Scientists are one step closer to defining a new chapter in geology, one in which humans have become the dominant driver of Earth’s climate and environment.
Out of 12 locations around the world, Crawford Lake in Ontario, Canada, has been selected as the site that would mark the official beginning of the Anthropocene, a proposed geologic epoch starting in the 1950s, researchers announced at a July 11 news conference during the Max Planck Society Conference for a Sustainable Anthropocene in Berlin.
The lake bottom’s sediments hold one of the most precise records of humans’ alteration of Earth, including upticks in plutonium from nuclear weapons testing, ash from burning fossil fuels as well as heavy metals and microplastics.
But the Anthropocene isn’t an official geologic epoch yet. Now, several more committees must approve of the proposed epoch before it can be added to the geologic time scale. Doing so would end the nearly 12,000-year-old Holocene Epoch, which encompasses the rise of humankind since the last ice age.
Scientists first started using the term Anthropocene in the early 2000s to refer to the ongoing time of humans altering the planet on a global scale. Although framed in terms of geology, the Anthropocene lacked a formal geologic definition.
Still, the idea spread. “It exploded so quickly into other disciplines without it being defined,” says earth scientist Simon Turner of University College London. So “that’s what we’ve been trying to do ever since.”
In 2009, the International Commission on Stratigraphy, the scientific group responsible for defining geologic time, convened a committee to characterize the Anthropocene and see whether it deserved a spot on the geologic time scale. Over a decade later, that committee has now chosen Crawford Lake out of the 12 candidate sites as the Anthropocene’s “Global Boundary Stratotype Section and Point,” a reference site that shows a change in its rock, ice or other…
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