge in human population and increased consumption during the "Great Acceleration" of the mid-20th century.

The study, co-authored by 24 members of the Anthropocene Working Group, shows that humans have changed the Earth system sufficiently to produce a range of signals in sediments and ice.

These are sufficiently distinctive to justify recognition of an Anthropocene Epoch in the Geological Time Scale.

This year, the Anthropocene Working Group will gather more evidence on the Anthropocene, which will help inform recommendations on whether this new time unit should be formalised and, if so, how it might be defined and characterised.