Friday, June 19, 2009

Being Colder Makes the Ice Melt

In a comment to my last post, Hagiograph cited a Nasa Study which said of the Holocene Climatic Optimum:



"These orbital changes can be easily calculated and predict that the northern hemisphere should have been warmer than today during the mid-Holocene in the summer AND colder in the winter. The paleoclimatic data for the mid-Holocene shows these expected changes, however, there is no evidence to show that the average annual mid-Holocene temperature was warmer than today's temperatures."
...
"In summary, the mid-Holocene, roughly 6,000 years ago, was generally warmer than today, but only in summer and only in the northern hemisphere. More over, we clearly know the cause of this natural warming, and know without doubt that this proven "astronomical" climate forcing mechanism cannot be responsible for the warming over the last 100 years. "
Source

It is a very easy thing to look on this blog and see if I have spoken of any warming in the southern hemisphere or in Antarctica during the Holocene Climate Optimum. NASA says there is no evidence for warming in the southern hemisphere. This is horse-hockey, ladies and gentlemen. Ignorance of the NASA writers is on display, but then, they do want to scare you into giving them your hard earned money in the form of taxes.


The interesting thing is that they are depending on models to tell them what the night time temperature is. All one can get from paleoclimatic information on the ground is indicators of average temperature. And all the indicators I have seen say the mean temperature was warmer by the 2-3 deg C seen in the map on the above referenced page. Those numbers are mean increases in temperature.

Let's look at the logic in the above statement that there is no evidence that Antarctica was warmer during the Climatic Optimum than today. It is sadly clear to me that people don't remember what they read on this blog from a few weeks back, nor do they look up data before responding to what is written.

If you do nothing else with this post read the bolded parts of the quotations below

From my post on March 23, 2009 here

The stability of floating ice shelves is an important indicator of ocean circulation and ice-shelf mass balance. A sub–ice-shelf sediment core collected during the Austral summer of 2000–2001 from site AM02 (69842.89S, 72838.49E) on the Amery Ice Shelf, East Antarctica, contains a full and continuous record of glacial retreat. The AM02 core site is ;80 km south of the floating ice shelf edge and contains a 0.5-m-thick Holocene surface layer of siliceous mud and diatom ooze of marine origin. Core data are supportive of sub– ice-shelf circulation models that predict the landward flow of oceanic water, and prove that the landward transport of hemipelagic sediments occurs beneath floating ice shelves over distances of at least ~80 km. An increase in sea-ice–associated diatom deposition in the upper part of the Holocene suggests that a major retreat of the Amery Ice Shelf to at least 80 km landward of its present location may have occurred during the mid-Holocene climatic optimum." Mark A. Hemer and Peter T. Harris, " Sediment core from beneath the Amery Ice Shelf, East Antarctica,"Geology; February 2003; v. 31; no. 2; p. 127–130, p. 127

How in the hell can NASA say that there is no evidence of the southern hemisphere being warmer when the Amery Ice Shelf was melted by 80 km during that period?

A question for NASA, if it was colder then than now, was it the cold that melted this ice cap? Utter illogic. The guy who wrote the NASA website ignored this evidence or didn't do sufficient research to know of it.

And from my blog on March 26, 2009 source

"Some studies in the northern Antarctic Peninsula suggest iceshelf
collapse in the mid-Holocene (Pudsey and Evans, 2001). To date, ice shelves farther south (south of 70[deg]S) have shown no catastrophic breakup, although some ice-shelf fronts are in retreat. This paper presents the first evidence of an early Holocene collapse of one of these more southern ice shelves."
M. J. Bentley, “Early Holocene Retreat of the George VI Ice Shelf, Antarctic Peninsula,” Geology, 33(2005):173-176, p. 173


They further note the time of its disappearance.

"“Our core chronology shows that the George VI Ice Shelf disappeared in the early Holocene, with the onset of collapse by 8170 14C yr B.P. (9595 cal. yr B.P.) and complete reformation by 7300 14C yr B.P. (7945 cal. yr B.P.). This coincides with deglaciation in many Antarctic coastal areas (Ingo´lfsson et al., 1998), and follows deglaciation of the western Antarctic Peninsula shelf (Anderson, 1999). The record of the George VI Ice Shelf collapse immediately postdates ice-core evidence of a widespread, sustained early Holocene climatic optimum (Masson et al., 2000; Masson-Delmotte et al., 2004) ca. 11–9.5 ka (Fig. 4). The collapse is also coincident with the influx of Circumpolar Deep Water onto the Antarctic Peninsula continental shelf, as demonstrated in the Palmer Deep marine record (Domack et al., 2001; Fig. 4).” M. J. Bentley, “Early Holocene Retreat of the George VI Ice Shelf, Antarctic Peninsula,” Geology, 33(2005):173-176, p.175


And Bentley concludes that the melting in the southern hemisphere was greater than what we see today. The NASA writer conveniently doesn't bother to tell you about this data, preferring instead to stick with the party line that there is no evidence of a warm southern hemisphere, which is entirely a bunch of horse-hockey.

"The collapse of a currently extant ice shelf shows that early Holocene natural ocean-atmosphere variability in the Antarctic Peninsula was greater than the recent, potentially anthropogenically influenced changes.
M. J. Bentley, “Early Holocene Retreat of the George VI Ice Shelf, Antarctic Peninsula,” Geology, 33(2005):173-176, p.176

Question for the illogical NASA writer: Was it the cold back then that melted the Amery and George VI Ice Shelves 8000 years ago? Or is this evidence of warming 8000 years ago in that most southerly of southern hemisphere locations?

Hagiograph, don't beleive everything you read which is written by a government employee who gets his funding and makes his living by scaring congressmen into giving him grant money.

And check me out to, but for goodness sake, actually check the data, don't just read one thing and conclude from the source that they are telling you the truth.

6 comments:

  1. This is a two-part "Comment" owing to size limitations on these html boxes.

    Part I
    As I said, I have absolutely NO PROBLEM with the earth being warmer in the past. I understand there may even be warmer temperatures to be found earlier in the geologic record. I have zero problems with the reality of that.

    What I do have problems with is the assumption that simply because the earth has gone through a variety of climatic shifts doesn't mean that modern human society can weather one (pun intended). And, for that matter, if there's evidence (as I have seen and posted on this blog) that indicates that mankind may be at least partially responsible for this, and there's something we _might_ be able to do to forestall it, then I really have a problem if we spend our time trying to blame "NASA" for trying to swindle us out of money through fear mongering.

    Firstly the link I posted was for NOAA, not NASA. But it's understandable that a small error like that would slip in. But it does show that we all are prone to error at times.

    Secondly, my simplistic understanding of the warm periods in Antarctica is that they were not necessarily at the same timeframe as Arctic and may have been localized.

    I found an article on a US Geological Survey site (I'm sure they, like NASA and NOAA are unaware of the earth sciences) that indicates

    "Although some consistencies in the onset and duration of warm and cold periods after deglaciation apparently exist, some records indicate significant differences from other records close by. These differences may partly be explained by dating uncertainties, overprinting of local factors, or possibly even misinterpretations of the proxies used. A comparison with the climate histories deduced from ice core records reveals, however, that the differences have at least partly to be caused by local effects and small-scale variations, which still need to be better understood and demonstrate the need of further research."

    (Link: http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea161.pdf)

    Note especially Fig. 2 which shows the variation of the onset and duration of warm periods.

    "The discrepancies found in changes in the climate developments around the coast of East Antarctica cannot fully be explained by dating uncertainties or misinterpretations of the proxies used. This is also indicated by a comparison with the climate histories deduced from ice core records (Figs 1 and 2; Masson et al., 2000). Hence, the differences have at least partly to be caused by local effects and small-scale variations, for example in moisture supply, wind directions, or sea-ice cover, which still need to be better understood and demonstrate the need of further research."

    (To be continued...)

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  2. Part II

    An article from Science Magazine (http://www.sciencemag.org/cgi/content/abstract/279/5353/1014) indicates that during the time of which you are speaking (~5,000 to 6,000 Yrs BP) the tropics were only about 1degC warmer.

    This is in line with other things that I've read that indicate that the global averge temperature increase was not necessarily homogenous across the globe during the Mid-Holocene.

    Yet another article from Quaternary Science Reviews, focusing on the Holocene temperatures in Europe states: "The traditional mid-Holocene thermal maximum is observed only over Northern Europe and principally during the summer" (Quaternary Science Reviews V 22, Issues 15-17, July-August 2003, Pages 1701-1716)

    Finally I did run across an article from Quaternary Research (V54, Nov 2000, Pg 348) that states: "All the records confirm the widespread Antarctic early Holocene optimum between 11,500 and 9000 yr; in the Ross Sea sector, a secondary optimum is identified between 7000 and 5000 yr, whereas all eastern Antarctic sites show a late optimum between 6000 and 3000 yr. Superimposed on the long time trend, all the records exhibit 9 aperiodic millennial-scale oscillations. Climatic optima show a reduced pacing between warm events (typically 800 yr), whereas cooler periods are associated with less-frequent warm events (pacing >1200 yr). "

    So it seems these researchers found several warming periods with some located around the 5,000 to 6,000 years BP region

    I have to admit, I'm a bit overwhelmed by the variety of dates and the number of "warm periods", and it kills me to quote a "Wikipedia" article, but I found the following to be nice summary of the varying time-frames:

    "In the far southern hemisphere (e.g. New Zealand and Antarctica), the warmest period during the Holocene appears to have been roughly 8,000 to 10,500 years ago, immediately following the end of the last ice age[7][8]. By 6,000 years ago, the time normally associated with the Holocene Climatic Optimum in the Northern Hemisphere, these regions had reached temperatures similar to those existing in the modern era, and did not participate in the temperature changes of the North. However, some authors have used the term "Holocene Climatic Optimum" to describe this earlier southern warm period as well."
    (http://en.wikipedia.org/wiki/Holocene_Climatic_Optimum)

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  3. To the first comment. Can humanity weather climate warming? Well, if we are that evolutionarily weak, or to stupid to adapt, then we, like every other species will go extinct.
    As I have documented here, the climate has gone up and down far more in the past than it is projected to over the next century. While one can prove that CO2 is increasing in the atmosphere, partly due to humanity, one can't prove that we are the only cause of warming. Secondly, the raw data is so incredibly bad that one can't use any thermometer based approach to know what is happening in the world's climate. That leaves us BELIEVING that the world is warming, or using (gasp) anecdotal data like first blossoming records. AGW folk always decry the use of anecdotal data except when they use it.

    Thirdly, what do you propose to do to stop it? If we outlaw all carbon based fuel, humanity, or a large chunk of us, will not survive the ensuing chaos. Slowing down the use of carbon based fuels will still cause lots of people to lose their jobs and they will be very unhappy.
    And don't ever forget that 1% of the world's carbon based fuel goes towards fertilizer to feed this mass of humanity. Using less means less to eat means more starve.

    So, what is your plan?

    The NOAA site (I stand corrected) also seems to assume that the Antarctic melting isn't there. While you assume that they aren't at the same time they assume it never happened. Both are wrong. They were both part of a period of time from about 10,000 to 5000 years ago called the Holocene Climatic Optimum And you can't get a local 80 km warming south of 70 deg S latitude. That takes a major heat wave. Also, the George VI ice shelf is just about as far south as one can go on the oceans, it is in between the mainland and an island, to melt it one needs warm air temperatures because Alexander island blocks deep oceanic upwelling as a cause.

    Yes, there are uncertainites in the dating but they all cluster to the Climatic Optimum time. I don't think anyone in their right mind would say everything everywhere happened on the same day, but it did happen all within the same 5000 year period at both poles--so what we see today is only a mere shadow of the melting that took place down there.

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  4. To the second comment (I do appreciate Hagiograph) your comments.

    You note that the tropics were not warmer during that period of time. Most models even today say that if global warming happens it will be greatest at the poles, so I don't find that surprising.

    "In its 1990 science report, the Intergovernmental Panel on Climate Change (IPCC) noted that global warming is expected to warm the poles faster than the tropics " http://archive.greenpeace.org/climate/polar/antarc_report/ant2.html

    Thanks for the QSR reference. I will get that article. It seems that there is indeed lots of evidence for warming down there.

    Here is the thing Hagiograph, from 10,000 years ago to about 5000 years ago, the Deuterium curve from Vostok's ice core says it was warmer there then than now. That doesn't mean that every day was warmer or every millennium was warmer. I am certainly not saying that. And as I said in my reply to your first note, not one says that everything happened simultaneously. What I am saying is that the climate people are not telling you everything and certainly not telling you the whole story.

    There is, as you just found, lots of evidence for early Holocene Warming--That is a long period of time. To make you feel better about quoting Wiki, I will as well

    "The Holocene Climate Optimum was a warm period during roughly the interval 9000 to 5000 years B.P"

    Above I said, 10000, but so what? That entire period shows signs all over the world of significant warming with relation to today's temperature, which is why I say that the NOAA site is a bunch of Holocene deniers--they deny that the world has already seen the warming we fear.

    Again, thanks for the QSR reference

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  5. "Thirdly, what do you propose to do to stop it?"

    That's a really, really good question. I am conflicted personally about what we can do. I've heard everything from advocates calling for the immediate cessation of coal-fired power plants to "weaning" strategies.

    I suspect the only reasonable approach is one in the middle somewhere. I think there's a lot each of us can do (and should do) and I think letting people waste as much petroleum as they can purchase isn't a good way to live. I live in a place where, even as recently as Saturday I saw someone tooling around to the store in a first-generation Hummer (!) I know it must make them feel powerful to be able to fuel that monster at current oil prices, but I don't think that they should necessarily be allowed to.

    Anymore than I think people should be allowed to waste water here in Southern California (we currently have a mandatory water usage limits in effect, enforcible by fines).

    Petroleum will one day run out. No big surprise. Probably sooner than later, so we'll have to learn how to adapt anyway. Coal we've obviously got a LOT more of here in the U.S. but we live profligately with regards to energy.

    It's going to be painful whatever we do, no doubt. There's no easy answer except "Do nothing", which is, in my opinion, dangerous not only from a global climate change perspective but from a resource perspective.

    One energy economist I read once said that future generations will probably laugh at us for 'wasting' petroleum on something as mundane as transportation. When I look around at the vast need for polymers, agrochemicals and plastics we NEED I tend to wonder if that assessment isn't correct.

    I wish I had a quick answer. I know we need to do something, and I'm trying to do something myself. But is it enough?

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  6. I really really appreciate your honesty about how difficult this problem is. Most people aren't that honest about the difficulty. I am published on running out of oil in 2000, wrote it in 1999. The sad thing is there is nothing we are going to do to stop us from running out of oil and the coal reserves we have in the US are far less than most people think. We don't have a 200 year supply of coal, maybe 100 years, at best.

    I will post something on the problems trying to do something about this soon.

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