The NAS panel mentioned the recent 5000-year organics from Quelccaya as being an important potential indicator of 20th century climatic uniqueness. (Lee seems to consider it some kind of smoking gun)
I’ll discuss Thompson’s abysmal publication of the data – in particular, his total lack of any stratigraphic information – in a few days, but first I want to refer to a couple of other articles which also discuss the recover of fossil tree stumps from receding glaciers in a less cavalier way than Thompson.
Wood and Smith 2004 discuss the recovery in 1999 and 2000 of 3000-year old in situ and detrital stumps from stream beds in the valley of the Saskatchewan Glacier, which is the largest outlet glacier of the Columbia Icefield located in northern Banff and southern Jasper National Parks (52o6’30”N;117o15’10”W). This is in the same general area as the Jasper tree rings collected by Luckman and published in Luckman and Wilson 2005 (discussed here here and here previously.) Perhaps one of Schweingruber’s sites comes from this very valley.
Caption Comment: Wood and Smith state that "the glacier flows in a NE direction for ~10 km through a steep-walled valley…Over the last century the Saskatchewan Glacier has experienced significant downwasting and frontal retreat."
Wood and Smith describe the discovery of the stumps, later dated by radiocarbon, as follows:
In late August 1999, a severe rainstorm resulted in stream avulsion along the NE flank of the Saskatchewan Glacier snout (117o8’45”W, 52o9’30”N). When first examined in early September, erosion through a 3- to 5- m sequence of glacial outwash and overlying till had exposed 17 sheared stumps rooted within a well-preserved paleosol (Figure 2). A further 29 recently deposited ice-proximal stimps rooted within a well-preserved paleosol were located 50 to 150 m downstream on the adjacent outwash surface. By September 2000, the meltwater channel had shifter southward and had eroded through 5 m of fluted moraine deposits exposing 2 additional rooted stumps and flushing an additional 40 detrital boles onto the outwash surface.
The stumps were rooted in a deeply weathered pedogenic surface and prior to their exposure were buried by 3-5 m of sediment. …there is an indication that the subfossil samples recovered in 1999 and 2000 were killed between ~2940 and 2760 14C years BP. With one exception, these dates collectively reflect the consequences of a single Neoglacial advance of the Saskatchewan Glacier into an established valley bottom forest.
Here is a picture:
Unfortunately Wood and Smith do not provide a cross-section map of the stratigraphy – something which would be mandatory in any geological presentation. (At least they have a location map and discuss the stratigraphy.) The information is certainly sufficient to deduce that the Neoglacial advance of ~2900-2700 BP overrode the stumps; and that, sediments transported by the glacier sealed the stumps in a 3- to 5-m bed of sediments. It’s my impression that the glacier retreated on at least one subsequent occasion and during that retreat, the forest would have returned upslope – I’m 99% sure that there are medieval trees in this location (since there are upslope trees) , but I would have to confirm this. Granting this assumption for now, such trees would growing in sediments that were above the 3000-year stumps, now sealed in the sediment bed. Think of an archaeolgoical tell in the Middle East with destroyed cities in strata on top of each other, older the deeper.
It’s my understanding that the LIA glacial advance in the Canadian Rockies was the largest since the last Ice Age (ending in the 19th and even early 20th centuries.) Presumably this advance may have bulldozed some of the overlying sediments further downslope, rendering it possible for the 3000-year old stumps to be exposed by stream erosion in the 20th century, as has happened.
If trees have grown upslope at any point during the past 3000 years, the discovery of rooted stumps in 1999-2000 does not imply anything about the uniqueness of the present glacier retreat. One needs much more information before any such conclusions can be considered: one needs information about the stratigraphy of the organics and an inventory of all other organics together with their stratigraphy. You also see why one wants to have a careful exposition of the discovery of Quelccaya organics, rather than Lonnie Thompson’s typical pamphleteering account, which unfortunately was accepted by PNAS as a scientific report.
Reference:
Wood, C., Smith, D. 2004. Dendroglaciological evidence for a Neoglacial advance of the Saskatchewan Glacier, Banff National Park, Canadian Rocky Mountains. Tree-Ring Research 60(1):59-65. url
Thompson, 2006, PNAS.
Climate Audit 
110 Comments
I agree that this is a better report and that Thompson needs to write precise, full papers on individual subjects. *Bites tongue*
I’m going to take a blog break. See you all after I get RL squared away. Have fun all. Cool discussion topics on this site.
Just as important, trees were growing 3,000 years ago at a point which was until recently covered over by the Columbia Glacier.
So we have another warm period which is warmer than today since there are no significant tree growth at the bottom of the glacial outflow channel (I have been there.)
re #2:
What I got from the article was that a general cooling period began approximately 4,000 years ago, causing the glacier to start advancing and that advance took several hundred years to reach these trees and shear them off. My question then becomes did these trees die because they were sheared off by the glacier or were they killed by the same cold temperatures that caused the glacier to advance?
Re:#2
As Steve points out, the area where the rooted stumps were found may very well *not* have been covered by the glacier during *all* of the time period since the trees were killed.
re #4:
The article implies this also when stating:
Wow! Great article Steve. You should be commended for blogging on it as it undercuts almost everything you’ve done on this issue. The implications are quite clear and yours and others comments on this article are just as fascinating. Again it’s articles like these that, without being too crass, make all your work seem pretty much inconsequential.
Fantastic then…if you say proxies are hard to interpret…you make a decent point but this however, in spite of everyone above falling all over themselves with some fairly ludicrous attempts to explain this away, is very difficult to ignore or nit pick or set asunder over statistical nuances.
My interpretation, the obvious interpretation, is that the current warmth has not been exceeded in over 4,000 years. Again Mann was very very likely right.
#6 It’s interisting to note your idea of a great article is based upon it’s conclusions less than its content.
Sorry meant to be “less so it’s content”
First of all, Mann is wrong because he made a variety of false claims – on verification statistics, robustness, confidence intervals. These claims are false regardless of whether climate followed a HS-stick shape. If there’s some other evidence of temperature history showing a HS-shape, such as glaciers, then so be it. however, I don’t think that this is it.
I’ve looked at a lot of stratigraphic diagrams in my career – I dare say that I’ve looked at a lot more than you or Mann. Please pay a little more attention to the stratigraphy as described here and stop making grandiose claims that don’t describe the stratigraphy as found here. .
I’m sorry Steve but you have no hesitancy to point out others “shoddy work”. As in , “…Thompson’s abysmal publication…”. But this claim seems based on panic and not on anything I can find in the article or the multiple referenced articles that ALL describe the same regional event with NO evidence or mention of finding say some 1000 year old stumps. I mean it doesn’t even make sense. A subsequent retreat and advance long enough to grown a new forest would likely have wash away the till burying these stumps and left them to rot in the weather. Newer stumps should have show up some where in the region by now but apparently there are none.
So were does your 99% confidence level come from. That’s way more then anything Mann ever claimed. You better hope some Medieval trees start showing up in the glacial till soon otherwise you might want to look for a new hobby because this one is looking defunct and irrelevant.
Re # 7
Sid in this case the content makes for a very strong conclusion. And again it’s not just here but also in the Andes and the Himalaya that we see this trend.
It would appear to me that the graph A from fig 8 in Thompsons PNAS 2006 article is a good baseline in which to put the trend of Holocene climate and the projected AGW into perspective.
Many medieval trees and stumps have been described in the area in Luckman’s various publications. One of the things that glaciers do is that they bulldoze off overlying sediments – this is not just special pleading in this case, but something that is very familiar to anyone who, like me, has lived in terrain shaped by glaciers. Very little overlying sediment is left in many parts of Canada on a grand scale.
The mechanism that intrigues me here – and I’m just noting it up, as each one of these notes is a big job to finalize – is that there are stratigraphic beds and the 3000-year stumps here are in a lower bed that has been overlain by sediments. I think that it is quite plausible – indeed probable – that there were younger sediments overlying the bed containing the stumps and that these younger sediments were bulldozed off by the glacier during its LIA advance. Typically in the Rockies there are LIA moraines at very considerable extensions. So sediments had to be bulldozed to make the moraine.
Sorry Steve but “stratigraphy” will not work to confuse the issue the way proxy reconstructions can be mired in statistics. That’s what’s so nice about this evidence. It’s so straight forward, easily reconfirmed and easily falsified. No statistics needed. Repeated findings of 4,000 and 5,000 year old fossilized plants from underneath glaciers around the world but not finding any 1,000 year old plants is all we need to know.
As these glaciers melt further back and we find even older trees and plants and no Medieval ones what are you gonna be left with? Your 99% confidence level about buried Medieval forest……I wouldn’t advise pushing this line of attack too hard.
Except there are medieval trees in this part of Alberta upslope of the modern treeline.
Steve, you’re wasting your time trying to be nice to George. I’ve argued with him for years and he’s simply a cheerleader for warmers. And he won’t argue the actual science, he’ll just produce argumentative, insulting drivil like:
George, please at least read my previous posts on the topic. Here’s something I wrote before: about Alberta.
There’s also similar evidence of advance and retreat in the Alps which I’ll post up in a day or two. The evidence of advance and retreat is widespread.
As you say, George, your position is easily falsified by the mere existence of medieval trees and I would appreciate it if you acknowledged this.
Yes Steve that’s my point. As these glaciers continue to recede and the debris below them are consistently dated >3-4- 5,000 years old and no debris from the MWP is found then the issue will be clear. From what I can see of the data that exist this already appears to be the case. What you’ve written above is not in context but I’d certainly like to learn more of the specifics and of the most recent data.
I think the issue of comparative warmth of the present time compared with the MWP can more likely be affirmed with this sort of glaciers data. Although I’d suggest this data is confirming the proxy data as well. I also think this is why the NAS states in their recent report that, “Other evidence from glaciers suggests that the recent warmth is unprecedented on millennial timescales….”
Dave,
Do you see any evidence form this article of MWP debris being uncovered? I see evidence that strongly suggest the area has been under ice until 1999 for over 3,000 years.
And Dave I have little doubt that I’m far more guided by the evidence while you are a slave to an unyielding ideology that’s incompatable with the facts.
gbalella My interpretation, the obvious interpretation, is that the current warmth has not been exceeded in over 4,000 years.
JK: The real question is whether or not today’s temperatures are unusual (and is man contributing to any unusual temperatures?) To find an answer to the first question, we look at past temperatures and see how today’s compare. As you just observed, it was warmer 4,000 years ago. So that particular piece of evidence shows that there is nothing unusual about today’s weather.
I think the real question is how do we compare to the last several interglacial periods? When we can be sure of a valid data going back that far, then we might be in a position to make a judgement about today’s weather. Before then we can only make irrelevant statements like “we are warmer than 400 years ago” (the middle of the “little ice age”), or 1000 or 2000 years. It does not matter.
Thanks
JK
No George. That would be you.
Is it just me or does this study have George/gballela really rattled.
Perhaps it is because Carbon 14 dating is solid science while hockey sticks are faked science. Perhaps it is because 3,000 year old trees and 1,000 year old trees beneath the Columbia glacier have the potential to really have an impact with the public in terms of finally understanding the garbage that has been thrown their way over the years.
I have got a slightly off-topic question. How did they calibrate the C14-Method. I mean you need some example as a reset to adjust your measurements and what range (in years) had it?
This is intruiging, because even C14-Methods uses the half-life period of C-Isotopes, if I am not entirely wrong. And (if my basic physics doesn’t leave me here)since we think that the amount of those Isotopes in the Atmosphere is constant over a huge range of time, but there might be divergences due to cosmic ray strikes.
23: The C14 that is found in biologicals was all produced in the atmosphere by cosmic rays. The half life is quite short, 5730 years, so there is no natural undecayed C14. Its production rate in the atmosphere is not constant, it is a function of solar activity. There is a decent summary of the calibration issues at this link.
Unfortunately I don’t see how data like this can tell us anything about past temperatures in relation to current, because the glacier is not currently in equilibrium, its retreating. So for example, the position of the glacier snout at the time these trees were growing may have been 100m (altitude) above present, but we do not know the position the glacier will stop retreating with current temperatures, it may be lower, higher or the same as when these trees were growing. In fact temperatures could have been lower than now when these trees started to grow (current tree line is above their position) with a glacier advancing after a warmer/wetter period but not having reached their position.
Re # 19
The bizarreness and complete lack of logical consistency in many of the above posts just blows me away. I have to wonder if some of you realize how inconsistent and weak your positions are yet you persist simply to be argumentative. Or do you actually think you’ve made a logically consistent argument?
It’s warmer then its been in 4,000 years and you say…apparently with a straight face…there is nothing unusual about todays weather. UN…….REALLLL!!!
The whole line of debate and the point of the audit is to determine if Mann et al had any credible reason to assume the decade of 1990’s was warmer then any in the last millennium.
This evidence strongly supports that not only was it likely warmer then any time in the last millennium it likely was warmer then any time in the last 5 millennium.
This means its likely or possible that it is warmer then civilization has ever seen and we might have 2-3C more of warmth in the pipe. And certainly we’ve never experience this RATE of change.
That makes AGW completely anomalous and likely very dangerous. Can you not see the dramatic effect on civilization of a 1 C change in climate over 500 years from the MWP to the LIA. Now imagine 3 C in 100 years with the peak being 2C higher then anything we’ve seen.
I deleted some flames. Please civil this up a bit.
What I find fascinating is how interest in subfossil wood from glaciers has waxed and waned. It is not like noone knew this wood was around and available to study. John Muir wrote about the retreat of the glaciers in his book “Travels in Alaska” published in 1915 which recounted trips from 1879-1890. He even writes about scavenging such wood to burn for warmth while exploring glaciers alone on foot. A fascinating book. Muir was a keen observer and a lively writer. He was also a man who seemed to be completely devoid of fear and common sense, but thankfully he survived all his adventures and was able to write about them.
A photo of exposed stumps from 1890: http://www.sierraclub.org/john_muir_exhibit/frameindex.html?http://www.sierraclub.org/John_Muir_exhibit/writings/travels_in_alaska/
I think that we cited John Muir in our E&E 2005 article, which has some interesting little asides that no one’s noticed. He hated sheep in the Sierra Nevadas, which he felt were ravaging the ecology. There have been articles linking late 19th century ravaging of meadow vegetation by sheep to 20th century explosive growth of trees in the US southwest – which has not been specifically linked to bristlecones, but there is evidence of sheep in very high meadows in the 19th century.
Can you give a page citaiton for your reference to the picture?
RE #25 muirgeo,
I don’t see the big deal here at all. 3000 to 4000 years geologically is an extremely small time scale. The evidence suggests that it was not just a bit warmer than today 3000+ years ago, it suggests it was warmer for a long time. The article states there was a well developed soil profile that these trees were rooted in. It takes a long time for a soil profile to become well developed (on the order of thoussands of years). Now if I am not mistaken, CO2 concentrations were lower 4000 years ago than today, yet we had much warmer weather for a relatively long period of time in that location where the stumps were found. If CO2 is this great warming culprit, how do you explain that? Lower CO2 concentrations yet warmer weather in parts of the Rockies? Odd. Nature doing that all be herself.
Oh my, I realize we now have BOTH George Muir and George Balella to deal with in this thread. It’s like old-home week. Anyway, whether Steve deletes my warnings or not, I know how both of you two operate and if he doesn’t want to listen, he’ll just have to learn the hard way.
Comparing 20th century records post-hoc (after the fact that a trend has been observed) to much earlier times, is, statistically, alot like the baseball fan who calculates batting averages by selecting his time frame to exaggerate the point that a hitter is batting anomalously poorly or well.
In fact there is a statistical cure to this problem:
Casella, G. and Berger, R. (1993), “Estimation With Selected Binomial Information or Do You Really believe that Dave Winfield is Batting .471?”, Journal of the American Statistical Association, 89, 1080-1090.
Now apply these methods to the 20th century warming trend vs. the one that led up to the MWP, and you will have a fair comparison.
Inferencing on the basis of stochastic time-series is a very tricky business, as any stock broker knows.
More importantly we are near the top of a peak in temperatures that started approx. 16,000 years ago, as per the link you posted the other day. meaning if we were not at the top of that natural peak, we could be as much as 12 degrees cooler than we are now, with the temprature 4000 years ago being warmer (Depending on which side of the natural cyucle we were on).
More importantly when we see a natural cycle that seems to be varrying greater than 13 degrees, I don’t see where less than a degree in a century is a big deal.
Alls I can say is, thank Jeff it’s getting warmer and not cooler.
Muirgeo:
Ya got any PROOF for this statement?
I don’t know. Last week it was ~75 in the morning and went to the 90s in the afternoon.
That’s like 15 degrees in a few hours.
SO certainly we have seen a greater rate of change.
TO which Muirgeo/Gembella will so “Over a century” Since we only have accurate data for one century out of 450 million centuries, give or take, it’s hard to make the comparison.
Hey anyone seen the Penguin Army video? Hilarous.
But no paleoclimatologist seems to know. They assume that everything contains a “signal”. Can you imagine anybody on the Team going in to Goldman Sachs with their little systems applied to the stock market?
The stock market image is important because that’s my starting point. One of the things that frustrated me about the NAS panel was NAS’ refusal to include someone with this perspective in the panel – relying on two fellow travellers like Nychka and Bloomfield to provide statistical input. In fairness, their conclusions were far more sensible than IPCC, but the report could have been so much better with a panelist with a different perspective.
re 18:
George you don’t have a clue about geological processes. The tree stumps emerged from the sides of the glacial valley where stata were eroded by the carving of the glacier and the subsequent collapse of the steep slope.
It’s an apples & oranges comparison, and so may be unfair, but … I think engineers & stockbrokers take uncertainty & error far more seriously than do paleoclimatologists.
Re# 36
And that’s significant why??? They’ve still been under a glacier until this recent unprecdented warming of over 4000 years uncovered them. It’s all very Mannian in its implications.
#38,
If it was at least this warm 4000 yrs ago, todays warming is not “unprecedented”. It is normal climate variation.
This deserves repeating:
Current deglaciation tells us nothing about the temp now vs any other period. Glaciers advance and retreat. Glaciers can advance during a warming trend, and retreat during a cooling trend. Their position is the integration of all climates up to the present, not the climate at any particular time – including the present.
RE: “My interpretation, the obvious interpretation, is that the current warmth has not been exceeded in over 4,000 years. ”
I am glad you don’t work for me. Sad excuses for attempted logic like this drive me nuts. Lack of critical thinking drives me nuts. I have no tolerance for such failings!
RE: #32 – “More importantly we are near the top of a peak in temperatures that started approx. 16,000 years ago” – and if one were to envisage the semi period glacial/interglacial “waveform” as something approaching a square wave, with the “top” only slightly rising in time, that is truly frightening. Here we sit, with Rome figuratively burning (or in this case, getting ready to freeze) playing our lyre known as “the AGW debate,” all the while, nature is truly getting ready to throw us a real curve ball. Instead of worrying about home insurance in the tectonically sinking Atlantic coastal areas, we ought to be asking ourselves “what will be our contingency plan for when the interglacial ends?”
RE: #40 – I’ve always got a liking of calculus applied to glaciers! Well put!
I don’t know. But if we start to see evidence, all of the Usual suspects on the warmer side are not going to say “Burn more fossil fuels to warm the earth”
RE: #44 – at the risk of generating significant ire from the “Green” legions, I would argue that the moment Man started to worry TOO much about the environment is the moment we started to stall in our progress. I believe we were meant to manage and meant to colonize other worlds. Self limiting, as the Greens would have us do, will cause us to actually crash, and revert back to a hunter gatherer existence, worshipping rocks and sticks and having no ability to forestall nature’s wrath. Rest assured, I beleive the countermeasures against contamination and other excesses put in place over the past 100 years were much needed. But to adopt, as the Greens want to, self imposed slowing of technological progress and scarcity in energy dissipation, is suicidal. The real solution to the next interglacial and many other woes is to give into our frontier spirit. Having settled the earth, now we must turn toward the stars. Eventually, the earth would be to the galaxy as “Old Europe” is the the Western World. A preserve of culture and history.
#43. You actually need a little calculus to model glaciers. At the summit, the width of the annual layers decrease over time more or less as negative exponential. To make this happen, some percentage of each layer is “extruded” downslope. In equilibrium at the summit, the annual accumulation would be matched by downslope extrusion. Accordingly you get a type of very slow movement in the glacier itself as the “extruded” ice moves downslope with other extruded material and the ice delivered to the forefield each year in equilibrium would be a type of integral.
I don’t believe that actually. Except for some rare cases (like concrete) man doesn’t loose technology. So long as there are survivors in any “crash” we can rebuild any particuarly technology. The amount of left over stuff will id in that. FOr instance I don’t know how to build a catalytic cracker, but I’m sure given acess to literature and a non-working system, I’m sure it could be figured out.
I’m not sure travel to the stars is even possible, in any real time frame.
Re #43
The paleoecologists make a similar error all the time when looking for relationships between past insect outbreaks and weather. A favourable growing season for an insect population X leads to population *increase* (i.e. dX/dt), not a certan population *level*, Xt. Weather in year t should correlate with dX/dt, not Xt.
.. and so insect populations, like glaciers, are often “out of equilibrium” with their environment.
Is there anything in the natural world that ever is in equilibrium ?
RE #50,
NO.
Re #35: I think you’d agree, Steve, that we need to start getting econometricians involved. The Frequency Domain approach to TS analysis is old and pretty crude – they shouldn’t be treating climate trends as signals. Climate Science is divorced from the statistical community and the statisticians they rely on, when they listen to statisticians at all, are “insiders” who have not kept current themselves.
On the John Muir page I linked to above: Just scroll down to the “Illustrations” page. The photo I mentioned is titled “Ruins of a Buried Forest, East Side of Muir Glacier”. What I thought was interesting in reading Muir’s book was that he seemed to have no doubt that most of the glaciers he was seeing were in a long-term retreat, even though his trips fell at the end or just after the end of the little ice age.
As to the impact of sheep. They can have dramatic impacts on trees at relatively high elevations, but at least in Utah where I work the most dramatically affected species are the aspen which are a short lived species (speaking of individual stems, not the clone as a whole). Many aspen clones expanded when sheep grazing first began to be controlled by the Forest Service in the early 1900s. I would expect that high-elevation conifers like bristlecones would not be heavily affected, except in recruitment of new seedlings. This is because sheep will browse conifers (though they are not preffered fare), but are too short to really impact all but the smallest trees – once the leader (topmost stem) is out of their reach the tree is basically home free. The period (approx 1850 – 1930) when huge sheep herds compteted for forage in the western US was relatively short in relation to the lifespan of these trees.
#44,
Sounds like the theme from the Rush album Hemispheres.
BTW,
I doubt anyone did (I certainly didn’t), but 60 minutes had a segment on global warming yesterday. They showed a promo that said something to the effect…”You’ve heard about global warming…Now, you’re going to see it”, followed by images of a piece of ice breaking off an iceberg and falling into the ocean. If it wasn’t so pathetic, it would have been funny.
Unforunately, that’s part of the danger of bad science. The majority of the public is easily misled and watching that kind of tripe only leads them further down the path. Heck, even Pat Robertson now proclaims we must do something about global warming because it’s been hot this summer. News flash Pat…It’s hot every summer. Some are just hotter than others. Despite the exceptional drought we’ve been suffering in N TX, it’s been less hot this year than in 98, 2000, and 2002. Why do people not understand that weather != climate.
Update on the Muir Glacier info. Muir mentions fossil wood and the buried forest in chapter XVII. In the following chapter he mentions that he scrounged up enough fossil wood to brew tea.
If someone has access to JSTOR this article looks to be an interesting read: http://links.jstor.org/sici?sici=0012-9658%28192304%294%3A2%3C93%3ATREHOG%3E2.0.CO%3B2-N&size=LARGE
#42 Pardon my dumb question: what causes the next ice age? Is there any agreement on this?
And please don’t say, “George Bush”…
Wiki Milankovitch cycle.
re 38:
George look at the map. The stumps are on the side of the glacier. If it were under the glacier the soil would have been buldozed away.
Re # 60
Hans that’s conjecture. My point would be they should have been bulldozed away. The fact that the weren’t ALONG with the fact that no MWP stumps are around suggest the ice has never retreated past this point in over 3,800 years.
RE #40
Yeah and up is down and down is up depending on if you live in the US or China. And thermometers could mean its cooling when really its warming but you never know because because becuase…were off to see the wizard the woderful wizard of ozzzzzzzzzzzzzzzzzzzzzzzz…….
Re # 39
So when my patient comes in with a 108 F temperature I’ll tell them not to worry its all normal variation because there once was a prince in Eygpt who had the same degree of temperature 4,000 years ago.
And if the temperatue of the Earth rises by 200 degrees …..not too worry…NORMAL VARIATION!!
#64 :
For your education. Please read the whole thing before posting again. You are angry and scared for no reason at all at the moment.
Title:
Sudden climate transitions during the Quaternary
Quote “The event at 8200 ka is the most striking sudden cooling event during the Holocene, giving widespread cool, dry conditions lasting perhaps 200 years before a rapid return to
—climates warmer and generally moister than the present–
This event is clearly detectable in the Greenland ice cores, where the cooling seems to have been about half-way as severe as the Younger Dryas-to-Holocene difference (Alley et al., 1997; Mayewski et al., 1997). No detailed assessment of the speed of change involved seems to have been made within the literature (though it should be possible to make such assessments from the ice core record), but the short duration of these events at least suggests changes that took only a few decades or less to occur. Coeval records from North Africa across Southern Asia, show markedly more arid conditions involving a failiure of the summer monsoon rains. Cold and/or aridity also seems to have hit northernmost South America, eastern North America and parts of NW Europe (Alley et al., 1997). Thinking of our densely populated present-day world, we can only hope that no similar event occurs in the near future. Smaller, but also sudden and widespread, changes to drier or moister conditions have also been noted for many parts of the world for the second half of the Holocene, since about 5,000 years ago (e.g., Dorale et al., 1992). One fairly strong arid event occurred about 4,000 years ago across northern Africa and southern Asia. It remains to be seen whether these later events will eventually fit into a consistant global 1500-year pattern of cold/arid events, the last of which may have been the Little Ice Age which ended about 350 years ago.
http://tinyurl.com/oywgk
#63 You don’t understand time or geology. 4000 years is not very much time at all considering the earths climate has been undergoing relatively dramatic shifts over the last 3 million years or so. The earths climate is not a medical patient, DUH. the analogy is rediculous, the earth can not get “sick”, geeeezzz. Re-read the temperature flux through the Holocene alone, then move back in time through the Quarternary and then make your way back into the Late Pliocene, then leave.
#63. RE correct me if I am mistaken, but I am pretty sure humanity was here on earth doing just fine 4000 years ago, with temps as least as warm as today.
Re#63, the prince in Egypt with the 108 degree temp was in deep trouble and probably died considering medical aptitude of the time. The Earth 200 degrees hotter was inhabitable.
Those analogies don’t compare at all to a situation when the Earth was warmer than today and yet perfectly habitable.
#86 that only would be important if the “”prevailing scientific wisdom” was in fact really wise. Note that it is in quotes. Note they didn’t say “prevailing scientific stupidity” they could have just as easily yet they “treated them like human beings” in an inter-office memo. Maybe they want to show “logistical and moral support” to climate change dissenters because they believe these are correct “scientific wisdoms” and they are thinking about the well being of many more people then “the previaling scientific” consensus usually does.
Show me this prevailing scientific wisdom, why it is wise, and why you believe it to be so.
Sort of like, “We must get rid of the medieval warm period”…or was it someone else who said that? Hmmmmm…
I also must have missed the movie Exxon and the rest of the evil oil companies did with funding that must have made Al Gore’s “An Inconvenient Truth” look like it was made with spare change. Can someone tell me what it was called so that I can go to Blockbuster and rent it? I must be the only one who hasn’t seen it.
RE# 80
Yes…maybe…but what you need to consider is the implications of said geological facts for society and the future. Stating climate change is “normal” denies the risk benefit analysis of a stable climate versus one that may well be changing more dramatically then anything since the dawn of civilization.
It’s a silly fatalistic attitude kinda like saying measles is a normal disease so why get vaccinated, kids drown in pools so why put up fences, houses catch on fire so don’t worry about stacking your old newspapers next to the furnance….come on now….
muirego
Pls do an audit on the following:
“Based on information that indicated a solar activity-induced increase in radiative forcing of 1.3 Wm-2 over the 20th century (by way of cosmic-ray flux reduction), plus the work of others that indicated a globally-averaged solar luminosity increase of approximately 0.4 Wm-2 over the same period, Shaviv calculated an overall and ultimately solar activity-induced warming of 0.47C (1.7 Wm-2 x 0.28C per Wm-2) over the 20th century.
Added to the 0.14C of anthropogenic-induced warming, the calculated total warming of the 20th century thus came to 0.61C, which was noted by Shaviv to be very close to the 0.57C temperature increase that was said by the IPCC to have been observed over the past century.
Consequently, both Shaviv’s and Idso’s analyses, which mesh well with real-world data of both the recent and distant past, suggest that only 15-20% (0.10C/0.57C) of the observed warming of the 20th-century can be attributed to the concomitant rise in the air’s CO2 content.”
–CO2 Science Magazine, 19 July 2006
gballela, the scientific uncertainty is disqueiting. But not nearly as disquieting as the way those uncertainties have been mishandled by the very ones we’re supposed to trust. You have them to blame for this. Persistent obfuscation has brought us where we are today.
Unfortunately, my friend, you can not reduce these uncertainties without discussing them, sorting them out, building models, and making new measurements. This is not laymen’s work. It is complicated.
Finally, suppose, as you do, AGW is a problem. Do you want to be placated with a band-aid, so that the annoyingly complex discussion will go away? Or do you want to know the real magnitude of the problem? Science is your solution, my friend. Wish that it were not so complex.
#83, I worked for a Automotive R&D company (new car testing) in the 90’s that tested those cars for normal use in a So. California typical commute or on a typical daily route. They were great for tottling around malibu so to speak, or ok around a neighborhood, however they ran out of juice in traffic commutes on freeways.
Our office was 20 miles from the GM plant and you had to take the 405 freeway north in California to get to our facility. They wouldn’t make it if there was any kind of bottle neck from an accident or just heavy bumper to bumber traffic on the freeway. Whomever you want to blame or fault conspiracy on to feel good about what you think you know, you should also know the cars sucked in reality of real world testing.
I think the new hybrids are a way better effort.
oops I posted in the wrong place . sheesh
Where were you spposed to post it> Are you taking about the EV1? Knew some guys that were big into that, met a few times with the EV club in Atlanta, GOt to drive a Corbin Sparrow EV. The guy that owned that drove an EV1 From Cali to Florida.
Of course to do so he had to beg people to let him plug it into their dryer power.
Re # 71
Charles,
I could be wrong but I belive this part,
Based on information that indicated a solar activity-induced increase in radiative forcing of 1.3 Wm-2 over the 20th century (by way of cosmic-ray flux reduction),
Re # 72
What uncertainty?
-CO2 is a GHG
-It’s levels are higher then they’ve been in 500,000+ years
-A correlation between CO2 and global temprartures is consistently documented in the ice core records
– best evidence shows maximal late Holocene vaiability at 1 C over 500 years
– current trends suggest 3 C of climate change over 100 years not unlikely
There is some certainty sure…but the above evidence based claims can not be discounted out of hand and if true suggest a very serious situation.
#79 Re Not true to both statements
“A correlation between CO2 and global temprartures is consistently documented in the ice core records” and “current trends suggest 3 C of climate change over 100 years not unlikely”.
The 2nd statement is from really bad GCM’s, common ego, they have all been discredited.
I don’t wish to encourage talk about cars, but hybrids have been used in big mining industry trucks for probably more than 30 years.
RE: #65 – (sarcasm)Oh, how dare you claim that the earth can not get “sick”! Don’t you know? The earth is ALIVE! The earth is GEYE-YEEEE-YAH! GEYE-YEEE-YAH, ALL HAIL GEYE-YEEE-YAH! Let us sacrifice on the altar of GEYE-YEEEE-YAH!!!(/sarcasm)
muirgeo,
If you don’t know what uncertainty I’m referring to, you may want to go back and read my posts. Just about every one of them is on uncertainty. It’s a problem. No, it’s THE problem.
Steve
Done for reasons of Torque, as wel as efficiency, electric motors provide excelent low speed Torque. When you think of it the same technology has been used in trains since the 20’s. Efficiency comes from running the diesel engines at ideal speed, buffering power requirements with batteries.
I’ve had a thought today about a diesel generator that also provides heating (via waste heat). Done right it could probably be economical.
As soon As Exxon sends me the next multi million dollar check I’ll sink it into developement.
Re# 81
What a stunning revelation bender. You mean climate science is not an exact science?
No, my dear friend, that would be understating the problem somewhat.
Re #64: The concluding paragraph of the linked article’s introduction:
“Sudden stepwise instability is also a disturbing scenario to be borne in mind when considering the effects that humans might have on the climate system through adding greenhouse gases. Judging by what we see from the past, conditions might gradually be building up to a ‘break point’ at which a dramatic change in the climate system will occur over just a decade or two, as a result of a seemingly innocuous trigger. It is the evidence for dramatic past changes on the timescale of centuries to decades which will be the subject of this review.”
And this is supposed to be reassuring in what way?
re 61:
here is a picture of the glacier in 1964 taken from this url
The area in red is the region of the paleosol with the tree stumps, this area was likely not covered by ice since the last ice age. Also very prominent is the split tongue, due to two source areas.
A previous poster claimed that glacier advances and retreats mean nothing. I don’t see how such movements could be irrelevant.
The way I think it must work is that in periods of global cooling the majority of glaciers will advance and when it warms the majority will recede. I certainly can accept that a particular glacier might advance during a warming period and another might retreat in a cooling period. That would only mean that we would need measurements from many sites. These statements seem almost tautological – we have more ice in an ice age.
It may be that any one glacier produces an anolmalous signal but if similar signals show up from many other glaciers the force of the argument takes on weight.
My first question is then: Is this one glacier anomalous?
The answer at least from anecdotal evidence presented here seems to be no – 4000 year old stumps are said to be common.
If these stumps are above today’s tree line then this would seem to be evidence that it was warmer 4000 years ago than it is today. However if they are below the present day tree line, I’m not sure what it means.
So my second question is: Are the ancient stumps above or below today’s tree line?
One of the posters above seems to be ideologically aligned with an antropogenic warming perspective. He takes comfort in the observation that although there are 4000 year old stumps there aren’t any 1000 year old stumps. If this is true at all receding glacier sites that would indeed be evidence that there was no Midieval Warm Period (MWP) but it would not bear on a Neolithic Warm Period (NWP). However evidence has been presented that 1000 year old stumps have been found.
My third question is are 1000 year old stumps near the base of receding glaciers common or rare or unknown?
Finally I observe that all sides seem to agree that there was a NWP. Mann made claims about the non-existence of the MWP not the NWP. The political importance of Mann’s theories rests on the assertion that the present day climate is unprecedented. So even if this glacier provided evidence against the MWP that would support Mann’s MBP98 conclusions, by providing evidence for a NWP it would seem to demolish the claim that the present day climate is unique.
#86. Hans, that’s a really inteesting URL. can you tell what the approximate distance is currently between the treeline and the glacier, measured up-down valley – it looks like it’s at least a km or so, maybe more?
The MWP in the Rockies would not have been as warm as the pre-Neoglacial around 4000 BP. For example, the bristlecone treeline was much higher around 4000 BP. One could readily picture a situation where the glacier receded in the MWP further than the present recession without the treeline advancing to the pre-Neoglacial position. Indeed, that would even seem probable.
#87. The position of the Team is that the Holocene Optimum (your NWP) is a regional effect – just like their MWP theory – and/or that it is explained by Milankowitch effects. It’s an interesting issue as well and is a big job to survey in useful detail.
#86. Hans, why do you think that the area in red wasn’t covered by ice in the maximum LIA expansion?
Steve, I would need a detailed map, here is another url
Glacier Flow Measurements with ERS Tandem Mission Data
Ian Cumming and Juan-Luis Valero Paris Vachon, Karim Mattar,
Dirk Geudtner and Laurence Gray
Abstract
Glacier flow measurements have provided one of the more striking applications of differential satellite SAR interferometry. In this paper, we summarize some results we have obtained on the Saskatchewan Glacier in the Columbia Icefield in the Rocky Mountains of western Canada.
re 90: The paleosol would have been bulldozed away by the ice. The trees are in growth position. Reminds me of the petrified forest in Belgium where I was two weeks ago (BTW Ferdinand says hi).
ref
The in situ Glyptostroboxylon forest of Hoegaarden (Belgium) at the Initial Eocene Thermal Maximum (55 Ma)
Review of Palaeobotany and Palynology, Volume 126, Issues 1-2, September 2003, Pages 103-129
M. Fairon-Demaret, E. Steurbaut, F. Damblon, C. Dupuis, T. Smith and P. Gerrienne
There’s really quite a substantial literature about glacier changes that’s pretty interesting anh might actually shed some light on past climate changes. Glacier changes were very much on the minds of Lamb, Bryson and pre-Hockey Team paleoclimatologists, but seem to have really dropped off the table in Hockey Team literature until very recently. I wonder why.
For the two Georges, who wer worrying about whether glaciers had overrun MWP forests in the Rockies, here’s the abstract from Luckman [Clim Chg 1993] “Evidence for climatic conditions between CA. 900-1300 A.D. in the southern canadian rockies”
RE: #35
an early investigator of the lunar nodal drought rhythm in the western U.S [based on tree-rings!] is said to have left science and did just that: went to Wall St and made a killing. R.G. currie, i believe, is this person.
Currie, R. G., 1981: Evidence for 18.6 year MN signal in temperature and drought conditions in North America since A.D. 1800. J. Geophys. Res., 86, 11055–11064.
“¢’¬?”¢’¬?, 1984a: Evidence for 18.6-year lunar nodal drought in western North America during the past millennium. J. Geophys. Res., 89, 1295–1308.
“¢’¬?”¢’¬?, 1984b: Periodic (18.6-year) and cyclic (11-year) induced drought and flood in western North America. J. Geophys. Res., 89, 7215–7230.
The glacier is also in google earth
52° 9’18.95″N 117°10’9.82″W
and here is a map
RE #87
Its quite simple. A glacier snout at the same point at different times can occur under totally different climates. The glacier may be advancing (cold) retreating (warm) or stable (mild). In the case of the Saskatchewan Glacier it is currently retreating, at the time these trees were covered it was advancing and therefore colder than now. (though it seems the ice may never have actually covered them, rather they were buried by outwash.)
Re number 86. Hi Hans. I’m afraid I disagree with you. First, the site sits within what seems to be a well-developed trimline (probably of LIA) age. Second, it doesn’t look like a split tongue, just a medial moraine with loads of supraglacial debris at the snout.
Re # 66
Correct me if I’m wrong but isn’t the paleo-evidence replete with major effects of rapid climate change on past civilizations.
RE # 98
Ditto.
Why is the assumption that glaciers retreat in warm and advance in cold.
Isn’t precepitation mush more important to a gaciers mass. Certainly a certain level of temprature is important as well. But snowfall is going to be more important, I would think.
#99 What is your point gbalella? Climate changes have advantages and disadvantages to humans and animals? Your #63 and 64 is contributing to what part of the dissucussion here?, and #66 responded to it trying to make sense of it, now you are agreeing with natural rapid climate change in #99? Or are you not agreeing?
I think gbalella et al. are trying to have it both ways. i.e. Natural rapid climate change is a powerful force to be feared TODAY, but not so powerful as being capable of producing unprecedented warming during the MWP. Has that got it, gbalella? Because if so …
#103 a flip-flop?
Bender, I also think maybe gballella reads this sentence: “I am pretty sure humanity was here on earth doing just fine 4000 years ago” different then the majority of us do? Is that true gballella? I get that from your #63 and then what you say in #99.
I read it as “4000 years ago humans were surviving”
Is that the thing? All this at a time when humans are surviving better then they ever have (if you look at statistics!); against all odds; throughout Earth history, we have to be afraid?
Re # 104
Humans were also “surviving” 20,000 years ago. I don’t fancy that climate much though.
RE#99
NO. Most of the civilizations that have ended in disaster did so via either volcanism, earthquake/subsidence/inundation/tsunami. I have only heard of a couple that ended due to drought.
#105 Paul yeah, I’ve read much James Michener or the even “Clan of the Cave Bear” series when I was younger to have a healthy and complete “what I fancy and what I do not” opinion of survival conditions! 😉
#106 Dane, weren’t droughts brought on mostly by the water on earth being frozen up during the little or big ice ages, not because of warming conditions? Not alot of vegetation grows in cold either. Thinking of times during Eqyptian Empires here about the droughts; I might be completly wrong though. Sorry if we are going off topic!
re 98:
Hi Stephan, Indeed looking more carefully with google earth my red area is a side moraine. Which makes it odd how a paleosol (figure 2) can survive so unharmed in a moraine. If I interpret figure 1 correctly, the stumps are located where the 1900 meter elevation line meets the glacier. Here is an enlargement of the Cumming map:
RE 105:
Paul G, I wouldn’t particularly either. It was cold w/extreme variability & generally much drier (a big tract of the SW US is one exception, tho). Amazon rainforests shrank & fragmented, much becoming savanna. Central America was much drier — parts almost semiarid. The Sahara desert was as big as ever. Global bioproductively must drop considerably during ice-ages (there are always regional exceptions, of course).
Maryland was a cold-steppe climate w/scattered boreal-like forests in the moister/sheltered spots. Those reminents survive today at the top of the highest Appalachian peaks. During the glacial recession, they gradually moved upward & northward (and were eventually pushed off the top of most mountains — localized extinction). Frazer and Balsam fir, Red & Black spruce, Tamarack are examples.
Re 108. Hi Hans.
Even quite delicate structures can survive under active and temperate glaciers. I’m not surprised that in situ trees and palaeosols had survived.