Ponderous Pachyderms Prevent Permafrost

Guest Post by Willis Eschenbach

Anthony Watts has pointed to a curious new paper in his article “Climate Craziness of the Week: The AGU peddles a mammoth climate change theory”  I thought I’d use it as an example of how I take a first cut at whether a theory is reasonable or not. The new paper claims that the extinctualization of the mammoths warmed the world.

The original article is reviewed on ScienceNow, and is accompanied by this image:

Figure 1. Mammoths, the animals that can blow both hot and cold.

Gotta love these folks, no matter what happens it changes the climate. I discussed in my post “Anthropogenic Decline in Natural Gas” the previous study that claimed that the loss of mammoth flatulence when the mammoths were extinctified was the cause of radical global cooling. Now the same mammoth extinctivication is claimed to have caused global warming. Here is the new claim:

Earth system scientist Chris Doughty of the Carnegie Institution for Science in Stanford, California, and colleagues decided to find out whether the change in Betula [birch tree] proliferation was connected to the disappearance of the mammoths. They started by studying Betula pollen records compiled from soil cores taken in Siberia and Beringia. Next, the team examined mammoth fossil records to establish the timeline for their disappearance from the region. They also used studies of elephant-feeding habits to estimate the impact of the loss of the mammoths on the grasslands, and they applied climate models to compute the effect of the vegetation change on global temperatures.

The results, the researchers report in a paper to be published in an upcoming issue of Geophysical Research Letters, suggest that when the mammoths disappeared, the Betula trees expanded across Beringia, forming forests that replaced as much as one-quarter of the grassland. The trees’ leaves, which are darker than grasses, absorbed more solar radiation, and their trunks and branches, which jutted above the snowpack, continued the effect even in winter. The researchers calculated that the mammoths’ disappearance contributed at least 0.1˚C to the average warming of the world around 15,000 years ago. Within Beringia, the warming due to the loss of the mammoths was probably closer to 0.2˚C, the team concluded.

To figure out if something like this makes sense, I generally do a back-of-the-envelope type of calculation. My cut on this particular one is as follows:

1. Figure out the surface area that we are talking about.

2. Figure out the change in albedo.

3. Figure out the change in forcing and thus the change in temperature.

First, the area. At the time in question, the mammoths were centered in an area called “Beringia”, which stretched from 60° to 75°N, and from 150°W to 170°E. This area comprises 0.6% of the surface area of the planet. Let’s triple that to make sure we have a conservative estimate, so we have 2% of the surface area.

Next, the change in albedo. “Albedo over the boreal forest”  gives the following figures:

Representative daily average albedo values in summer are 0.2 over grass, 0.15 for aspen, and 0.083 for the conifer sites. In winter the corresponding mean albedo for snow-covered grass, aspen, and conifer sites with snow under the canopy are 0.75, 0.21, and 0.13. … . Forest albedo increases at all sites in winter (with snow on the ground under the canopy) as the ratio of diffuse to total solar flux increases.

From this we can see that the difference is small in the summer. It is theoretically larger in the winter, but in the winter there is very little heating from the sun because it is so low on the horizon. In addition, this increases the albedo of all surfaces, because of the increased reflectance due to the low angle of incidence. Finally, the low birch trees described in the source article would have greater winter albedo than the aspen, because more of the snow would show through underneath.

So lets use .2 and .8 for the summer and winter albedo for grass, and .15 and .55 for the summer and winter albedo for dwarf birch. These average out to .5 for grass and 0.35 for dwarf birch. This means birch growth increases the absorbed sunlight by about 50%. However, not all of the land surface will be changed. Let’s be real generous and say that half the land surface in the mammoth area is actually where they graze, although it is likely much less than that. There’s a lot of barren land that far north, mountains and bogs and such. So the increase in absorbed sunlight might be 25%. Then the authors (above) say that the extinguination of the mammoths would change a quarter of the grazing area. So we’re down to about a 6% change in albedo. (In fact it will be less, because the higher winter albedo affects less incoming sun, but we’ll leave it at that to make sure the figures are conservative).

Now, how much will that change the absorbed sunlight? Well, Anne Wilber et al. put the annual surface sunlight absorbed by the surface at 60°-75°N (the mammoth range) at 100 W/m2. They also give an average albedo for the area of 0.34.

But the most interesting thing about the Wilber et al. study is this: in the far northern regions, the average net short wave (the amount of sunlight absorbed by the surface) has almost nothing to do with the surface conditions. Figure 2 shows the map of the downwelling short wave (DSW, the amount of sunlight striking the surface) and the net short wave (NSW, the amount of sunlight absorbed by the surface) averaged over the year.

Figure 2. Solar flux. (a) Solar radiation striking the surface (downwelling shortwave, DSW). (b) Absorbed solar radiation (net shortwave, NSW) at the surface.

In Fig. 2(b) we see that while in the tropical regions there are clear differences between things like deserts, rainforests, and the ocean, this is not true in the far North. Up there in Mammothville, you can see very little difference between energy absorbed by the ocean and the land. In addition there is very little variation within the land itself, with the exception of the perpetual ice cover of Greenland.

This is for two reasons. First, the surface radiation in the far north is dominated by clouds, not the surface. Second, the composition of the surface makes little difference. The surface albedo is high because of the low angle of the sun, not because of the exact composition of the surface.

In any case, we can see that any changes in the surface albedo of the far north, such as the change due to mammoth extinctualations, do not affect the overall albedo very much. The Wilber et al. study puts the change in ground cover as explaining only about 2% of the absorbed sunlight. That’s the maximum that changing the surface albedo will do.

So the maximum change from mammoth extinguishment is 2% of the absorbed sunlight due to surface albedo, times 100 W/m2 insolation in the mammoth area, times 2% of the surface covered by mammoths, times a 6% increase in absorbed sunlight from the surface change due to birch growth. This gives us a change of about 0.0025 watts per square metre … which using the Stefan-Boltzmann law gives us a temperature change of .00045°. This would be increased by the greenhouse effect by about 35%. That would give us a temperature change of 0.0006° …

Now my estimate could be low by an order of magnitude (a factor of 10). Seems doubtful, because I’ve used fairly conservative numbers. But it’s certainly possible. Mammoths might have covered a larger area, my other estimates could have been low, this kind of calculation is usually only good to within an order of magnitude.

And it’s possible that it is out by two orders of magnitude. But I’d say that was very doubtful. And that’s how far wrong it would have to be to match their estimate of a .1°C change from mammoths.

My conclusion? Nothing firm, because this is a back-of-the-envelope calculation. However, the calculation says that it’s very doubtful that mammoth exstrangulation caused the planet to warm … I’d have to see a whole lot of very solid data before I’d believe that one.

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60 thoughts on “Ponderous Pachyderms Prevent Permafrost

  1. This was not long after the ice retreated? Didn’t CO2 levels rise then after the sea warmed? The birch tree growth is therefore mostly due to the growing stimulus from extra CO2?

  2. Well, that’s another Global Warmavilification calculavarificated! As the, finally politico-defenestrated MandelDarkOffspring misght say, ‘Next’.

  3. So, if we want to avoid further global warming now, we just increase the number of elephants in the world?

  4. Willis – I love back-of-the-envelope calculations that establish the ball-park, especially when backed by a strong critical faculty – something that seems extra-ordinarily lacking in many supposedly scientfic papers!
    A further note – mammoths are open country animals. Do they keep the country open – certainly more than it would be, but tree cover, especially birch and aspen in such northern latitudes is also effected by moisture – it grows in hollows and wetlands, and I suspect large areas of Beringian tundra would have been very dry and windswept.

  5. Willis,
    In the least, your calculations suggest the peer reviewers didn’t bother to challenge the authors of this study on their assumptions. Beyond that, your calculations suggest the climate models they used to ultimately make these calculations may have been put to heroic use here.
    The authors clearly want to lend credence to the orthodox idea that the earth’s climate system is inherently unstable, subject to produce measurable temperature changes in the entire global system just because a few tens of thousands of mammoths die out in an isolated corner of the planet. This isn’t science anymore, it folklore.

  6. Well, I always knew dealing with climate change would be a “mammoth” task.
    “extinctualization, extinctivication, extinctualations, exstrangulation” …
    Stop that, please — it hurts — actually makes me feel like I’m back in social studies 101.

  7. Edward Bancroft says:
    July 2, 2010 at 3:13 am (Edit)

    So, if we want to avoid further global warming now, we just increase the number of elephants in the world?

    I, for one, welcome our new elephant overlords …

  8. Mammoths caused global warming by farting too much while they were still alive! That’s why they shaved their fur off hid out with the elephants. So that the wrathful prehistoric MGW avenging humans couldn’t find them.

  9. extinctualization, extinctified, extinctivication, extinguination, extinctualation, extinguishment… Wow, Willis, you certainly expanded my vocabulary! 🙂

  10. I think mentioning climate change in the mammoth article was a brilliant move. It obviously generates hundreds of thousands of new readers throughout the world.

  11. How can these people actually publish this kind of nonsense and keep a straight face? This is like claiming squirrels in the Sequoia/Redwood area grow bigger in order to get their little arms around those giant trees! What a mammoth load of manure.

  12. Willis, thanks for the elucification! This line caught in my head for some reason, can’t make sense of it.
    Finally, the low birch trees described in the source article would have greater winter albedo than the aspen, because more of the snow would show through underneath.
    I’m thinking at that those latitudes we’re talking meters of snow on the ground in winter, both aspen & birch have no leaves, so why would more snow show underneath birch?

  13. Good morning. Anyone has seen the Mann report yet? A 4 pm Independence Day weekend dump in the future?

  14. Anders L- says:
    I think mentioning climate change in the mammoth article was a brilliant move. It obviously generates hundreds of thousands of new readers throughout the world.

    Not to mention a fat little amount of grant money for the next thesis

  15. Willis,
    Love your logic!
    If this was a true statement of mammoths, then we are in a whole world of hurt as millions of bison were killed in a very short period of time in our history.
    Where is the correlation there?
    Truly shows how bad our science and “peer-reviewed” system is.

  16. I’m a bit confused by your calculation.
    You’ve given 6% as the change in albedo due to the changing vegetation. Wilber et al calculated it at 2%. Not a big difference given that you’re deliberately being conservative.
    However, when you come to calculate the actual temperature change, you use both of these figures and multiply your estimate (6%) by theirs (2%). Unless I’m missing something, this is double counting. This is where your two order of magnitude error comes in.

  17. You have to be very careful with unqualified albedo values. In addition to the dependence on incidence angle, it depends very heavily on whether one is talking about visible light only or the entire solar radiation. Given that almost exactly 50% of terrestrial solar radiation is infrared (mostly “near” infrared close to the visible), this makes a big difference. Snow, especially when new and powdery, is very reflective in the visible, but substantially less so in the near infrared, while green vegetation is much more reflective in the near infrared than visible. Thus the difference between the two for the total solar irradiance is less than one would think by looking only at the visible. (This is why the ice-albedo feedback does not, by itself cause “runaway” large climate changes.)

  18. instead of breeding elephants, we could just cut down every tree where it snows most of the year. simple!

  19. This is a beat-up using lots of words to say effectively nothing. It had to be, because the issue is essentially a non-issue. It goes back to a 2001 report “New Ages for the Last Australian Megafauna: Continent-Wide Extinction About 46,000 Years Ago ”
    The crucial sentence in this report is; “Our results RULE OUT extreme aridity at the Last Glacial Maximum as the cause of extinction, BUT NOT other climatic impacts; a “blitzkrieg” model of human-induced extinction; or an extended period of anthropogenic ecosystem disruption.” (my capitals)
    In a subsequent report referred to by Anthony Watts;
    ” Headline; Man-made global warming started with ancient hunters”
    Note the definitive statement, then go to the referred AGU release’.
    AGU Release No. 10–15 30 June 2010 For Immediate Release
    Read the opening sentence with my capitals.
    WASHINGTON—Even before the dawn of agriculture, people MAY HAVE caused the planet to warm up, a new study SUGGEST.
    Note the deception in the headline? Definitive versus non-definitive.
    Then read Anthony’s opening paragraph in ““Climate Craziness of the Week: The AGU peddles a mammoth climate change theory”
    “Yes, our forebears started global warming by hunting the woolly mammoth. Right. Must be the mammoth albedo effect, much like the sheep albedo effect. Oh, wait, no it’s birch trees albedo calculated via pollen proxy. The mammoths stopped eating birch trees, that’s wot did it. And those hunters used cooking fires too. Gosh. I wish I had more time to refute this, travel beckons, but I’m sure readers can lend a hand in comments.”
    A poor attempt at humour by ridicule. The ‘hunt to extinction’ hypothesis was put to rest by Dale guthrie;
    “New dates on animal fossils nail down for the first time when horses and mammoths disappeared in the far north–and show that the mammals did not die off all at once when prehistoric hunters arrived. “There was no sudden impact,” says paleobiologist Dale Guthrie of the University of Alaska in Fairbanks.
    Guthrie’s new report is at odds with a long-standing hypothesis that prehistoric hunters rapidly killed off mammoths and elephants at the end of the Ice Age about 11,000 years ago on several continents.”
    Read the text on the photograph used, note the words “could have”.
    What a colossal waste of words and time on a climate change non-issue. Time to come back to reality.

  20. Perhaps the potential warming was off set by the reduction in the amount of CO2 expelled by cavemen (and women to be PC) not having to chase the mammoths all over the place. Let’s also reduce the CO2 due to the elimination of the vast barbies needed to cook the meat.

  21. Wouldn’t albedo increase as all those dark-haired beasts disappeared to be replaced by light-reflecting white snow? I think you need to figure in the surface area of mammoths into your calculations. 😉

  22. The back-of-the-heffalump calculations are fun, but as Anthony suggested, the speculation was patently ridiculous on its face. What’s worrisome is the likelihood that the AGU, Carnegie-sponsored ‘study’ was undertaken in all seriousness, and not as a spoof.
    But the authors are doubtless laughing all the way to the bank.
    /Mr Lynn

  23. This reminds me of a study some botanists did where they said the appearance of some flower changed the climate because it reflected more light. They never show how this occurred, they just say the flower popped up around this time so it must have caused the change in climate……give me a break.
    Living things adapt to changes far more readily than they change their environment.
    This is nonsense on so many levels.

  24. Edward Bancroft says:
    July 2, 2010 at 3:13 am
    So, if we want to avoid further global warming now, we just increase the number of elephants in the world?

    The second half of the equation is to pay people to pick up the elephant droppings and properly store it for carbon sequestration.
    Bonus: It’s a green job!

  25. Do people actually pay these guys to come up with this stuff? Have they noticed that this massive unprecedented manmade global warming spike we’re suffering is at the tail end of the steady drop in global temperatures over the last 11,500 years or there abouts, & considerably colder than that time by several degrees, at least according to the central Greenland ice-core data? Now, ice-ages last for around 90,000-120,000 years, inter-glacials for around 10,000-15,000 years. That means we’re on borrowed time perhaps?
    dr kill, I thought the Mann report was the same as the Climategate reports. Very few pages & full of Bovine doodoos!

  26. Curious Yellow says:
    July 2, 2010 at 5:22 am
    “[…]
    WASHINGTON—Even before the dawn of agriculture, people MAY HAVE caused the planet to warm up, a new study SUGGEST.
    Note the deception in the headline? Definitive versus non-definitive. […]”
    Curious Yellow, MAY, COULD, SUGGEST, etc – was there ever one AGW study that doesn’t use these words in every conclusion? AGW never makes a prediction, AGW never says something definitive, AGW is not a scientific theory. It’s always WOULD, COULD, MAYBE, MAYBE NOT, DUNNO, WE THINK IT WAS CO2, COULDN’T HAVE BEEN ANYTHING ELSE.
    You want us to wait for a study or version of the “theory” that makes a verifiable prediction? In other words, you want us to stay silent FOREVER because there will never be a verifiable prediction. Sorry no deal.

  27. I get so confused. Now I understand that dinosaurs were not mammals, but (without bothering to do the research) one would assume that, having a similar herbivorian diet, that dinosaurs would have farted methane at roughly the same levels as mammoths, and that having a similar bulk that they’d have trampled down the birch trees to a similar extent as the mammoths.
    However, as I recall things, there was a massive temperature DROP at the time that the dinosaurs disappeared. How could that have happened.
    Oh, and continuing with the buffalo extinction, not only did the extinction of the buffalo not cause global warming, their extinction was shortly followed by one of the worst blizzards in recorded history the famous blizzard of 1888.
    Sigh, if only I were a scientist with a grant, perhaps I could wrap my head around these conundrums.
    http://en.wikipedia.org/wiki/Great_Blizzard_of_1888

  28. Sending you a box of blank envelopes.
    I once spent a futile year trying to teach my employees this seemingly simple skill. No luck. The urge to overcomplication, especially amongst the scientifically inclined, was dominant.
    Ah ya, it became a good interviewing tool as well.
    1. estimate the number of 42 year old males in the US.
    2. estimate the number of people landing at O hare in a year.

  29. If mammoth extinction caused global warming what was the cause of Mammoths being frozen to death, practically in-situ, in Siberia? Obviously the Siberian mammoths were caught in a climatic tipping point not of their own making.

  30. Steve Keohane says:
    July 2, 2010 at 4:04 am

    Willis, thanks for the elucification! This line caught in my head for some reason, can’t make sense of it.
    Finally, the low birch trees described in the source article would have greater winter albedo than the aspen, because more of the snow would show through underneath.
    I’m thinking at that those latitudes we’re talking meters of snow on the ground in winter, both aspen & birch have no leaves, so why would more snow show underneath birch?

    Curiously, during the ice ages Beringia didn’t have a whole lot of snow, because it was too dry.
    In addition, the taller a tree is, the more branches it has, and thus the lower the albedo.

  31. Edward Bancroft says:
    July 2, 2010 at 3:13 am
    So, if we want to avoid further global warming now, we just increase the number of elephants in the world?
    ________________
    Nuke says:
    July 2, 2010 at 6:47 am
    The second half of the equation is to pay people to pick up the elephant droppings and properly store it for carbon sequestration.
    Bonus: It’s a green job!
    ________________
    I suggest we assign the job to Hansen, Mann, Schmidt and Jones among others.

  32. Peter Ellis says:
    July 2, 2010 at 5:09 am

    I’m a bit confused by your calculation.
    You’ve given 6% as the change in albedo due to the changing vegetation. Wilber et al calculated it at 2%. Not a big difference given that you’re deliberately being conservative.
    However, when you come to calculate the actual temperature change, you use both of these figures and multiply your estimate (6%) by theirs (2%). Unless I’m missing something, this is double counting. This is where your two order of magnitude error comes in.

    Peter, thanks for an interesting question. According to Wilbur, a 100% change in the surface albedo would only make a small change (a few percent) in the amount of solar radiation absorbed by the ground. We see this in the very slight change between sea and land in the northern areas.
    But we don’t have a 100% change in the albedo from the elephanticide. We have only a 6% change in the albedo. So we need to multiply the two together.
    w.

  33. DirkH says: “Curious Yellow, MAY, COULD, SUGGEST, etc – was there ever one AGW study that doesn’t use these words in every conclusion? AGW never makes a prediction, AGW never says something definitive, AGW is not a scientific theory. It’s always WOULD, COULD, MAYBE, MAYBE NOT, DUNNO, WE THINK IT WAS CO2, COULDN’T HAVE BEEN ANYTHING ELSE.”
    Moreover, somehow, those weasel words, could, would, might, and may, when translated into political terms, instantly become shall, must, have to, and “there will be consequences for non-compliance.”
    Science-weasels seem to think that in the social upheaval that follows a UN takeover, they will be at the top of the heap. Not so. Remember what happened in Russia? Intellectuals were among the first to be decimated by the new socialist regime. Their continued existence was unnecessary and…inconvenient.
    http://www.ibiblio.org/expo/soviet.exhibit/attack.html

  34. Mescalero says:
    July 2, 2010 at 9:36 am
    If mammoth extinction caused global warming what was the cause of Mammoths being frozen to death, practically in-situ, in Siberia? Obviously the Siberian mammoths were caught in a climatic tipping point not of their own making.
    ————-Reply
    No, they’re to blame. Let’s call it Pachyderm Global Warming Suicide–PGWS. They apply the same reasoning to CO2, arguing that it repeatedly caused warming and when it got tired of working overtime, it lost warming capacity (or something like that) and that caused the next Ice Age. They should call it the lazy double lag.
    But of course there is a corollary to the elephant problem–They’re claiming humans are going cause Global Warming Suicide, too. Let’s call it HGWS.

  35. Our atavic memories of mammoths are positive because of all the good moments we experienced barbecuing them ☺

  36. Thanks for another entertaining and revealing article Willis. Beyond the face-value ridiculousness of this fringe AGW trumpeting it seems there is a need in the CAGW camp to rewrite paleo-climatic history in order to fill the mammoth sized holes it blows in the hypothesis.
    Another thing it seems to demonstrate, yet again, is how old fashioned confirmation bias can be given an air of respectability when passed off as a computer simulation, and how any computer model with uncertain input parameters will probably carry a bias in one direction or another.
    I’m no mathematician, so I’d appreciate any thoughts from people here on whether my reasoning is valid: A modeler can only include known parameters in a model, even if the specific values of these are vague trends. Known parameters will tend to be ones that stick out from the crowd or are pertinent to the modeler’s field of study, and ones that have a significant dynamic range (like ocean oscillation, surface temperatures). This will bias the outcome of the model at the expense of countless ‘quieter’ parameters not included due to their being unknown, not seen as pertinent, being too chaotic to compute or occurring over a larger timescale than the model is designed to cope with. In the real world however, the combined mass of these ignored parameters may act to reduce the significance of parameters that have been included to the final result. Even if you tweak the included parameters until the model works regressively you might be adding yet more weight to the known parameters at the expense of the unknown to give an artificially biased prediction- like pushing down one bubble in the wallpaper only to cause a worse one to pop up elsewhere. Predictions will always favor ‘something interesting happening’ over ‘nothing interesting happening’ because the modeler is only including interesting looking factors in the first place.
    The reliance on open-ended models in climate science reminds me of the Wizard of Oz – when you pull apart the IBM supercomputer, you’ll find inside a frail human being. Unfortunately in ‘climate science’ the wizard has so much faith in the machine he doesn’t even seem to realise he’s pulling the strings. The other day I heard the expression ‘to a carpenter, everything begins to look like a nail’. Maybe it could be that to a climate scientist, everything looks like anthropogenic global warming?

  37. Rocky Road–
    The next question. If we have found frozen mammoths in Siberia, why haven’t we also found frozen remains of human hunters out to exterminate the mammoths. Might it be that the humans saw the tipping point coming and headed south?

  38. Willis – I love your ballpark reestablishmentifications! If every writer at least thought about reasonability, the world might be a saner place.

  39. Funny that. Mammoths, I infer, ate what a northerner calls grass. That little short stuff a few inches high, I presume. I would have imagined that the eating habits of the mammoth would have been akin to that of the African Elephant, being equipped with very similar eating utensils which give him little in common with a sheep. He eats predominantly leaves. He shuns grass, proper grass four or five feet high, in favour of the leaves of trees and fair sized bushes. Seen several hundreds at least in my time, mostly along the Zambezi Valley, but have never seen them in anything that I would describe as grassland. Seems to me that on what I call grassland he would starve. On balance I would think that tree growth would prosper in the absence of the elephant, and the mammoth I suppose, as the younger stuff wouldn’t get pushed over, but the very much lesser spread of seed would likely push matters somewhat in the opposite direction. I don’t know a worthwhile thing about mammoths I should say, so maybe I am not qualified to comment.

  40. You couldn’t make this up.
    Mild weather batters Britains first ‘green’ Island
    __________________________________
    When the inhabitants of the remote Scottish island of Eigg put their faith in the wind and rain to provide all their electricity they did not reckon for one thing – mild weather.
    Now the 95 residents are being asked not to use kettles, toasters or other kitchen appliances after uncharacteristically mild weather caused a critical shortage of power.
    http://www.telegraph.co.uk/earth/energy/hydro_electricenergy/7858960/Power-rationed-on-green-island-Eigg-after-mild-weather-causes-drought.html

  41. Well…we all know Mr. Eschenbach should robustify his data a bit more…
    Willis. I loved the Simpsons allegory – I, too, shall welcome our elephant overlords.
    A bunch of megafauna went extinct (or went through the process of extinctification) about 10,000 years ago. These include the Giant Short Faced Bear, the American Lion, the Dire Wolf (spinning at my window), the Sabre Toothed Cat and the Mammoth. Oh yeah…and Clovis Man. Did they change the climate or did the climate change them? The American Lion could have taken down a modern grizzly bear for a snack. Somehow I fail to see how the existence of the Mammoth could affect climate one way or the other. Climate, on the other hand, could certainly affect the existence of the Mammoth.

  42. Ken Harvey says:
    July 2, 2010 at 1:14 pm
    “Funny that. Mammoths, I infer, ate what a northerner calls grass. ”
    http://www.ucmp.berkeley.edu/mammal/mammoth/about_mammoths.html
    “From the preserved dung of Columbian mammoths found in a Utah cave, a mammoth’s diet consisted primarily of grasses, sedges, and rushes. Just 5% included saltbush wood and fruits, cactus fragments, sagebrush wood, water birch, and blue spruce. So, though primarily a grazer, the Columbian mammoth did a bit of browsing as well.

    But of course you’re right… it seems strange that mammoths should shun leaves when elefants love them and are well-equipped to reach them. Maybe the mammoth populations had to resort to gras after destroying all the trees.

  43. I’ve often wondered how the eradication of the Bison might have affected methane levels and consequently AGW induced ‘cooling’ or ‘warming’, take your pick. :o)


    The bison were the largest native herbivore on the plains of the West.

    Prior to the white man’s arrival on the North American continent, bison were the most numerous of all grazing animals. Estimates of their numbers are only speculative, but may have ranged from 30,000,000 to 75,000,000.
    ….
    By 1889, there were fewer than 1,000 bison left in the United States.”

    source: New Mexico State University
    ***********
    AGWers have managed, within the space of several months, to spew out two opposing theories regarding Mammoths causing cooling and warming. Actually this is their new mode of operation: AGW cause warming and cooling, co2 causes warming and cooling, floods and drought etc.

  44. At the time in question, the mammoths were centered in an area called “Beringia”
    Actually, at the time (15,000 BP), mammoths ranged across North America and Eurasia. Mastodons ranged across Africa and Central and South America as far south as southern Chile. So the area calculation might need adjusting. Some more interesting factoids:
    Mammoths were around for some 4 to 5 million years or more (Pilocene, possibly Miocene origins). We don’t really know how their populations might have waxed and waned during those and subsequent epochs. Both were cosmopolitan herbivores and ate tree leaves, grass, and d*** near anything green.
    Mammoths were good eating. People loved mammoths and mastodons, for dinner. Homo erectus dined on mammoths at least as far back as 1.5 mmy BP.
    All told, over 40 species and 30 genera of large mammals in the Western Hemisphere went extinct since the Older Dryas, including mammoths, mastodons, giant ground sloths, glyptodonts, saber-toothed tigers, camels and horses. In Eurasia the number of extinctions is higher, and many genera still extant elsewhere (like hippos) were extirpated from Europe and northern Asia.
    Stone Age human beings probably had something to do with that. Whether the extinctions and extirpations changed the albedo or megafaunal methane emissions, I don’t know. People also burned entire landscapes, continents even, which resulted in charcoal-colored albedos for at least a few months every year — and less, not more, forests (contrary to the authors’ claim).
    Our Holocene is not the first interglacial. It may be the longest lived in 650,000 years, however. If people have had anything to do with that, I say we deserve a pat on the back.

  45. 1. The earth has shown over and over again that it is anything but unstable, it does what it does because it was designed by a creator to do what it does and when it does.
    2. I’d rather smell more elephants and their excrement than what passes for peer reviewed science on the side of the AGW.

  46. Jimbo,
    The best I’ve heard so far is an agreement from a regular over at skeptic science (the home of those skeptical of skeptics)… that co2 used to follow warming trends but now, warming trends follow co2 trends due to changes in the earths atmosphere and greenhouse effect.
    oiii my head hurts and I need a beer.

  47. Mike D. says:
    July 2, 2010 at 4:13 pm

    At the time in question, the mammoths were centered in an area called “Beringia”
    Actually, at the time (15,000 BP), mammoths ranged across North America and Eurasia. Mastodons ranged across Africa and Central and South America as far south as southern Chile. So the area calculation might need adjusting. Some more interesting factoids: … [much interesting stuff snipped] …

    You are correct. However, I restricted myself to the northern area, because that’s where the authors claimed that the albedo contrast between grasses (which get covered by snow) and birch trees (which don’t) is high. Everywhere else, the birch trees and the grasses would have about the same albedo, so swapping one for the other wouldn’t make much difference in absorbed sunlight.
    Also, Beringia (unlike much of the NH extratropics) was relatively ice free during the last glacial.

  48. Excerpted from another source:
    ~~~~~~~~~~~~~~~~~~
    The Beresovka mammoth was found in a sitting position, although it had slumped down the slope probably in a frozen block before discovery.28 The unique position of this mammoth indicates that the sliding probably did not change the original position of the mammoth at death. Even the trees were still generally upright in the material that slid down the hill.29
    Russian researcher Tolmachoff reported several upright mammoth carcasses in Siberia. One of the carcasses was found in 1839, on the Shangin River, a tributary to the Indigirka River, in an upright position and protruding from a cliff.31 Another upright mammoth was also discovered in a cliff on the New Siberian Islands.32 Tolmachoff33 himself found parts of the skeleton of a mammoth on the coast of the Arctic Ocean, “… protruding out of frozen bluff in a more or less upright position.” He mentions in words similar to Howorth’s how Brandt was impressed about these upright mammoths:
    Brandt was very much impressed by the fact that remnants of the mammoth, carcasses and skeletons alike, sometimes were found in poses which indicated that the animals had perished standing upright, as though they had bogged.34
    Strangely, scientists investigating three woolly mammoths and two woolly rhinos, including the Beresovka mammoth, found they all died by suffocation.35 For a live animal to die of suffocation, it had to be buried rapidly or drowned.
    Several of the carcasses have broken bones. Both of the upper front leg bones and some of the ribs of the Selerikan horse were broken.36 It was also missing its head. The Beresovka mammoth had a broken pelvis, ribs, and right foreleg.37 It takes quite a force to break the bones of a mammoth. The broken bones have inspired the story that the Beresovka mammoth was grazing on grass and buttercups when it accidentally fell into a crevasse in the permafrost. Then it was rapidly covered and suffocated.38 Buttercups, as well as leaves and grasses, were found in the mouth of the Beresovka mammoth between its teeth and tongue.39
    ~~~~~~~~~~~~~~~~~~
    Source: http://www.answersingenesis.org/home/area/fit/chapter1.asp

  49. jorgekafkazar says:
    July 2, 2010 at 10:38 am
    …..Science-weasels seem to think that in the social upheaval that follows a UN takeover, they will be at the top of the heap. Not so. Remember what happened in Russia? Intellectuals were among the first to be decimated by the new socialist regime. Their continued existence was unnecessary and…inconvenient.
    http://www.ibiblio.org/expo/soviet.exhibit/attack.html
    ________________________________________________________________________
    Not to mention dangerous since they had already proven they were activist types AND traitors.
    Thanks for the reference. I have been looking for it for a while.

  50. JJB MKI says:
    July 2, 2010 at 11:22 am
    “[…] I’m no mathematician, so I’d appreciate any thoughts from people here on whether my reasoning is valid: A modeler can only include known parameters in a model, even if the specific values of these are vague trends. […]”
    Interesting ideas but the problem is much simpler than that: The modelers of current GCM’s estimate a lot of parameters at their whim because they don’t know them. To this day they don’t know whether aerosols have a warming or cooling net effect. They use this degree of freedom to optimize the parameters in such a way that the GCM’s do a correct hindcasting of the past 100 years. In this process, they practically end up with curve fitting and get no prove or disprove about whether they have the physics right. In other words, they make the models output the correct temperature series by tuning parameters.
    They know that it’s a whimsical approach but can’t say so publicly; it would jeopardize further funding. It’s an open secret hidden behind a bewildering array of complicated-sounding papers (which are all bogus science because they build on the flawed pseudo-evidence delivered by flawed models).

  51. So many mamooth carcasses found in sitting or standing position would indicate a sudden, abrupt, extremely fast cooling like the one shown in the blunder movie The Day After tomorrow.
    An increase of sudden cooling events of short duration in the weather (as Heinrich events) could explain it. I would like to have a time travel machine…

  52. I did not bother to read the initial paper. Did anyone bother to compute the temperature change from the albedo variation due to the mammoth fur itself? It’s adorned with pretty dark fur. So it means that the less mammoth there are, the lighter the globes becomes and cools down further.
    Seriously, I find that their jump from correlation to causation is utterly appalling, and even more appalling is that this kind of stuff finds research budgets, and certainly is held as sensical by some of the newer generation of future scientists. THAT is the real menace.

  53. I have an Albedo calculation model and can confirm Willis’ numbers are about right.
    But why do the climate scientists spend so much time studying a small increase in a few small birch trees when not one of them has actually calculated the Albedo affect from the all that snow, glacier and sea ice during the ice ages which were also melting at this time period.
    The extent of glaciers and sea ice (which have the highest Albedos of any surfaces) decreased by over 40 million km^2 and you can’t find a reasonable estimate of this affect anywhere. (Hansen has an artificially low one and there are a few other half-hearted attempts but the scientists have time to simulate effectively a Zero birch tree effect but not time for the Albedo of the Earth as a whole during the ice ages or 15,000 years ago).

  54. More likely they’ve got causation backwards, assuming their correlation inference is correct.

  55. DirkH says:
    July 2, 2010 at 7:38 am
    Curious Yellow says:
    July 2, 2010 at 5:22 am
    You didn’t get it, don’t turn a statement with a caveat into definitive. That’s all.

  56. Willis:

    Mammoths might have covered a larger area…

    Actually, this is a big “DUH.”
    The very first mammoth bones discovered (at least by western scientists) were all the way over in Europe, and the range of some of the subspecies extended down all the way into Nicaragua and Honduras. That is one helluva range – the length of Russia plus the length of the Rocky Mountains plus the length of the Sierra Madres. Why does this study only talk about ones in Beringia? (or did I misunderstand this point?)
    FYI: In the Arctic Ocean, the New Siberian Islands and Liakhov Island north of Siberia quite a distance from Beringia have entire hills composed of mammoth bones mixed with the dirt. The hills are piles of bones, essentially, and are about 200 feet high. BTW, mixed with the mammoth bones are the bones of rhinoceros and hippopotamus. No one has ever explained what the heck those animals were doing off the northern coast of Siberia.
    Also, the nearest real trees to those islands are about 1,000 miles to the south. There is no evidence that trees ever lived that far north, which begs the question: Where was there enough food for the mammoths in the far, far north of Siberia, much less on the islands to the north?

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