Exploring abrupt climate change induced by comets and asteroids during human history

In praise of intellectual honesty

Broecker, Shermer and Defant reverse opposition to Younger Dryas Impact

A little blue bird tweeted this weekend that the Younger Dryas Impact was off her radar since she was “not aware of widespread community acceptance of the proposal.”

This got me to thinking about the timing of “widespread community acceptance” versus influential early critics who have come to recant their skepticism. I believe that public acceptance is at best a trailing indicator of agreement that a hypothesis is valid, since there are sociological and institutional risks that inhibit expert acceptance of radical new ways of thinking. A better indicator at this point in the paradigm shift seems to me the thinking of thought leaders who reverse their previous opposition to the impact hypothesis based on their own research.

I offer three examples which have not been widely recognized, but indicate the worm has turned on the Younger Dryas Impact.

Wally Broecker says a Cosmic Impact caused the Younger Dryas

Most significantly is the late life embrace of the impact hypothesis by the “father of global warming” and Younger Dryas research, Dr. Wallace Broecker. The Tusk posted on Broecker’s reversal a few years ago (see link above). It would seem that the intellectual father of the ancient climate crash attributing his signature period to a cosmic impact might gain some attention. Or at least acknowledgement that, while not widely accepted, his view in favor of the hypothesis carries great weight.

Unfortunately, outside of James Powell’s wonderful paper last week, Broecker’s reversal has been completely ignored. That is sad in the context of the validity of the hypothesis itself, but also because his change of mind would demonstrate Broecker’s intellectual integrity — a vanishing quality in science — and a tribute to the man himself.

I remember pleading with Science’s Richard Kerr to do a piece on this discovery. He thought about it and decided that, as he had written a very negative piece about the original idea, he didn’t want to revisit the subject.

Although I don’t for a minute believe that this impact did in the mammoths and the Clovis people, I do think that it triggered the YD.
Nothing to see here. Move on.

My second and third examples are two former Younger Dryas Impact critics who gained a global audience on the Joe Rogan Experience. Joe invited America’s skeptic Michael Shermer, and his sidekick for the show Dr. Marc Defant, to debate the heretical Graham Hancock and Randall Carlson on the Younger Dryas Impact.  Shermer and Defant appeared for hours in 2017 on the world’s largest interview program, and took the “nay” side of debate impact.

Here is Shermer and Defant’s new thinking on the hypothesis less than three years after their very public opposition, and the contemporaneous posts here on the Tusk. Links in bold.

America’s skeptic changes mind on #ydih

I love Michael Shermer and listen regularly to his own podcast and appearances on other shows. He is an intellectually honest leftie, and if you are not familiar with his insights, I highly recommend them. The only thing lacking on those podcasts is his elaboration regarding our subject.

Recant: Pro-science skeptic Dr. Marc Defant now supporting #YDIH based on Powell book

Our third hero of honest discourse is Marc Defant. He attributes his change of heart to a rare practice among Younger Dryas Impact skeptics: Reading. At the suggestion, surprisingly, of Graham Hancock, Defant read James Powell’s book detailing the solid science behind our favorite theory. (Interestingly, Powell, like Defant, was once a skeptic concerning the cosmic impact.) It certainly did the trick as you can see below.

I recently had some correspondence with Graham, and he suggested I read a recent book by James Lawrence Powell entitled Deadly Voyager: The Ancient Comet Strike that Changed Earth and Human History (2020). It is a superb book and has absolutely convinced me there were comet airbursts at the Younger Dryas. And the airbursts probably killed the megafauna which in turn, caused the Clovis culture to cease existence (partly by diminishing human numbers but also because there was no need to have Clovis spearheads that could kill nonexistent megafauna). I have not been keeping up with the debate since 2017, and so I was thrilled to see the new evidence that has come to light and the lack of scientific merit in the studies that attempted to dismiss the hypothesis.

We can only hope that other scientists and influencers, obscure and prominent, are also seeing the light — if perhaps behind the scenes. If they’ve cracked Powell’s book and read his comprehensive review (and that from Martin Sweatman) it would be difficult to remain ignorant of the progress of the hypothesis, and the very poor treatment it has taken from the “community.”

It might take some time, but that little blue bird is gonna turn around and fly back to the truth.

Broecker - An extraterrestrial impact at the onset of the Younger Dryas_

Click to Amazon

3 Responses

  1. George: one of my most enduring memories from our attendance at the 2009 AGU Meeting in San Francisco centers on Dr. Broecker. I was at my poster, saw him approaching, and stepped forward to engage him with my work. Enraged, he stormed at me and hollered “No impact, no impact!” and breezed by.

  2. George: one of my most enduring memories from our attendance at the 2009 AGU Meeting in San Francisco centers on Dr. Broecker. I was at my poster, saw him approaching, and stepped forward to engage him with my work. Enraged, he stormed at me and hollered “No impact!” and breezed by.

  3. One almost gets the impression that throughout history the Anointed Councils of the Wise are to Science as the Giant Trees with their tangled roots, prolific thickets and draped vines are to explorers, or the submerged rocks and shoals would be to navigators on the seas.
    Evidently there are many alleged Scientists who perceive ALL Knowledge as having been fully revealed at the moment of their own ordainment into the priestly sanctum. Any new observation, claim, or insight to arise after is profoundly suspect, wrong thought, impiety… Sacrilege… without thorough and vigorous challenge, testing and verification by AUTHORITY. And until that process has concluded, to press claims of New Knowledge WITHOUT the imprimatur of the WISE is nothing else but HERESY, deserving of chastisement, punishment, suppression… and in case of sufficient provocation, DEATH.

    Hey! It’s a system that seems to have worked for Millennia, right? Why Change NOW? ‹ =ºÞ

Leave a Reply

Your email address will not be published.

Subscribe for Updates

Tax deductible donations to the Comet Research Group can be made here