The first atomic bomb blast July 16, 1945 marked the dawn of the Anthropocene era — a new chapter in the Earth’s geological history, an international team of scientists has proposed.
Nobel Prize-winning atmospheric chemist Paul Crutzen coined the term Anthropocene 15 years ago to mean the age of widespread human influence over the planet.
Since then, the idea has spread widely through both the sciences and humanities.
But if the Anthropocene is to be a geological epoch — when should it begin?
Humans have long affected the environment, and ideas as to when the Anthropocene might start range from the thousands of years ago with the dawn of agriculture, to the Industrial Revolution — and even to the future — for the greatest human-made changes could still be to come.
Now, members of the Anthropocene Working Group, that formally analysed the Anthropocene, have suggested that the key turning point happened in the mid-twentieth century.
The proposal, signed by up to 26 members of the working group, is that the beginning of the Anthropocene could be considered to be drawn at the moment of detonation of the world’s first nuclear test — July 16, 1945.
“Like any geological boundary, it is not a perfect marker — levels of global radiation really rose in the early 1950s, as salvoes of bomb tests took place,” said lead author Jan Zalasiewicz from University of Leicester in Britain.
“But it may be the optimal way to resolve the multiple lines of evidence on human-driven planetary change. Time – and much more discussion – will tell,” Zalasiewicz, who also chairs the working group, noted.
The scientists put forward their contention in a paper published in the journal Quaternary International.
Jan Zalasiewicz, Colin N. Waters, Mark Williams, Anthony D. Barnosky, Alejandro Cearreta, Paul Crutzen, Erle Ellis, Michael A. Ellis, Ian J. Fairchild, Jacques Grinevald, Peter K. Haff, Irka Hajdas, Reinhold Leinfelder, John McNeill, Eric O. Odada, Clément Poirier, Daniel Richter, Will Steffen, Colin Summerhayes, James P.M. Syvitski, Davor Vidas, Michael Wagreich, Scott L. Wing, Alexander P. Wolfe, Zhisheng An, Naomi Oreskes, When did the Anthropocene begin? A mid-twentieth century boundary level is stratigraphically optimal, Quaternary International, Available online 12 January 2015, ISSN 1040-6182,