Humans really are unique compared to other species. Although we share many characteristics with other animals, we are able to send missions into interstellar space, find new worlds, write and speak in hundreds of languages, heal ourselves with technology, and completely reorganize the environment around us, for good and bad.
As a result of this, scientists think that we belong in our own geological age, and it looks like they have finally agreed when the so-called “Anthropocene” began – 1950, marked by the sudden spike in plutonium debris left behind by nuclear weapons testing at the start of the Cold War.
The Anthropocene Working Group (AWG), an organization comprised of scientists and academics from all over the world, recently voted on five separate motions relating to the currently tentative geological time period, with 34 out of 35 members concluding that there is enough evidence to conclude the Anthropocene is detectable at high resolution in the geological record.
“Human impact has left discernible traces on the stratigraphic record for thousands of years,” the AWG said in a statement. “However, substantial and approximately globally synchronous changes to the Earth System most clearly intensified in the Great Acceleration of the mid-20th century.
“The mid-20th century also coincides with the clearest and most distinctive array of signals imprinted upon recently deposited strata. Hence, the mid-20th century represents the optimal beginning of a potential Anthropocene Epoch.”
Ultimately, 30 members of the AWG decided the Anthropocene should be formalized, with just three against the motion and two abstaining.
It has also been decided that the time period will be an “Epoch”, which means that it is a longer than an Age, but not as long as a Period. For example, the Maastrichtian Age is the very last segment of the Late Cretaceous, the final chapter in the history of the non-avian dinosaurs. In this case, the Cretaceous is the Period, and the Late Cretaceous is the Epoch.
Right now, we are in the Quaternary Period, and within this, we are in the Holocene Epoch, which began 11,700 years ago when the glaciers began to retreat and the world warmed. This will now change to the Anthropocene Epoch, which will last tens of millions of years.
There are plenty of markers of human activity, including the fact that plastic has entered the rock cycle, the spike in carbon dioxide in the atmosphere from burning fossil fuels, and the sudden jump in species extinction rates. However, the AWG have settled on the plutonium fallout from the atomic weapons tests that began in earnest in the 50s as the “primary signal”.
There were several options for the start date choice, including around the start of the Industrial Revolution and 7,000 years ago, around the time that advanced agriculture and livestock farming became widespread and methane produced by it began to gradually, but noticeably, warm the climate.
However, by 1950, all human activity had accumulated to the point wherein it was clear beyond any reasonable doubt that we had significantly altered the environment – and what better primary marker to have to underline this than the debris left over from the mushroom clouds of atomic weapons?
In order to make it official, a specific rock unit will need to be found and chosen as containing the “golden spike” – a collection of signals, including the primary signal, which clearly marks the start of the Anthropocene. Only then can an official request be made to the International Union of Geological Science, so for now, we’re still officially lounging around in the Holocene.