Could Mammoth Remains Challenge Current Climate Paradigm?

[Andre]

It may be known that the roots of current climate concerns and alarmism are in the study of paleo climate, especially the last 'ice age' http://www.aip.org/history/climate/

It seems that things all add up, especially ice core records and proxies as well as oceanic isotope proxies. However, new discoveries are made on a regular basis and a more close examination of the details is possible. For instance the north Siberian plains, once the biotope of the Woolly mammoth, is worth a close investigation.

So what follows is a fragment of a manuscript I'm working on for discussion. It's that past that triggered my "independent" ideas, encouraged by several of the researchers in that area.

Quoting from own concept. Note that this only describes the various publications, which should all be in this list. No theory development whatsoever. It just intends to show that things do not add up nicely.

The popular impression of the Siberian mammoth habitat is that of Arctic tundra where the animals used to cope with bitter cold, sparse vegetation, and extensive snow cover in the long Arctic winters. Recent research has mapped the maximum extent of the several Late Pleistocene Weichselian advances, revealing that the amount of ice on Siberia has been greatly overestimated. Actually, apart from some glacial advances in the North west shallow seas of Russia, the Kara sea and Barendsz sea, there was very little polar ice sheet if any (Gualtieri et al 1998, 2000, Mangerud et al 2002, Hubberten et al 2004). The East Siberian Ice Sheet (Grosswald 1997) proved to be none existent

However, extensive research reveals a dry, perhaps moderately cold, mostly treeless habitat, still capable of producing abundant fodder for the large grazers, referred to by various authors as “tundra–steppe” or “Mammoth steppe” encompassing most of the Northern Hemispheres moderate lattitudes (Guthrie, 2001; Walker et al, 2001; Yurtsev, 2001). Even during the Last Glacial Maximum (~23 ka to 18 ka Cal BP), the steppe existed south of the Eurasian ice sheets of Scandinavia and the northern Russian coastal areas (Huntley et al., 2003), eastward across Siberia and exposed continental shelves to the north, and via Beringia into Alaska and the northern Yukon (Ritchie, 1987), as well as south of the Laurentide Ice Sheet in central and eastern North America (Lister and Bahn, 1995)

The climate was generally arid, and supposedly cold. However, the vegetation of this habitat included a unique combination of herbaceous and dwarf-shrub taxa, which are absent in the present Arctic tundra regions (Yurtsev, 2001), but which are generally common at much lower latitude steppe habitats in the continental climate areas that characterize central parts of both North America and Eurasia. (Guthrie, 1990, 2001; Zazula, 2006). Despite the high latitudes, the steppe vegetation (mainly grasses, sedges, forbs and artemisia) was productive enough to sustain an abundance of grazing herds of large herbivores throughout the seasons, like Mammuthus primigenius, Equus species, reindeer/caribou (Rangifer tarandus), muskox (Ovibos moschatus), Saiga antelope (Saiga tatarica) and other, now extinct species like the giant deer or “Irish elk” (Megaloceros giganteus) and the woolly rhino (Coelodonta antiquitatis). Predators included brown bear (Ursus arctos) and wolf (Canis lupus) as well as the Siberian amur tigers (Panthera tigris altaica), but also now extinct cats like the steppe lion (Panthera leo spelaea) and sabertooth cats (Smilodon species). Insect remains show both that temperatures were moderate often exceeding todays values and snow cover during winter was thin or even absent on these grassy steppes (Kuzmina, 2001, Sher et al 2002, Schirrmeister et al 2002)

Alfimov et al., 2003 suggest with the Mutual Climatic Range (MCR) method on fossil insects that summer temperatures the Lower Kolyma were some 3º higher than present that it was a few degrees higher than present around 13-14 ka 14C BP (16.7 – 15.3 Ka Cal yar BP) Another restraint on minimum temperatures for instance shows the research on the Yukagir mammoth, discovered in Northern Yakutia, Arctic Siberia, Russia (71° 52’N - 140° 34 E). Its age is established to be 18,560 14C years, which calibrates to ~22,160 years Cal BP, placing it at the beginning of the Last Glacial Maximum (Mol et al 2004). The intestine remains showed a variety of species abundant at moderate to higher latitudes amongst which pollen of Sanguisorba officinalis (Aptroot A, B van Geel 2006). This species is currently only moderate winter hardy (USDA Hardiness zone 4-5) suggesting likewise for Northern Siberia just prior to the last glacial maximum and nowhere near glacial conditions

Thus, fodder remained probably available throughout the year and continuous migration to fresh feeding grounds was facilitated by the dry ground. Fungi spores reveal that the density of large animal herds could have been significantly high, at least locally (Mol et al., 2006, Aptroot and Van Geel 2006). A relative abundance of algae spores (Andreev et al., 2002) reveals that lake and river levels were mostly low, further supporting the concept of an arid steppe--a distinctly different landscape than the Arctic tundra of today. In North Siberia for instance, the prevailing tundra is much wetter with permafrost, and the vegetation growth is unable to sustain more than a few larger grazers like musk ox and reindeer

Clearly the biological proxies of the Siberian Mammoth Steppe in the Late Pleistocene certainly challenge the current paradigm the transition of the Last Glacial Maximum. It appears that the arctic conditions in North America were neutralized by the mild conditions in Siberia, challenging the idea of the extreme cold conditions of the Last Glacial Maximum and hence the assumed related role of CO2

 

[Ivan Seeking]

So it is your intent to post "your concept" without a prior publications of that concept? Has your assertion that things "don't add up nicely" been published in an appropriate journal?

In other words, do climate change experts consider this to be significant, or is this your conclusion or a conclusion found at blogs?

 

[Andre]

maybe check the peer reviewed published references again. Nothing in the compilation is my conclusion.

http://www.geol.lu.se/personal/prm/PDF_papers%20full%20text/QSR_2004_QUEEN_hubberten.pdf for instance is freely available with compilations of several others

 

[Andre]

Another interesting case is the Fishhook mammoth, published in http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VGS-4G6J891-1&_user=10&_coverDate=01%2F31%2F2006&_alid=994101190&_rdoc=1&_fmt=high&_orig=search&_cdi=6046&_sort=r&_docanchor=&view=c&_ct=9&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=63f22ebc4eb76e4bc8fd8eab5bd77df6

Interesting details are in this conference abstract (reflected in the publication)

...The so-called Fishhook mammoth is a 20,620 +/- 70 year old () Mammuthus Primigenius individual (note carbon dating converts to ~24,670 Cal BP, using Intcal04 conversion table)...

The Fishhook mammoth reflects the northern expansion of mammoth populations during the cold period of the Early Sartanian (25,000-18,500 B.P.(carbon dating)) onto the Taimyr Peninsula, which was largely ice free at that time...

..The occurance of Larix needles in the matrix of the gut sample of the Fishhook mammoth is especially interesting, since the site where the carcas was found is situated at about 200 km north of the present tree line...

And that was the cold(est?) period in northernmost Siberia?

 

[Andre]

Let's look at http://www.geol.lu.se/personal/prm/PDF_papers%20full%20text/QSR_2004_QUEEN_hubberten.pdf again.

We are interested in fig 6 page 1339 (7):

with the caption:

Fig. 6. Summer climate changes and the dated record of mammals in the Laptev Sea area (from Sher et al., in preparation).

(a) Fossil-insect record in
the Mamontovy Khayata section, Bykovsky Peninsula. Percentage of selected ecological groups of insects (minimum number of individuals in each
sample equals 100%): Thermophilous xerophiles:
1—steppe species;
2—other xerophilous insects (except tundra ones);

Insects, currently common in tundra:
3—dry tundra inhabitants (prefer warmer sites);
4—Arctic tundra insects (plotted from the right axis).

14C ages in the left column are calculatedfrom two separate regression equations after about 40 AMS dates.

(b) Climatic and environmental interpretation of the insect assemblages from the Mamontovy Khayata section.

(c) Radiocarbon dates of mammal bones from the Laptev Sea area (number of dates in 2500-year intervals). The latest available dates for mammoth and horse are indicated at the top.

We see quite some variation in biotopes and apparent temperature regimes. The sudden spikes starting at 15,000 years are interesting. Would this be in synch with the greenland ice cores or?

More later.

 

[Andre]

So let's look at the oxygen isotope ratios of the ice in one of the Greenland ice cores (GRIP):

Source

The isotope ratios (green graph) change during different processes in the water cycle, during evaporation, condensation and transportation ('raining out'). These changes are directly dependent on temperature, therefore it is inferred that the isotope ratios are a proxy for temperatures (for instance Jouzel et al 1997). With a quick glance on the black time scale on the left and comparing it with fig 6 of Hubberten et al 2004, it appears that -at 15,000years- the big spikes correlate closely. These spikes are known as the Bolling Allerod interstadial btw. So it is very well possible that this kind of comparisons may have convinced the researchers many years ago that things added up nicely indeed.

There is a big problem though, we are comparing apples with oranges, and there are some issues with carbon dating that was unknown in the early days. Due to a rather large variation in 14C radiocarbon ratios in the atmosphere the carbon dating method has large irregularities. Ardious labor on this problem has produced a rather robust calibration table, latest version: INTCAL04, showing up to several thousand years of differences between carbon dating and counted dating, as the ice cores annual layers are counted.

Therefore the carbon dates are added in red at the right side of the Y-axis using the calibration table. Now we see that the 15,000 carbon years of Hubberten et al, 2004 translates to some ~18,000 real counted or calendar year, hence the warming in Siberia appeared to have started well before the warming signal of the ice core isotope proxies on Greenland. Things seem not to add up so nicely at all.

 

[Andre]

So it appears that we have a bit of a 'mystery' to solve for the period spanning roughly 14,500-17,500 years ago, when the interpretation of the isotopes in the ice cores suggest very 'cold' but the Mammoth steppe suggest "warmest Tundra Steppe" being warmer than today, at least in the summer, and warmer than the interval 48-24,000 carbon dated years ago.

Now we have been here last year, when I posted a lot more evidence for that 'mystery':

(...) So let’s focus on that first deviation period between 17.5 and 14.5 thousand years ago, known as Periglacial or Oldest Dryas when the northern hemisphere seemed to remain as cold as ever while the Antarctic clearly seem to warm and let’s check some recent studies covering that period, in which I converted the carbon dates (Ka BP) to calendar dates (Ka Cal BP) with the INTCAL04 table

(quote from a draft article which merely sums up the essence of the studies)

Stone et al (1998) obtain Cosmogenic 36Cl ages for two samples from ice-scoured basalt outcrops of 17.6 ± 1.4 and 17.4 ± 1.3 cal. ka BP, at the The Storr, Isle of Skye, Scotland and provide minimal dates for the onset of ice-sheet thinning

A radiocarbon date of 13 870 ± 150 BP (c. 17.0–16.2 cal. ***ka BP) is maximal for ice-sheet deglaciation at Loch Ashik in eastern Skye (Walker et al., 1988; Walker and Lowe, 1990), Ballentyne et al 1998)

Vescovi et al 2007 reconstruct the vegetational history of the southern side of the Alps shows that Alpine deglaciation must have started before 18,000–17,500 cal yr BP south of the Alps

Clark (2003) examines evidence from alpine glacial deposits in the American Cordillera and observes glacial retreats In the Sierra Nevada, between 17,000 and ~15,000 14C yr BP(~20,100-18,500 cal yr B.P. and in the North Cascades by ~17,000 36Cl yr BP; in southern Idaho at 13ka BP (15,3 ka Cal BP).

Sandgren et al (1999) observe that sedimentation of Lake Kullatorpssjön in South Sweden started 14,660 14C years BP, recalibrated to 17,820 Cal BP years, denoting the time of deglaciation.

Andrews (2000) investigates the NE margin of the Laurentide Ice sheet in Canada and observes initial deglaciation at 14.5 ka or 17.5 ka Cal BP.

Kovanen and Easterbrook (2001) report rapid deglaciation in the North Cascades in Washington between 14 500 and 12 500 14C yr B.P (17.5 – 14.7 ka Cal BP)

Ager (2003) analyses the late Quaternary vegetation and climate history of the central Bering land bridge from St. Michael Island, western Alaska and infers a clear warming between 15 and 13 ka BP (ca 18.5 ka – 15.3 Ka Cal BP ).

Glover (2004) find carbon dates of 16500-15000 14C years BP for basin forming associated with glacial retreat, which calibrates to 19,700 – 18.,500 Cal years BP. Clastic to biologic sedimentation transition happened at 13,370 14C years, which calibrates to 15,900 cal years BP.

Hill et al 2006 find also indication early deglacial warmth 2 ka before the formal termination and remark that those findings "are consistent with a growing number of records from around the globe that exhibit pre-Bølling warming prior to Termination IA, and extends the record of such processes to the northern Pacific

Hubberten et al 2004 reconstruct Summer climate changes Laptev Sea area based on a fossil-insect record in the Mamontovy Khayata section, Bykovsky Peninsula (fig 6) and find a substantial summer climate improvement in two steps around 15 ka 14C yeasrs BP and 14 Ka 14C years BP, which calibrated to ~18,5 – 16,7 Ka Cal years BP

Shakun et al 2007 (Jemen) A gradual increase in moisture thereafter was interrupted by an abrupt drying event at 16.4 ka, perhaps related to Heinrich event 1.

Jacobi et al 2007 reconstruct precipitation variations in Northern Brazil for the last 20 ka deduced from biotic δD values, An abrupt change from arid towards much wetter conditions occurred from 17.3 to 16.8 k and coincides with a change from savannah to rainforest taxa. isotope data show only a small rise in aridity during Younger Dryas event (13–11.5 ka).

References should be in this list

Denton et al (2006) compile the these problems:

GH Denton, WS Broecker, RB Alley, 2006; The mystery interval 17.5 to 14.5 kyrs ago, Past Global Changes (Pages) Volume 14 No 2 August 2006, pp14-17

Abstract
The time period between the beginning of Heinrich event #1 (H-1) and the onset of the Bølling/Allerød rivals the Younger Dryas in importance to our understanding of how the planet responds to abrupt mode switches. This interval also constitutes the onset of the most recent termination, arguably the most fundamental climate shift of the last 100-kyr glacial cycle. As some of the responses during this time appear to be mutually contradictory, we term it the “Mystery Interval”.

Obviously the biggest contradiction is that the isotopes of the Greenland ice cores suggested cold whereas the melting ice sheets and the changes in flora suggested warm in the Northern Hemisphere.
That should have triggered the curiousity, but it hardly did.

Now with the abundance of reports for warming of that 17.5k to 14.5 k 'mystery' - interval and the discrepancy between warming of the two hemispheres, as the southern hemisphere has similar warming timing, there may be enough reasons to revisit the interpretation of the isotopes of the greenland ice cores.

I did that and I can demonstrate with normal physical- hydrographic knowledge, that other processes than warming and cooling can have similar effects on the isotope signatures of the Greenland isotopes. Those may be more consistent with all geologic and paleo-climatal records. This is not theory develloping, but merely the alternate application of existing knowledge. The question is, can I discuss this in these forums?

 

[lisab]

This is not theory develloping, but merely the alternate application of existing knowledge. The question is, can I discuss this in these forums?

I'll be disappointed with PF if the answer to that question is "no."

I'm an adult, I can think for myself...hearing alternative interpretations of observations won't warp my (also very little ) brain.

 

[Andre]

Thanks for the support, Lisa

I think it's legal to elaborate on the isotopic hydrographic processes and demonstrate what the consequences are of variations in parameters. But ultimately it all boils down to the sciencific method:

1: Observing phenomona (variation in isotopes in the ice cores)

2: Formulate a plausible construction to explain it (hypothesis): isotopes are temperature proxies. However such a hypothesis is always a choice out of several possiblities. It could be something else. Therefore:

3: Make predictions based on those constructions

4: test it. Now, the original tests with field observations may have been done against carbon dated records, which may have looked good. However the accurate calibration of carbon date became available later and the tests may never have been revisited.

So the different studies on isotopes agree on temperature differences in the order of magnitude of ten degrees along those spikes. However the siberian mammoths and their reconstructed biotopes clearly refute such a temperature swing. On the contrary, where the isotopes are low, their biotopes are warmer than today. But also as seen the isotope spikes are not consistent with the other temperature indicators like the insect remains or glacial retreats. Hence with the current state of the science, it appears that some of the isotope variations have other causes than temperature.

We could stop here, nothing in the next phase, right or wrong can undo these results. The scientific method now calls for a revision of the hypothesis. That's not to me to do, but I could indicate which processes in the hydrografic cycle may have similar effects to temperature swings.

Obviously the implications of this evidence is rather extensive. First of all, there is a very tight correlation of methane greenhouse gas with these isotopes, see for instance Flueckiger et al 2004. But what if that is not directly related to temperature?

Anyway I intend to start a new thread about the isotopes in the ice cores and the hydrographic cycle since it would drift too much off topic in this thread.