Birth of the modern: Canadian site nominated as “Golden Spike” on the occasion of the Anthropocene
A team of geologists, after examining sites around the world, have concluded that a small, deep lake in southern Ontario should mark the birth of the modern world.
A few sediment layers from around 1950 at the bottom of Crawford Lake, they say, show more clearly than anywhere else how human activities have changed the functioning of the planet to such an extent that a new geological epoch must be proclaimed: the Anthropocene, or the epoch from people.
“It’s a little sobering,” said Francine McCarthy, a geologist at Brock University who was part of the research team of the International Union of Geological Sciences’ Anthropocene Working Group.
“In that short time the system has turned around and can’t go back to how it used to be.”
Her group says the lake along the Niagara Escarpment should be considered the site for the so-called “Golden Spike,” which marks the beginning of the Anthropocene. The recommendation was announced Tuesday at the International Congress on Stratigraphy in Lille, France.
Geologists will debate the issue in the fall, including whether the Anthropocene should be declared at all. The issue will come to a final vote at the International Union of Geological Sciences in August 2024.
That will end a debate that geologists have had since 2009: Have humans altered the functioning of the planet profoundly enough to change the geology, and if so, should a new geological era be declared?
Some geologists initially suggested that a new era should begin with the industrial revolution, when fossil fuel burning began in earnest.
But many currently prefer the year 1950.
That’s when plutonium-239 begins to appear in geological strata. The element does not occur in nature and is the result of widespread nuclear weapons testing.
The year also coincides with the beginning of the so-called “Great Acceleration”, a time when everything suddenly seemed to take off.
A 2015 paper in the journal Anthropocene Review produced 12 graphs covering everything from population to GDP to fertilizer use to dam construction to energy use to international travel. They all peak dramatically around 1950.
Many of these accelerations appear in the geologic record.
Fertilizer use changes which nitrogen compounds are deposited. Atmospheric changes change what filters down from the air.
“Anything that came out of chimneys or tailpipes, that’s what we’re seeing,” McCarthy said.
All 12 candidates who qualified for the Golden Spike showed the same signs, McCarthy said.
“It is a tipping point. It runs on a dime, everywhere.”
The scientists chose Crawford Lake because of the remarkable clarity and depth of the sedimentary record. Due to its considerable depth – 80 feet – and narrow surface of a few acres, Crawford’s depths never mix and are essentially cut off from the world.
That allows sheer layers of sediment to float from the surface, leaving a climatic and atmospheric record so untouched that large swaths of it can be read year after year, stretching back to the area’s indigenous users in the 13th century.
Markers of the Great Acceleration are evident in Crawford, McCarthy said.
“Tests done in independent labs confirm that all these things, like dominoes, are changing very, very quickly around 1950,” she said in a news conference last week.
“So I think that’s why the Anthropocene Working Group ultimately chose our site.”
McCarthy acknowledged that some geologists are not convinced of the need for a new era.
“It has never been done before for something so recent and such a short interval. It meets with resistance because it falls outside the norm.”
Others argue that 1950 could at most be the beginning of a new era of our current era, the now 12,000-year-old Holocene. It would be called the Crawfordian era.
Anyway, McCarthy said the concept unites geology with the humanities.
“Historians and earth scientists usually don’t have much in common. But in the case of the Anthropocene, yes.”
The idea also caught on in popular culture.
“It resonates with people,” she said.
If nothing else, MCarthy said the selection of Crawford Lake as the Golden Spike of the Anthropocene would finally define what we mean by the term.
“When we say the word Anthropocene and have the word epoch behind it, we mean exactly what is defined based on Crawford Lake. That is what the Golden Spike would do.”
This report from The Canadian Press was first published on July 11, 2023.
