James Hansen: About Those Boulders…

August 8, 2015

One of the boggling images that was included in James Hansen’s recent dire warning on climate change and sea level rise, were pictures of gigantic boulders, that may have been moved to high ground during violent storms in the Eemian period, a warm spell like the one we are moving into, some 120,000 years ago.

For the Eemian, the cause of the warming was orbital, a change in the Earth’s orientation to the sun. In our time, scientists understand well that those orbital forcings are actually bringing a very slight cooling effect for the last several thousand years, until the human-caused spike in greenhouse gases spiked planetary temperature in the last century.

Part of the warning from Dr. Hansen is that in a warm period, additional heat in the atmosphere may fuel monster storms, and that paleo-artifacts like these boulders are indicators that such storms were features in a world much like the one we are headed for in coming decades.

Washington Post:

In the model employed by Hansen and his coauthors, this cooling and freshening of the oceans eventually leads to a shutdown of the oceans’ circulation, and warm waters trapped at depth below a cold fresh surface layer in the Antarctic region, continually eating away at ice sheets from below. It also triggers a globe with ever-warming tropics but cold poles — leading to a large contrast in temperatures between the mid-latitudes and the polar regions.

A larger temperature contrast between the tropics and the poles, the researchers posit, would then strengthen winter storms or so-called extratropical cyclones, which draw their energy from such contrasts. The study therefore contemplates more powerful storms. It notes research suggesting that in the Eemian period, the last time the world saw major sea level rise of as much as 5 to 9 meters (between 16 and 30 feet), gigantic waves apparently moved huge boulders from the seafloor to the top of hills in the Bahamas.

“During this last warm interglacial, not much warmer than the present, [the world saw] not only a higher than present average sea level, but ultimately a significantly higher sea level that required the melting and or collapse of probably both Greenland and West Antarctica, along with basically this great oceanic disturbance,” says Paul Hearty, a geologist at the University of North Carolina, Wilmington who is one of Hansen’s co-authors on the new paper, and conducted the research on the Bahama boulders. “There were storms, and a lot of more catastrophic type events associated with this big climate shift.”

hansensmallJames Hansen for Earth Institute, Columbia University:

In plain English, the boulders are old rock of “hammer-ringing” hardness. They sit on younger softer (“punky”) Eemian-era substrate. The boulders are limestone formed on the floor of the North Atlantic Ocean at least 300-400 thousand years ago.

The boulders had to be placed there (on the cliff facing the North Atlantic) in the late Eemian or immediately thereafter before sea level had fallen much from its high Eemian level. It required powerful long-period waves from the Northeast to scour the ocean floor and lift the boulders. The boulders are all located at the apex of a narrowing horseshoe-shaped embayment; ocean waves funneled into this embayment generate huge surge and splash as they reach the cliffs.

One might have guessed that the boulders were deposited by a tsunami, but accompanying (V-shaped) “chevron” ridges and run-up deposits suggest otherwise. The chevron ridges and run-up deposits are located along the 900 kilometer eastern front of the Bahamian Islands at places most susceptible to ocean incursion. The power of the storms is indicated by the fact that the chevrons extend as much as several kilometers inland and the run-up deposits on hills immediately adjacent to the chevrons reach heights as great as 30-40 m above today’s sea level.

The suggestion in (former New York Times writer Andrew) Revkin’s comment on our paper that the boulders were instead remnants of erosion is dismissed readily. The “simple drawing…explaining boulder formation through chemical weathering” can be dismissed by going to Eleuthera and examining the boulders. One of them is shown in Fig. 1.

Appearance might be enough, but there is ample scientific evidence. The boulders are much older than the substrate on which they rest. Also the orientation of the original bedding planes of the boulders (i.e., the horizontal level at the time the limestone was formed from carbonate sediments on the ocean floor) can readily be discerned. The bedding planes are at a variety of angles, as expected for boulders tossed from the ocean.

An important characteristic of the chevrons is imbedding of lesser younger chevrons within those that penetrated furthest inland. This is an expected result of storms while sea level was falling, as Earth moved into the post-Eemian ice age. If, instead, the imbedded chevrons were caused by a tsunami, a series of tsunamis would be required.


11 Responses to “James Hansen: About Those Boulders…”

  1. Why does Hansen say “former” NYT writer?

    • dumboldguy Says:

      Maybe because he was a reporter for the NYT for ~15 years but moved on to a new job in 2009? Although he does some blogging for the NYT, he is not technically a “reporter”.

      A better question is when are we going to be able to use “former” when talking about climate deniers and trolls.

      And an even better question is why are you worried about Revkin’s status when you have the boulders and Hansen’s paper to talk about?

      • Oh, so he’s a blogger just like me, climate denier Steven Goddard, with no published peer-reviewed scientific papers. Now I can be taken seriously, too!

        • dumboldguy Says:

          No, Steve, he’s not a blogger “just like you”. He may not have written any peer-reviewed papers, but he has a degree in biology and has written some books om climate change. He gets it, you don’t, which is to be expected since your training is in electrical engineering. (BTW, did you sign the Oregon Petition with all those other ignorant engineers who know nothing about climate science?).

          And don’t hold your breath waiting to be “taken seriously”—ain’t gonna happen.

          • You just wait and see. I was cited by The Blaze last week.

          • dumboldguy Says:

            Yeah, being cited by The Blaze is proof positive that you are a denier asshole, since they don’t deal with climate change truth there, only BS.

            The Blaze is the creation of that looney-tune Glenn Beck, who was too looney even for Fox News and got fired. And the article is by P-Guy Veer, a looney tune Canadian libertarian who writes mainly about economics, not climate science (a field that he obviously lacks expertise in, just like you).

            Your “citation” was to your nicely data -tampered data-tampering graph. BFD! It was part of a long article that was full of all the cut-and-paste denier BS that has been making the rounds for years, including Climategate. The sleight of hand with June 2015 being “only the ninth warmest MONTH on record” at the end was classic.

            If I were you, I wouldn’t be bragging about being mentioned on The Blaze. What kind of ink have you been getting on the “legitimate” lying BS denier sites like WUWT?

          • Mr. Sinclair, you know very well I was a regular blogger on WUWT before Watts let me go. He is now actively undermining my efforts for personal gain.

            If you don’t think I can make it, I’ve two words for you: Donald Trump.

          • DOG, tonyhellerexposed is staying in character. Read his blog. You’ll stop barking.

          • dumboldguy Says:

            Who’s barking? I subscribe to his blog, and occasionally assist him in his efforts, as you can see in my comments here:


          • Wow! Good one. You too do an excellent job of staying in character, DOG.

  2. indy222 Says:

    Currently, we’re seeing a lessening of the polar/tropical temperature gradient, causing, many think, the big loops in a more wandering Polar Jetstream, and slower moving more intense storms. Hansen’s paper indicates that this gradient reverses as the ocean currents shut down. So if I’m interpretting this correctly, we expect more intense storms both when the polar/tropical gradient weakens (now), and also when it strengthens (sometime in the future)? So, we’ve been living for thousands of years in a Goldilocks situation as far as storm intensity goes?
    Not picking any fights here, just checking my understanding.

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