Scientists have picked the bottom of Crawford Lake in Ontario as the “golden spike” to mark the start of a new proposed geological epoch — the Anthropocene. The announcement was made at a media conference in Berlin Tuesday by a group of scientists called the Anthropocene Working Group — more on them later.
Here’s why the lake was chosen and what evidence it provides that humans have made such big changes to the Earth that we may be in a new geologic time period.
Crawford Lake is unusually deep compared to its surface area. That gives it qualities that help it preserve climatic, ecological and environmental records. (Cole Burston/The Canadian Press)
What’s an epoch? And why are scientists proposing a new one called the Anthropocene?
Geologists measure the history of the Earth using the geologic time scale (its official name is the International Chronostratigraphic Chart) — kind of like a calendar, except that it’s divided into much bigger divisions than days, weeks or months.
For example, “periods” like the Jurassic and Cretaceous are tens of millions of years long and divided into epochs that are typically millions of years long.
Until now, our current epoch has been the Holocene, which started at the end of the last ice age 11,700 years ago.
But in many fields, including science, researchers and thinkers had already been discussing the huge impact humans have had on the Earth — including mass extinction and climate change, the kind of changes that typically mark the start and end of epochs.
About two decades ago, Nobel prizing winning chemist Paul Crutzen popularized the idea that science should recognize that impact with a new geological epoch, the Anthropocene, Prof. Jürgen Renn,director at the Max Planck Institute for the History of Science in Berlin, said at a news briefing about the new announcement.
“He said, ‘You know, we cannot say with all these changes that we are living still in the Holocene,'” Renn said. “It’s not just about climate change. It’s not just biodiversity loss. It’s not just the sediments that humans are moving. It’s all of this together.”
WATCH | Half of world’s species in decline:
Half of world’s species in decline, study suggests
2 months ago
Duration 2:03
A new study suggests half of the world’s species are in decline, amounting to what it warns is the widespread erosion of global biodiversity and another signal the planet is entering a mass extinction.
He added that much of the ongoing change is effectively irreversible, such as the melting of glaciers around the world: “These changes that we have induced already will only unfold in the next decades and centuries.”
The International Commission on Stratigraphy, a group of geologists within the International Union of Geological Sciences, is the scientific body that officially decides when epochs begin and end. In 2009, it asked a group of geologists, paleontologists and other scientists, the Anthropocene Working Group, to look into whether there was enough scientific evidence to back up Crutzen’s proposal of a new epoch.
One of the group’s key jobs has been to identify and describe a “golden spike” marking the start of the new proposed epoch.
Crawford Lake was chosen among 12 “golden spike” candidates around the world after a series of votes by the Anthropocene Working Group.
People look out on the water from the shore of Crawford Lake in Milton, Ont., on Friday, July 7, 2023. Scientists have picked the Canadian lake as the ‘golden spike’ to mark the start of a new proposed epoch, the Anthropocene. (Cole Burston/The Canadian Press)
What exactly is a ‘golden spike?’
A “golden spike” is the ideal marker showing where one epoch ends and another begins — typically at a major global event such as a mass extinction or climatic shift. Such events are generally visible in the form of layered evidence like changing fossils in rock deposited over time.
Layers in the sediment core from Crawford Lake show a distinct white layer in 1935 from dust storms during the Great Depression and accompanying droughts. The 1950 layer contains plutonium and is proposed as the start of the Anthropocene epoch. (Krysten Serack-Lafond)
As you might guess, “golden spike” is actually a nickname for a more technical scientific term: global boundary stratotype section and point (GSSP).
Thesection is the series of layers (also called “strata”, which is what makes it a “stratotype” section) where there’s physical evidence of the big event (the point) that marks the end of one epoch and the start of the next.
It’s chosen as a reference that can be used to compare evidence of that event in other parts of the world.
Where is Crawford Lake and what’s so special about it?
Crawford Lake is a relatively small lake about 60 kilometres west of Toronto. The lake is inside a conservation area that shares its name outside the town of Milton. It’s on the Niagara Escarpment, which is made of limestone rock. The rock forms a bowl that holds the lake.
The park has hiking trails, as well as a reconstructed 15th-century longhouse village. Archaeological excavations show several hundred Attawonderon or Wendat people lived near the lakeshore from the 13th to 15th centuries.
The park surrounding Crawford Lake has hiking trails, as well as a reconstructed 15th-century longhouse village. Archaeological excavations show several hundred Attawonderon or Wendat people lived near the lakeshore from the 13th to 15th centuries. (Turgut Yeter/CBC)
The lake itself is less than 300 metres across at its widest point, but very deep for its size — 24 metres, meaning a seven- or eight-storey building sitting on the lake bottom would just barely break the surface.
Because of that, Crawford Lake is meromictic — that is, it’s a rare type of lake where the bottom layer of water doesn’t mix with upper layers.
Francine McCarthy, an earth sciences professor at Brock University in St. Catharines, Ont., who has been studying the lake, said that means the bottom of the lake is “completely isolated from the rest of the planet, except for what gently sinks to the bottom and accumulates in sediment.”
There is also some handy chemistry happening in the water. Remember how it’s surrounded by limestone? The rock contains calcium and carbonate that dissolve in the water, but crystallize out in the surface waters when it gets warm — how much depends on that year’s climate. The crystals fall down as white layers that mark each summer like tree rings, covering the pollen, dead microorganisms, pollution particles and other debris that accumulate the rest of the year.
Together they provide a record of the climate, environmental and ecological conditions each year. Because the shores of Crawford Lake were inhabited by humans hundreds of years ago, it also allowed scientists to compare human impacts then and now.
McCarthy and her team have drilled cylinders called sediment cores out of the bottom of the lake that preserve the annual layers so that they can be examined and tested in the lab.
Francine McCarthy from Brock University points at the layer of sediment in a Crawford Lake mud core that shows the global plutonium spike from nuclear weapons testing that marks the beginning of the proposed Anthropocene epoch. (Mercury Films Inc./Nick de Pencier)
What’s the global event that’s been proposed to mark the start of the Anthropocene?
Originally, Crutzen had proposed the Industrial Revolution of the 19th century as the start of the Anthropocene.
But it turns out scientific evidence of the Industrial Revolution from that time is mostly only seen in Europe and not other parts of the world, said Colin Waters, honorary professor of geography, geology and the environment at the University of Leicester in the U.K. and chair of the Anthropocene Working Group.
Because of that, scientists began proposing that the start of the Anthropocene should be marked by evidence of nuclear weapons tests in the 1950s, such as radioactive plutonium, which is detectable worldwide.
“It’s a very clear marker,” Waters said.
But it also coincides with increased burning of fossil fuels, use of industrial fertilizers and other human impacts that leave a clear scientific signal — together called “The Great Acceleration” by environmental historian John McNeill.
And so radioactive plutonium has been chosen as the marker for the start of the Anthropocene in the Crawford Lake sediment core.
Samples from each year in the Crawford Lake sediment core sit in a tray, ready to be tested for plutonium. (University of Southampton)
Why is the Anthropocene epoch controversial?
Members of the Anthropocene Working Group themselves acknowledge that this isn’t a typical geological division.
Typically, layers of rock and often fossils are used as markers between different periods of time, but in this case, rock hasn’t had time to be deposited.
Renn said the “geology of the present” is a new challenge. “That’s very, very unusual.”
It’s not only that rocks haven’t had time to form, but also the materials and signals being measured and referenced, such as plutonium and microplastics, are very new and different from those of the past.
The mushroom cloud of the first test of a hydrogen bomb, Ivy Mike, looms over the Pacific Ocean in 1952. The plutonium is detectable all over the world, but isn’t one of the usual materials referenced in the geologic time scale. (Reuters)
But some researchers argue it’s just too soon to call this a new epoch.
John-Paul Zonneveld, a professor at the University of Alberta and a member of the North American Commission on Stratigraphic Nomenclature, acknowledged that humans have made big changes and left their permanent mark all over the Earth, but he said he feels “we’re in the middle of the event. We’re not in the new time stage yet.”
Joseph Deloges, a professor of geography and earth sciences at the University of Toronto who hasn’t been involved with the Anthropocene Working Group, has a similar perspective, and says it’s a challenge.
“Whatever you try and define in terms of the Anthropocene means it’s changing as you go along. And so some would argue that’s not what the nomenclature is set up for,” he said.
He added that while climate change has been quite dramatic, it may not yet match the scale events like asteroid impacts that have ushered in some other new time periods on the geologic timescale: “Some would argue we’re not quite there yet in terms of the catastrophe.”
WATCH | This lake contains evidence of how humans have transformed the earth:
What the ‘doomsday glacier’ can teach us about the fate of Earth
1 year ago
Duration 6:31
The Thwaites glacier is an Antarctic glacier that spans roughly 120 kilometres. Climate scientist David Holland talks to The National co-host Ian Hanomansing about what Thwaites — sometimes called the ‘doomsday glacier’ — can tell us about the fate of the planet.
The Anthropocene is still just a proposal. What needs to happen for it to become an actual epoch?
The Anthropocene Working Group still needs to come up with an “auxiliary” GSSP out of eight other sites. Then the proposal needs to pass three more votes with a “supermajority” of more than 60 per cent, including one at the International Commission on Stratigraphy and a final one from the International Union of Geological Sciences.
“It’s a very conservative process, you know,” said Waters, “and probably there’s good reason for that because you don’t want to establish the formalization of the unit if it’s not grounded on very strong evidence.”
He added that it’s also possible that the geological community will decide that the Anthropocene is simply a new stage within the Holocene epoch (after the Meghalayan, which started 4,200 years ago), and not a new epoch in itself.
In any case, the Anthropocene Working Group hopes a decision will be made in time for the International Geological Congress in Busan, Korea, in August 2024.
Braxton Whitehead said Friday he has verbally committed to Arizona State, making him the first member of a Canadian Hockey League team to attempt to play the sport at the Division I U.S. college level since a lawsuit was filed challenging the NCAA’s longstanding ban on players it deems to be professionals.
Whitehead posted on social media he plans to play for the Sun Devils beginning in the 2025-26 season.
An Arizona State spokesperson said the school could not comment on verbal commitments, citing NCAA rules. A message left with the CHL was not immediately returned.
A class-action lawsuit filed Aug. 13 in U.S. District Court in Buffalo, New York, could change the landscape for players from the CHL’s Western Hockey League, Ontario Hockey League and Quebec Maritimes Junior Hockey League. NCAA bylaws consider them professional leagues and bar players from there from the college ranks.
Online court records show the NCAA has not made any response to the lawsuit since it was filed.
“We’re pleased that Arizona State has made this decision, and we’re hopeful that our case will result in many other Division I programs following suit and the NCAA eliminating its ban on CHL players,” Stephen Lagos, one of the lawyers who launched the lawsuit, told The Associated Press in an email.
The lawsuit was filed on behalf of Riley Masterson, of Fort Erie, Ontario, who lost his college eligibility two years ago when, at 16, he appeared in two exhibition games for the OHL’s Windsor Spitfires. And it lists 10 Division 1 hockey programs, which were selected to show they follow the NCAA’s bylaws in barring current or former CHL players.
CHL players receive a stipend of no more than $600 per month for living expenses, which is not considered as income for tax purposes. College players receive scholarships and now can earn money through endorsements and other use of their name, image and likeness (NIL).
The implications of the lawsuit could be far-reaching. If successful, the case could increase competition for college-age talent between North America’s two top producers of NHL draft-eligible players.
“I think that everyone involved in our coaches association is aware of some of the transformational changes that are occurring in collegiate athletics,” Forrest Karr, executive director of American Hockey Coaches Association and Minnesota-Duluth athletic director said last month. “And we are trying to be proactive and trying to learn what we can about those changes.
Karr was not immediately available for comment on Friday.
Earlier this year, Karr established two committees — one each overseeing men’s and women’s hockey — to respond to various questions on eligibility submitted to the group by the NCAA. The men’s committee was scheduled to go over its responses two weeks ago.
Former Minnesota coach and Central Collegiate Hockey Association commissioner Don Lucia said at the time that the lawsuit provides the opportunity for stakeholders to look at the situation.
“I don’t know if it would be necessarily settled through the courts or changes at the NCAA level, but I think the time is certainly fast approaching where some decisions will be made in the near future of what the eligibility will look like for a player that plays in the CHL and NCAA,” Lucia said.
Whitehead, a 20-year-old forward from Alaska who has developed into a point-a-game player, said he plans to play again this season with the Regina Pats of the Western Hockey League.
“The WHL has given me an incredible opportunity to develop as a player, and I couldn’t be more excited,” Whitehead posted on Instagram.
His addition is the latest boon for Arizona State hockey, a program that has blossomed in the desert far from traditional places like Massachusetts, Minnesota and Michigan since entering Division I in 2015. It has already produced NHL talent, including Seattle goaltender Joey Daccord and Josh Doan, the son of longtime Coyotes captain Shane Doan, who now plays for Utah after that team moved from the Phoenix area to Salt Lake City.
A community legal clinic in Kingston, Ont., is denouncing the mayor’s calls to clear an encampment and close a supervised consumption site in the city following a series of alleged assaults that left two people dead and one seriously injured.
Kingston police said they were called to an encampment near a safe injection site on Thursday morning, where they allege a 47-year-old male suspect wielded an edged or blunt weapon and attacked three people. Police said he was arrested after officers negotiated with him for several hours.
The suspect is now facing two counts of second-degree murder and one count of attempted murder.
In a social media post, Kingston Mayor Bryan Paterson said he was “absolutely horrified” by the situation.
“We need to clear the encampment, close this safe injection site and the (Integrated Care Hub) until we can find a better way to support our most vulnerable residents,” he wrote.
The Kingston Community Legal Clinic called Paterson’s comments “premature and misguided” on Friday, arguing that such moves could lead to a rise in overdoses, fewer shelter beds and more homelessness.
In a phone interview, Paterson said the encampment was built around the Integrated Care Hub and safe injection site about three years ago. He said the encampment has created a “dangerous situation” in the area and has frequently been the site of fires, assaults and other public safety concerns.
“We have to find a way to be able to provide the services that people need, being empathetic and compassionate to those struggling with homelessness and mental health and addictions issues,” said Paterson, noting that the safe injection site and Integrated Care Hub are not operated by the city.
“But we cannot turn a blind eye to the very real public safety issues.”
When asked how encampment residents and people who use the services would be supported if the sites were closed, Paterson said the city would work with community partners to “find the best way forward” and introduce short-term and long-term changes.
Keeping the status quo “would be a terrible failure,” he argued.
John Done, executive director of the Kingston Community Legal Clinic, criticized the mayor’s comments and said many of the people residing in the encampment may be particularly vulnerable to overdoses and death. The safe injection site and Integrated Care Hub saves lives, he said.
Taking away those services, he said, would be “irresponsible.”
Done said the legal clinic represented several residents of the encampment when the City of Kingston made a court application last summer to clear the encampment. The court found such an injunction would be unconstitutional, he said.
Done added there’s “no reason” to attach blame while the investigation into Thursday’s attacks is ongoing. The two people who died have been identified as 38-year-old Taylor Wilkinson and 41-year-old John Hood.
“There isn’t going to be a quick, easy solution for the fact of homelessness, drug addictions in Kingston,” Done said. “So I would ask the mayor to do what he’s trained to do, which is to simply pause until we have more information.”
The concern surrounding the safe injection site in Kingston follows a recent shift in Ontario’s approach to the overdose crisis.
Last month, the province announced that it would close 10 supervised consumption sites because they’re too close to schools and daycares, and prohibit any new ones from opening as it moves to an abstinence-based treatment model.
This report by The Canadian Press was first published Sept. 13, 2024.
