PETM: A Distant Mirror of Climate Change

December 18, 2017

Really brilliant new video from the PBS Eons series, great review of what we know about one of the most critical and mysterious moments in “recent” earth history, the Paleocene Eocene Thermal Maximum.

I find reviewing what we know we know, as well as what we know we don’t know, is a useful exercise.

I’ve posted on this before, so re-upping that here:

PETM, the Paleocene – Eocene Thermal Maximum.

That’s the last time in earth history that things changed in a way similar to the way they are changing now. It was 55 million years ago, give or take a millenium.

Scientific American (sub required – you can also buy single issues) has an article by one of the real experts, Lee Kump, comparing the pace at which the earth changed during the most recent Great Warming event.  As the sobering graph shows, the current CO2 buildup is prodeeding at a blistering pace compared to the ancient past.  Current rates of change are thousands of times faster than normal, and even 10 times faster than one of the most spectacular geological changes in the record.

The PETM bears some striking resemblances to the human-caused climate change unfolding today. Most notably, the culprit
behind it was a massive injection of heat-trapping greenhousegases into the atmosphere and oceans, comparable in volume to
what our persistent burning of fossil fuels could deliver in coming centuries….. New answers provide sobering clarity. They suggest the consequences of the planet’s last great global warming paled in comparison to what lies ahead, and they add new support for predictions that humanity will suffer if our course remains unaltered.

The PETM had a big impact on life in the oceans, as evidenced by this sediment core.

According to Kump:

..Today investigators think the PETM unfolded something like this: As is true of our current climate crisis, the PETM began, in a sense, with the burning of fossil fuels.

At the time the supercontinent Pangaea was in the final stages of breaking up, and the earth’s crust was ripping apart, forming the northeastern Atlantic Ocean.

As a result, huge volumes of molten rock and intense heat rose up through the landmass that encompassed Europe and Greenland, baking carbon-rich sediments and perhaps even some coal and oil near the surface. The baking sediments, in turn, released large doses of two strong greenhouse gases, carbon dioxide and methane.

Judging by the enormous volume of the eruptions, the volcanoes probably accounted for an initial buildup of greenhouse gases on the order of a few hundred petagrams of carbon, enough to raise global temperature by a couple of degrees. But most analyses, including ours, suggest it took something more to propel the PETM to its hottest point.

When the gas releases began, the oceans absorbed much of the CO2 (and the methane later converted to CO2). This natural carbon sequestration helped to offset warming at first. Eventually, though, so much of the gas seeped into the deep ocean that it created a surplus of carbonic acid, a process known as acidification.

Moreover, as the deep sea warmed, its oxygen content dwindled(warmer water cannot hold as much of this life-sustaininggas as cold water can). These changes spelled disaster for certain microscopic organisms called foraminifera, which lived on the sea floor and within its sediments. (the whitish colored sediment at the bottom of the core here – PS) The fossil record reveals their inability to cope: 30 to 50 percent of those species went extinct.

The message of the graph, and the core, are clear. We are changing the planet at a rate unprecedented outside of the most severe convulsions the planet has seen in 4 billion years of history. We do not know what the results will be.
I don’t think I want my children and grandchildren to find out.

In the video below, James Hansen’s abbreviated lecture on paleo-history since the PETM.


6 Responses to “PETM: A Distant Mirror of Climate Change”

  1. stephengn1 Says:

    Hanks video here, while somewhat informative, is simplistic, incomplete and even irresponsible from an ecological point of view

    Evolutionary pressure is a tricky thing to calculate, especially over whole diverse biomes or interlocking ecosystems. The rate of climatic change in such areas is all important and can be the adaptational difference between a system of ecosystems that adapt and mass extinction

    My hope is that it won’t play into the ignorant and overly simplistic denier narrative that “CO2 is life”. CO2 IS life, but it’s also death. Rate of change and the ability to adapt well and in time to respond to multiple changes is everything

  2. grindupbaker Says:

    There’s a PETM talk “Global Warming 56 Million Years Ago: What it Means for Us” from Dr. Scott Wing at

    • J4Zonian Says:

      I found Wing good on geology (mostly), pretty bad on politics and solutions, mainly because of a few misconceptions and no organized thinking on that, as well as his not considering certain things at all, including psychology, which must be a if not the major consideration. He seems like a sweet, gentle, smart guy who like all of us just doesn’t certain realities, but he’s forced to talk about them here anyway.

      He’s ridiculously, absurdly, insanely optimistic about the speed of ice melt & SLR—51:00. (Wing says 7.5 m SLR in 5000 years; but it’s very likely that we’ll have at least 1/4 of that in the next 80 years–10-20 times faster, and accelerating, especially if we do no more than we are now to avoid calamity.

      That means 150 million+ refugees by 2100 just from this one cause, and that seems like a similarly ridiculously low estimate; I don’t think a billion refugees is out of line a lot sooner. And we’re constantly finding new feedback and instability mechanisms we hadn’t expected (as we did last month), making the projections more alarming all the time.) And it’s important to recognize that the more disasters we have in the next few years–storms, floods, fires, failed states… the less able we’ll be to implement the solutions needed to avoid accelerating even faster to the worst possible outcomes. IOW, we gotta make enormous changes right the hell now or we are, as Jason Box said, “fucked”.

      Wing also does the snapshot mistake with chemical agriculture Nitrogen use— thinks that because it IS one way now, it MUST be that way always. Later (58:00) makes the opposite mistake about ecosystem ”restoration”. Also takes Smil’s domestic vertebrate estimate (54:00)—65% of vertebrate biomass, humans 30%, wild 3%, without mentioning that INvertebrates VASTLY outnumber and outweigh verts on Earth, and the fact that either humans or Smil concentrate only on verts (ignoring the infinitesimal % of yeasts who are “domestic”, e.g.) that this presents a grossly false picture of how much of the world is ”human”]. However, as populations of almost every type of living being plummet astoundingly fast, that ratio is changing.

      On land, btw—where by far most of the Earth’s biomass is—plants outweigh animals by 1000 times, with about 18% of the plant biomass eaten by animals in any time period and that replaced by growth. (In the oceans, animals outweigh plants by 30x, and eat most of the plant biomass.)

      Dr. Wing’s also wrong on what to do to stop climate catastrophe and planting for sequestration in the questions—at 1:29, eg. The answers are Efficiency, Conservation, Wiser Lives, Clean Safe Renewable Energy, Reforesting, Small Scale Low Meat Organic Permaculture and Some Other Stuff.

      And Wing blows it on population by not saying we’re leveling off, etc. and by saying he’s not worried about human extinction. He should be. We should be. Earlier, he blew it by not understanding that people need the truth, need to know how dire it is, although they also need to be shown and told the solutions. Again, last q: Is there a technological solution to this? OF COURSE THERE IS! THE SOLUTIONS LISTED ABOVE ARE THE TECHNOLOGICAL SOLUTIONS! ECWLCSRERSSLMOPASOS Not geoengimagicalism, which he sorta gets right.

      At 1:25:xx he goes way wrong on what to do–almost no clue at all about what’s needed, what will work, and what won’t. R&D are great, but D2–Deployment–is what’s massively needed right now with the technology we already have.

      A carbon tax is not enough now; it’s too late for such incrementalist solutions to be the main thing we do. We need, as an umbrella for all our actions, a US WWII level citizen and industrial mobilization, globally. We need to nationalize and shut down the fossil fuel industry as fast as possible as it’s replaced with ECWLCSRE.

      I think there are much better sources of information: almost anything Kevin Anderson says, almost everything David Roberts and Joe Romm write, almost everything here at Climate Crock. potholer 54, Inside Climate is very good… Climate State comes highly recommended.

  3. indy222 Says:

    Kevin Anderson is, yes, one of the few who will not sugar-coat the dire situation and the necessity for anti-growth by the wealthy nations especially.

    On agriculture, it’s certainly true to save our soil – which some estimate we’re losing at 1%/yr – we need to go away from Big Ag’s “Green Revolution” and no-till, no-pesticide organic growing… but what very few will acknowledge is that farmers didn’t go towards Big Ag because they want to destroy their own farmland, they did it because they were economically forced to, to cut their costs in order to get their crops sold. I get impatient with the greenies who get all misty-eyed at campaigning for mass movement to eco-friendly all-green organic no-til farming world wide. Beautiful images until you realize…..The truth is, that is much much more labor-intensive and therefore much much more expensive food, and the result of that in this world of 7.5 billion people, will be famine, wars, riots, and death by the millions (except, the 1%’rs will have no problem paying their grocery bills, of course).

    • J4Zonian Says:

      Yes, it’s very likely the switch to small scale low meat organic permaculture will have to be accompanied by even bigger economic changes. But since rich people are the main causes of climate catastrophe and the larger ecological crisis, we have to do that anyway, if we want to survive. If we want enough global stability to be able to implement all the changes needed to avoid cataclysm, we need to provide whatever it takes for poor people to get all the clean safe renewable energy they need to live more productive and fulfilling lives (and not hate rich people and the US). We need to reduce inequality from both ends, using the wealth the rich have stolen, hoarded, and used in rent-seeking to finance the move to clean safe renewable energy, provide transformation in the lives of the poor, educate, and transform industry, agriculture and forestry.

      Talking about how hard that is, or unlikely, given what’s preciously known as “political reality” (the first word removes all meaning from the second) is pointless, as it is physical, chemical and ecological reality and they take precedence over opinion and politics. It’s not that I want us to do this, it’s not that it would be nice… it’s that either we do this or we’re unlikely to survive as a civilization, and probably most life on Earth will be wiped out.

      We have many problems that would be solved by the same multifaceted program that would solve the climate crisis. The labor needs of permaculture, mostly revolving around perennials, are perfectly suited to the population path we need to follow–high population now, declining very soon and high labor needs setting up the perennial systems and lower needs maintaining and harvesting. The imperative here has as much to do with the means as the ends. That is, the things shown to reduce population growth–political and economic equality, education and empowerment of all especially women, security in sickness, age and hard times plus free access to contraception–are good and necessary things in their own right if we want to solve the climate crisis and survive the next century.

      Labor intensiveness is not an evil; it’s a solution and an accompanying condition to solutions. We need to be less “productive”, that is, people in the US need to do less economic tasks, which are all, in the end, essentially turning nature into trash. We need to concentrate more on experiences and less on things, that is, living instead of possessing. So many people in the food industry are thoughtlessly proud of what they think of as the exceptional efficiency of the US food system, but is really only one facet–fewer people directly farming per calorie. What a moronic value! The fossil to food EROEI is abysmal–we use many calories of oil etc. to produce each Calorie of food. We devote an enormous amount of machinery, effort, expertise etc. to growing foods inappropriate to the local climate, transporting food thousands of miles, over-processing and wasting food, etc. etc.

      We need to spread out food production to more people and more land, (yards, roofs, etc.) we need to work less at jobs doing what most jobs do–trivial and destructive tasks in a trivializing and destructive economic system. So many changes like this have been things we wished for for a long time. Will we do them? I don’t know. I only know it’s now not a question of wanting; it’s a question of doing them or not surviving.

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: