New peer reviewed paper says "there appear to have been periods of ice free summers in the central Arctic Ocean" in the early Holocene, about 10-11,000 years ago

What an ice free Arctic might look like from space

We all know how much NSIDC’s Dr. Mark Serreze has been touting the idea of the “Arctic death spiral“,  and we’ve had predictions of ice free summers in 2008, 2013, 2015, 2020, 2030, 2040, 2050, 2060, 2070, and 2100 to name a few. Other forecasts don’t give specific dates but say things like within 5 years10 years, 20 years, 30 years, 100 years, decades, and sooner than expected. Such “all over the road forecast certainty” doesn’t really build any confidence that any of these climate soothsayers have any idea when or even if the Arctic will be “ice free” in the summer in the next 100 years.

Now, inconveniently, we have this new paper via ScienceDirect New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling which says that their studies show that the early Holocene might very well have had ice free summers. This is interesting, because as this generally well accepted graph shows, temperature was higher then. But there’s more.

File:Holocene Temperature Variations.png

From the description for this graphic: The main figure shows eight records of local temperature variability on multi-centennial scales throughout the course of the Holocene, and an average of these (thick dark line). (to 10000 BC-2000CE (from 0 — 12000 BP)) The records are plotted with respect to the mid 20th century average temperature, and the global average temperature in 2004 is indicated. An inset plot compares the most recent two millennia of the average to other recent reconstructions. At the far right of this plot it is possible to observe the emergence of climate from the last glacial period of the current ice age. During the Holocene itself, there is general scientific agreement that temperatures on the average have been quite stable compared to fluctuations during the preceding glacial period. The above average curve supports this belief. However, there is a slightly warmer period in the middle which might be identified with the proposed Holocene climatic optimum. The magnitude and nature of this warm event is disputed, and it may have been largely limited to high northern latitudes.

But, the other rub of the early Holocene is CO2 in the atmosphere. We know from ice core records that CO2 concentration has varied with ice ages.  Coming out of the last ice age into the Holocene, we know that atmospheric CO2 concentrations rose as CO2 came out of the oceans as they warmed. This graph from the American Association for the Advancement of Science (AAAS) shows that the early Holocene (~10,000 years before present), had a rise coming out of the ice age and then had CO2 concentrations stabilize lower than that of today, about 260-270 ppm:

Figure 1. Top: One sigma-calibrated age ranges for the 14C control points 1, 2 and 6 as an indicator of the possible age range of the CO2 record reconstructed from stomatal frequency. The labels are the same as in Wagner et al. (1). Center and Bottom: Atmospheric CO2 concentration reconstructed from stomatal index (bullet ) (1) and direct measurements of CO2 concentration of air enclosed in bubbles in the ice cores from Taylor Dome (lozenge ) (3, 4) and Vostok (square ) (7, 8).

This new paper in the journal Quaternary Science Reviews throws a formidable monkey wrench into the the theory that CO2 induced warming is the cause of current Arctic ice loss. Because if we had ice free summers ten thousand years ago at ~ 260 ppm CO2, and we had warmer temperatures than today, we can’t then conclude that an additional 100 ppm of CO2 since then would be the cause of an ice free summer in the Arctic today. And ice free summer at lower CO2 and higher temperature is an incongruity with today’s theory of the “Arctic Death Spiral”.

Here’s the paper abstract:

About this Journal

Quaternary Science Reviews

New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling

Martin Jakobssona, , , Antony Longb, Ólafur Ingólfssonc, Kurt H. Kjærd and Robert F. Spielhagene

a Department of Geological Sciences, Stockholm University, 106 91 Stockholm, Sweden

b Department of Geography, Durham University, Science Site, South Road, Durham DH1 3LE, UK

c Faculty of Earth Sciences, University of Iceland, Is-101 Reykjavik, Iceland

d Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen, Denmark

e Academy of Sciences, Humanities and Literature, Mainz, and Leibniz Institute of Marine Sciences, IFM-GEOMAR, Wischhofstr. 1-3, D-24148 Kiel, Germany

Accepted 26 August 2010.
Available online 2 October 2010.

Abstract

Terrestrial and marine geological archives in the Arctic contain information on environmental change through Quaternary interglacial–glacial cycles. The Arctic Palaeoclimate and its Extremes (APEX) scientific network aims to better understand the magnitude and frequency of past Arctic climate variability, with focus on the “extreme” versus the “normal” conditions of the climate system. One important motivation for studying the amplitude of past natural environmental changes in the Arctic is to better understand the role of this region in a global perspective and provide base-line conditions against which to explore potential future changes in Arctic climate under scenarios of global warming. In this review we identify several areas that are distinct to the present programme and highlight some recent advances presented in this special issue concerning Arctic palaeo-records and natural variability, including spatial and temporal variability of the Greenland Ice Sheet, Arctic Ocean sediment stratigraphy, past ice shelves and marginal marine ice sheets, and the Cenozoic history of Arctic Ocean sea ice in general and Holocene oscillations in sea ice concentrations in particular. The combined sea ice data suggest that the seasonal Arctic sea ice cover was strongly reduced during most of the early Holocene and there appear to have been periods of ice free summers in the central Arctic Ocean. This has important consequences for our understanding of the recent trend of declining sea ice, and calls for further research on causal links between Arctic climate and sea ice.

~~~~~~~~~~~~~~~~~~~~~~~~~~

Thumbnail image

Fig. 1. Map showing the locations of some of the studies included in the papers presented in this special issue. Numbers refer to Table 1, which contains the references to the respective study. Some of the papers on the Arctic Ocean involve sediment cores from a large spatial area; these are only plotted with boxes enclosing the areas of the studied cores. Furthermore, Cronin et al. (2010) analyzed sediment cores from virtually the entire central Arctic Ocean and, therefore, there is no number representing that study on the map. The maximum extensions of the Eurasian Ice Sheet during the late Quaternary compiled by the QUEEN project (Svendsen et al., 2004) are shown. LS: Late Saalian (>140 ka), EW: Early Weichselian (100–80 ka), MW: Middle Weichselian (60–50 ka), LGM: Late Weichselian (25–15 ka). The speculative extent of an MIS 6 ice shelf inferred by Jakobsson et al. (2010) is shown by the hatched area enclosed by a gray stippled line. The approximate spatial minimum cover of sea ice during 2007 is shown with a white shaded area enclosed by a black stippled line as a comparison to the median extension for the period 1979–2005 shown by a blue stippled line (Data is from National Snow and Ice Data Center). MJR: Morris Jesup Rise; YP: Yermak Plateau. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

================================

h/t to WUWT reader “josh”

Addendum: Some follow up graphic from comments, in my response to Richard Telford:

Here’s an interesting plot of solar insolation at 65 degrees north over time. To give readers an idea of this line, here is a map:

65 north line

(Map from WikiMedia) Fairbanks, AK is at 64.5° N

The plot below shows how insolation varied with the Milankovitch cycles at 65° N. I’ve added the deltas comparing 10KYA to present.

Milankovitch insolation forcings

The “Fermi Paradox” blogger who originally made the graph I annotated wrote: The graph shows the insolation in W/m^2 at 65 degrees norther latitude from 20ky before present to 10 ky in the future, calculated with the program insola from J. Laskar et al. The four plots are for the two months after the summer solstice and the two months before. It can be seen that the change in insolation over time is quite significant. Note though that this only applies at high latitudes – the global mean barely changes at all.

Note the magnitude of the change in insolation from 10K years ago to present, from 15 to 40 Watts/m2

Now look at this image from NOAA’ s Environmental Research Laboratory (ESRL):

GHG and other forcings

CO2 accounts for 1.4 Watts/m2 of forcing in the last 150 years, so compared to the forcings of the Milankovitch cycles (at least at 65N) it is an order of magnitude lower. My point is that given the small impact of CO2 in forcings, it is not likely to be the driver of Arctic ice melt in the present, just like it wasn’t much of a significant factor 10K years ago.

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Dave F

Why couldn’t the phase changes of water lead to different levels of climate stability, overwhelming other constituents in the climate system? If you look at the historical evidence, it seems that in the current continental alignment patterns, when ice is the dominant phase for water, the temperatures are colder (duh, I know) and more variable. When liquid is the dominant phase, temperatures are warmer and less variable.
Without speaking to the quality of samples or appropriateness of proxy, the proxies used in the above graph seem to indicate this as you move out of the ice age. All the gibberish about thirty year trends is nonsense when you look at this information. For instance, whatever the dark red proxy is shows a long term cooling trend. So does the cyan colored proxy. Could we really be on a long term cooling trend since the end of the last ice age? No, but interesting that there are two separate proxies that show this.
Still, the amount of ice in the hydrological cycle seems pretty important to the climate. This is one reason why I think Hansen’s attempts at deriving climate sensitivity from the LGM are useless in a largely ice free Holocene.
Yet another thing to consider is the log effect of LW absorption CO2 has. Look at the fast rise in the black line, which released large amounts of CO2 from the ocean. On that point, I haven’t heard much quibble from proponents. Why wouldn’t water vapor have amplified that more so than it would now? Despite the large releases of CO2, the climate largely stabilized when the transition from ice-dominant to vapor-dominant completed. Could it be that water vapor is a stabilizing force in our atmosphere and that as we move away from the sun, evaporation will lessen and renew the importance of CO2 in the atmosphere? For a little while at least…

Northern Exposure

Oh dear, oh me, oh my…
This paper is going to be tarred and feathered over at the Not-So-Real Climate website.
Can’t wait to read their pseudoscience rebuttals and he-man chest poundings in 3…2…1…

Dave F

Additional thought to my last paragraph:
When that black line takes off to the sky, it reaches a point where water vapor begins to coalesce into clouds. Is there any proof of the frequency of clouds in the paleo-climactic records? Or that they even existed? That may sound silly, but I think that it is an important point to consider.

HaroldW

I must protest against the phrase “climate solons.” Solon means a legislator, and I certainly don’t want Hansen et al. making my laws.
REPLY: I meant to say “soothsayers” but instead wrote “solons” for some reason. Fixed, thanks – A

Michael

But doesn’t this mean someone could have made millions of dollars shipping goods through the North West Passage at the time of the ice free conditions? If only I could have been alive at the time. I could have been a billionaire then, by cornering the market in NWP shipping.

I just want to make sure I understand the point of the post.
In the early Holocene temperatures were higher than they are now and there is evidence to suggest that there may have been summers where the central Artic Ocean was completely ice free.
Yet CO2 was lower then that it is now
So therefore we cannot conclude that the dramatic increase in CO2 concentrations in the atmosphere in the past 150 years that is a direct result of human activity is one of the principal drivers in the current warming trend?
Did I get that right?
Cause its my understanding that there can be factors that drive global temperatures other than CO2 concentration and perhaps those other factors were in play 10000 years ago.
I don’t know of any Climate Scientist that claims that they can tell you what the global average surfact temperature might be based purely on knowing the concentration of CO2 in the atmosphere.
The science behind Global Warming/Climate Change, as I understand it, concludes that when you look at all the factors that might drive global temperatures, the factor that is driving temperature right now is CO2. I don’t think that they conclude that it was always the major forcing factor.
So how does this research fundamentally challenge the basic conclusions of Climate Change/Global Warming?
REPLY: Why should we bother to try explaining it, you will simply say These People are Nuts

Dave F

Additionally (or P.P.S, lol) when considering the phase changes of water, consider the evaporation of water. If ice melts, we experience runoff, evaporation, pooling, geological changes in mineral deposits, and a whole host of things. runoff, evaporation, and pooling are the important ones. As the ice melts, some water evaporates, some runs to the sea, and some will pool in various areas for various reasons. Water that has pooled will continue evaporating. Water that has runoff cannot. Water that has evaporated cannot. As the Earth loses water to runoff and evaporation, the atmosphere will become drier and lose water vapor. eventually, the clock runs out, and the atmosphere loses the necessary amount for Earth to become an extremely cold place to live, halting most evaporation processes. On our way away from the Sun wrt Milankovitch. Just an additional thought. I think that the hydrological cycle is much more important than climate scientists have considered. The key piece being evaporation, because evaporation is work performed by he energy in Earth’s climate.

“The science behind Global Warming/Climate Change,….”
Whoa! science, what science Uncle Walt?
Manmade global warming is Swiss Cheese Science – Full of holes that we’re supposed to not notice and not comment on. And if we do, we’re the unhinged ones!
That sounds like a winning strategy. How’s that working these days?
It seems more like a political crusade with the added side benefit of claiming “I saved the planet!”
If you want to do something useful Uncle Walt, you can help promote these two efforts.
http://www.lutw.org/
http://www.samaritanspurse.ca/ourwork/water/default.aspx

crosspatch

One thing we need to keep in mind is our perspective of arctic sea ice. The LIA lasted, give or take from roughly 1300 to 1850. This was *the coldest* period of the Holocene since the Younger Dryas.
How many accurate descriptions of Arctic ice conditions do we have prior to the 14th century? Our good documentation of Arctic ice conditions begins in the middle of the LIA. We are probably *still* recovering from that event. That event lasted long enough that it would be rational for many people to consider that condition to be “normal” If a certain place had sea ice for 300 years and now in the past 100 has none, and there is no documentation of what the place was like >300 ya then it would be logical to think that some would believe that icy condition was “normal” and today’s conditions are “abnormal” when in fact, we could well be experiencing conditions that are closer to “normal” for the Holocene than they were 200 years ago.

AlanG

The chart looks pretty much like any of the interglacials from the Vostok ice cores – a very rapid rise out of the ice age followed by a slow descent into the next one. We really need a credible explanation as to why this happens. CO2 was never going to explain it. Two separate positive feedback mechanisms are needed to explain the slow decent into, and steep rise out of, an ice age. Any suggestions from anyone?
What I’m considering at the moment is there may be a limit to the maximum possible height of the polar ice sheets. Once they reach a certain height (10,000ft+) then precipitation of new ice stops stops as it’s too high up there to snow. This then stops the removal of water vapor from the polar atmosphere by snowfall. There is always going to be melting at the edges because of the lower latitude and GHG warming from the water vapor and whatever CO2 is in the atmosphere.
Once the precipitation stops then all that remains is the melting from the edges. Evaporation from the melt water maintains the higher humidity and rainfall helps to melt the ice further up. Removal of the edges causes the glaciers to flow more strongly which transports the bulk of the ice to lower latitudes for melting. There you have a possible positive feedback mechanism.
Ice is the ‘great big switch’. It causes a big jump in albedo and a big drop in humidity. The reverse it true when it melts. The binary nature of ice leads to two states – glacial and interglacial. Unfortunately the melted ice from the ice sheets has left no record. If we know (or could model) how they built up and melted, then we might see the two positive feedback mechanisms at work.
Whatever the cause, we are in a bog standard interglacial and the descent to the next one is well under way. CO2 is the minor player. Water vapor is always the main GHG. The Greenland GISP2 temperature chart shows lower highs and lower lows since the end of the Minoan warming so the descent started about 3200 years ago.

anna v

You have taken the wiki page for the first figure, and the data come from
The following data sources were used in constructing the main plot:
1. (dark blue) Sediment core ODP 658, interpreted sea surface temperature, Eastern Tropical Atlantic: M. Zhao, N.A.S. Beveridge, N.J. Shackleton, M. Sarnthein, and G. Eglinton (1995). , Paleoceanography, 10(3): 661-675. doi:10.1029/94PA03354
2. (blue) Vostok ice core, interpreted paleotemperature, Central Antarctica: Petit J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J., Delaygue G., Delmotte M., Kotlyakov V.M., Legrand M., Lipenkov V., Lorius C., Pépin L., Ritz C., Saltzman E., Stievenard M. (1999). , Nature, 399: 429-436. doi:10.1038/20859
3. (light blue) GISP2 ice core, interpreted paleotemperature, Greenland: Alley, R.B. (2000). , Quaternary Science Reviews, 19: 213-226. doi:10.1016/S0277-3791(99)00062-1
4. (green) Kilimanjaro ice core, δ18O, Eastern Central Africa: Thompson, L.G., E. Mosley-Thompson, M.E. Davis, K.A. Henderson, H.H. Brecher, V.S. Zagorodnov, T.A. Mashiotta, P.-N. Lin, V.N. Mikhalenko, D.R. Hardy, and J. Beer (2002). , Science, 298(5593): 589-593. doi:10.1126/science.1073198
5. (yellow) Sediment core PL07-39PC, interpreted sea surface temperature, North Atlantic: Lea, D.W., D.K. Pak, L.C. Peterson, and K.A. Hughen (2003). , Science, 301(5638): 1361-1364. doi:10.1126/science.1088470
6. (orange) Pollen distributions, interpreted temperature, Europe: B.A.S. Davis, S. Brewer, A.C. Stevenson, J. Guiot (2003). , Quaternary Science Reviews, 22: 1701-1716. doi:10.1016/S0277-3791(03)00173-2
7. (red) EPICA ice core, δDeuterium, Central Antarctica: EPICA community members (2004). , Nature, 429(6992): 623-628. doi:10.1038/nature02599
8. (dark red) Composite sediment cores, interpreted sea surface temperature, Western Tropical Pacific: L.D. Stott, K.G. Cannariato, R. Thunell, G.H. Haug, A. Koutavas, and S. Lund (2004). , Nature, 431: 56-59. doi:10.1038/nature02903

I have an objection with averaging proxy temperatures coming from different proxies and different locations.
As we see in the plot , there are much larger variations than the average shows. If each curve, because of the methodology is out of phase or its calibration with temperature is not stable over the years ( as with tree rings, other factors at other times might influence the proxy analogue) averaging them is like mixing cold soup with hot soup.
One should look at the individual curves and how they compare with the present .

a jones

I do not doubt that at warmer periods in the Holocene the Arctic ocean may have been navigable: but for all practical purposes not for the last few hundred years.
What I do find fascinating is the folklore from over a thousand years ago that you could indeed sail across the roof of the world. And that that folklore exists in two separate cultures, the Norse and thus northern European culture BUT also in Chinese culture too.
The legend persists and drove the British to explore the possibility for two hundred years: without success
Legend is just that, we have nothing to show that it was so, but we do know that these two cultures were the first to develop ships, although of very different designs, which were capable of reaching and indeed crossing the Arctic ocean. Just over a thousand years ago.
And that they did explore it: although we have no written records of the result.
Folklore is no reliable guide to the past but often seems to contain more than grain of truth and when two separate cultures which never really met until several hundred years later both tell tales of the same thing that supposedly happened a thousand years ago then perhaps it was really so.
Whatever the Arctic ocean is icebound today: but it might possibly become open to navigation once again nut not in my lifetime I imagine.
Kindest Regards

MikeA

Good to see another post about climate. Are there any useful cross references to sea-level, temperature and climatic conditions at this time? I assume that coming out of an ice age had a cause that was independent of C02, although as you have pointed out, the co2 feedback may well have contributed. The thought had come to my mind that there is a message here about climate sensitivity. If the change in orbit/inclination or whatever that started the change is known. The C02 change is known, so the post-ocean C02 release temperature should give a good indication of climate sensitivity. I think we can forget about arctic ice let’s move on to the next challenge.

nc

Found this-
The Piri Reis map shows the western coast of Africa, the eastern coast of South America, and the northern coast of Antarctica. The northern coastline of Antarctica is perfectly detailed. The most puzzling however is not so much how Piri Reis managed to draw such an accurate map of the Antarctic region 300 years before it was discovered, but that the map shows the coastline under the ice. Geological evidence confirms that the latest date Queen Maud Land could have been charted in an ice-free state is 4000 BC.”
http://www.world-mysteries.com/sar_1.htm

Mike McMillan

If we had thousands of feet of ice over Chicago during the last ice age, is it reasonable to assume the Arctic Ocean was then solid to the bottom (salt water notwithstanding, not that I know)?
The Holocene thaw would then take a while to turn it back into an ocean, thousands of years for it to refill, reconnect with the Pacific, and get settled into a stable body of water with stable circulation patterns. We could easily expect an overshoot in the process that would leave it ice free for a while.

Mike McMillan

anna v says: October 30, 2010 at 11:59 pm
You have taken the wiki page for the first figure, and the data come from
The following data sources were used in constructing the main plot: . . .

You missed the folks at the bottom, emph. mine –
Additional data used in inset plot and for matching temperature scale to modern values. Colors match those used in Image:2000 Year Temperature Comparison.png.
1. (orange 200-1995): P.D. Jones and M.E. Mann (2004). , Reviews of Geophysics, 42: RG2002. doi:10.1029/2003RG000143
2. (red-orange 1500-1980): S. Huang (2004). , Geophys. Res Lett., 31: L13205. doi:10.1029/2004GL019781
3. (red 1-1979): A. Moberg, D.M. Sonechkin, K. Holmgren, N.M. Datsenko and W. Karlén (2005). , Nature, 443: 613-617. doi:10.1038/nature03265
4. (thin black line 1856-2004): Instrumental global annual data set TaveGL2v [2]: P.D. Jones and A. Moberg (2003). , Journal of Climate, 16: 206-223.

MartinGAtkins

bublhead says:
October 30, 2010 at 10:50 pm
The science behind Global Warming/Climate Change, as I understand it, concludes that when you look at all the factors that might drive global temperatures, the factor that is driving temperature right now is CO2. I don’t think that they conclude that it was always the major forcing factor.
There are many instances of “scientists” trying to attribute CO2 to nearly every climate or extinction event throughout history. Here is just one example.

The latter observations strongly suggest that a massive input of 13C-depleted carbon entered the ocean or atmosphere at the start of the PETM. The event has become a focal point of geoscience investigations because it is perhaps the best past analog in which to understand the fate and consequences of current fossil fuel emissions on an intermediate time-scale (>1000 years).

http://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum
If it is not cited as the cause it nearly always attributed as the dominant driver of climate shifts. CO2 is the manic obsession of todays university inspired Marxist science.
Wild swings of CO2 have always been shown to be the result of and not the cause of climate changes and extinctions.
As the article says CO2 has been lower through the Holocene epoch even when temperatures have been much warmer than now.
Why?

richard telford

I am not quite sure how you can write a post about the early Holocene warm period and not mention that orbital (Milankovitch) forcing gave higher summer insolation in the early Holocene. It suggests either that you don’t really understand the issues, or you don’t want your readers to. The conclusions of this paper are entirely reasonable – you will be hard pressed to find any palaeoclimatologists who are surprised that sea ice extent was lower in the early Holocene. When it gets warmer, ice melts. Ice doesn’t particularly care whether it is warm because of high insolation or high CO2 levels.
REPLY: Oh Mr. Telford, anything for denigration as usual. Good to see your MO has not changed. Here’s an interesting plot of solar insolation at 65 degrees north over time. To give readers an idea of this line, here is a map:
65 north line
(Map from WikiMedia) Fairbanks, AK is at 64.5° N
The plot below shows how insolation varied with the Milankovitch cycles at 65° N. I’ve added the deltas comparing 10KYA to present.
Milankovitch insolation forcings
The “Fermi Paradox” blogger who originally made the graph I annotated wrote: The graph shows the insolation in W/m^2 at 65 degrees norther latitude from 20ky before present to 10 ky in the future, calculated with the program insola from J. Laskar et al. The four plots are for the two months after the summer solstice and the two months before. It can be seen that the change in insolation over time is quite significant. Note though that this only applies at high latitudes – the global mean barely changes at all.
Note the magnitude of the change in insolation from 10K years ago to present, from 15 to 40 Watts/m2
Now look at this image from NOAA’ s Environmental Research Laboratory (ESRL):
GHG and other forcings
CO2 accounts for 1.4 Watts/m2 of forcing in the last 150 years, so compared to the forcings of the Milankovitch cycles (at least at 65N) it is an order of magnitude lower. My point is that given the small impact of CO2 in forcings, it is not likely to be the driver of Arctic ice melt in the present, just like it wasn’t much of a significant factor 10K years ago. -Anthony Watts

Thomas

I can only read the abstract, but is this really all that surprising? Variations in the Earth’s orbit will change the amount of sunlight reaching the Arctic in the summer, and we had the last peak around 9000 years ago.
http://www.eoearth.org/article/Milankovitch_cycles
More heat causes melting of the Arctic, and whether this heat comes from Milankovitch cycles or CO2 doesn’t matter, thus the claims that this should somehow contradict that current melting of the Arctic is due to more CO2 is misplaced.

Ralph

What will such a melt period do to the ice deposition on Greenland?
They confidently count ice-rings back into the past, to achieve a geological chronology, but during such a warm period they may be missing a few thousand ice-rings (years).
.

AlanG

I think my post above is agreeing with what Dave F is saying bit I would add albedo to water vapor as another positive feedback. Both act as positive feedback in the descent into, and the exit from, an ice.

Malaga View

John Kehr has an interesting posting on “Climate Sensitivity of the Northern Hemisphere” which indicates that the Milankovitch cycle can increase summer insolation by 11% (50 W/m2) in the Nothern Hemisphere… which is consistent with the Holocene peaking when the Artic has an ice free summer.
Unfortunately we are now on the downward slope… and as John Kehr states in his article: Although change in forcing is slow, it is relentless
http://theinconvenientskeptic.com/2010/10/climate-sensitivity-of-the-northern-hemisphere/
The current interglacial was “triggered” by a change in the orbital parameters of the Earth’s orbit that caused the NH to have a period where the amount of energy it received during the summer increased 11%, or about 50 W/m2. The temperature of the NH changed about 12-14 °C with that change in energy.
…..
While the temperature change is larger for the NH alone, so is the change in solar energy (forcing). Although change in forcing is slow, it is relentless. Every summer, over the course of 10,000 years, gets slightly more energy than the summer before. This results in more and more melting of the ice sheets. Summers 10,000 years ago in the NH received 10% more solar energy than the they do now.
PS
The article is also a really great demonstration of why it is just crazy to construct and monitor Global Averages (even if they were possible)… the North and South have different climate sensitivities… and the Global Average can hide a multitude of sins.

Ian H

The really vital message here is that the arctic can be ice free without triggering any of the conjectured `tipping points’ leading to runaway warming. It suggests that an ice free arctic is something that has happened before and will likely happen again. An ice free arctic is not a disaster.

Malaga View

I also think this is the best Long Term forecast I have seen:
http://theinconvenientskeptic.com/wp-content/uploads/2010/10/Pleistocene-moll_NL-550×275.jpg

Kev-in-UK

Totally agree with anna v; it is illogical and misleading to average proxy temps together.
At best proxy data only gives trends – it cannot realistically give specific temperatures or CO2 contents or whatever other parameter being ‘assessed’.
Hence, to my mind, further averaging proxy data is like averaging the peoples of the world – yep – we are all human – but heck, our cultures are extremely different!

Ian H

Dave F: “As the Earth loses water to runoff and evaporation, the atmosphere will become drier and lose water vapor. eventually, the clock runs out, and the atmosphere loses the necessary amount for Earth to become an extremely cold place to live, halting most evaporation processes. …”

Your comment makes no sense. Run off and evaporation just move water from one part of the planet to another. The planet doesn’t lose water.

dwright

I didn’t read the meat of the article or any of the comments.
I’m happy to bask in the glow of real science starting to peek out of the totalitarian boot heel that describes the last 20 years of academia.
My name is Wright, feel free to call me wrong. I don’t hide from debate.
We all know who does.

Christopher Hanley

The graph comes from Wikipedia which in turn comes from the Global Warming Art project prepared by Robert A. Rohde:
http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png
I’m a layman, not a scientist, but some one who is already seeing his electricity bills soar because of this CAGW nonsense. IMO anything on climate from Wikipedia must be taken ‘cum grano salis’.
At the bottom of the Wiki page is a most important caveat: “Though all of this data is published, and the methodology is similar to previously published methodology, and resulting average is similar to previously published interpretations of the Holocene, even so, no peer reviewed scientific publication has ever combined precisely these data in precisely this way. Hence, any interpretation of that average must be regarded with skepticism”.
I’m always suspicious of Wiki’s “thick dark line[s]” — in this case, as in the ‘hockeystick’, it is meaningless.
How can the average of a bunch of arbitrarily chosen proxy curves mean anything when grafted on to an instrumental series or, in this case, with the current (at the time of preparation) instrumental value stuck on?

Bulbhead
Sorry, you are misinformed, the general belief (by climate scientists) is that climate and Co2 has been relatively stable through the ages until we came along, increased CO2 and changed the climate.
http://www.metoffice.gov.uk/climatechange/policymakers/policy/slowdown.html
Extract “Before the twentieth century, when man-made greenhouse gas emissions really took off, there was an underlying stability to global climate. The temperature varied from year to year, or decade to decade, but stayed within a certain range and averaged out to an approximately steady level.”
tonyb

” bublhead says:”

So how does this research fundamentally challenge the basic conclusions of Climate Change/Global Warming

?
It doesnt.

UK Sceptic

It was farting polar bears and walruses, innit?

Rob R

Sorry I havent read through the comments. But it might pay to save that wikipedia Holocene temp graph for before it meets with a few Wiki edits. One wonders how it has survived intact for so long.

Greenland ice-core dating based on 10Be, the current standard, may be unreliable due to contamination . Even cores from neighbouring boreholes can be vastly different, which may be reason why many of proxies give contradicting results.
I have looked into the recent 10Be data, used by Dr. McCracken for calculating the heliosphere strength, and found that even as recently as Dalton minimum there could be significant errors.
More details available 10Be ? .

TJA

Somebody tell the EPA that the polar bears will be fine. Wait, they don’t care.

Christopher Hanley

If there have been periods of ice free summers in the central Arctic Ocean in the early Holocene, I hazard to suggest that there have been other periods of ice-free summers in more recent times:
http://omniclimate.files.wordpress.com/2009/03/fig01.gif

m white

” bublhead says:”
So how does this research fundamentally challenge the basic conclusions of Climate Change/Global Warming
http://wattsupwiththat.com/2010/10/30/might-arctic-warming-lead-to-catastrophic-methane-releases/
Might Arctic Warming Lead to Catastrophic Methane Releases?
Apparently not

Jason F

If there is less ice isn’t there therefore more water vapour?

Jason F (2010/10/31 at 2:51 am)
You asked about increase in water vapour – I was refered to a paper the other day in commments on another thread:
“The central role of diminishing sea ice in recent Arctic temperature amplification” http://www.nature.com/nature/journal/v464/n7293/full/nature09051.html
The paper measures up to 10% increase in humidity (June-Oct) in the period 1989-2008.

kwik

Malaga View says:
October 31, 2010 at 12:56 am
Aha, back to classical old fashion plain science now? Looks so much more familiar!
But, alas, the patients are controlling the asylum now. We were busy slaving away, paying our taxes and supporting our familys.
Sorry.

HelmutU

If the value s of the ice-core data in the graph are correct, than the CO2-concentration 12000 years before present was below 250 ppm. Life would no longer exist on earth, because all plants stop assimilation, when the CO2 concentration falls below that value.

old construction worker

‘TJA says:
October 31, 2010 at 2:12 am
Somebody tell the EPA that the polar bears will be fine. Wait, they don’t care.’
How will those polar bears survive an ice free Arctic? How will they find their there favorite meal, seals? Or will they invade Montreal looking for easier pray?
Could we herd them toward Washington?

DaveF

nc 12:20 am:
I followed the link you gave about the Piri Reis map. At the bottom of the page there’s a section entitled “Modern analysis of the Piri Reis map – Surprising Conclusions” and shortly afterwards a ‘read more’ link to the rest of the article which quite comprehensively debunks the claims that earlier map-makers had modern knowledge and technology that was subsequently lost.

“At the far right of this plot it is possible to observe the emergence of climate from the last glacial period of the current ice age. ”
Do you mean left?
John M Reynolds

Joe Lalonde

Anthony,
You could definately have warmer temperatures and the trade off would have been less atmospheric pressure. But only to a point. The interesting link with water and salt is that the oceans have been becoming fresherwater over time due to the planetary slowdown and centrifugal force.
Follow the yellow brick road, follow the yellow brick road, follow, follow, follow, follow, follow the yellow brick road……..to the past.

Amino Acids in Meteorites

Global warming scientists say the Arctic has never been ice free but it is going to be ice free because of global warming. Now that a peer reviewed work shows far less ice in the Arctic than now, and it’s not the first to do so, global warning believers say it’s a meaningless paper—it doesn’t (or the won’t let it) change what they believe.
You see, nothing will change religious zealotry. Blind faith is blind.
You can see that nothing will change their mind. Proof of strong negative feedback from H2O didn’t change their mind. ClimateGate didn’t change their mind. If those two things didn’t change their mind then one could conclude they don’t want to change their mind.
“The Americans are not here. We are pushing them back. We are cleaning them out.”
–Baghdad Bob

Tom in Florida

” and calls for further research on causal links between Arctic climate and sea ice.”
Ah ha! Must be budget time.

rbateman

The longest running Ice Core:
http://www.robertb.darkhorizons.org/TempGr/Vostok.JPG
says that we have begun to round down the slope into the next Ice Age.
It was also (from the same graph) very stable at the end of the previous Ice Age as well as during the Holocene.
Ditto for the previous Ice Age and Interglacial. So much so, that it’s a very good probability that we have (as some suggest) already entered the beginning of the end of the Holocene Interglacial.
Each Ice Age is different, and it’s very obvious from spending time with Ice Core runs that there are 2 major waves that, over hundreds of thousands of years, have merged to form the Greater Interglacials, and are now pulling apart to form the Lesser Interglacials.
Looking for a 2nd peak in this Interglacial? Not the best odds, not at all.

hunter

@bublhead,
The point is that it was warmer, the Arctic icecap was gone, and the Earth did just fine.
Whatever forced the changes during the study period, loss of the icecap did not trigger, as AGW theory claims, a run away disaster. Polar bears seals whales and walrus all did fine.
And the increased temps did not cause a tipping point of run away positive feedbacks.
The methane did not bubble up from melting permafrost and poison life or cook the planet.
The point is that AGW- the idea that we are facing a global climate disruption due to CO2- is not supported by the history.
Is that something you are willing to deal with or will you seek to avoid the topic?

John Whitman

My quick thoughts based on the post are:
1. The artic in an ice free condition was not a risk, even to polar bears during the early Holocene. Today it would be a benefit to mankind and even polar bears.
2. The rate of the temp increase to the peak temp of the Holocene ~8,000 yrs ago was more dramatic than that of the last 150 yrs. Mankind and biodiversity did not end ~8,000 yrs ago. Ahhhh, quite the contrary, it flourished.
3. We are slowly sliding into the next glacial period, relentlessly but very very slowly. So no catastrophic ‘we are all going to freeze’ headlines, please. We have had enough of the ‘burn’ hype . . . . . ‘freeze’ hype is not an alternative option.
4. The graphic entitled “Holocene Temperature Variations” in the post is an upside down hockey stick with the handle pointing at the future Apparently Mother Nature is a hockey fan. : )
5. The temps at ~8,000 yrs ago were, conservatively, approximately of the order of the last 30 yr. It is hard to tell with that tiny inset when compared to the bigger chart. And the CO2 concentrations were not comparable to today’s higher levels. There was another cause operative in the Holocene. So Milankovic effect in combination with other effects did give natural cycles that were higher than the total of all of the speculations of current mankind effects and . . . . . . the world did not end; it thrived.
My unborn great-great-great grandchildern are smiling at me from my resident DNA.
John

GregL

On the same page as references, is the abstract for this supporting paper:
Temperature and precipitation history of the Arctic Original Research Article
Quaternary Science Reviews, Volume 29, Issues 15-16, July 2010, Pages 1679-1715
The Last Glacial Maximum (LGM) peaked not, vert, similar21 ka ago, when mean annual temperatures over parts of the Arctic were as much as 20 °C lower than at present. Ice recession was well underway 16 ka ago, and most of the Northern Hemisphere ice sheets had melted by 6 ka ago. Solar energy reached a summer maximum (9% higher than at present) not, vert, similar11 ka ago and has been decreasing since then, primarily in response to the precession of the equinoxes. The extra energy elevated early Holocene summer temperatures throughout the Arctic 1–3 °C above 20th century averages, enough to completely melt many small glaciers throughout the Arctic, although the Greenland Ice Sheet was only slightly smaller than at present. Early Holocene summer sea ice limits were substantially smaller than their 20th century average, and the flow of Atlantic water into the Arctic Ocean was substantially greater. As summer solar energy decreased in the second half of the Holocene, glaciers re-established or advanced, sea ice expanded, and the flow of warm Atlantic water into the Arctic Ocean diminished.
So the Arctic sea ice extent vaties with temperature and Arctic temperature varies with solar radiation and the ice free period in the early Holocene is due to orbital changes. This says nothing about today except that the fall in sea ice extent is due to an increase in Arctic temperature.

Jeremy

So polar bears survived all this holecene warmth? Even in an ice-free Arctic the polar bears didn’t all drown?
My my how the eco-zealot lies are unraveling.
“Nothing travels faster than light, with the possible exception of man-made climate change, which follows its own rules”.