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 years, 10 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.
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 (
) (1) and direct measurements of CO2 concentration of air enclosed in bubbles in the ice cores from Taylor Dome (
) (3, 4) and Vostok (
) (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:
New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling
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.
~~~~~~~~~~~~~~~~~~~~~~~~~~
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:
(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.
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):
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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R. Gates says:
October 31, 2010 at 5:20 pm
True, but this sort of study does do two things…
First, it quiets the people that claim that the Arctic hasn’t been ice free in the past 100+ thousand years, see:
http://tamino.wordpress.com/2010/10/16/anthony-watts-pants-on-fire/#comment-44936
Second, it provides evidence that losing the (summer) Arctic sea ice isn’t the world-killer that the CAGW crowd seems to scream. As a person that believes in (some of the) AGW but not in the CAGW rantings, I consider this study very important.
-Scott
Is there a consensus on whether the impact of Milankovitch forcing increasing or decreasing? If not, what are the opinions?
“you’ve offered no evidence that CO2 is driving changes in Arctic ice then or now.”
Has anybody ever argued that changes in CO2 at 10kBP was an important forcing?
RobertInAz says:
October 31, 2010 at 10:08 pm
The orbital dynamics behind Milankovitch forcing are well understood, but the details of how the changes in insolation affect climate are not completely understood.
Milankovitch are more important in redistributing insolation by latitude and season than they are in affecting global averages. Milankovitch forcing also changes very slowly – it is important on millennial timescales, not decadal.
Insolation values can be obtained from
http://www.ncdc.noaa.gov/paleo/forcing.html
That’s not how I read that graph.
Here is one including more recent studies:
[MOD COMMENT – no link given – mj]
Driftwood and whalebone studies have suggested that around 10-9000 years ago the Arctic had a lot of open water. Then there Rapid Climate Change leading to cold temperatures and severe ice conditions. Those driftwood studies and ice core studies all suggest alternations at millennial time scales between periods of severe ice and high percentages of open water. Mayewski (2004) also reviews the Arctic ice core data that reveal several periods of Rapid Climate Changes where temperatures drop, often by several degrees in a few decades.
When Dr. Mark Serreze posted recently here about the state of Arctic Ice, he referred to a paper he co-authored “The History of Arctic Ice” 2010 Polyak et al., where they state “the severity of present ice loss can be highlighted by the break up of ice shelves at the northern coast of Ellesmere Island (Mueller etal.,2008), which have been stable until recently for at least several thousand years based on geological data (England et al.,2008).”
Maybe Serreze and the others were striving for dramatic effect by selectively using highly speculative geological data (driftwood data). Or perhaps it was their advocacy , that has taken their science to the dark-side. But their portrayal of the Ellesmere Ice Shelf stability simply stretches the truth. Most studies shown tremendous climate variability over the past 10,000 years with sudden rapid coolings followed by warming, not 5000 years of stability! So I investigated the validity of their claim.
First, Polyak and Serreze’s claim that the Ellesmere ice shelves have been stable for 5000 years, ignores the well documented calving of 600 km2 of the Ward Hunt Ice shelf in 1961. (Holdsworth, 1971) It also ignores the 1946 document existence of a 700 km2 ice island that was determined to be part of the Ellesmere ice shelf. These early dates are prior to the dates when the disastrous effects of CO2 are purported to first attacked the Arctic, and suggests natural variation and natural causes. But lets assume that the 194 break up was due to global warming.
The sole basis for Serreze and Polyak’s 5500 years of stable ice shelf claim, is based on the absence of driftwood behind the small section of the Ellesmere Island Shelf. So their claims needs a some background info to understand and evaluate.
The potential for driftwood to land on Ellesmere Island is a function of 3 factors. 1) How much sea ice is available to carry the wood, 2) Shifts in the sea level pressures and wind patterns that can alter the Transpolar Drift. This effects the current’s ability to deliver wood to Ellesmere island that would more typically go out the Fram Strait and to Svalbard, and 3) Access to Ellesmere Island beaches. An Ice Shelf or multiyear ice (ice shelves are just thicker multiyear fast ice) can block driftwood access landward of the ice. But open water is not absolutely necessary to access the beaches as icebound driftwood can be pushed over the fast ice.
Due to the way currents transport driftwood in the Arctic, Svalbard receives orders of magnitude more driftwood than Ellesmere or other places in the Canadian Arctic Archipelago. And therefore Svalsbard provides better sample sizes and a more sensitive indicator of overall Arctic sea ice changes. Haggblom 1982, published the classic study of driftwood patterns on the islands of Svalbard. Using studies from the timber industries, he created a table of maximum time driftwood could stay afloat before its increased density due, to water-logging, would cause it to sink. Amongst the conifer trees, Spruce trees could stay afloat up to 17 months while Larch and Pine trees could stay afloat 9-10 months. Hardwoods with different xylem tissue, like Birch, Aspens and Willows stay afloat only 6-10 months. Also, the larger the trunk (due to smaller surface-to-volume ratios) the more slowly it became waterlogged. Likewise the presences of bark or how dry the wood was initially affected the rate of being waterlogged.
Then based on known speeds of currents Haggblom estimated that it would take 5 years for driftwood to reach Svalbard after being flushed from Siberia or other boreal forests in to the Arctic waters. Since the maximum time before sinking was 17 months, if the Arctic waters were ice free, all logs would become waterlogged and sink before reaching Svalbard. In order for the driftwood to reach Svalbard wood had to become frozen into the pack ice, raised above the water-line, and transported via ice floes for most of its journey. Thus the amount of driftwood, the species and size of the driftwood, can serve as proxies suggesting concentrations of Arctic sea ice vs open water, while C14 dating and the elevations zones where the wood is deposited, suggest the age within about 100 years error bars.
Haggblom characterized patterns of Svalbard driftwood into general times of severe ice, moderate ice and high percentages of open water. But even within those time spans, he detected a lot of variability. For example, the zone that corresponds from the present time to about 800 years BP, is littered with various lines containing abundant driftwood in many-sized pieces from conifers and hardwoods, The presence of the remains unique to Siberian vessels known as “lodja” or “sitji” helped date parts of this line. The abundant driftwood and lack of Bowhead whale bones, suggested severe sea ice conditions, but these were alternating with less wood suggesting less severe ice conditions a. In accord with the Svalbard time lines, there is the Little Ice Age where there were at least three cold periods around 1650, about 1770, and 1850, with intermittent periods of slight warming.
From that zone, there is an abrupt transition. Hoggblom dated that net driftwood zone to range between 800-1700 BP.He suggested that the Arctic experienced mostly open water because in stark contrast to the earlier zone of abundant driftwood, this was relatively empty of driftwood with only a few large Spruce or Larch trunks. However there were whale bone lines in this zone. This all suggested a warmer period and high percentages of open water. This suggestion is supported by an abundance evidence centering the Medieval Warm Period between 950 and 1200 years BP. Archaeological evidence indicates the Norse and Thule cultures moved into Greenland and Ellsmere Island during this time.
This warm period is also suggested in paper Serreze and Polyak actually cited by Anderson “A highly unstable Holocene climate in the subpolar North Atlantic: evidence from diatoms” in which the authors equate current Arctic temperatures to a period 1600 years ago, which is also the time indicated in Svalbard by no driftwood suggesting high percentages of ice free ocean.
Further examining of the paper they referenced, (England 2008), raised few more suspicions. England(2008) presents a map of the Ellesmere Island with locations of dated driftwood, and the location of the Ellesmere Island Ice Shelf as it is believed to have existed in 1906, and which they suggest had been stable for over 5500 years. Polyak, Serreze et al state “An even longer perspective for the outstanding magnitude of the modern warming and related ice loss is provided by the history of ice shelves at the northern coast of Ellsemere Island, which are made of super-thickened landfast ice supported by pack ice in the adjacent Arctic Ocean. These ice shelves have been stable for most of the last 5.5 kyr based on driftwood ages(England etal.,2008)”
In England (2008) they show the extent of the 1906 ice shelf would have covered Clements Markham Inlet. When showing the time periods of dated driftwood they state “In Clements Markham Inlet a temporary cessation occurs approximately 3500 cal yr BP, after which driftwood re-enters intermittently to the present.” However the phrase “re-enters intermittently to present” actually refers to just a few samples dated between 1900-2100 years ago, followed by a several hundred year absence of driftwood, until a few more samples that were dated to what appears to be the last hundred years.
So by England’s own analysis, the whole Ellesmere Ice shelf as defined in 1906, was not intact for 5500 years, at least not around the Clements Markham Inlet when the driftwood landed a few different times during that time span.
Furthermore the absences of driftwood at the Clements Markham Inlet after 3500 years, and between 500 and 1900 years ago, dates also correspond to the broad time periods of warm open waters from the Svalbard data. This suggests that during those corresponding times, driftwood was not available to any parts of Ellesmere. Therefore the lack of driftwood may not infer the presence ice shelves that blocked beach access. A more likely speculation, since Svalbard data corresponded to warmer open water, is that the ice shelves were likely reduced or absent, and despite potential access, there was no driftwood able to reach the beach’s.
Finally the sparse Ellesmere driftwood and dates is insufficient to provide any evidence of decadal fluctuations in ice cover. Often there were several hundred years between driftwood dates. Thus fluctuation less that 100 years would not be reocgnized.
So England’s conclusions about a stable ice shelf must be viewed as speculation at best. Furthermore England’s speculative conclusion was mostly referring to the Ward Hunt Ice Shelf which is one small section of the Ellesmere Shelf . But Polyak and Serreze in attempt to show the “severity” of the current ice decline, not only make the speculation about Ward Hunt Ice Shelf stability appear certain , they expand this to include the whole Ellesmere Ice Shelf stating “These ice shelves have been stable for most of the last 5.5 kyr” . There is a hint of missing integrity here by these authors of History of Arctic Ice.
We have been told by the Warmists that there would be an Arctic feedback loop. That is that the more sea ice retreats each year, the more dark sea is exposed, the more heat is absorbed leading to less ice next September and so on….
This feedback loop has been shown in this post to have not kicked in during the Holocene despite ice-free central Arctic ocean. Does this mean that this theory for the Arctic is false? Is my question valid? Am I missing something? Comments appreciated.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VBC-51509K7-1&_user=10&_coverDate=10%2F02%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1520547417&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=4864f509bd7183b0f225da2036305798&searchtype=a
http://wattsupwiththat.com/2010/10/30/new-peer-reviewed-paper-says-there-appear-to-have-been-periods-of-ice-free-summers-in-the-central-arctic-ocean/#comment-520353
I have done a write up related to this as well. I tie in a variety of other factors as well.
http://theinconvenientskeptic.com/2010/11/nh-summer-energy-the-leading-indicator/
John Kehr
The Inconvenient Skeptic
Scott says:
October 31, 2010 at 9:18 pm
R. Gates says:
October 31, 2010 at 5:20 pm
There can be many different causes that lead to the same effect, and there is no logical or justifiable reason to draw the conclusion that the existence of one precludes the existence of others.
True, but this sort of study does do two things…
First, it quiets the people that claim that the Arctic hasn’t been ice free in the past 100+ thousand years, see:
http://tamino.wordpress.com/2010/10/16/anthony-watts-pants-on-fire/#comment-44936
Second, it provides evidence that losing the (summer) Arctic sea ice isn’t the world-killer that the CAGW crowd seems to scream. As a person that believes in (some of the) AGW but not in the CAGW rantings, I consider this study very important.
-Scott
_____
I wouldn’t disagree with your general statement and my statement was simply to point out that one cause does not in any way preclude another so that those sceptics who would insist that this kind of study proves that CO2 can’t cause warming.
We know that CO2 levels are up 40% since the 1700’s and furthermore, that they are at their highest levels in at least 800,000 years. The central question is only a matter of sensitivity– both in the amount of CO2 as well as the relatively rapidity with which the levels have grown (geologically speaking). Human activity over the past few hundred years represents essentially a continuously “CO2 volcano”, and for anyone to suggest that just because the earth may have been warmer in the past when CO2 was not this high, says nothing about what kinds of effects the speed and levels of CO2 in our modern era might cause.
R. Gates says: October 31, 2010 at 5:20 pm
This is an interesting study, but there is a logical fallacy (not made in the study by the way) in drawing a conclusion that just because CO2 levels may not have been the driver behind a warmer Arctic during the Holocene Optimum, that they couldn’t be the driver behind a warmer Arctic now.
They need the positive feedback of water vapour to cause the catastrophic rise in temperature the AGWers believe will happen, it does not matter what caused the rise in temperature in the past, without the positive feedback of the main greenhouse gas water vapour there is no catastrophe, it didn`t happen in the past warmings and it will not happen in future warmings. CO2 can`t do it on its own.
This is nothing to do with the arctic but what caused this warming.
http://i446.photobucket.com/albums/qq187/bobclive/swissglacier.jpg
I have to agree with anna v, dumping data from all over the world into a “Shake and Bake” bag and attempting to draw any logical conclusion about a single region like the Arctic isn’t logical.
All the studies I’ve read related to this fascinating era indicate the temperature change was far more extreme in the NH. Unfortunately, very little ice core analysis has been done on the Alaska glaciers or if it is available, I haven’t been able to locate it.
One recent study postulated the importance of the Bering Strait as one of the triggers for the glacial shifts. The Bering Strait is 49M at its lowest point and the drop in Pacific Ocean depth at the glacial maximum was approximately 150M. IPCC cites 120M which is in dispute and may be corrected in the next report.
Salinity in Arctic waters via the Bering Strait has also been attributed to the Arctic Ice minimum in 2007. I believe the statement was, it accounts for more than half of the ice melt in 2007.
Ice free Arctic during this period isn’t supported by sediment samples taken at/near the North Pole however the samples indicated ice free conditions from earlier periods.
A 150M drop in Ocean levels, decreased fresh water Arctic input from a dryer Siberia and lack of Bering Strait input, dryer conditions would promote evaporation, Glaciers and sea level drop cutting off a significant portion of the Canada discharge from the Arctic, as well as higher salinity, and additional exposed land mass along the Siberian coast would have all contributed to declining summer ice formation.
As far as I can tell, CO2 had very little to do with glacial changes — was a byproduct of temperature change.
Interesting aside: there is also evidence of human hunting artifacts in Alaska dating to 13-14k BP and Mammoth remains well within the Arctic circle above Alaska and on islands off the coast of Siberia.
Anyone have historical cloud data that shows the current warming cannot be attributed to changes in cloud cover?
…
…
…
No? No support for the attribution to CO2?
rbateman:
Thanks for the link to the 800,00 yr. Vostok graphic. I will add it to my standard 400,000 year graphic that came from Frank Lansner’s article in WUWT. And, if one scrolls down to the last graph of this article, you find that an ice core collected by NOAA, about 10,000 miles from the Vostok core, shows similar results. Namely, that we insignificant little humans had better prepare for a coming ice age.
If the sun, as Mr. Lansner posits, should go into a 1,000 or 10,000 year solar minimum, what might then happen? Will it matter at all what CO2 or water vapor or anything else has to do with the current warming?
I find it striking that on any of these proxy temp/CO2 graphs, that the vast majority of time during the last 400 or 800 thousand years has been spent well below the -2 degree centigrade variance from the current optimum (if I understand that correctly). Can anyone say “Ice Age?” Chicago under a mile of ice? No, wait. That’s nuts according to the aptly named “bublhead”. All I know is, as a technically oriented non-scientist, and a very visually oriented person, those graphs practically shout out that we are living in a warm period that is on borrowed time. We may be in the start of a 10,000 year solar minimum (or whatever the hell may cause the next temp decline), or it may not happen for another 10,000 years. Either way, this insistence on CO2 as the driver seems nuts to me. It is just a very successful diversion created by unscrupulous businessmen and their political cronies, to elevate them to powerful positions and riches that will assure their continued power. But hey, we should be grateful that they are trying to take care of us little guys, right?
http://www.robertb.darkhorizons.org/TempGr/Vostok.JPG
It is too bad there is no real way to get the H2O content of the atmosphere from the ice cores. I’ll bet that H2O goes up before CO2. As more water moves to liquid phase and becomes available for the hydrological cycle, CO2 is released from the oceans and ice packs. And this fooled some paleo types into thinking it was a driver and not a passenger. Still, there seem to be two levels of stability that correlate with whether ice is in liquid or solid phase.
I just stumbled onto this website by accident but I wanted to say a couple of things. First of all I wanted to say that I have read somewhere that before 2 millions years ago we had a period of several million years where we didn’t have any ice ages. And then there was a period before that where we did have them. I guess that is long term. I also wanted to say that if someone fills a glass up to the brim with ice and ice water, and then allows the ice to melt, the level of the liquid will be lower in the glass than it was originally with the ice in it. Is science so sure that ocean levels were lower during the ice age? One final note to Darren Parker: I plan on looking up this “The Secret of Atlantis” by Otto Muck. I know that there is another book out there by a person from India that says that Atlantis was in the South China Sea and sank beneath the waves because of the volcano Krakatoa.
Anthony, you are a funny man. I will not argue the quality of your interpretation. This is not the place.
I’ll just point something that academics consider somewhat important.
You quote in your title that “there appear to have been periods of ice free summers in the central Arctic Ocean”.
The paper instead says “there appears even to have been periods of ice free summers in large parts of the central Arctic Ocean”.
“Quoting is serious business”.
Several papers have suggested that there is a 1400-1500 year cycle, and since the warm period around 10,000, years ago there have been periodic cold snaps in the Arctic seemed to correspond with this time span.
Keeling for whom the CO2 curve is named after, in addition to warning about increased CO2, noticed climate changed due to natural causes that affected temperature and CO2. He noticed strong forcing, consistent with observed temperature periodicities, occurred at 9-year intervals close to perihelion.
http://www.pnas.org/content/94/16/8321.abstract
He also proposed that the larger 1400 cycles were due to a rectified lunar tidal forcing. The tidal affected the vertical mixing bringing cold water to the surface and thus effecting climate dynamics.
http://www.pnas.org/content/97/8/3814.abstract
I believe it was discussed here a while back.
Dave F says: It is too bad there is no real way to get the H2O content of the atmosphere from the ice cores. I’ll bet that H2O goes up before CO2.
Looking at it from the other pole, the South Pole is one of the driest places on earth. The do experiments on long wave radiation there to help eliminate cloud and water vapor effects. So with H2O out of the way, inland enough to take oceanic influences out of the equations we have a natural experiment where you can see the trend in temperature due just CO2 and whatever unknowns left over. Nature’s South Pole experiment shows significant cooling trends, despite the CO2
Slightly OT, but relevant to ice conditions in the early Holocene. Motl discusses it here:
http://motls.blogspot.com/2010/07/in-defense-of-milankovitch-by-gerard.html
(The links to the pdf on Motls page don’t seem to be working right now.)
This is a pretty important paper, IMO. Look at Fig 2 & 3 in the pdf. There is a remarkable statistical correlation between June solar insolation at 65 deg north and ice-volume changes — 99%! You almost never find such close correlations in climate science. To me, this leaves little room for any CO2 effect in the north polar regions as far as ice-volume changes go. Motl agrees.
This is interesting, because as this generally well accepted graph shows, temperature was higher then.
Clearly it doesn’t, to the contrary it shows temperatures are higher now!
beng says:
November 2, 2010 at 8:03 am
Slightly OT, but relevant to ice conditions in the early Holocene. Motl discusses it here:
http://motls.blogspot.com/2010/07/in-defense-of-milankovitch-by-gerard.html
(The links to the pdf on Motls page don’t seem to be working right now.)
This is a pretty important paper, IMO. Look at Fig 2 & 3 in the pdf. There is a remarkable statistical correlation between June solar insolation at 65 deg north and ice-volume changes — 99%! You almost never find such close correlations in climate science. To me, this leaves little room for any CO2 effect in the north polar regions as far as ice-volume changes go. Motl agrees.
Since the links don’t appear to work I haven’t been able to check that but the Motl page talks about ‘rate of change of ice volume’ and ‘June insolation at 65ºN’ but his graphs don’t show data more recent than about 10kyears ago.
Phil. says:
November 2, 2010 at 8:56 am
This is interesting, because as this generally well accepted graph shows, temperature was higher then.
Clearly it doesn’t, to the contrary it shows temperatures are higher now!
=========
And, there it is in a nut shell : )
The tendency of Climate Science drifts to the child-like as it attempts to attribute Global conditions to regional anomalies. How can anyone claim something is Global in Nature when the nature of the system has always achieved a balance at its most extreme points?
Phil., here’s a link that I got to work for the Roe paper:
http://earthweb.ess.washington.edu/roe/Publications/MilanDefense_GRL.pdf
[Note: TinyURL compresses URL’s to manageable size. Easy to use: http://tiny.cc ~dbs]
Nope, that works from the Yahoo search page, but not embedded in this page — sorry. A quick search should bring up a working link to the pdf — it did for me.
beng says:
November 2, 2010 at 8:03 am
This is a pretty important paper, IMO. Look at Fig 2 & 3 in the pdf. There is a remarkable statistical correlation between June solar insolation at 65 deg north and ice-volume changes — 99%! You almost never find such close correlations in climate science. To me, this leaves little room for any CO2 effect in the north polar regions as far as ice-volume changes go. Motl agrees.
Thanks for the working link, on quibble with your post, it isn’t a statistical correlation of 99% it’s “The SPECMAP record has zero lag and HW04
record is lagged by only 1 kyr, in order to show the maximum lag correlation with the
insolation time series of –0.8 and –0.4, respectively. Autocorrelation estimates suggest that the SPECMAP and HW04 time series of dV/dt have 106 and 123 degrees of freedom respectively. Therefore, in both cases the correlations are significant at well above the 99% confidence level.”