Anthropocentrism, big impact on climate

[Andre]

Let's do another one.

The idea that humans can and have had a big impact on climate is increasingly thriving. Apparently we are the central factor -Anthropocentrism. It started with Ruddiman who had produced a http://courses.eas.uAlberta.ca/eas457/Ruddiman2003.pdf .

How come, well the paleolithic man started to change his environment, cutting down forests to build villages, burn fires and have land for agriculture. This would remove the carbon sink function and would increase the CO2 in the air.

So what do you say about that?

 

[pattylou]

Hi Andre!

Pretty depressing, eh? As I recall, we agree that deforestation is a "bad thing."

It sounds like you read the SciAm article (based on the timing of your post.) The original is 3 years old and speaks about rice paddies too.

What do I think? Either the idea is too far fetched, or it's right - in which case a runaway greenhouse seems inevitable.

What do you think?

 

[Mk]

Why is deforestation bad?

 

[pattylou]

becomes harder and harder to sequester carbon dioxide, whether the CO2 is produced by man or not. (IOW, the forests-are-good thing is easier to agree on than the source or causative ffect of CO2vs.warming.)

Well, deforestation also reduces habitat. That may be the basis for me and Andre agreeing that deforestation is bad, assuming that my memory is right and we agree that it's bad.

Yeah, I know, this is almost unreadable. Flag me if I don't make any sense.

 

[Andre]

Good to see you, Patty. Yes we agree, deforestation is bad for biodiversity, soil preservation, food chains and microclimate and some more. And the reason for the thread was this article (may be the same as the SciAm? another study.

It argues that the bubonic plague decimated the population in the medieval period reversed the antropogenic deforestation. They see concurent CO2 level changes in leaf stomata

Counting stomata (pores) on ancient oak leaves provided van Hoof's team with a measure of the fluctuations in atmospheric carbon dioxide for the same period.

"Between AD 1200 to 1300, we see a decrease in stomata and a sharp rise in atmospheric carbon dioxide, due to deforestation we think," says Dr van Hoof, whose findings are published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.

But after AD 1350, the team found the pattern reversed, suggesting that atmospheric carbon dioxide fell, perhaps due to reforestation following the plague.

The researchers think that this drop in carbon dioxide levels could help to explain a cooling in the climate over the following centuries.

I had a discusion with the author showing him that his leaf stomata CO2 reconstruction, which correlated positively with ice cores, did not correlate with the more recent multiproxy climate reconstruction known as http://home.wanadoo.nl/bijkerk/correlation-stomata-co2.GIF . This should put some question marks at that CO2 - global temperature relationship.

Moreover the period of interest of Ruddiman, the second half of the Holocene, shows similar patterns: http://home.wanadoo.nl/bijkerk/10000.gif

The graph shows the temperature reconstructions based on the Greenland Ice cores (black) and the Antarctic ice cores (grey) versus CO2 (red)

So CO2 is still not a major climate driver and I have loads of new evidence. But posts should not be too long. Interested?

 

[pattylou]

No, not particularly, though it's nice to see you as well. (Have you noticed that the conversations on message boards don't really go anywhere?)

I've enjoyed being less active on the internet and I don't wish to get too into message boards again.

Nothing personal.

 

[Andre]

Well hoping to see you around very occasionally.

Indeed conversations here are mostly a conflict of interest. Each party's objective being to make a point and being right, rather than a common desire to find the truth.

It's probably all about the http://www.accessexcellence.org/RC/AB/BC/chamberlin.html

The habit of precipitate explanation leads rapidly on to the development of tentative theories. The explanation offered for a given phenomenon is naturally, under the impulse of self-consistency, offered for like phenomena as they present themselves, and there is soon developed a general theory explanatory of a large class of phenomena similar to the original one. This general theory may not be supported by any further considerations than those which were involved in the first hasty inspection. For a time it is likely to be held in a tentative way with a measure of candor. With this tentative spirit and measurable candor, the mind satisfies its moral sense, and deceives itself with the thought that it is proceeding cautiously and impartially toward the goal of ultimate truth. It fails to recognize that no amount of provisional holding of a theory, so long as the view is limited and the investigation partial, justifies an ultimate conviction. It is not the slowness with which conclusions are arrived at that should give satisfaction to the moral sense, but the thoroughness, the completeness, the all-sidedness, the impartiality, of the investigation

That's why I'm trying to scrutinize everything.

The moment one has offered an original explanation for a phenomenon which seems satisfactory, that moment affection for [one's] intellectual child springs into existence, and as the explanation grows into a definite theory [one's] parental affections cluster about [the] offspring and it grows more and more dear ... There springs up also unwittingly a pressing of the theory to make it fit the facts and a pressing of the facts to make them fit the theory ..

Therefore, despite the apparent exhaustive dealing with the subject of Anthropogenic Global Warming, I would like to suggest one question whenever the next alarmist message emerges about sealevels glaciers, storms, what have you: "Suppose that the cause of that warming is something else than antrhropogenic greenhouse gas effect?".

And that something else can be found here: Fortunately a short thread.

 

[pattylou]

"Suppose that the cause of that warming is something else than antrhropogenic greenhouse gas effect?".

Well, that's easy. Then nothing we do will really matter - unless we identify the non-anthropogenic effect and reverse it somehow.

But, since we won't reach certainty that it is not anthropogenic (ie there will always be some concern that human activity contributes), it continues to make sense to try to reduce emissions, reduce population load, look at the long term consequences, and continue to try to research the situation.

We do have a much better understanding of climate than thirty years ago, after all, and that's because science has been trying to understand the factors that contribute to climate.

(I'm still not here. I mean it.)

 

[Andre]

Well, that's easy. Then nothing we do will really matter - unless we identify the non-anthropogenic effect and reverse it somehow.

Well I guess that the (huge) albedo changes may or may not have cyclic interaction with ocean surface temperatures and for some reason that cycle is somewhat stronger than the last one in the 1940ies. But that's very tentative.

But, since we won't reach certainty that it is not anthropogenic (ie there will always be some concern that human activity contributes), it continues to make sense to try to reduce emissions, reduce population load, look at the long term consequences, and continue to try to research the situation.

We do have a much better understanding of climate than thirty years ago, after all, and that's because science has been trying to understand the factors that contribute to climate.

We could have a good understanding if it wasn't for the continuous attempt to overestimate the sensitivity to GHG forcing due to positive feedbacks. If there were positive feedbacks life at Earth would have ceased to exist long time ago. As the albedo research suggests the feedback -actually gain- may be strongly negative or we're dealing with a gain of less than 0,5. With the psysical measurable (Stefan Boltzman) forcing of 0,7 degrees dynamically initially to 1,2 degrees steady state after some centruries for doubling CO2. The negative feedback would make that less than half. Which suggests that whatever good reasons there are to cutback emisions, climate is not one of them.

(I'm still not here. I mean it.)

Then, have a good time elsewhere.

 

[scott1]

Why is deforestation bad?

Because plants help take in the carbon dioxide we breath in and turn it into oxygen that we can breath.If hunans > plants that makes the air balance so we have less air to breath.
The Rain forest helps a lot with truning carbon dioxide into oxygen and cutting them down would make things very unblanced.

 

[Mk]

Because plants help take in the carbon dioxide we breath in and turn it into oxygen that we can breath.If hunans > plants that makes the air balance so we have less air to breath.
The Rain forest helps a lot with truning carbon dioxide into oxygen and cutting them down would make things very unblanced.

How quickly is it going? I remember Thomas Malthus wrote about the population bomb in the 1700s, which could've happened without technology.

 

[Mk]

Well I guess that the (huge) albedo changes may or may not have cyclic interaction with ocean surface temperatures and for some reason that cycle is somewhat stronger than the last one in the 1940ies. But that's very tentative.

Are they really huge or are you sarcasticizing? I never read that paper somebody posted in the global dimming thread. I even saved it too.

Then, have a good time elsewhere.

Wow you guys civilly really don't like each other.

 

[Andre]

Are they really huge or are you sarcasticizing? I never read that paper somebody posted in the global dimming thread. I even saved it too.

Yes they are, seriously, 10-11% is huge:

http://home.wanadoo.nl/bijkerk/albedo-temp.GIF
http://home.wanadoo.nl/bijkerk/albedo2.GIF

which gives Earth blackbody temperature variations of about 3 degrees Kelvin/Celsius, as I said, it dwarfs the greenhouse factor with only a few tenth C at the most.

you guys civilly really don't like each other.

No, your perception is wrong. Its just that I'm non native tongue and not very good at subtly conveying emotions. I do wish Patty all the best. After all, running a family is priority #1.

 

[Mk]

which gives Earth blackbody temperature variations of about 3 degrees Kelvin/Celsius, as I said, it dwarfs the greenhouse factor with only a few tenth C at the most.

Are you approximating Earth to a black body to get its black body temperature?

 

[quantumcarl]

Let's do another one.

The idea that humans can and have had a big impact on climate is increasingly thriving. Apparently we are the central factor -Anthropocentrism. It started with Ruddiman who had produced a http://courses.eas.uAlberta.ca/eas457/Ruddiman2003.pdf .

How come, well the paleolithic man started to change his environment, cutting down forests to build villages, burn fires and have land for agriculture. This would remove the carbon sink function and would increase the CO2 in the air.

So what do you say about that?

Deforestation happens. Landslides, volcanos, fires, infestation, disease and floods. They all kill trees/plants. All these factors have happened long before humans chopped down trees to make paper and houses.
Did the climate change because of these natural occurances? Yes. Sometimes the climate would change drastically and globally to the point of a volcanically induced nuclear winter.

However, naturally occurring deforestation happens randomly and usually to the benefit of the environment, spurring new growth with more sunlight and so on. Whereas humans continue to deforest everything in sight, leaving little time for reforestation between clear cuts. I can see how this could push deforestation and the climate a little further than the occassional blight of bugs or volcanic blow out... perhaps all the way to the extinction of those concerned.

 

[Andre]

Are you approximating Earth to a black body to get its black body temperature?

Have a look http://www.ldeo.columbia.edu/~kushnir/MPA-ENVP/Climate/lectures/energy/Greenhouse_Effect.html

See expression 5: (sorry Latex not working on this machine)

G = σTe^4 = (1-A) S / 4

Te is the blackbody temperature,

A is albedo, normal 0,3

S is solar flux

σ is the Stefan Bolzman constant (5,67 * 10-8)

Reworked in expression [5] to solve temperature:

Te = ((1-A) S / 4 σ)^1/4

Solving this equation with S = 1376.6 and Albedo 0,3 gives a blackbody temp of 254.9K. You can check with google that 255K is indeed quite synonym to black body temperature. So far, so good.

So what would a 10% variation of albedo give?

A = 0.27: Te =257,6K (+ 2.7 K)

and

A = 0.33: Te = 252.1 (- 2.8 K)

This would be the average temperature of a rotating (heating and cooling) Earth without any secondary thermal effects like GHG or latent heat or heat transport, conduction, etc.

So if none of those effects would have worked the 10% albedo change of the last decade should have given an average global temperature change of 2.8K

But it was only 0.5 - 0.6 K.

Now you can model whatever you like but reducing such a enormouos insolation difference by a about a factor 5 (or 20% feedback) would suggest a very strong negative feedback from al the thermal processes. The same strong negative feedback could nullify changes in greenhouse effect.

 

[Andre]

... Whereas humans continue to deforest everything in sight, leaving little time for reforestation between clear cuts. I can see how this could push deforestation and the climate a little further than the occassional blight of bugs or volcanic blow out... perhaps all the way to the extinction of those concerned.

Anthropogenic deforestation is a big problem but there are positive sounds. In Africa there is a single woman fighting it, succesfully. She won the nobel price for peace. Meet http://nobelprize.org/peace/laureates/2004/press.html and have deep respect for such an accomplishment.

 

[pattylou]

If there were positive feedbacks life at Earth would have ceased to exist long time ago.

I don't know what exactly you are getting at - so I hope I am not taking you out of context here:

You can't conclude that the existence of positive feedbacks precludes life from continuing.

For one thing, some cycles (eccentricity of orbit, wobble of the earth, etc) would change the amount of energy coming into the system - Those cycles could offset a positive feedback loop.

For another thing, the presence of one positive feedback doesn't mean that other types of feedback aren't also at work. For example, the snowball Earth idea was a positive feedback cooling trend and most life stopped. But volcanism eventually allowed enough gasses to accumulate to escape the snowball. Thus, as one feedback changes the climate, other factors - in this case the accumulating emission of CO2 from volcanoes with no plants to absorb it - can tip the planet back.

For a third thing, there have been mass extinctions - perhaps due in some part to "positive-feedback" climate - and at least the ediacaran extinction seemed to be pretty absolute. Yet, microorganisms tend to survive those sorts of events because they are so genetically resilient. And life resumes.


-Patty

(Aside to MK: I chuckled at your "civil dislike" comment. It reminds me of the Cheers episode where Sam is with a girl in a hotel, "before," and he is folding his socks, because "he's not an animal, after all.")

 

[Andre]

Patty,

I think the wording "positive feedback" is not correct, in a linear closed loop system, positive feedback means per definition instability where any displacement from the normal value means an accelerated increase of that displacement, which is not stopping until the system crashes. The nightmare for the physical system designers. What is meant here is non-linear feedback and system gain.

About Snowball earth, remember the philosophy of TC Chamberlain about hasty conclusions and sticking to it. So some researchers find glacial stratifications on the apparent paleao equator and bingo we have snowball Earth. Later research has shown though that normal oceanic benthic activity has prevailed throughout the period, suggesting that the oceans were just open, business as usual. it is suggested that this period looked a lot like the modern times with occasional increases of polar ice sheets.The snowball Earth has melted.

Yes, there have been large mass extinctions indeed, seven now I believe, two more have been identified. The causes are moderately ambiguous. There are several catastrophic occurrences associated with most events, remarkable are several combinations of bolide impacts (large meteorites) followed by antipode basaltic flood volcanism. Most intriguing study here:

http://www.mantleplumes.org/WebDocuments/Antip_hot.pdf

 

[Mk]

She won the nobel price for peace.

How did she win the Nobel peace prize? I thought they gave it to more deserving people. Cutting down trees does not really constitute much violence to me, and there is no genocide she stopped.

 

[pattylou]

About Snowball earth, remember the philosophy of TC Chamberlain about hasty conclusions and sticking to it. So some researchers find glacial stratifications on the apparent paleao equator and bingo we have snowball Earth. Later research has shown though that normal oceanic benthic activity has prevailed throughout the period, suggesting that the oceans were just open, business as usual. it is suggested that this period looked a lot like the modern times with occasional increases of polar ice sheets.The snowball Earth has melted.

The idea isn't "hasty" - it's been around for fifty years. The evidence extends beyond low-latitude glaciation evidence, as well ---

~Reappearance of BIFs

~Carbon isotope ratios

~Cap carbonates (This latter point was predicted by the theory, and found to be true.)

I don't believe ocean benthic activity seriously undernmines the theory, as the point is that climate can respond to a feedback loop, becoming more and more severe (in this case, as albedo increases and other factors concurrent with glaciation.) But, thank you for pointing me to the article.

... I'm glad we agree that past conditions on the Earth have led to mass extinctions, and I'm glad you acknowledge that climate cannot be ruled out as a contributing factor to those extinctions.

 

[Andre]

Perhaps that this information about evidence for snowball Earth originates from http://shadow.eas.gatech.edu/~jean/paleo/Hoffman_1.pdf

Unfortunately, it is currently not within my scope to dive into it too deeply. I was trusting the judgment of a specialist, http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=25003&start=76 who did study these things and said about it only last month:

We have evidence, either direct or indirect, in the UK for at least two major glaciations prior to the ones we normally argue about. One is in the late Ordovician - and there is excellent evidence for that within the Welsh borderlands with sequences indicative of relatively rapid sea-shallowing and erosion such as channel-cutting. There is direct evidence for this event elsewhere in the world. The other is in the Dalradian sequence of late Precambrian age - the Port Askaig tillite of W Scotland, a metamorphosed sedimentary rock of glacial origin. This glaciation is the one that has at times been referred to as "snowball earth", now thought to be an unlikely scenario.

I do admit and apologize that this is not enough detail to address the elements that you mention -especially with the strenght of correct predicitions- but it's all a logical game of Clue (Cluedo) which I said only minutes earlier here:

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=27765&posts=9

Yes it's all a delicious game of Clue (Cluedo) Whodunnit? You are allowed to hypothese but only following the strict rules of (forensic) logic and physical laws. Was it Ms Scarlet in the Library with the rope? Perhaps, perhaps not. It's from ruling out a series of negatives, it could not be this because of that, it cannot be that because of this. But in the end there is a single solution...cont'd.

Notice the high level of knowlegde around there. That's where I learned a lot of this business.

Anyway, sure climate can contribute to extinctions. There is an elegant hypothesis about the Ordovician extinctions (multiple event) that the forming of supercontinent Gondwana cause large deserts inlands to far away from moisture sources and subsequently the move of that continent towards the southpole causing huge land ice caps, the double kill.

An interesting paper: http://www.essc.psu.edu/~bjhaupt/papers/3paleo.hhpss/Herrmann_et_al_3Paleo_2004b.pdf

Notice that the authors attribute a certain role to CO2 but also that they are talking about a range of 8 - 18 time preindustrial pCO2 (280 ppmv) which is 2240 ppmv to 5040 ppmv, values that we can't even imagine now, where we struggle with 380 or 400 or 500 ppmv. And still no trace of global warming then, just a major ice age with large extinctions.

So what caused these extinctions? Wasn't the geology setting the stage whereas climate finished the job?

 

[pattylou]

"So what caused these extinctions? Wasn't the geology setting the stage whereas climate finished the job?"

I'm sure mass extinction events are multifactorial. There's an interesting graph that suggests that volcanism is closely associated with mass extinctions, for example, rather than impacts - though impacts obviously affect everything from local destruction at the site to global climate changes.

Anyway, I heard it put forth just today that anoxia (O2 levels dropping to 16%) may have contributed to the permian extinction event.

I don't know how we got to this point in the discussion, but if extinctions are multifactorial, then large-scale deforestation, and massive anthropogenic CO2 emission - are still every bit as troubling as ever in terms of their potential to affect climate.

 

[quantumcarl]

Notice that the authors attribute a certain role to CO2 but also that they are talking about a range of 8 - 18 time preindustrial pCO2 (280 ppmv) which is 2240 ppmv to 5040 ppmv, values that we can't even imagine now, where we struggle with 380 or 400 or 500 ppmv. And still no trace of global warming then, just a major ice age with large extinctions.

So what caused these extinctions? Wasn't the geology setting the stage whereas climate finished the job?

Geology and climate seem to have played a role in the extinction of the Wooly Mammoth, Rhino, Blue Bison and other larger mammals. The impression is that a sudden cold snap froze wooly mammoths as they were eating grass. Today their muscle is still wrapped around the bone, sometimes 40,000 years later. But, here are some quotes that dispute the catstrophy theory and even the instant ice age theory.

"Lapparent attributes the extinction of the mammoth to a gradual increase in cold and a decrease in the supply of food, rather than to a cataclysmic flood." (Guthrie 1990)

"...Quackenbush (1909) concluded that the partial mammoth mummy from Eschscholtz Bay, Alaska, was so deteriorated as to exclude 'sudden fall in temperature" theories...'" (Guthrie 1990)

Apparently the climate change, over time, was enough to negatively effect the diet of the wooly mammals. They could withstand the temperature changes with their hearty physiology but they needed to eat enormass amounts of food. With the change in the weather the food became more scarce and less diversified.

I am still doing research on Mammoth diet and climate at the time of the burial of the Berezovka mammoth. Types of data being studied, stomach and mouth contents of the said mammoth, stomach contents of other mammoths found. Lake bottom sediment cores, showing pollen and vegetation over the last 10,000 years. Comments by Guthrie on how the climatic changes of the ice age affected the ratio of edible vegetation from then to present. Estimation of snow depths on the Mammoth Slope are also being covered and have a large bearing on extinction of the mammoth and other large Ice Age mammals.

And here are some of the dates taken from the frozen carcasses of the earlier types of mammals.

Mammoth Carcass Radiocarbon Dates

Earlier Age Group

Siberia

Adams (Lena River) Mammoth, 1799 36,000-37,000 years
Beresovka mammoth, 1900 more than 39,000
Shandrin mammoth, 1971 42,000 years
River Indigirka woolly rhino 38,000 years
Selerikan horse, 1968 35,000-40,000
'Dima', 1977 40,000
Khatanga mammoth, 1977 more than 50,000 Alaska

Fairbanks, mammoth hair 32,000-34,000
Fairbanks, bison, 1951 31,000
Fairbanks, bison, 1979 36,000Later Age Group

Siberia

Taimyr Peninsula mammoth, 1948 11,500
River Berelekh mammoth remains, 1970 12,000
Yuribemammoth, 1979 9,700

Alaska

Fairbanks, mammoth 15,400
Fairbanks, another bison 12,000
Fairbanks, hoof of horse, 1981 17,200
Fairbanks, musk ox 17,000

NOTE: The Beresovka mammoth is the one that Ted kept claiming was 'instantly frozen' by catastrophe. This is totally untrue, according to the scientists who did the actual research in 1900.

About RC14 dating:
http://www.allaboutarchaeology.org/is-carbon-dating-accurate-faq.htm

There appear to be two distict periods of climatic change and it is possible the changes were brought about by geological changes.

Charles Hapgood proposed the theory of "crustal shift" where the crust shifts around on the more liquid magma of the cores.

One idea here is that as an area of land slips into a polar region, the climate changes, perhaps gradually, as it gives into the weather of a polar region. This would contribute to the extinction of most species. But, human adaptability could avoid that fate. Take the Inuit for example.

(source: http://www.talkorigins.org/faqs/mammoths.html)

 

[Andre]

I'm sure mass extinction events are multifactorial. There's an interesting graph that suggests that volcanism is closely associated with mass extinctions, for example, rather than impacts - though impacts obviously affect everything from local destruction at the site to global climate changes.

Yes here is that graph, Actually, some events like the Perm and the Cretaceous/Tertiary events are both characterized by an (posible) initial bolide impact (Bedout and Chicxulub) followed by antipodal(!) massive basalt flood volcanism (Siberian traps and Deccan traps). Double strikes must be much more effective. And something for the geophysisists to work out, the possible relation between the two.

also http://rst.gsfc.nasa.gov/Sect18/Sect18_4.html

Anyway, I heard it put forth just today that anoxia (O2 levels dropping to 16%) may have contributed to the permian extinction event.

I can imagine that a half USA sized Volcanic event like the http://www.solcomhouse.com/yellow3.jpg chemically reduced many thousands cubic miles of limestone, increasing the CO2 of the atrmosphere with several (10-20) percent a percent being 10,000 ppmv (against the current 375 ppmv). That's also a way to reduce the oxygen levels to anoxic values.

I don't know how we got to this point in the discussion, but if extinctions are multifactorial, then large-scale deforestation, and massive anthropogenic CO2 emission - are still every bit as troubling as ever in terms of their potential to affect climate.

But the scale is microscopic after all that vehemence in this post here. I agree about the deforestation, not the CO2. However, oddly enough reforestation can also cause extinctions as my next post for QC will show.

 

[Andre]

Geology and climate seem to have played a role in the extinction of the Wooly Mammoth, Rhino, Blue Bison and other larger mammals.

Thanks, QC you brought right on the focus of my research, the "late Pleistocene, mega fauna extinction", about the wooly mammoth etc. BTW there is a awful lot of new material about that
http://www.sciencedirect.com/science?_ob=IssueURL&_tockey=%23TOC%236046%232006%23998579999%23606772%23FLA%23&_auth=y&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=30762d60686c93ca75bd963f9fb73a30.

Be sure to download all the articles. Those are free right now, but that won't last long, probably. Especially recommended is http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VGS-4G6J891-1-1Y&_cdi=6046&_user=10&_orig=browse&_coverDate=01%2F31%2F2006&_sk=998579999&view=c&wchp=dGLbVlz-zSkzk&md5=f0fac4ff2b6b3eaf371642c27b2fe9de&ie=/sdarticle.pdf

I happen to work closely together with the first author.

Anyway remember the Clue (Cluedo) game, I talked about two posts earlier? The murderers and their locations were the Storegga Slide area - Ormen Langen gas fields of Norway (North Atlantic) for Eurasia, The Amazon fan (Caribbean) for North America. Their weapon: massive oceanic methane bubble streams that disrupted ocean flow patterns causing dramatic changes in precipitation patterns that destroyed the extensive steppe habitats by...reforestation! But extensive winter snowfall and changing the solid soils into swamps and marshes also contributed decisively.

I told about that earlier in this thread. My study pal presented it officially at the http://www.mammothsite.com/CongressProgramDRAFT.pdf and the paper is due this month. Here is the presentation home.wanadoo.nl/bijkerk/BB.ppt[/URL] but only understandable with the [URL]http://home.wanadoo.nl/bijkerk/Hot%20Springs.doc[/URL] Enjoy.

 

[quantumcarl]

Thanks, QC you brought right on the focus of my research, the "late Pleistocene, mega fauna extinction", about the wooly mammoth etc. BTW there is a awful lot of new material about that
http://www.sciencedirect.com/science?_ob=IssueURL&_tockey=%23TOC%236046%232006%23998579999%23606772%23FLA%23&_auth=y&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=30762d60686c93ca75bd963f9fb73a30.

Be sure to download all the articles. Those are free right now, but that won't last long, probably. Especially recommended is http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VGS-4G6J891-1-1Y&_cdi=6046&_user=10&_orig=browse&_coverDate=01%2F31%2F2006&_sk=998579999&view=c&wchp=dGLbVlz-zSkzk&md5=f0fac4ff2b6b3eaf371642c27b2fe9de&ie=/sdarticle.pdf

I happen to work closely together with the first author.

Anyway remember the Clue (Cluedo) game, I talked about two posts earlier? The murderers and their locations were the Storegga Slide area - Ormen Langen gas fields of Norway (North Atlantic) for Eurasia, The Amazon fan (Caribbean) for North America. Their weapon: massive oceanic methane bubble streams that disrupted ocean flow patterns causing dramatic changes in precipitation patterns that destroyed the extensive steppe habitats by...reforestation! But extensive winter snowfall and changing the solid soils into swamps and marshes also contributed decisively.

I told about that earlier in this thread. My study pal presented it officially at the http://www.mammothsite.com/CongressProgramDRAFT.pdf and the paper is due this month. Here is the presentation home.wanadoo.nl/bijkerk/BB.ppt[/URL] but only understandable with the [URL]http://home.wanadoo.nl/bijkerk/Hot%20Springs.doc[/URL] Enjoy.[/QUOTE]

This is fascinating! Thank you for your in-depth studies and continued research in these areas.

[quote]The murderers and their locations were the Storegga Slide area - Ormen Langen gas fields of Norway (North Atlantic) for Eurasia, The Amazon fan (Caribbean) for North America. Their weapon: massive oceanic methane bubble streams that disrupted ocean flow patterns causing dramatic changes in precipitation patterns that destroyed the extensive steppe habitats by...reforestation! But extensive winter snowfall and changing the solid soils into swamps and marshes also contributed decisively.[/quote]

Reforestation would contribute to the diminishing of edible flora. Acrid soil and increasing shade would decrease diversity of plants.

What sort of geological event would cause the release of enough methane to disrupt ocean flow patterns? The only other example of this kind of event I know of has been studied in Bermuda, and the amounts of methane released in this case were minimal.

"Methane Ice"

[url]http://www.abc.net.au/science/k2/moments/s1068479.htm[/url]

"Methane Gas Blowouts"

[url]http://edugreen.teri.res.in/explore/renew/bermuda.htm[/url]

 

[Andre]

Have you seen the size of the tusks of Wooly mammoths?

Check the anatomically correct replica of the Yukagir mammoth mummy that was on display on the EXPO in Japan last year. (I coauthered the book "the making of.." of s replica including the detailed scientific research on it. Now we are waiting for it to be published.)

See the problem? His tusks evolutionized this way as a status symbol on the steppes without obstacles. In the massive boreal forests that emerged as a result of the clathrate gun, there was no room to manoeuvre. He got stuck between the trees. Moreover He required hard soils to walk on, and was hampered by soft moist swampy marshes. Furthermore, his metabolism and molars were highly specialized on hard steppe grasses. But the meters of snowfall in wintertime made that he could not reach his food anymore.

More later.

 

[Andre]

About the late Pleistocene marine methane hydrate it would help to study http://geosci.uchicago.edu/~archer/reprints/archer.ms.hydrate_rev.pdf a bit, paying especially attention to the reference to Maslin et al 2004, Mienert et al 2005 and Bryn et al (2005). The key publications. Our conclusions are slightly different than Archer's though. There is a lot more to it when integrating the hypothesis with all the other proxies (geologic, ice cores and oceanic proxies).

The mammoths fit very well in the anthropocentric thread as the overkill hypothesis is extremely persistent. However from the onset it is very clear that there was hardly a human around in North Siberia where the last Mammoths really thrived before the sudden demise. The number of papers that refute the overkill in America is now exceeding the claim though. However it's irrelevant and in the paper we do not discuss it, avoiding unnecesary digression.

One detail that has been observed several times: Why is the Yukagir mammoth replica dark gray whereas the majority of the mammoths are depicted reddish brown? The answer is that the fur remains of mammoths have oxydized to that color, giving a false idea about the color of the animal. Fresh recovered mammoth fur from the permafrost shows that dark grey color, but it turns brown after a few days exposure to the air.

 

[quantumcarl]

Have you seen the size of the tusks of Wooly mammoths?

Check the anatomically correct replica of the Yukagir mammoth mummy that was on display on the EXPO in Japan last year. (I coauthered the book "the making of.." of s replica including the detailed scientific research on it. Now we are waiting for it to be published.)

See the problem? His tusks evolutionized this way as a status symbol on the steppes without obstacles. In the massive boreal forests that emerged as a result of the clathrate gun, there was no room to manoeuvre. He got stuck between the trees. Moreover He required hard soils to walk on, and was hampered by soft moist swampy marshes. Furthermore, his metabolism and molars were highly specialized on hard steppe grasses. But the meters of snowfall in wintertime made that he could not reach his food anymore.

More later.

I have handled Mammoth Ivorys... very impressive in size etc...
I hadn't thought of the tusks of the mammoth getting in the way of foraging or of getting around (because of forest growth). Typically, upon the changing of a desirable environment they would migrate to one that suited their needs.

Woolly mammoths could not cope with the rapidly changing environment and increasing human predation toward the close of the last glaciation, and most became extinct about 11,000 years ago. However in 1993 came the startling announcement that dwarf woolly mammoths radiocarbon dated between 7,000 and 3,700 years ago lived on Wrangel Island. So while the pyramids and Stonehenge were being built in Egypt and England respectively, dwarf mammoths roamed the relic mammoth steppe on this small island off the coast of northeastern Siberia!

From: http://www.beringia.com/02/02maina2.html

There are also many accounts of human artifacts being found amongst mammoth remains or in the very least, depicting the mammoth as well as using mammoth bone and ivory to make decoration and tools.

However from the onset it is very clear that there was hardly a human around in North Siberia where the last Mammoths really thrived before the sudden demise.

Many of these correlations were found in Siberia and "plains of Russia" where you seem to mention there was little if any contact between Mammoths and Humans.

Paleolithic hunters apparently killed woolly mammoths in large numbers in Eurasia, particularly in Ukraine, where the species was of great economic importance. In the Old Crow Basin of the Yukon, mammoth limb bones often show signs of breakage by humans, who probably developed special methods for making and using tools of mammoth bone. In Alaska, a fluted point made by an early hunter was found with bones of a young elephant, probably those of a woolly mammoth.

A great variety of Paleolithic structures, tools and carvings have been made from mammoth bones and tusks. Examples are: ice age huts (more than 70 were found across the Russian Plain), needles, awls, harpoons, boomerangs, cleavers, shaft wrenches, musical instruments, figurines, dolls, bracelets, beads, pendants and combs.

In fact there is a lot of evidence that Mammoths and the like were hunted and helped toward an extinction by the paleolithic peoples. I know this points to antrhopocentric reasoning... but... sometimes these things happen.

What I find interesting is that there is no evidence that I've heard of or read or found myself that suggest the mammoths were near forests. I suppose they'd already migrated away from undesirable conditons as is evident with the "dwarf mammoths" from the "relic mammoth steppe on the small island off the coast of northeastern Siberia" .

What I did find was mention of the boreal forest's biodiversity and how that feature supports a large number of grazers:

With the relatively minor importance of fire over long periods of time, the swamp forest developed a structure maintaining a high biological diversity. An important issue for maintaining long-term biodiversity in the boreal landscape must be to create a mosaic where different forest types are present, with a variety of structures, substrates and processes, to provide a certain degree of freedom for species to move around in the landscape.

From: http://links.jstor.org/sici?sici=1100-9233(199705)8%3A2%3C295%3ALDOVAD%3E2.0.CO%3B2-C

It appears that there exists more than one "murderer" that we can hold reponsible for the extintion of mega-fauna that once began to roam, freely across the Eurasian and NA steppes over 150,000 years ago.

 

[Andre]

Donald K. Grayson, and David J. Meltzer (2003) http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WH8-47TX02J-2&_user=10&_handle=V-WA-A-W-AU-MsSAYVW-UUW-U-AAVVCAAZWU-AAVWUEWVWU-DABAEACDD-AU-U&_fmt=summary&_coverDate=05%2F31%2F2003&_rdoc=7&_orig=browse&_srch=%23toc%236844%232003%23999699994%23405950!&_cdi=6844&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=e7881d8463fcc9ad8f1213813e1b138a
Journal of Archaeological Science Volume 30, Issue 5 , May 2003, Pages 585-593

Abstract
The argument that human hunters were responsible for the extinction of a wide variety of large Pleistocene mammals emerged in western Europe during the 1860s, alongside the recognition that people had coexisted with those mammals. Today, the overkill position is rejected for western Europe but lives on in Australia and North America. The survival of this hypothesis is due almost entirely to Paul Martin, the architect of the first detailed version of it. In North America, archaeologists and paleontologists whose work focuses on the late Pleistocene routinely reject Martin's position for two prime reasons: there is virtually no evidence that supports it, and there is a remarkably broad set of evidence that strongly suggests that it is wrong. In response, Martin asserts that the overkill model predicts a lack of supporting evidence, thus turning the absence of empirical support into support for his beliefs. We suggest that this feature of the overkill position removes the hypothesis from the realm of science and places it squarely in the realm of faith. One may or may not believe in the overkill position, but one should not confuse it with a scientific hypothesis about the nature of the North American past.

And this is the conclusion of a library of studies. Dick Mol has taken hours to explain us that men did not do it. Several mass graves that where thought to be the results of slaughter turned out to be accumulations of remains in several thousands years. There were no humans in along the North to North East coast of Siberia but yet an abundance of mammoths that persished in some 400 years after the onset of the Preboreal Holocene at 11,653 +/-26 years ago because there was nowhere to migrate to. The whole of Siberia was changed into Boreal forest, marshes and swamps and shallow lakes. No more grass steppes, the only habitat they had known.

Those dwarf mammoths of Wrangel Island turned out to be normal sized mammoths that did survive until 7-4000 years ago. The error was made due to an early mistake in the determination of a molar. After that, several normal sized remains were found. It appeared that the steppe vegetation had managed to resist all those changes on the mainland unlike other islands like the Zemlya Severnaya island (October Revolution islands) with a large mammoth population without people. The Mammoth went extinct there as well due to the loss of habitat.

However like Anthropogenic Global Warming, Anthropogenic extinction of the mammoth tales will probably never disappear regardless of the evidence against it.

 

[quantumcarl]

And this is the conclusion of a library of studies. Dick Mol has taken hours to explain us that men did not do it. Several mass graves that where thought to be the results of slaughter turned out to be accumulations of remains in several thousands years. There were no humans in along the North to North East coast of Siberia but yet an abundance of mammoths that persished in some 400 years after the onset of the Preboreal Holocene at 11,653 +/-26 years ago because there was nowhere to migrate to. The whole of Siberia was changed into Boreal forest, marshes and swamps and shallow lakes. No more grass steppes, the only habitat they had known.

Those dwarf mammoths of Wrangel Island turned out to be normal sized mammoths that did survive until 7-4000 years ago. The error was made due to an early mistake in the determination of a molar. After that, several normal sized remains were found. It appeared that the steppe vegetation had managed to resist all those changes on the mainland unlike other islands like the Zemlya Severnaya island (October Revolution islands) with a large mammoth population without people. The Mammoth went extinct there as well due to the loss of habitat.

However like Anthropogenic Global Warming, Anthropogenic extinction of the mammoth tales will probably never disappear regardless of the evidence against it.

With what you have presented I can believe that, for the most part, the Mammoths and their kindred species were most probably brought to extinction due to the loss of a habitat which was brought about by the warming of the area. What may have happened with all the physical evidence of mammoth ivory tools, huts and decorations is that people found these remains, since they collected over a span of many millenia, and used what they'd found.

I can also see why humans wouldn't have made contact with many of the surviving mammoths etc... with a swamp/boreal forest separating the areas inhabited by the two species (human and mega-fauna).

So, the "myth" as you say can be explained by infrequent encounters with large herds, perhaps. And, at times, there may have been a kill that resulted in the evidence sited above.

When it said (above) that the mammoths were the base of a thriving economy out of today's Ukraine area this may have been an economy based on remains such as tusk and bone and even furs (since they were well preserved in permafrost)

Once again, thank you for your in-depth and non-anthropocentric view on the matter!

 

[Mk]

When it said (above) that the mammoths were the base of a thriving economy out of today's Ukraine area this may have been an economy based on remains such as tusk and bone and even furs (since they were well preserved in permafrost)

That sounds either made up or a not exaggerated. Mammoths were around when we were cavemen. Cavemen do not have "thriving economies."