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Laschamps-ing at the bit

Filed under: — gavin @ 26 February 2021

A placeholder to provide some space to discuss the paper last week (Cooper et al, 2021) on the putative climate consequences of the Laschamps Geomagnetic Excursion, some 42,000 yrs ago.

There was some rather breathless reporting on this paper, but there were also a lot of sceptical voices – not of the main new result (a beautiful new 14C dataset from a remarkable kauri tree log found in New Zealand), but of the more speculative implications – both climatically and anthropologically.

On twitter there were some good threads covering multiple aspects of the paper (and the lead author):

But let me make a couple of different points. We have occasionally discussed the Laschamps event here as a counter-example to the notion that changes in galactic cosmic rays have a major impact on climate. A reversal or near-reversal of the geomagnetic field would be expected to greatly increase the GCR getting to the lower atmosphere – in far greater amounts than over a solar cycle, or grand solar minimum (like the Maunder Minimum). So if people want to postulate a big role for GCR there, they needed to explain why there wasn’t a much bigger signal at 42kya too. These authors are thus not the only people to have looked for significant climate impacts at this time. They are perhaps the first to claim to have found them…

To be clear, the modeling that was done in this paper was good (if extreme) and suggested that the geomagnetic event combined with a severe grand solar minimum (much bigger than the Maunder minimum) would cause significant depletion of the ozone layer and some shifts in the annular modes. But the ozone depletion is less than we’ve seen due to anthropogenic ozone depletion since the 1980s, and the surface climate changes don’t seem very significant at all – especially compared to the massive variability exhibited in the ice cores throughout the last ice age (particularly in Marine Isotope Stage 3 – the Dansgaard-Oeschgar events). At best these are nuanced and subtle climate effects, and certainly not anything apocalyptic (despite Stephen Fry’s dulcet tones).

Finally, it should be called the Laschamps event (with a final, and etymologically correct, ‘s’) after the village in the Auvergne where it was first identified. There is unfortunately 50 years of legacy references to the “Laschamp” excursion, but hopefully it isn’t too late to fix!

References

  1. A. Cooper, C.S.M. Turney, J. Palmer, A. Hogg, M. McGlone, J. Wilmshurst, A.M. Lorrey, T.J. Heaton, J.M. Russell, K. McCracken, J.G. Anet, E. Rozanov, M. Friedel, I. Suter, T. Peter, R. Muscheler, F. Adolphi, A. Dosseto, J.T. Faith, P. Fenwick, C.J. Fogwill, K. Hughen, M. Lipson, J. Liu, N. Nowaczyk, E. Rainsley, C. Bronk Ramsey, P. Sebastianelli, Y. Souilmi, J. Stevenson, Z. Thomas, R. Tobler, and R. Zech, "A global environmental crisis 42,000 years ago", Science, vol. 371, pp. 811-818, 2021. http://dx.doi.org/10.1126/science.abb8677

30 Responses to “Laschamps-ing at the bit”

  1. 1
    James Charles says:

    “This last major geomagnetic reversal triggered a series of dramatic events that have far-reaching consequences for our planet. They read like the plot of a horror movie: the ozone layer was destroyed, electrical storms raged across the tropics, solar winds generated spectacular light shows (auroras), Arctic air poured across North America, ice sheets and glaciers surged and weather patterns shifted violently.

    During these events, life on earth was exposed to intense ultraviolet light, Neanderthals and giant animals known as megafauna went extinct, while modern humans sought protection in caves.”
    https://theconversation.com/earths-magnetic-field-broke-down-42-000-years-ago-and-caused-massive-sudden-climate-change-155580?fbclid=IwAR0ZgP1y35DPaquBxFAm4AMLGo8vXWtIQkfc47q7yIHWmJvJnZ0HphK35G8

  2. 2
    Russell Seitz says:

    Jessica, play the tree, not the man.

    Nature says Cooper was sacked for unwokemanlike conduct, and reports his dismissal “did not relate to the quality or integrity of his research or any other research conducted with the centre. ”

    Besides being on a par with teak for durabilty and rot resistance, ( The then-40 year old Kiwi kauri boat I sailed in 1975 is still merrily circumnavigating) kauri trees are famed as prodigeous producers of an impermeable varnish resin that, like amber, can protect the physical and chemical integrity of embeded organic materials. Finding a fossil tree of the stuff two millennia in diameter is a serious research windfall.

  3. 3
    J Doug Swallow says:

    Cap Allon at Electroverse has been mentioning about Earth’s magnetic poles switching for some time now. There is physical evidence that this happened 42,000 years ago and that the climate was subjected to drastic changes. There is, to date, no empirical evidence that carbon dioxide has anything to do with the Earth’s climate, such as making it warm up or change.
    MAGNETIC POLE SHIFT + LOW SOLAR ACTIVITY: “A GLOBAL ENVIRONMENTAL CRISIS” HAS BEGUN
    FEBRUARY 22, 2021 CAP ALLON
    Even the mainstream has awoken to the “cataclysmic” threat that is the combo of low solar activity and a weakening magnetic field… The flipping of the Earth’s magnetic poles together with a drop in solar activity 42,000 years ago could have generated an apocalyptic environment that lead to the extinction of megafauna and to the end of the Neanderthals, reports the Guardian, citing a new paper published in the journal Science, co-authored by Prof Chris Turney of the University of New South Wales. The Laschamp excursion was just one of many in “recent” times, with these magnetic excursions (not full-blown reversals) appearing to hit approximately every 12,000 years:
    Years Ago Magnetic Excursion Ice Event Extinctions
    ~12,000 Gothenburg Younger Dryas Global Disaster
    ~24,000 Lake Mungo Heinrich 2 Eurasia
    ~35-37,000 Mono Lake Heinrich 4 N. America
    ~40-47,000 Laschamp Heinrich 5 Global Disaster
    ~60,000 Vostok/Greenland Heinrich 6 Australia
    ~72,000 Toba Heinrich 7a Global Disaster
    https://electroverse.net/low-solar-activity-magnetic-pole-shift/

  4. 4
    Mark J Fiore says:

    Hi folks I am an amateur climate change guy who follows the climate news a lot.(Harvard,1982,Boston College Law School,1987 SFUSD sub for 19 years, all high sshools)Been a member of Realclimate for many years.I am not a scientist like all of you are.I know that.I used to read all the posts on Realclimate.For the past few years I have not.But I have been following the climate news closely.Many years ago I said the melting of the methal hydrates on the shallow sea floors was going to be a huge issue, and many here in this site said not to worry about it, that the data was nothing there.Please note that now we see exactly what I was saying, namely that we are in for a massive methal hydrate melt and an ongoing massive peat moss melt.injection billions of tons of greenhouse gas into the atmopshere.This will be the tipping point,and a final rise of 6C is inevitable once 2C locks in,which it has already.2C locks in 4 C, which locks in 6C,due to the peat moss and methal hyrdte melt over the next 30 years.End of story.Please forgive my amateurness in not posting this comment in the methal hydrte thread.Gavin et all, what do you think NOW of the methal hydrate melt.I BELIEVE THAT IF 55 GtcO2e HUMAN EMISSIONS DOES NOT FALL TO ZERO WITHIN 5 YEARS FROM NOW THE 6c RISE IS UNAVOIDABLE,WITHIN 4 CENTURIES.tHANKS FOR LETTING ME POST AND IF THIS NEEDS TO BE DELETED BECAUSE i COULD NOT FIND THE RIGHT THREAD THEN, MY ESTEEMED SCIENTISTS, DELETE AWAY.lol.

  5. 5

    JDS, 2–

    There is, to date, no empirical evidence that carbon dioxide has anything to do with the Earth’s climate, such as making it warm up or change.

    That statement wasn’t true any of the previous times it was alleged. Still not true now.

    Tedious.

  6. 6
    nigelj says:

    “There is, to date, no empirical evidence that carbon dioxide has anything to do with the Earth’s climate, such as making it warm up or change.”

    Yes there is. Plenty. Details of empirical evidence that humans are causing global warming:

    https://skepticalscience.com/empirical-evidence-for-global-warming.htm

  7. 7
    MA Rodger says:

    Kevin McKinney @5,
    The problem with this denialist troll is his determination to present nonsense. While he may not appreciate what his comment @2 is saying in responding to the OP above which sets out how Cooper et al (2021) contains “speculative implications – both climatically and anthropologically.” The denier JDS responds by quoting an OP of an obscure climate change denier called CAP ALLON who is happy telling the word how Cooper et al (2021) and all its “speculative implications” is in complete agreement with his own crazy views on the matter, views that appear to have resulted in the “blacklisting” of this denier CAP ALLON’s work.
    As they say, “No matter how fine they slice it, deniers serve only phoney baloney.”

  8. 8
    Ray Ladbury says:

    @3 There is to date no evidence that JDS has in his head anything more complicated than a ganglionic bulge and no evidence that his learning curve has a positive slope.

  9. 9
    Jeremy Grimm says:

    I am not sure how to regard the recent descriptions of the Laschamps event and the reversal of the Earth’s magnetic field. I was unsure how to regard the climate events described — the magnetic field events disturbed me. If the Earth’s magnetic field flipped polarity, what effects could that have on our electrical and electronic equipment? Would a flipping of the Earth’s magnetic field coupled with at solar flare be greatly unlike a Carrington event?

    [Response: On those grounds we do have cause to be concerned. Not every key piece of electronic equipment will be resilient to the changes in the geomagnetic field. Clearly, that would not however have been much of a concern for the Neanderthals though… – gavin]

  10. 10
    J Doug Swallow says:

    #6 27 Feb 2021 at 8:36 PM nigelj says: “Yes there is. Plenty. Details of empirical evidence that humans are causing global warming:” and then directs me to John Cook’s Skeptical Science site to attempt to verify what nigelj is maintaining.
    This is The Truth about Skeptical Science
    Skeptical Science is a climate alarmist website created by a self-employed cartoonist, John Cook (who apparently pretends to be a Nazi).
     http://www.populartechnology.net/2012/03/truth-about-skeptical-science.html?fbclid=IwAR3gx9eO77-KCIrJl9Bq_N8QOKbCYiafC6D8rX9a0X_pBZr_xSUbcsBQ8IY

    It appears that nigelj’s trace gas, CO₂, that make up only between .03-.04% of the total atmosphere has fallen down on the job.
    At least 2 400 cold temperature records broken or tied in the U.S. from February 12 to 16, 2021  February 18, 2021 at 22:13 UTC (9 days ago)
    At least 2 400 preliminary daily cold temperature records, including cold maximums and minimums, were broken or tied at longer-term sites (75+ years of data) in the United States from February 12 to 16, 2021. The cold snap peaked from February 14 to 16. Another winter storm will affect a large area from Friday, February 19 — from the Lower Mississippi Valley into the Mid-Atlantic and Northeast.
    https://watchers.news/2021/02/18/2400-cold-temperature-records-broken-or-tied-us-february-2021/

  11. 11
    J Doug Swallow says:

    #7 27 Feb 2021 at 8:58 PM MA Rodger says: “The denier JDS responds by quoting an OP of an obscure climate change denier called CAP ALLON who is happy telling the word how Cooper et al (2021) and all its “speculative implications” is in complete agreement with his own crazy views on the matter, views that appear to have resulted in the “blacklisting” of this denier CAP ALLON’s work”.

    This is what the site that MA Rodger referenced, and also what Gavin referenced, said about the Laschamps event and he needs to explain how it is different from what CAP ALLON reported.
    “We use ancient New Zealand kauri trees (Agathis australis) to develop a detailed record of atmospheric radiocarbon levels across the Laschamps Excursion. We precisely characterize the geomagnetic reversal and perform global chemistry-climate modeling and detailed radiocarbon dating of paleoenvironmental records to investigate impacts. We find that geomagnetic field minima ~42 ka, in combination with Grand Solar Minima, caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record”.
    https://science.sciencemag.org/content/371/6531/811

  12. 12

    JDS 3: Cap Allon at Electroverse has been mentioning about Earth’s magnetic poles switching for some time now.

    BPL: Electroverse.net is a crackpot site pushing the idea that suns don’t work by nuclear fusion, but by an electrical process, and that electricity and not gravity dominates large-scale motion. It’s utter pseudoscience.

    JDS: There is physical evidence that this happened 42,000 years ago and that the climate was subjected to drastic changes.

    BPL: Yes, there’s some evidence for that, though it’s disputed.

    JDS: There is, to date, no empirical evidence that carbon dioxide has anything to do with the Earth’s climate, such as making it warm up or change.

    BPL: There are mountains of empirical evidence for it. You’ve been pointed to that evidence in the past. Not very honest for you to repeat that charge anyway, is it?

  13. 13
    BrettnCalgary says:

    Mr. Swallow has produced almost the whole last page of the Bore Hole, yet his efforts are so low rent that he can’t even make the Crank Shaft. That must be embarrassing.

  14. 14
    nigelj says:

    “Skeptical Science is (allegedly) a climate alarmist website created by a self-employed cartoonist, John Cook (who apparently pretends to be a Nazi).”

    Misleading at best. Cook did some graphics design early in his career but also has degrees in physics and psychology and has wide employment experience. He has also won numerous climate related awards and written several books. Detailed CV below. And Cook doesn’t write each article: Scepticalscience also employs numerous scientists, and environmental experts and engineers on a voluntary basis. But the troll JDS is consistently unable to falsify evidence, and instead always resorts to personally attacking the writer.

    https://skepticalscience.com/docs/John_Cook_CV.pdf

  15. 15
    CCHolley says:

    It would appear that JDS hasn’t gotten the memo that the fossil fuel industry and their lackey *think tanks* have stopped wasting their funds on the promotion of climate denialism as it has become glaringly obvious to most of the population that it is actually warming with an increase in extreme weather events and that the warming is driven by CO2 emissions. They have instead switched to other misinformation strategies to delay action such as attacking the solutions. I would assume most of the remaining troll deniers are either crackpots or less likely perhaps Russian. Not too hard to guess where JDS falls.

  16. 16

    JDS, #10–

    No, Dr. John Cook–PhD U. Western Australia, 2016, in cognitive science–is not an “unemployed cartoonist.” He’s on faculty at George Mason U., teaching (what else?) cognitive science, particularly as it pertains to climate change.

    https://www.climatechangecommunication.org/portfolio-view/john-cook/

    Not hard to find that out… so it’s unclear why JDS would shred his credibility yet smaller by lying (or making careless allegations, if I’m charitable.)

    JDS, #11–

    Weather.

    For some more weather:

    https://www.voanews.com/europe/sweden-breaks-february-record-high-temperature

    Still pretty tedious.

  17. 17

    #13, Brett–

    Yes. I will admit that JDS (or, latterly, just DS) is not lacking in industry. His attempts to make up for the lack of quality by sheer quantity are futile but sort of cute, in a perverse way. Their tedium is threatening to overwhelm that however, and likely will do so before long.

  18. 18
    J Doug Swallow says:

    #12 28 Feb 2021 at 8:07 AM Barton Paul Levenson says: “BPL: Electroverse.net is a crackpot site pushing the idea that suns don’t work by nuclear fusion, but by an electrical process, and that electricity and not gravity dominates large-scale motion. It’s utter pseudoscience”. After making this assertion regarding Electroverse and how it views the sun, I’m sure that Barton Paul Levenson will be happy to provide the link that shows that what he said is true about Cap Allon & Electroverse. One can wonder at why folks like Barton Paul Levenson  & MA Rodger seem to be so paranoid regarding Electroverse, which basically is a site that lists current weather events around the globe and provides the local sources from where those post emanated; but, obviously BPL & MA Rodger see that as a threat to their agenda. Then we see where Cap Allon & Electroverse get their information about the sun.
    “Solar Activity Forecast for Next Decade Favorable for Exploration
    Jun 12, 2019
    The ability to forecast these kinds of events is increasingly important as NASA prepares to send the first woman and the next man to the Moon under the Artemis program. Research now underway may have found a reliable new method to predict this solar activity. The Sun’s activity rises and falls in an 11-year cycle. The forecast for the next solar cycle says it will be the weakest of the last 200 years. The maximum of this next cycle – measured in terms of sunspot number, a standard measure of solar activity level – could be 30 to 50% lower than the most recent one. The results show that the next cycle will start in 2020 and reach its maximum in 2025”.
    https://www.nasa.gov/feature/ames/solar-activity-forecast-for-next-decade-favorable-for-exploration

  19. 19
    J Doug Swallow says:

    [edited. Just stop. Endless lists of newspaper articles showing it was cold somewhere in the winter are so tedious and boring that one wonders how anyone conscious can even bear to cut and paste them in. Anything similar will just get trashed.]

  20. 20
    J Doug Swallow says:

    #17 28 Feb 2021 at 6:46 PM Kevin McKinney says: “Yes. I will admit that JDS (or, latterly, just DS) is not lacking in industry. His attempts to make up for the lack of quality by sheer quantity are futile but sort of cute, in a perverse way. Their tedium is threatening to overwhelm that however, and likely will do so before long”.
    I am sure that when Kevin McKinney is at himself, and hitting on all cylinders, that he will be able to overwhelm me with his brilliance and depth of knowledge about the subject that he seems to not want to deal with, anthropogenic climate change. What follows tells the true story of the rise in CO₂ that folks like Kevin McKinney tremble in fear over.

    Natural disasters
    Summary
    • Natural disasters kill on average 60,000 people per year, globally.
    • Globally, disasters were responsible for 0.1% of deaths over the past decade. This was highly variable, ranging from 0.01% to 0.4%.
    • Deaths from natural disasters have seen a large decline over the past century – from, in some years, millions of deaths per year to an average of 60,000 over the past decade.
    • Historically, droughts and floods were the most fatal disaster events. Deaths from these events are now very low – the most deadly events today tend to be earthquakes.
    • Disasters affect those in poverty most heavily: high death tolls tend to be centered in low-to-middle income countries without the infrastructure to protect and respond to events.
    https://ourworldindata.org/natural-disasters#number-of-deaths-from-natural-disasters

  21. 21
    MA Rodger says:

    The troll J Doug Swallow is so intent on waving and shouting out, displaying his stupidity for all to see, that he fails to see it himself. And maybe with all this waving and shouting he has also managed to poke himself in the eye and so cannot see anything.

    The OP above criticises Cooper et al (2021) ABSTRACT so the idiot troll @3 sets out an account of the same subject by pointing to some nonsense webpage which is saying it is in full agreement with the very same Cooper et al (2021).
    Then, when @7 I make note of this bizarre interjection from the troll, the troll responds @11 insisting that I “need … to explain the difference when @7 I was saying they are the same!!

    Of course there is stark difference between Cooper et al (2021) and the crazy webpage.
    While Cooper et al talk of terrestrial geomagnetic field reversals causing “synchronous global climate and environmental shifts that caused major environmental changes, extinction events, and transformations in the archaeological record” (and gets criticized for it), the crazy webpage goes for the whole hog talking of ” devastation … (that) is truly “cataclysmic” … they blanch the planet of life and set things up anew — look at them as the true “great reset”.” The major failings of Cooper et al (2021) is thus transmogrified into total lunacy.

    The crazy webpage is not alone in this looney-speak. Thers is the blather from one of the co-authors in the press saying the 42k event “probably would have seemed like the end of days,” and together with three more of the 33 co-authors there is the ‘thunderbolts and lightening very very frightening me’ account linked @1 above.
    But the requested “need” is apparently to compare and contrast the Cooper et al (2021) with the crazy webpage and, given the Abstract & other reports, I cannot imagine such blather appears in Cooper et al (2021).

  22. 22

    JDS 10: It appears that nigelj’s trace gas, CO₂, that make up only between .03-.04% of the total atmosphere has fallen down on the job.

    BPL: 0.0000001% of fluorine in the air will kill you. This has been pointed out to you before. The volume fraction is completely irrelevant. To keep bringing it up when it’s already been explained to you why it’s wrong is dishonest.

    JDS: At least 2 400 cold temperature records broken or tied in the U.S. from February 12 to 16, 2021 February 18, 2021 at 22:13 UTC (9 days ago)

    BPL: Over the past 30 years, hot records are running two to one over cold records.

  23. 23

    Sorry, I got that wrong. The lethal dose of fluorine is a hundred times greater: 0.00001%. My bad.

  24. 24
    Richard G Creager says:

    J Doug Swallow #10- What’s your point?

  25. 25

    JDS, 20–

    Er, no, natural disasters aren’t “the true story of the rise in CO₂.” But RC would be a good place to learn what is, if a person actually wanted to learn.

  26. 26
    MA Rodger says:

    Barton Paul Levenson @22,
    The rebutting of bold nuttier-than-fruit-cake AGW assertions isn’t scientifically productive but, given how many of these denialists are swivel-eyed loons, succinct rebuttals are providing a service to humanity.
    On the “but the CO2 concentration is only a tiny tiny 400ppm” argument I feel the response should be to point out that while 400ppm by volume may be tiny-tiny, the size of the air molecules is tiny-tiny-tiny-tiny which makes 400ppm rather a lot. Indeed, described in words which puerile denialists would understand, 400ppm(v) is ‘big-big’.
    Thus, the 3.2 trillion tons of CO2 in today’s 5.5 quadrillion ton atmosphere represents 6.3kg of CO2 above each square metre of Earth, which perhaps doesn’t sound a lot. If it covered the planet in a film of dry ice, it would be just 3.7mm thick.
    But because molecules are tiny-tiny-tiny-tiny, anything passing through that amount of CO2 in a straight line would have to negotiate its way through at least 10½ million molecules. And of course, the same is true if those molecules were scattered through 50km of atmosphere.
    And 10½ million is undeniably a ‘big-big’ number.

  27. 27

    BPL: Electroverse.net is a crackpot site pushing the idea that suns don’t work by nuclear fusion, but by an electrical process, and that electricity and not gravity dominates large-scale motion. It’s utter pseudoscience.

    JDS: After making this assertion regarding Electroverse and how it views the sun, I’m sure that Barton Paul Levenson will be happy to provide the link that shows that what he said is true about Cap Allon & Electroverse.

    BPL: Gladly. Try here:

    https://www.youtube.com/watch?v=T9q-v4lBGuw&ab_channel=ProfessorDaveExplains

  28. 28
    Ray Ladbury says:

    J. Doug Swallow@18 OK, I know I will regret this, but if the force driving Mr. Sun is electromagnetic, then where the fuck do all the solar neutrinos come from?

  29. 29
    Russell Seitz says:

    Has Doug Swallow tried comparing notes with Scott Biddle?

    If they formed a team, they could be the toast of Texas

    https://vvattsupwiththat.blogspot.com/2021/02/climate-deniers-revive-confederacy-of.html

  30. 30
    AIC says:

    Reading the later part of the Laschamps paper is quite interesting (out there?), especially the speculative discussion about the Adams Transitional Geomagnetic Event. One key sentence: We describe this as the “Adams Transitional Geomagnetic Event” (hereafter Adams Event”), named after the science writer Douglas Adams because of the timing (the number “42”) and the associated range of extinctions (footnote to “Last Chance to See”, by Adams and Carwardine). As everybody knows, Douglas Adams wrote on environmental issues, especially endangered species, and is perhaps best known for “The Hitchhiker’s Guide to the Galaxy”.
    Discussion from there goes to a reduction in the ozone layer leading to increased surface UV, so early humans began to use caves for protection from UV, and to use red ochre as sunblock.

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