Crawford Lake, near Toronto, Canada, was chosen on Tuesday as the global benchmark for the start of the Anthropocene, the new geological epoch characterized by humanity’s impact on Earth that scientists are trying to make officially recognize. The stratified sediments at the bottom of this small, one-square-kilometre body of water, laden with microplastics, ash from burning oil and coal, and fallout from nuclear bomb explosions, is the best evidence that a new chapter of Earth’s history has opened up, concluded the members of the Anthropocene Working Group.
“Only then can they be subject to peer review and the evidence and arguments can be truly assessed,” added the scientist, who leads this commission responsible for developing the frieze methodically dividing the 4.6 billion years of the Earth’s history into geologic eras, periods, epochs and ages. The general opinion is that an approval will be very difficult. Renowned geologists believe that the technical criteria are not met to qualify the Anthropocene as a new “epoch”, even though they recognize that a rupture occurred in the last century.
If the bar of two-thirds majority voting by the ICS and another committee were crossed, however, the proponents of the Anthropocene would still have to convince the guardians of the International Union of Geological Sciences (IUGS), known to be intransigent on the modifications of the international chronostratigraphic charter.
There is still a long way to go, but a major step has been taken with the choice of this Canadian lake as the physical embodiment of the Anthropocene, from a final list of nine candidates, including the sediments of a bay in Japan, the mud of a crater in China, the traces in an ice core or those on coral reefs. “The data show a clear shift from the mid-twentieth century, taking the Earth system beyond normal Holocene boundaries,” Andy Cundy, a professor at Britain’s University of Southampton and fellow of the working group.
Sediments from Lake Crawford “provide exceptional evidence of environmental change over the past millennia,” said task force chair Simon Turner of University College London. And these changes are playing out in dramatic fashion: the first week of July was the hottest on record globally, wildfires out of control have been ravaging Canada for months, while the United States and China are facing to unprecedented heat, flooding and drought.
