Millions of years from now, could alien geologists pinpoint a distinct time when humans changed the world? An international team of scientists says they could, by looking at the crushed-up remains of concrete, aluminum and plastics.
Further evidence would come in the form of dramatic spikes in radioactive fallout and fossil-fuel particulates, the researchers report in this week’s issue of the journal Science. And if environmental trends proceed the way most scientists think, the aliens also could document the signs of sea level rise and mass extinctions – perhaps including our own.
“All of this shows that there is an underlying reality to the Anthropocene concept,” the University of Leicester’s Jan Zalasiewicz, a co-author of the study, said in a news release.
Many scientists have said our current era should be called the Anthropocene Epoch rather than the Holocene Epoch, thanks to the ways in which human activity is drastically altering global ecosystems. The latest study lays out detailed evidence arguing that the Anthropocene Epoch is already geologically distinct, with its start dated to around 1950.
“Not only would this represent the first instance of a new epoch having been witnessed firsthand by advanced human societies, it would be one stemming from the consequences of their own doing,” the scientists write.
In this updated view of the geological record, the Anthropocene would come after the Holocene. The Holocene began about 11,700 years ago when the world warmed up in the wake of its last glacial period. Before the Holocene, there was the Pleistocene Epoch, when mammoths walked the earth. All of these epochs are part of the Quaternary Period, a geological time that goes back 2.6 million years.
The latest study was written by 24 members of the Anthropocene Working Group, which is led by Zalasiewicz. Last year, members of the working group argued that the start of the Anthropocene could be dated even more precisely to July 16, 1945, the day when the world’s first nuclear bomb exploded.
In a different study, they said the deep holes burrowed into the earth for mining and energy exploration could serve as additional evidence of the Anthropocene Epoch.
The researchers plan to gather more evidence over the course of 2016. Their findings will be incorporated into recommendations for formalizing the geological definition of the Anthropocene with the International Commission on Stratigraphy.
The British Geological Survey’s Colin Waters is the lead author of the Science study, “The Anthropocene Is Functionally and Stratigraphically Distinct From the Holocene.” The “Welcome to the Fabulous Anthropocene Era” sign shows an art installation created by Robyn Woolston to mark the 80th anniversary of Edge Hill University’s Ormskirk campus in Britain. Find out more about Woolston’s 2013 installation, titled “Habitus.”
