BY MIKE MAGEE

When it comes to our earthly survival as a human species, words are often under-powered and off-the-mark. Clearer concepts, definitions and terms are required for clarity. Here are five terms that are useful and worth remembering:

1. Planetary Boundaries
2. Earth Systems
3. Human Perturbations
4. Planetary Scale Destabilization
5. Holocene Epoch vs. Anthropogenic Epoch 

These terms all tie back to a single source – a child of World War II, only seven when his home in Amsterdam was overrun by Nazis. His father was a waiter, his mother a cook in a local hospital. He’d later recall with a shudder the Fall of 1944, the beginning of “hongerwinter” (winter of  famine) which he blamed for stunting his growth and contributing to his short stature. The event also exposed him to death for the first time, losing several classmates to starvation and frozen temperatures that winter.

There were no early signs of brilliance. He attended a technical school and prepared for a life in construction. He met a Finnish girl, Terttu when he was 25, and they settled in a small town 200 km north of Stockholm. It was his wife who recognized his potential first, pointing him toward a newspaper ad for a job as a programmer at the Stockholm University’s Meterorologic Institute (MISU). No matter that he had no experience in computer programming. They moved to Stockholm. He worked and they both took college courses. By age 30, with sponsorship from the world’s expert on acid rain and first chairman of the Intergovernmental Panel on Climate Change (Bert Bolin), he received a master’s degree in meteorology. Five years later, after focusing on stratospheric chemistry, he earned his doctorate.

When he died at 87, with Terttu, two daughters and three grandchildren at his side, Paul Crutzen was 87 years old.  A tribute in Scientific American at the time stated “Paul Crutzen [may have been] the greatest scientist of all time.” This was not because he had been granted the 1975 Nobel Prize in Chemistry (without ever having taken a chemistry course) for discovering how ozone was formed in the stratosphere; or for his coining the term “Nuclear Winter” to describe the planetary devastation that would follow a nuclear attack in 1984; or for being the major adviser on global warming to Pope Francis in preparing his encyclical Laudato Si’/”On Care For Our Common Home”prior to the Paris Climate Accords in 2015.

No, what Crutzen is especially remembered for is a momentary lapse in his usually pleasant and calm demeanor while serving on a panel of The International Geosphere–Biosphere Programme (IGBP) for the the International Council for Science (ICSU) at its May, 2000 meeting in Cuernavaca, Mexico. The speaker at the mic, in outlining the current challenge of maintaining the Earth’s life support systems referred once too often to the Holocene Epoch, that is the period of roughly the last 11,700 years of our planet’s existence when humans were able to survive, thrive and develop in general harmony with their host planet. In a moment of spontaneous scientific combustion, Dr. Crutzen muttered in a muted but still audible whisper, “Let’s stop it. We are no longer in the Holocene. We are in the Anthropocene.”

A hushed silence fell over the crowd as the world’s top Earth scientists were forced to acknowledge an uncomfortable truth – man was destroying the planet. Summarized in a report a few days late, Crutzen wrote, “Considering these and many other major and still growing impacts of human activities on earth and atmosphere…it seems to us more than appropriate to emphasize the central role of mankind in geology and ecology by proposing to use the term ‘anthropocene’ for the current geological epoch.”

For scientists in the field, this was a call to action. As the American Meteorological Society later recounted, “From the perspective of Earth system science, many well-respected scientists in that field are convinced that the transformation from the Holocene to the Anthropocene, a term clearly defined by Crutzen in a moment of exasperation, is truly a once-in-a-lifetime event.”

Nine years later, Crutzen’s colleagues from Stockhom University, Will Steffen and Johan Rockstrom, published a paper on “the environmental limits within which humanity can safely operate.” In that paper, “A Safe Operating Space For Humanity” published in Nature, they proposed nine “planetary boundaries” to gauge “the continued development of human societies and the maintenance of the Earth system(ES) in a resilient and accommodating state.” In there view, measuring and ongoing monitoring of these boundaries would provide “a science-based analysis of the risk of human perturbations” that might “destabilize the ES on a planetary scale.”

But in the world of international geoscience, laying out human responsibility for planetary stress is one thing, but declaring an end to the 11,700 year Holocene Epoch was quite another. In effect, Crutzen was provoking a geological revolution, and that is why a hush fell over the crowd that day.

But coming out of the original 2000 Mexico meeting of the International Geosphere-Biospere Program, participants were energized and decided to form a 40 member global Anthropocene Working Group (AWG). One arm focused on defining planetary boundaries (PB), and specific data measures for each, while another would explore sites that might provide geologic proof in soil samples of the irreversible impact of humans on their planet, and support the now widely held belief that a new geologic epic had indeed been launched 

After extensive analysis, a new paradigm with 9 planetary boundaries was published in 2009 and reviewed in 2015 and included “a science-based analysis of the risk that human perturbations will destabilize Earth state at a planetary scale.” The list with associated measures included: : 

1. Climate Change (CO₂ concentration in the atmosphere < 350 ppm);
2. Ocean Acidification (Seawater Aragonite levels – crystal calcium carbonate ≥ 80% of pre-industrial levels).
3. Stratospheric Ozone (less than 5% reduction in total atmospheric O₃ from a pre-industrial level).
4. Nitrogen/Phosphorous Cycle  (artificial eutrophication of air, soil, water)
5. Global Freshwater supply (< 4000 km³/yr of consumptive use of runoff resources).
6. Land System use(< 15% of the ice-free land surface under cropland).
7. Biosphere Integrity (an annual rate of loss of biological diversity of < 10 extinctions per million species).
8. Novel Chemicals (emissions of toxic compounds such as synthetic organic pollutants and radioactive materials, but also genetically modified organisms, nanomaterials, and micro-plastics).
9. Atmospheric Aerosols (natural and manmade dust deposited in the lower atmosphere).

The control measures track shifts from Holocene conditions that are human mitigated. For example, CO2 concentrations during Holocene fluctuated around 280 ppm. Since 1950, they have risen to 350 ppm, a level that geologic studies demonstrate last existed on our planet 300,000 years ago. In 2022, the level hit a new record of 417 ppm

The Planetary Boundary (PB) framework was designed to promote maintenance of a “desired Holocene state” that has served human development well. A “safe operating space” for human society development on Earth is not a luxury. By 2015, it was determined that four of the planetary boundaries had already been breached including climate change, biosphere integrity (diversity), biogeochemical flows ( nitrogen and phosphorus cycles ), and land-system change. Seven years later, in 2022, a 5th boundary (introduction of novel entities – formerly “chemical pollution”) was crossed.

At the same time, the 40 member Anthropocene Working Group labored on in search of a single site that might yield a core geologic bore sample that proved that man in real time had shifted Earth’s basic geology. In 2023, Colin Waters, the AWG’s chair reported “We see a clear, abrupt, and global transition from the previous Earth epoch to something new”, and announced the six finalists –   “a peat bog in Poland’s Sudeten Mountains;  Searsville Lake, in California; Crawford Lake, in Ontario; a seafloor in the Baltic Sea;  a bay in Japan;  a water-filled volcanic crater in China; an ice core drilled from the Antarctic Peninsula;  and two coral reefs, in Australia and the Gulf of Mexico.”

On July 11, 2023, Canadian Geographic proudly broadcast, “The Anthropocene is here — and tiny Crawford Lake has been chosen as the global ground zero.” As the article stated “Its nomination still needs to be voted on by three higher bodies of geologists over the coming year, but if they, too, approve the candidacy, Crawford Lake will be endowed with the ‘golden spike,’ a literal brass marker that signifies that the planet shifted, in about 1950, from one unit of geological time to the next.”

Why Crawford Lake? Turns out this “humble little lake” has a very rare geochemical mix including a depth to surface area mix that prevents top and bottom layer mixing, and prominent oxygen levels within its bottom layer. The fact that it is a “meromictic” lake (meaning its top and bottom layers never mix) makes it unique in all of North America. Over the years, as material settled to the lake bottom it was sealed by distinct couplets of calcite deposits that market summer and winter. This allowed core samples to be accurately dated. For example, in 1970, corn pollen found in one of the layers was able to be accurately dated by stratigraphers to the Middle Ages.

What they are looking for in the soil and stone are concrete markers. According to published reports, dry ice frozen core samples were able to be dated back over 1000 years. More relevant to the Anthropocene, “By 1950 or so, a rapid, dramatic increase of carbon-based particles shows up from industrial processes, including coal-fired steel-making in a nearby Hamilton foundry, as well as a rapid rise in plutonium from nuclear testing, a change in nitrogen isotopes from fertilizer use, and the chemical fallout from acid rain.” 

These, and other findings, allowed 75 local scientists to champion Crawford Lakes candidacy with Francine McCarthy, a geologist at Brock University in the lead. She stated, “If people see that stratigraphers, a conservative bunch of geologists, are willing to put a line on the timescale and call it by the name that recognizes — that admits — the role of humans as a causal agency, then that’s mammoth.”

Were Paul Crutzen alive, he would surely agree that the announcement of the 39th Epoch in our 4.6 billion year planetary history was not a call for celebration, but rather a call to action. The challenge for human and planetary survival is now scientifically linked, and no less urgent than was Paul’s own childhood survival during the “hongerwinter” of 1944.

Mike Magee MD is a Medical Historian and regular contributor to THCB. He is the author of CODE BLUE: Inside the Medical-Industrial Complex (Grove/2020).