Micropaleontologist Dr Francine McCarthy goes deep into the sediments of Crawford Lake, a small and unassuming lake in the Niagara Escarpment town of Milton, Ontario. In 2023, Dr McCarthy led a team that identified Crawford Lake as the best location on earth that captured evidence of human caused planetary change. Endorsed by the Anthropocene Working Group, It was proposed as the best ‘golden spike’ site of the Anthropocene. Dr McCarthy shares how she first encountered the lake, her research on microscopic organisms of the Great Lakes Region, and personal reflections on the Anthropocene.
Bio:
Dr Francine McCarthy is a professor of Earth Sciences at Brock University in St. Catharines, Ontario. She is a micropaleontologist who reconstructs paleoenvironments through careful analysis of small organisms fossilized in lake sediments. Her research has spanned small lake to marine environments and everything in between. She has worked around the world but primarily focuses in the Great Lakes Region of Canada. Her interdisciplinary research has been conducted in collaboration with several geologists, biologists, geographers, and archaeologists from government, university, and the private sector.
This conversation is hosted and produced by Catherine Polcz with Music by Carl Didur.
[00:00:00] I'm Catherine Polcz and this is Plant Kingdom.
[00:00:13] I'm recording in beautiful Sydney on the lands of the Gadigal people of the Eora nation
[00:00:18] and pay respect to their elders past, present and future.
[00:00:22] Plant Kingdom is a conversation series about plants, nature and environment featuring
[00:00:27] scientists, artists, researchers and writers.
[00:00:31] We release two conversations each month and hear from people who have an intimacy with
[00:00:35] plants and nature.
[00:00:37] Today's conversation is with Dr. Francine McCarthy.
[00:00:41] This is a very special conversation for me when we go deep into Crawford Lake, a small and
[00:00:47] unassuming lake in my hometown of Milton, Ontario.
[00:00:51] Last year Crawford Lake was identified by the Anthropocene Working Group as the best
[00:00:55] location on earth that records evidence of human cause planetary change.
[00:01:01] Or in other words it was proposed as the golden spike site of the Anthropocene.
[00:01:07] Next with this story I reached out to Francine McCarthy, the leader of Team Crawford.
[00:01:12] Dr. Francine McCarthy is a professor and graduate program director at Brock University in St.
[00:01:18] Catherine's, Ontario.
[00:01:19] She is a micro paleontologist who reconstructs paleo environments through careful analysis
[00:01:25] of small organisms fossilized in lake sediments.
[00:01:29] She's worked around the world but primarily focuses in the Great Lakes region of Canada.
[00:01:34] Her interdisciplinary research has been conducted in collaboration with geologists, biologists,
[00:01:39] geographers and archaeologists from the government, university and private sectors.
[00:01:45] Here's our conversation.
[00:01:46] Thank you so much Francine.
[00:01:56] I really wanted to start with a bit of background on your research and your specialty before
[00:02:01] diving right into Crawford Lake which I'm really, really excited to speak with you
[00:02:05] about.
[00:02:06] You have the amazing specialty on your website of being a micro paleontologist.
[00:02:13] What does that mean?
[00:02:15] So we study very, very small fossils that you can't see with the naked eye.
[00:02:20] And are there specific geologic eras or periods that you're most interested in?
[00:02:25] Almost exclusively my research has been on the Cenozoic era which is the since the
[00:02:31] dinosaurs became extinct and very much focused on the last couple of million years which we
[00:02:38] call the quaternary period and even more specifically on the last few thousand years.
[00:02:45] So the interval of time when here in North America there's interaction between humans
[00:02:53] and the environment that we can really discern in the sedimentary record.
[00:02:57] So the time since indigenous people began living in fixed settlements and practicing
[00:03:04] agriculture that's really my area of specialization.
[00:03:08] Yeah, very, very recent is like hundreds of thousands of years, tens of thousands?
[00:03:14] Thousands.
[00:03:15] Thousands, yeah.
[00:03:18] And I think you have just covered this but are there particular regions where you do
[00:03:22] a lot of research?
[00:03:23] Is it centered around kind of Great Lakes region or?
[00:03:28] Certainly the Great Lakes region is my number one research area in part because I live here
[00:03:36] but also because even before I lived here my master's thesis was on Lake Ontario, one
[00:03:42] of the Great Lakes.
[00:03:43] So I came from Nova Scotia to Ontario to study Lake Ontario.
[00:03:49] So yeah, the primary focus has been the Great Lakes but I've worked in other parts of Eastern
[00:03:55] North America quite a bit in Massachusetts actually for various reasons and I've worked
[00:04:02] in the oceans, the North Atlantic and the North Pacific Ocean.
[00:04:06] So I have worked a fair bit around the world but almost always in the Northern Hemisphere
[00:04:13] and at mid latitude.
[00:04:16] Yeah, well there's enough water to keep you busy in that region.
[00:04:21] And what kind of organisms or records can you find in the lake beds?
[00:04:27] Well, there are all kinds of different things.
[00:04:30] So there are algae, the primary producers, the base of the food chain, there are a number
[00:04:36] of different kinds of algae.
[00:04:37] The kind I focus on most is dinoflagellates.
[00:04:40] They produce a little resting cyst that preserves in the sediments.
[00:04:46] There are various kinds of green algae like if you ever, especially in the late summer,
[00:04:51] go to a shallow pond you'll see that green scum over the top of the lake.
[00:04:56] Those are various kinds of green algae and they also leave a fossil record.
[00:05:02] There are numerous kinds of algae that live in lake waters that preserve in the sediments
[00:05:09] and then there are the things that eat the algae, so the little zooplankton
[00:05:13] and then all the way up the food chain.
[00:05:14] So once they get big enough that you can see them with the naked eye like little fish,
[00:05:19] I don't study them.
[00:05:20] I specifically study things that you have to look under the microscope to see.
[00:05:24] So I mostly study the little algae but I also study the little zooplankton that eat the algae.
[00:05:32] I guess what can you piece together about the environment and our climate
[00:05:39] based on what the composition is that you're finding?
[00:05:44] So the algae mainly indicate the conditions in the water
[00:05:51] that are either conducive to them being happy or not.
[00:05:56] So there are different kinds of algae that like colder conditions or warmer conditions
[00:06:00] but mainly the thing that will control whether you have a lot of algae or not
[00:06:06] and which kinds you have is the availability of nutrients.
[00:06:10] So there's a concept called eutrophication,
[00:06:12] the increase in nutrient availability in bodies of water
[00:06:17] that is something that the fossil record of algae really helps you understand
[00:06:22] and because whenever people are living and doing what it takes to make a living
[00:06:29] in the vicinity of a body of water,
[00:06:31] they do cause the concentration of nutrients to increase.
[00:06:38] So that's the main thing that we can see from looking at the algae
[00:06:42] and the little zooplankton that eat the algae.
[00:06:45] In the same slides that we look at under the microscope,
[00:06:50] we also see lots of pollen,
[00:06:52] which is actually what I started working on for my master's thesis
[00:06:57] and the pollen records the vegetation
[00:07:00] and the vegetation is closely controlled by climate.
[00:07:03] So in the same slide,
[00:07:05] the pollen can tell us most about the climate, temperature, precipitation, etc.
[00:07:12] Whereas the algae and the little zooplankton,
[00:07:16] things like kludosaurans for instance or rotifers,
[00:07:20] little tiny animals that eat the algae
[00:07:23] will tell us a lot about the nutrient concentration.
[00:07:27] The other thing that I should mention before I leave this topic
[00:07:31] is that there are various characteristics of a body of water
[00:07:35] that are important to algae, not just the nutrients.
[00:07:38] Acidification has been particularly a few decades ago
[00:07:43] was a huge issue before they amended the amount
[00:07:47] of the concentration of emissions that would come out of factories and industry
[00:07:53] and that acid rain reduced the pH, made it more acidic.
[00:07:58] And so we do actually see significant changes
[00:08:02] in the population of algae
[00:08:04] and the little guys that eat the algae
[00:08:06] associated with that kind of change in the water quality
[00:08:11] which is also human induced because it is a pollution issue.
[00:08:18] Yeah, and have those communities and lakes recovered
[00:08:23] since the legislation and policy around? Yeah.
[00:08:29] Yeah, they have certainly recovered from the acid rain issue
[00:08:37] has been dealt with in large part because the technical fixes,
[00:08:44] the scrubbers and so on really very efficient at lowering
[00:08:48] the sulfur dioxide emissions especially.
[00:08:52] And that we see very clearly, the recovery in the lakes.
[00:08:57] What we don't see is much of a recovery
[00:09:03] after nutrients have been added.
[00:09:05] And that tends to be true when we look at lake ecosystems
[00:09:14] that there are some aspects like pH that are fairly easy to redress.
[00:09:20] And there are others like the change in the ecosystem associated
[00:09:24] with eutrophication that are kind of one way.
[00:09:29] Yeah, acid rain is always kind of used as an example, a success example.
[00:09:34] But there's never one problem is there, which is the colossal topic
[00:09:40] we'll get into. Right.
[00:09:42] I mean, and just on that, I mean Lake Erie was declared dead
[00:09:46] a long time ago and then it came back to life.
[00:09:48] And now it's dying again for different reasons.
[00:09:50] So I mean, you can fix some problems, but then others flare up.
[00:09:55] And yeah, so that's part of the interesting challenge,
[00:09:59] but it's also frustrating.
[00:10:01] And what did that mean?
[00:10:03] Lake Erie was declared dead.
[00:10:04] Is all was that what it kind of sounds like that all the life had died?
[00:10:09] Yeah. Well, I mean, it was the headline in the, you know,
[00:10:12] I think it was Life Magazine, Lake Erie is dead.
[00:10:15] And literally, I mean, there were rivers that caught on fire and burn for days.
[00:10:20] Yeah. What's it called?
[00:10:22] The quiet Hoga? Yeah.
[00:10:24] Yeah. There were huge dead zones.
[00:10:28] And now there are dead zones again.
[00:10:29] I mean, they have come back for different reasons than back in the 60s.
[00:10:34] But yeah. Yes, there were success stories with remediation.
[00:10:39] Lake Erie, the Lake Erie of today is much less obviously polluted
[00:10:45] than the Lake Erie of the 60s and 70s.
[00:10:47] But there are still significant issues.
[00:10:50] And the people of Toledo know that very well because their water supply
[00:10:55] was municipal water supply was like they had to turn it off.
[00:10:59] They had to stop taking water from Lake Erie for several days
[00:11:03] as of the harmful algal bloom a few years ago.
[00:11:07] A few years ago. Yeah.
[00:11:09] It's kind of easy to take for granted all of the work and benefits
[00:11:14] we get from the Great Lakes system, isn't it?
[00:11:16] Yeah. And just kind of on that, I read in one of your interviews
[00:11:20] that Rachel Carson was an inspiration for you when you were younger.
[00:11:25] Yeah. Yeah.
[00:11:27] Yeah. Yeah, very much because it, you know, she was a,
[00:11:30] she was a biologist who recognized the
[00:11:36] the holistic ecosystem and how easy it was to disrupt it.
[00:11:43] And for human activities, even well-meaning activities like DDT
[00:11:48] to, you know, prevent insects from spreading and causing issues
[00:11:56] had ramifications that were not obvious to the engineers,
[00:12:00] the chemical engineers who invented DDT, you know,
[00:12:03] so that there are unknown unimagined consequences of actions
[00:12:09] that are initially well-meaning.
[00:12:12] And it takes an awful lot of effort to convince the system
[00:12:18] to recognize that the short-term benefits don't really outweigh
[00:12:24] the long-term consequences to the ecosystem.
[00:12:27] So, you know, thinner eggs and birds and raptors and so on
[00:12:31] in the silent spring, right?
[00:12:33] So to me, it's similar when we think of the Anthropocene
[00:12:39] because more and more people in the community,
[00:12:44] not just scientists, are becoming convinced that this really is
[00:12:49] a different planet than the one their grandparents or great-grandparents inhabited.
[00:12:56] And there are powerful systems that are built around essentially
[00:13:02] a 19th to 20th century concept of progress.
[00:13:06] And it's that myth of unending growth that our,
[00:13:13] not only our economies are built on, but our concept of what we can achieve
[00:13:18] in our lives and what our children can achieve depends on.
[00:13:21] It's that quote-unquote the American dream.
[00:13:23] And it's simply not possible that if you calculate the cost of that dream
[00:13:33] of never-ending growth, there is a finite point that there,
[00:13:38] it is a fixed planet with fixed limited resources.
[00:13:42] And we are approaching the point where that is going to be hit.
[00:13:48] The thing about Anthropocene is that it's very much intertwined.
[00:13:52] So what the Anthropocene working group was asked to do,
[00:13:55] it was asked to look at the geologic record, the sediments of our planet
[00:14:02] to see if there was truth reality to the statement that we're no longer living in the Holocene.
[00:14:10] That was what Paul Krutzen insisted from his studies of the atmosphere
[00:14:16] and that the system was fundamentally different than it had been for 12,000 years
[00:14:21] and therefore we should call it something different.
[00:14:23] We should view it differently and deal with it differently because it was different.
[00:14:29] Yeah, there's so much there.
[00:14:31] And I think it's really interesting for the non-geologists,
[00:14:37] the power of the concept of the Anthropocene
[00:14:40] and putting that in part of the geologic timescale that covers the history of Earth,
[00:14:45] the history of life, that long-term thinking.
[00:14:48] Long-term thinking is part of what's missing, right?
[00:14:51] And to think about time going forwards and backwards in that timescale
[00:14:55] I think has been really powerful for a lot of people.
[00:14:59] Yeah, and there are people who are resistant to the idea
[00:15:05] that we can possibly be in a different geologic interval of time.
[00:15:10] I compare it to when the asteroids struck the planet
[00:15:15] and caused that mass extinction of dinosaurs and a whole bunch of other things.
[00:15:20] They didn't all die on the same moment that the asteroid hit, right?
[00:15:24] It took, you know, who knows, it took decades at least let's say.
[00:15:29] But if there had been geoscientists,
[00:15:33] stratigraphers living at that time and lived through that cataclysmic event,
[00:15:39] how long would it take them to say,
[00:15:43] like that moment that the asteroid hit, you know, before and after those are fundamentally different things.
[00:15:48] Let's call it the end of the Mesozoic era
[00:15:51] and call it the beginning of the Senozoic era because it's really very different.
[00:15:55] And when you look at the sixth great mass extinction,
[00:16:00] it's not that different from the mass extinction that separated the Senozoic from the Mesozoic
[00:16:08] and there are so many other changes to the Earth system that are fundamental.
[00:16:15] Yeah, you look at the data, you look at the number of things that have become extinct,
[00:16:19] you look at the way these systems like the atmosphere, the oceans, you know,
[00:16:23] the biosphere, all of the different Earth systems interact
[00:16:26] and you think, my goodness, this is more different than any time,
[00:16:31] not only in the last 12,000 years but probably in the last 3 million years.
[00:16:39] So how much data do you need before you agree that let's just call it what it is
[00:16:45] because the danger of not calling it a different name,
[00:16:51] not accepting that Anthropos humans were the driving force,
[00:16:58] the danger is that we remain complacent, we remain on the same path
[00:17:05] and that's the danger because you know, like they say,
[00:17:11] the first step to getting over an issue is naming it.
[00:17:16] But for the geologic intervals or eras, epochs,
[00:17:21] what kinds of events traditionally define those?
[00:17:24] Is it always kind of a mass extinction or swinging temperature?
[00:17:27] I know, is it that life looks totally different in those periods?
[00:17:32] Well all those things, exactly.
[00:17:35] Extinction events, major changes in climate, those are the things.
[00:17:40] So the whole of scene that we're still officially living in
[00:17:45] until the geologists put a line on the time scale
[00:17:48] is itself defined by climate change,
[00:17:52] it's defined by warming at the end of the quote unquote last Ice Age
[00:17:56] and it is subdivided into three different ages
[00:18:00] and those three different ages are subdivided according to,
[00:18:03] or on the basis of rather subtle changes in climate,
[00:18:09] much more subtle than the ones that we've experienced since the mid 20th century.
[00:18:15] Do you remember when you first heard about the concept of the Anthropocene?
[00:18:20] Is it something that always resonated with you or?
[00:18:23] Yeah, I actually do remember because I was reading in my mailbox
[00:18:28] there came an issue of GSA Today which is the Geological Society of America's
[00:18:34] monthly publication and on the cover title of the article was
[00:18:39] Are We Living in the Anthropocene?
[00:18:42] And so I flipped through it and I actually scanned it
[00:18:46] and used it as a slide in my lecture in my first year course that year
[00:18:50] because it seemed very relevant to me that people, geoscientists were looking at this issue.
[00:18:55] It didn't occur to me that 10 years later I would be invited to be part of that working group
[00:19:00] and that four years after that that I would be proposing Crawford Lake
[00:19:05] and its varved sediments as the Golden Spike.
[00:19:09] Golden Spike is a little brass plaque that they put on sediments
[00:19:16] that have a line that show exactly where one interval of time starts.
[00:19:24] And yes, what's the story of you getting involved in the research?
[00:19:30] Well I've been familiar with Crawford Lake since I did my Masters in Toronto in 1984.
[00:19:38] I first saw the lake with my supervisor who had a long history of working on the lake
[00:19:44] and after I got my faculty position at Brock
[00:19:49] I did do some research with some of my students on the lake
[00:19:53] and it was my colleague Martin Head who works five doors up the hall from me
[00:19:58] who was a member of the, it was the vice chair of the
[00:20:02] Sub-Commission on Quaternary Stratigraphy
[00:20:05] who was aware of Crawford Lake and its annual like tree ring like record
[00:20:11] and when he came back from a meeting of the Anthropocene Working Group in 2018
[00:20:18] he told me that they had reached the conclusion that
[00:20:23] the time was now to look for a Golden Spike
[00:20:27] to actually define the Anthropocene as a formal interval of geologic time, the epoch
[00:20:33] and on the flight home from wherever it was he was I think it was Norway
[00:20:38] it occurred to him that one of the places that might have a chance of being
[00:20:43] a really good record was Crawford Lake because of its layered sediments
[00:20:49] but also because of its location protected yet readily accessible
[00:20:54] with an interesting history of pre-anthropocene human impact
[00:20:59] as well as a potentially strong record of human impact
[00:21:04] that caused this shift in the planet
[00:21:07] and no one had up until Martin invited me to spearhead this effort
[00:21:13] no one had actually looked in detail at the 20th century
[00:21:17] to see if there was this record of that great acceleration
[00:21:21] so yes, that's how I became involved. Martin stopped by my office
[00:21:25] told me that the Anthropocene Working Group was ready to work on this
[00:21:30] and was I willing to do the hard work that it would take to put a team together
[00:21:34] and do the analysis so I said yes and here we are.
[00:21:38] I mean it's very exciting for me to talk about Crawford Lake
[00:21:41] I told you this earlier and I was so excited for this conversation
[00:21:44] Crawford Lake is in Milton, Ontario which is my hometown
[00:21:49] and it's a place I spent a lot of time at hiking around that lake
[00:21:53] and going to the Halton conservation areas on the escarpment
[00:21:58] and I guess I always experienced it as a plant person
[00:22:02] I was looking more at the forests
[00:22:05] they're really home for me with the white cedar
[00:22:07] and the mixed sugar maple
[00:22:09] and looking at the little forest understory
[00:22:12] so thinking about the lake was really not something
[00:22:15] I had really thought about
[00:22:17] I knew it was very deep from the interpretation
[00:22:20] I knew there was this story about
[00:22:22] I don't think that sign is still up there anymore
[00:22:24] about horses falling through the ice
[00:22:26] it was kind of eerie when you read about it
[00:22:29] but I guess for...
[00:22:31] can you describe Crawford Lake
[00:22:33] and what makes it really unique from your research perspective?
[00:22:38] Yeah, so well as you say
[00:22:41] it's in a really unique area
[00:22:44] and that it's on the Niagara escarpment
[00:22:46] which is a UNESCO biosphere reserve
[00:22:49] it's got a beautiful forest
[00:22:52] right around the lake itself
[00:22:54] and it is relatively sparse
[00:22:57] because the soil is very very thin
[00:23:00] when the indigenous people first started farming
[00:23:03] the land on the hill above the lake
[00:23:06] they, without knowing it, affected the lake
[00:23:10] and the concentration...
[00:23:13] or both the concentration
[00:23:15] the number of algae we see increased dramatically
[00:23:18] but the kinds of algae that were happy
[00:23:20] were no longer the algae that are happy
[00:23:23] in low nutrient lakes
[00:23:25] and after the indigenous people left Crawford Lake
[00:23:28] and dozens of other satellite villages in the area
[00:23:32] in the 15th century
[00:23:36] or possibly early 16th century
[00:23:38] for reasons that remain unclear
[00:23:40] there wasn't a return back to the conditions
[00:23:44] that had existed before the indigenous settlement
[00:23:48] and the lake itself is special
[00:23:53] because it is so deep compared to its size
[00:23:57] so it takes you what, 10 minutes to walk around
[00:24:00] something like that
[00:24:01] and it is 23, 24 meters deep
[00:24:05] you really notice how deep it is
[00:24:07] when you're putting out cable to get to the bottom
[00:24:11] it is a very very deep lake
[00:24:13] so it doesn't mix by wind
[00:24:16] so the bottom is undisturbed
[00:24:19] and that's why we get those amazing layers
[00:24:22] of sediment, those varves
[00:24:24] so it's called a meromictic lake
[00:24:26] and there are half dozen meromictic lakes
[00:24:29] in Ontario, something like that
[00:24:31] and maybe a dozen I don't...
[00:24:33] I haven't done a count
[00:24:34] so they're rare
[00:24:35] they're not super rare
[00:24:37] but Crawford Lake is
[00:24:40] amongst all of those rare meromictic lakes
[00:24:43] it is almost unbelievably well suited
[00:24:48] to be the type section
[00:24:51] to define this Anthropocene
[00:24:53] it is, it has, it checks off all the boxes
[00:24:58] One more thing about Crawford Lake
[00:25:02] that I read that you wrote
[00:25:03] that I thought was really cool
[00:25:06] was just how it even formed
[00:25:09] like is it unique to that limestone
[00:25:13] escarpment area?
[00:25:15] was it a cave?
[00:25:17] how did it form?
[00:25:18] yeah
[00:25:19] so it's a cave that whose roof caved in
[00:25:23] that's what a sinkhole is
[00:25:24] and there are sinkholes
[00:25:25] like all over Florida for instance
[00:25:27] and so limestone is fairly easily dissolved
[00:25:32] it's soluble
[00:25:33] so that's why there are a lot of caves
[00:25:35] in limestones
[00:25:36] and when the roof cave's in
[00:25:38] it's like a sinkhole
[00:25:39] and yeah so the way that
[00:25:42] the Crawford Lake basin formed
[00:25:45] allows the lake itself
[00:25:47] to have those unique properties
[00:25:49] that allow the sediments to accumulate
[00:25:51] and have that perfect
[00:25:53] the geologic record of the way the world was
[00:25:57] before that great acceleration
[00:26:00] and the way it's been since
[00:26:04] yeah what was so kind of really unexpected
[00:26:08] was the Anthropocene
[00:26:09] you think about all this global change
[00:26:11] on this global level
[00:26:12] and do you think there's going to be
[00:26:14] a really grand site or something
[00:26:17] I don't know how the process
[00:26:19] of defining a golden spike site is complex
[00:26:23] do you think it would be as big
[00:26:24] as the enormity of the Anthropocene
[00:26:28] yeah and then that was just so powerful
[00:26:30] to kind of pin it down to a place
[00:26:33] that you know well
[00:26:34] and Milton too
[00:26:35] just kind of the suburban town
[00:26:37] it's very similar to other towns
[00:26:39] it feels like
[00:26:40] you know it could be many places
[00:26:41] in southern Ontario
[00:26:43] and I guess that's what the Anthropocene
[00:26:45] and the change looks like
[00:26:46] how we live
[00:26:48] and I think one of the things too
[00:26:50] is that excuse me there have been
[00:26:52] a really great film called Anthropocene
[00:26:55] it's Brotosky I think who
[00:26:58] Edward Brotosky the aerial kind of
[00:27:01] that's right
[00:27:02] and the imagery is striking
[00:27:05] but it focuses on the ugly
[00:27:09] so it focuses on the techno sphere
[00:27:12] and the ugliness of industrial output
[00:27:16] and Crawford Lake is not like that
[00:27:19] Crawford Lake is very pretty
[00:27:20] it's very calm
[00:27:22] it's very serene
[00:27:23] so yes it is the best place
[00:27:26] to record that shift from Holocene
[00:27:29] to Anthropocene
[00:27:30] but it's not striking in awe inspiring
[00:27:33] like the Grand Canyon
[00:27:34] and it's not striking like you know
[00:27:36] polluted beach
[00:27:38] you know and with plastics
[00:27:40] and you know it's
[00:27:43] it's not what you expect
[00:27:45] the poster child for the Anthropocene
[00:27:48] to be
[00:27:49] and yet it is by far
[00:27:54] it is an excellent site to define it
[00:27:57] yeah
[00:27:58] yeah it becomes a microcosm
[00:28:01] for the Anthropocene right
[00:28:03] this story is told in different ways
[00:28:05] everywhere on this planet
[00:28:07] right
[00:28:08] and it's a very inviting place to visit
[00:28:10] so I think in terms of having people
[00:28:14] engage with the story
[00:28:16] it's not hard to get to
[00:28:18] and there's all sorts of interpretive facilities
[00:28:21] so I'm hopeful that people will
[00:28:24] will come to Crawford Lake
[00:28:27] to give some careful thought
[00:28:29] to what we're doing to the planet
[00:28:31] and how we can fix it
[00:28:34] we have to be aware
[00:28:36] but if we get crippled by anxiety
[00:28:39] we're not going to help either
[00:28:41] so it's not a chicken little
[00:28:42] the sky is falling down
[00:28:44] it's wake up
[00:28:45] and let's do something about it
[00:28:48] yeah
[00:28:49] and in respect to some of the
[00:28:51] in respect to climate change for example
[00:28:53] a lot of those solutions exist
[00:28:55] and we're not waiting for
[00:28:57] technology and understanding
[00:28:59] it's really the will to
[00:29:01] organization to implement renewables
[00:29:05] yeah and there are probably solutions
[00:29:07] that we haven't thought of yet
[00:29:09] but they have to be thought of
[00:29:11] yeah
[00:29:12] and how do you
[00:29:14] how do you even sample the sediments
[00:29:16] of the lake
[00:29:17] yeah so you can sample the sediments
[00:29:20] with a quote unquote a regular
[00:29:22] core but that tends to squish
[00:29:25] and compress those annual layers
[00:29:27] so we've used primarily
[00:29:29] freeze-coring
[00:29:30] and my colleague Tim Patterson
[00:29:32] who I've known since we were undergraduates
[00:29:34] together at Dalhousie
[00:29:35] back in the early 80s
[00:29:37] we have been working together
[00:29:39] on Crawford Lake because he has
[00:29:41] the expertise and all the tools
[00:29:44] to take these freeze-cores
[00:29:46] and curate them
[00:29:47] so the majority of the freeze-cores
[00:29:49] are curated at Carleton University
[00:29:52] in Ottawa where he works
[00:29:54] one core is now at the Canadian Museum of Nature
[00:29:57] it is the one we proposed as the Golden Spike
[00:29:59] another core is at the Royal Ontario Museum
[00:30:02] I have one core in my lab
[00:30:04] but the vast majority of the cores are in his lab
[00:30:06] and then the sub-sampling
[00:30:08] of each layer
[00:30:09] the sediments from one given year
[00:30:11] separate from the one above and the one below
[00:30:14] that tedious but important work
[00:30:17] has been primarily done in his lab
[00:30:20] and sent to specialist labs around the world
[00:30:24] to analyze everything from plutonium
[00:30:27] to fly ash particles
[00:30:29] to stable isotopes
[00:30:31] so we didn't
[00:30:33] we did some of the analyses
[00:30:35] but we didn't do all of the analyses
[00:30:38] because specialists were commissioned
[00:30:42] to analyze those really key changes
[00:30:47] that Anthropocene Working Group
[00:30:49] wanted to make sure that
[00:30:51] all of the potential Golden Spike sites
[00:30:54] had analyzed
[00:30:55] and in this in the sediment
[00:30:57] so it can be it can be red like tree rings
[00:31:00] like pinpointed into an exact year
[00:31:03] how does that work yet?
[00:31:05] Yeah, yeah, we have
[00:31:07] each year is quite distinct
[00:31:10] so if you show us a picture of the core
[00:31:13] we can tell you that's 1952 or 1935
[00:31:18] and you just collect that thin layer of sediment
[00:31:22] and put it in a vial
[00:31:24] and that's 1935 or 1952 or whatever
[00:31:29] Yeah, amazing.
[00:31:30] So in respect to Anthropocene
[00:31:32] what was the evidence
[00:31:35] that Crawford like recorded really specifically?
[00:31:39] Well, I think it's important that
[00:31:42] all the sites we studied recorded the same thing
[00:31:44] and it recorded this
[00:31:45] all the sites record the same thing at the same time
[00:31:48] that's the point of it being a new interval of time
[00:31:51] it's not just at Crawford Lake
[00:31:53] it's not just in the Peat Bog in Poland
[00:31:57] the Peat Bog in Poland records the same thing as
[00:32:00] Crawford Lake as the Antarctic ice sheet, etc
[00:32:03] so it's that massive change in the atmosphere
[00:32:07] in the oceans and the entire earth
[00:32:10] so at Crawford Lake we record those things
[00:32:14] so amongst the evidence that we find
[00:32:18] and these various sites are fly ash particles
[00:32:22] so from industrial processes like
[00:32:25] steel making like in Hamilton
[00:32:27] where you have very, very high combustion of fossil fuels
[00:32:31] like the coking coal that you need to turn iron into steel
[00:32:35] just kilometers away, yep
[00:32:37] we see a sharp, sharp increase in fly ash particles
[00:32:42] in Crawford Lake in 1952
[00:32:44] and same time that we see Ivy Mike
[00:32:47] so that's why 1952 is the, according to us
[00:32:51] the first year of the Anthropocene
[00:32:53] Ivy Mike was, is the name given to the first H-bomb
[00:32:56] was detonated in the Marshall Islands in
[00:33:00] 1952 on November 1st at 7.15 in the morning local time
[00:33:06] which at Crawford Lake was 2.15 in the afternoon
[00:33:09] on the 31st of October of 1952
[00:33:12] and that is an incident that we use to mark
[00:33:16] the boundary between the Holocene and the Anthropocene
[00:33:20] so that's just one example
[00:33:22] but there are all sorts of products of
[00:33:26] human industry, changes in atmospheric composition
[00:33:30] changes in water quality
[00:33:33] all of these things change very, very quickly
[00:33:37] at Crawford Lake and but they also change
[00:33:39] at all of these other sites
[00:33:41] And you're telling me last time
[00:33:44] the, about the particles from the nuclear tests
[00:33:48] being able to, being identified
[00:33:51] to the month or to the day in the sediments
[00:33:53] at Crawford Lake?
[00:33:55] Whenever nuclear explosions, above ground
[00:33:58] nuclear explosions occur
[00:34:00] material goes up into the upper atmosphere
[00:34:03] those mushroom clouds that you picture
[00:34:05] when you hear about a nuclear explosion
[00:34:07] and that fallout falls out of the atmosphere
[00:34:11] and it accumulates on the surface of the planet
[00:34:15] so within like let's say a year of the mushroom cloud
[00:34:18] all of that stuff has fallen back down to planet Earth
[00:34:21] right? So that accumulation we can test
[00:34:25] for plutonium 239 for instance
[00:34:28] is a key radionuclide, something that is produced
[00:34:32] by these atomic bombs and these hydrogen bombs
[00:34:36] in particular if you've seen Oppenheimer
[00:34:38] hydrogen bombs are that much more powerful
[00:34:41] than the atomic bombs
[00:34:43] and we see the fallout of radionuclides
[00:34:48] all around the world at all of the sites that we studied
[00:34:50] but at Crawford Lake
[00:34:52] we see not only the massive increase
[00:34:56] in radionuclides with the H bombs
[00:34:59] starting in 1952 but we actually have a really good record
[00:35:03] of the early testings
[00:35:05] in the southwestern United States
[00:35:08] because the winds from the southwestern United States
[00:35:12] come over the Great Lakes Basins
[00:35:15] so very few other sites on the planet
[00:35:18] actually have very good records of 1945 to 1951
[00:35:24] so that the geologists look for the geologic evidence
[00:35:28] and yeah that's what we did, that's what we found
[00:35:32] and it turned out that the best place to
[00:35:35] that records it in the geologic record
[00:35:37] is the deep basin of Crawford Lake
[00:35:40] in those annually layered sediments
[00:35:43] that allow us to pinpoint precisely to the year
[00:35:47] when different things happen
[00:35:49] so that we have light tree rings
[00:35:51] we have the ability to confidently assign years
[00:35:55] to every year through the 20th century
[00:35:58] and identify when it was that the system
[00:36:03] seemed to be overwhelmed by the products of human industry
[00:36:08] and that great acceleration of human industry
[00:36:11] the Second World War and the post-war boom
[00:36:14] that seems to be what tipped the balance
[00:36:18] the tipping point of the planet's ability
[00:36:22] to continue to absorb those changes
[00:36:25] and keep doing what it was doing
[00:36:27] and now it's on a different path
[00:36:33] Incredible
[00:36:34] And another aspect of just the process of sampling
[00:36:39] that is very special about this
[00:36:42] was that you were working with First Nations community
[00:36:45] and that there were healing rituals performed during sampling
[00:36:48] is that right?
[00:36:50] Yeah so the world view of the Indigenous people
[00:36:54] is that the world around us is imbued with personhood
[00:36:58] so what we would call inanimate objects like lakes
[00:37:01] to them they have personhood
[00:37:03] and when we recognized this
[00:37:06] that they felt it was sort of an assault on the lake
[00:37:10] to be poking, prodding it
[00:37:12] we worked with them to try to minimize the harm
[00:37:17] maximize the healing
[00:37:19] and so yes that's what we did
[00:37:21] and one of our one of the grad students on our team
[00:37:24] grad student at Queens University in Kingston
[00:37:27] is herself Indigenous
[00:37:28] she's Anushnabe
[00:37:30] so she was the person on our team
[00:37:33] who facilitated that process
[00:37:36] who engaged in those practices
[00:37:41] I guess we've spoken a little bit about this
[00:37:44] already in the conversation
[00:37:45] but the International Union of Geologists
[00:37:49] voted down the proposal to make it official
[00:37:52] but the idea is already widely accepted
[00:37:55] there's no putting it back
[00:37:57] it's doing its work out there already
[00:37:59] and your contributions of Crawford Lake
[00:38:02] and telling that story
[00:38:03] and publicly talking about the Anthropocene
[00:38:06] surely is a really big part of that
[00:38:08] Are there...
[00:38:10] I guess what was that disappointing for you?
[00:38:14] What are kind of your reflections
[00:38:17] of kind of the bureaucracy of that process?
[00:38:20] This has been an enormous privilege to
[00:38:23] spend so much time
[00:38:26] working on the geology of Crawford Lake
[00:38:29] and the hydrology and the limnology
[00:38:32] the things that currently live in the water column
[00:38:35] of the lake and the things that accumulate
[00:38:38] their fossil record in the sediments
[00:38:40] so yeah it's been an enormous privilege
[00:38:43] and then more recently
[00:38:45] in the last couple of years
[00:38:48] the interest from
[00:38:52] people who aren't scientists at all
[00:38:54] people who are artists, people who are social scientists
[00:38:57] people who are philosophers
[00:39:00] people who are interested in the lake
[00:39:03] for completely different reasons than I was
[00:39:06] people whose indigenous ancestors
[00:39:09] lived around the lake
[00:39:11] so such a variety of people
[00:39:13] with a variety of reasons to be fascinated
[00:39:16] by the same place
[00:39:18] that has been
[00:39:21] super interesting
[00:39:23] and I'm becoming increasingly interested in that
[00:39:26] non-geological aspect
[00:39:29] as I've been exposed to
[00:39:32] these different ways of looking at the lake
[00:39:35] the meaning of what we have found
[00:39:38] the potential significance of what lies
[00:39:41] meet those waters of Crawford Lake
[00:39:44] why it has been discussed
[00:39:47] literally around the world
[00:39:50] the word Crawford Lake has been
[00:39:53] translated into umpteen languages
[00:39:56] in newspapers around the world at different times
[00:39:59] and that is just incredible
[00:40:02] because you used to walk around it when you were young
[00:40:05] and it's not like the Grand Canyon
[00:40:08] where you think holy smokes
[00:40:11] this is like stupendous
[00:40:14] it's just very calm
[00:40:17] and yet it is of potentially such enormous significance
[00:40:21] to everyone on the planet
[00:40:24] and that's
[00:40:27] biggest privilege of my academic life
[00:40:30] has been to study
[00:40:33] and then explain
[00:40:36] discuss, promote what we found to people
[00:40:39] because the finding, the doing the science
[00:40:42] is only part of it
[00:40:44] and to be able to communicate
[00:40:47] and engage people
[00:40:50] and that has been
[00:40:53] just as interesting as doing the work
[00:40:56] Yeah, there's definitely no putting
[00:40:59] Anthropocene back in the box
[00:41:02] Yeah, the care and
[00:41:05] honor that you put into researching a lake
[00:41:08] and spending so much time with it
[00:41:11] is significant
[00:41:13] I made sure that on the 31st of October
[00:41:16] when I hit send on the proposal
[00:41:19] that my emotional investment ended there
[00:41:23] and I could not feel
[00:41:26] I could not allow the actions of others
[00:41:29] to dictate how I felt about what we'd accomplished
[00:41:33] to a certain extent I was successful in doing that
[00:41:36] so when I heard
[00:41:38] totally unexpectedly that they were going to vote no
[00:41:41] I was dismayed, I wasn't shocked
[00:41:44] I was dismayed and the reason I was dismayed
[00:41:47] was that I felt that
[00:41:50] like you said earlier we are in the Anthropocene
[00:41:53] the genies out of the bottle is not going back
[00:41:56] and for a group of geologists, stratigraphers
[00:41:59] to refuse to be relevant
[00:42:02] to what society needs
[00:42:05] to do
[00:42:07] I think that was a very bad
[00:42:09] well them im aside
[00:42:12] it's so rare to be able to get to work
[00:42:15] on a project that is as huge
[00:42:18] and as impactful
[00:42:21] you said it's been
[00:42:23] I think the most important work
[00:42:26] that you've been able to do
[00:42:29] what's it kind of been like
[00:42:32] for you to lead and contribute to this work?
[00:42:35] Yeah, it's like I said, it's been an honor. It's been oddly humbling, which is interesting because of course I've been in the public eye a lot, but it's been, it's awe inspiring to be able to reach so many people, to communicate such important things and have them largely listened to.
[00:42:59] And I've been invited to speak at so many places and the most exciting one to me is the Vatican, or the Pontifical Academy of Sciences to have an invitation to address that body was like totally unexpected.
[00:43:14] My dad would have been so proud. But these are the two address people who have the opportunity to reach people and influence decisions.
[00:43:24] And that to me is amazing. One of my colleagues is working with the UN. There are all sorts of ways that we're reaching people who are listening and whether the strategist ever do. I can't let that affect how I feel about the work we're doing.
[00:43:45] That was my conversation with Dr. Francine McCarthy. Thank you for listening and thank you to Francine for sharing her work.
[00:44:03] Plant Kingdom is hosted and produced by me, Catherine Polts. Our music is by Carl Dider. Listen to us wherever you get your podcasts and check out our website at plantkingdom.earth.