Researchers identify July 16 1945 as key time boundary in the history of the Earth

Humans are having such a significant impact on the Earth that they are changing its geology, creating new and distinctive strata that will persist far into the future, according to Dr Jan Zalasiewicz and Professor Mark Williams from the Department of Geology.

The Anthropocene, a new epoch first proposed by the Nobel Prize-winning atmospheric chemist Paul Crutzen just 15 years ago, covers an interval of geological time dominated by human influence.

But if the Anthropocene is to be a geological epoch – when did it begin? The research team has suggested that the turning point happened in the mid-twentieth century. This signified a ‘Great Acceleration’ of population, of carbon emissions, of species invasions and extinctions, of earth moving, of the production of concrete, plastics and metals, and also signaled the start of the nuclear age.

The start of the Anthropocene, the researchers suggest, could be the detonation of the world’s first nuclear test: on July 16^th 1945. The beginning of the nuclear age, it marks the historic turning point when humans first accessed an enormous new energy source – and is also a time level that can be effectively tracked within geological strata, using a variety of geological clues.

This year, the Anthropocene Working Group will put together more evidence on the Anthropocene, including discussion of possible alternative time boundaries, with the hope of formalising a date in 2016.

Watch an interview with Dr Jan Zalasiewicz recorded for the New York Times's Dot Earth blog:

• Press Release

• The article 'When did the Anthropocene begin? A mid-twentieth century boundary is stratigraphically optimal' was published in Quaternary International on 12 January.

Examples of Anthropocene research:

• How ‘technofossils’ have left an unprecedented legacy on the Earth
• How humanity will have a permanent effect on the ‘underworld’
• Will rats one day grow to 'giant' proportions?