Measuring Sticks

From time to time, readers here have something to offer other readers which can’t easily be conveyed in the comment section.  And, from time to time, I’m eager to get someone else’ perspective.  Long time reader, Hank, as graciously offered to write a few posts for Suyt’s space.  I’ve happily agreed.

Today, he’s wrote a post which for many of us is mostly old hat, although towards the end of the post you may have a surprise.  It seems we get new readers all the time here.  Because of the broad areas of subjects we discuss, many may not be familiar with this information.  I should also note, not everyone agrees with some of the information provided.   Any formatting difficulties are my doing.

A Guest Post by Hank Hancock.

As a medical / technology researcher with a good educational background in mathematics, the one thing that constantly catches my attention is how graphs are misused in both sides of the climate debate to prove a point. I’m not saying all graphs are wrong, just some graphs are wrongly used in ways that do not accurately represent what the data is saying.

Our natural world is full of rhythms. The climate is no exception. The climate naturally warms and cools regionally and globally in response to a number of short term, multidecadal, multi millennial, and longer term cycles that coincide with periodic changes in our planet’s oceanic thermohaline circulation, orbital variations and inclinations called Milankovitch cycles, solar activity cycles, and even cosmic ray galactic cycles. These cycles intertwine with each other to modulate the temperatures of our planet up and down on various time scales. Here’s a list of natural cycles that are believed to affect the temperature of our planet to varying degrees:

  • Solar Cycles:
    ·11 year Schwabe Cycle
    ·22 year Hale Cycle
    ·87 year Gleissberg Cycle
    ·176 year King Hale solar cycle[1]
    ·210 year Suess Cycle (aka. de Vries Cycle)[2]
    ·900 year Bond Event Cycles[3]
    ·2,300 year Hallstatt cycle[4]
    ·6,000 year (as of yet unnamed) cycle[5]
  • Thermohaline Oceanic Cycles:
    ·65 year Atlantic Multidecadal Oscillation (AMO)[6]
    ·80 year Pacific Decadal Oscillation (PDO)[6]
    ·Variable short timescale El Niño-Southern Oscillation (ENSO)[6]
    ·Short timescale North Atlantic Oscillation (NAO)[6]
  • Milankovitch Orbital Cycles:
    ·22,000 year procession (wobble)[7]
    ·41,000 year axial tilt[7]
    ·110,000 and 400,000 year eccentricity[7]
  • Cosmic Ray Cycles:
    ·Decadal and millenial cosmic ray fluctuations (following solar activity)[8]
    ·140 million year cycles traversing galaxy spiral arms.[8]

I’m sure I’ve overlooked a few. My purpose is not to quantify the effect of the above cycles but to make the point that they are natural cycles.

Keeping in mind that these are fairly regular cycles, we can neatly represent them as peaks and troughs (increasing and decreasing effects on the climate) as in a sine wave.  Consider the following graph of a pure sine wave:

image

Notice that when we use a measuring stick, shown as the green line, that is exactly one full wave length of the cycle (the length from one peak to the next peak of the cycle) we get a zero trend line (the red line). As long as we keep the appropriate length measuring  tick, we can slide it in any direction and no matter where we position it, we will always get a zero trend line. The figure below demonstrates this point. Here I’m shifting the measuring stick to the right and measuring two different points on the sine wave.

image

Notice that although the measurement points are different, the trend remains zero. This again confirms that the sine wave has a zero trend. You can play around with the measuring stick and confirm that anywhere you slide it, it will always produce a zero trend line. In this case, our measuring stick is of correct length and it is telling us the truth.

What happens when you shorten the measuring stick to, say, 3/4 of the length of the sine wave? Think of this in terms of the second graph you drew earlier. Recall that it too had a shorter timeline (measuring stick). Depending on where you slide the measuring stick to, you will change the slope of the trend being measured. The next two figures demonstrate this rather strikingly:

image

Above, we are measuring two points that intersect the measuring stick on the sine wave.  Notice that the trend is positive. Now, lets slide the measuring stick to the left and take two new measurements.

image

You can see that it radically changed the slope of the trend to negative. Realize that both trends are false. We know the true trend for the sine wave is zero.  Now we’re starting to see the problem. If you attempt to measure the trend using a measuring stick that is too short, the trend will always be a contradiction to what the data is saying.

There is a raging debate in the blogosphere regarding what time scale differentiates weather from climate. Most climatologists agree that the smallest unit of climate measurement is 30 years. I think it’s fine to average weather over 30 years to arrive at the climate for that period but it’s not fine to use 30 years as the timeline to represent climate history as is commonly done because it is misleading. The current climate and climate history must be taken into proper context for graphs with trend lines to have any real meaning.

Our present interglacial period, called the Holocene Epoch, started approximately 12,000 to 14,000 years ago. We’re very near the end of our present interglacial period and on the doorstep to the next ice age if mother nature keeps on schedule as depicted below.

image

Above, I drew in a horizontal blue / red bar towards the bottom of the graph. The blue depicts each glacial period (ice age) and the red depicts each interglacial period (warm age) across the 450,000 year timeline. As you can see, the warm period we presently live in is of similar length to the others. Also notice that the temperatures we’ve experienced in our current interglacial period are cooler than previous interglacial periods.

Now, lets zoom in on just our current Holocene interglacial period with the graph below.  It represents the last 12,000 years of our climate history, starting with our climbing out of the last glacial (ice age).

image

You can see that even in our interglacial, our temperatures follow roughly an 900 to 1200 year cycle of heating and cooling. This overall cycle is formed by the additive and subtractive effect of the various solar and thermohaline cycles enumerated above coming together but, for the most part, there is good correlation to the Bond Event cycles. Notice how the above graph looks a lot like the sine wave we played around with earlier.

At the very bottom right corner of the timeline, I drew in a purple and green horizontal bar. It’s kind of small. The green portion of the bar, which is barely even noticeable represents 30 years – the smallest measure of climate by today’s standards. The purple portion of the bar represents our entire instrument record – the period of time in which man has been measuring and recording temperatures. What do you notice about the temperature trend across the timeline covered by the combined purple and green portion of the bar? The climate is most definitely warming.

Now, draw a straight line from the top peak of the first Holocene Climate Optimum (HCO) to the peak of our current warm period at the far right of the graph. What do you get?  That’s right, our climate has been gradually cooling since the HCO.

Funny how, depending on how long the measuring stick is, it tells us something very different. So, are we warming or cooling? Well, both actually. We are in an intermediate short term warming phase of an intermediate cycle superimposed on a climate that is gradually cooling towards the next ice age.

The 30 year measuring stick that is so often used in portraying global climate is entirely too short to say anything about the bigger climate picture. All it can tell us is if we are warming or cooling across the 30 year measurement period, nothing more. That’s about as useful as knowing that we’ve warmed since last night. Yea, we expect that but on the grander scale of climate history, how do today’s temperature changes compare?

Here’s an example of a graph I pulled from the Internet that shows global warming:

had3nh

Do you see the measuring stick fallacy? The graph is meaningless to speak to global warming because the measuring stick is only 140 years long.

I extracted the trend line from the graph and overlaid  in red on top of a 30 proxy temperature reconstruction by Dr. Ljungqvist [9] below.  [editorial:  This is not the recent dendro post at WUWT]  There is some divergence between the the proxy record and the adjusted instrument record but that’s not my point of interest. Look at the length of time the Wikipedia graph covers. It’s too short to tell the full story of the current climate cycle we’re in.

CWP

When we talk about global warming, it has been been drummed into our heads that the globe is warming at unprecedented rates. Unprecedented implies “like never before.” Well, how do the slope and extent in today’s temperature compare to, say, the Medieval Warm Period? Using a little Photoshop magic, lets move today’s instrument record back a thousand years. What do we see? Proof of global warming a thousand years ago!

MWP

My point is global warming is almost always presented using graphs that, yep, show global warming but they’re showing only a small part of a cyclical temperature history that omits the history so that we don’t have a sense of the true context of what is shown.  When we lengthen the measuring stick to place it into context, what we see is quite revealing.

References:
1. R. K. Tiwari and K. N. N. Rao, Solar and tidal reverberations of deglaciation records
from the tropical western Pacific: a clean spectral approach, GEOFIZIKA VOL. 16-17
1999-2000

2. Braun, H; Christl, M; Rahmstorf, S; Ganopolski, A; Mangini, A; Kubatzki, C; Roth, K;
Kromer, B (10 November 2005). “Possible solar origin of the 1,470-year glacial climate
cycle demonstrated in a coupled model”. Nature 438 (7065): 208–11

3. Gerard Bond, et al; A Pervasive Millennial-Scale Cycle in North Atlantic Holocene and
Glacial Climates, Science 14 November 1997: Vol. 278. no. 5341, pp. 1257 – 1266

4. “The Sun and Climate”; U.S. Geological Survey.

5. Xapsos, M. A.; Burke, E. A. (July 2009). “Evidence of 6 000-Year Periodicity in
Reconstructed Sunspot Numbers”. Solar Physics 257 (2): 363–9. doi:10.1007/
s11207-009-9380-3

6. Knight, JR er al. “A signature of persistent natural thermocline circulation cycles in
observed climate.” Geophysical Research Letters 32 (2005):L20708.

7. Milankovitch, M. 1920. Theorie Mathematique des Phenomenes Thermiques produits
par la Radiation Solaire. Gauthier-Villars Paris.

8. Henrik Svensmark; Influence of Cosmic Rays on Earth’s Climate, Solar-Terrestrial
Physics Division. Danish Meteorological Institute, Lyngbyvej 30. DK-2100 Copenhagen,
Denmark

9 Ljungqvist, F.C. 2009. N. Hemisphere Extra-Tropics 2,000yr Decadal Temperature
Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data
Contribution Series # 2010-089. NOAA/NCDC Paleoclimatology Program, Boulder CO,
USA.

Update:  Thanks to astute observation and keen eyes of commenter “thallstd“, this post has been updated to address his concerns.   The graphs have been updated.  The current warming graph has changed to reflect the Northern Hemisphere warming.  The Ljungqvist have been updated with this overlay and the time resolution issue fixed.  Our thanks to thallstd.  —— James

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45 Responses to Measuring Sticks

  1. Bruce of Newcastle says:

    One irony is the ‘et al’ of the Knight paper includes a certain Dr Mann of recent fame.

    It would be interesting to ask him about the thermohaline cycle and the clear-as-proverbials big 64 year AMO sinusoidal in their Figure 1. But he’s probably too busy twittering and doing book signings to respond.

    On my simple arithmetic the 60-ish year cycle contributed 0.27 C of the 0.82 C rise in HadCRUT temperatures from 1900 to 2000 because of exactly the endpoint problem that Hank identifies. Joe D’Aleo had a post this week with much the same data, but presented more clearly. Add another 0.4 C or so from the solar magnetic and TSI components and the residual fits Lindzen’s number for sensitivity very neatly. Which says that the CAGW hypothesis is wrong.

  2. jimash1 says:

    I have been pointing out for years the idiocy of starting the record in the 1880’s,
    because as far as I know the 1880’s are famous for the blizzards and inclement weather.
    http://files.usgwarchives.net/sd/history/robinson/liii.txt
    Isn’t it amazing how we use the words that fit ?
    Like inclement when the weather sucks.
    And Optimum, for when the climate is good ?

  3. gallopingcamel says:

    This posts demonstrates how smart the IPCC was to choose 1850 as the start date for their alarmist fantasies.

  4. kim2ooo says:

    Reblogged this on Climate Ponderings and commented:
    Corruptions in graphs

  5. miked1947 says:

    Biological and geological evidence shows the regions of the globe were warmer in the past. However we do not have enough accurate data to determine even a regional temperature over any meaningful period of time, let alone global temperatures, to less than 5C accuracy.
    The trap I see is trying to show definite time periods to cycles that have only recently been realized when there is still not enough accurately recorded data to support those time lines.
    These are variable cycles that have average lengths rather that fixed periods. They are also reactions to outside forces rather than causes.
    Once we realized that regional cycles were longer than thirty years, thirty years should have been discarded as a measure to judge climate by. We know that some regional cycles are close to 60 years which would mean 60 years is one wave or data point. We also know that a global cycle is over 100,000 years. that means anything less, when considering global conditions, is weather.

    Other than those minor issues it was a good post that showed many of the problems with the current state of “Climate Science”. Which is not science at all.

    • HankH says:

      There was much I could have said as disclaimers but I had to limit the number of words. Here’s one that didn’t make the cut but I think is in agreement with your observation.

      As a FCC licensed RF engineer, I work with very short scale cycles all the time and have to account for all sorts of problems with measurement. Take a single radio frequency from one transmitter and look at it from a distance and you’ll see all kinds of distortion in amplitude and phase from the original wave due to reflections and different propagation delays from different paths, etc… Take the measurement two inches away from the original spot and you’ve got a whole different set of interactions. On the receiving end the waveforms are very different but have some, if barely recognizable, resemblance to what left the transmitter.

      Now, look at many transmitters from multiple sources and spectrums and you’ve got a real clump of interacting waves to untangle. As you change measuring sticks, some frequencies loose scope and new ones dominate that timeline. Some are harmonics and random phase interactions from signals outside of the spectrum the measuring stick is selected for. This is not unlike climate cycles.

      There are traps but the scientist in me says spring them to see how they work. The mistake would be in using your foot rather than a stick that you can throw away. Understanding why they are traps and why they are there tells us something about the system that allows for them.

      • miked1947 says:

        Hank:
        Because I was involved in RF and other communications frequencies led me to make the comments I made regarding your post. I dealt with 10 hertz up into the mega hertz ranges. one of my jobs was finding disrupters and separating signal from noise through frequency discrimination.
        Have fun with Stefan!

        • HankH says:

          Ah, then you truly understand the issues of sorting real from what looks real. I kind of figured you might have such a background because your comment had that level of insight. Working at ELF and VLF frequencies, my guess is you were working on underwater communications?

        • miked1947 says:

          Just Communications at all levels as an analyst and trouble shooter.

  6. Hank, you really forgot to include Paris Hilton’s menstrual cycle; the global shonky science to be completed. Is it too difficult for you people to understand that: climatic changes have nothing to do with your phony GLOBAL warmings. No need GLOBAL warmings, for climate to keep changing = as; no need GLOBAL warming – to get from winter into summer climate / to get from dry into wet climate. I can see why you people are scared from real proofs – you have wasted big part of your life, collecting crap… crap shouldn’t go to waste – should be passed to other victims / suckers…?

    Hank, I wish I can find something that is correct in your text; but what you are showing, is what makes Green People to grow and multiply; not the green vegetation. Cow dung is the best organic fertilizer for the vegetation; but your bull-dung collection is what makes the Warmist to grow, multiply and prosper. Saturday’ cycle, Monday’s cycle, Domesday cycle. Climatic changes are NOT uniform for the WHOLE planet. Some places climate improves / other places deteriorates – ”GLOBAL warming disease”, is a mental disease / imaginative – not reality; shouldn’t be mixed or confused with the big / small climatic changes.

    Sahara has bad climate; Brazil has good / DIFFERENT climate; that’s what climate is. Nothing to do with the ”hallucinative” GLOBAL warmings.. The water on the beach in your neighborhood when rises by 2m, water in all oceans doesn’t go by 2m up – it means: on other places the water goes down by 2m; or by 1m, but on larger area. SAME GOES WITH THE TEMPERATURE. It gets warmer some place; BECAUSE is gone colder another place.

    The only good that is going to come out of sick Warmist misleading propaganda, is: when the society realizes, what sorts of ”CON”’ has being going on in the ”shonky climatology” hopefully they will introduce a rule for the future: one profession to check on other professions; before some avalanche of crap gets out of control, as it is with climatology. Climatology epidemic will be cured by reliable sciences as physics, chemistry. The Reds cannot manipulate those – they are not as your ”mythological cycles” The truth always wins on the end. It will be proven: if the climatology or prostitution is the oldest and most dishonest profession; or is it one and the same profession, under two different names..

    • HankH says:

      In other words, science has no capability to measure anything and all we can do is make stuff up so we can ourselves scientists and impress the feeble minded. And you see right through it. Our climate system is either so chaotic that there are no discernible cycles or at static equilibrium such that cycles don’t exist. Climatology is all crap. Scientific inquiry is the devils playground. The scientist that you yourself identified as getting it right, Milankovitch, is wrong too. Everything I presented is demonstrably wrong by your “proofs.”

      What am I missing in your rant?

      • HankH July 14, 2012 at 7:46 pm

        Hank, scientist that can measure; they are into physics, chemistry. Climatology is NOT a science. Climatology is as studding horoscope, or Disney scripts. Should be made as science; where for malpractice, ”real scientists” end up in jail. Nostradamus tactic ”predictions” 2] finding imprint for something that shouldn’t be there under today’s climate – then declaring the WHOLE PLANET warmer, INCLUDING THE sea 2/3 of the planet that was warmer; is very, very naughty – then next generation reads it and think that is ALL factual. Real Science has capability of measuring / climatologist don’t / some don’t want to. If you refuse to understand my formulas, real proofs and facts; that can be all replicated in a controlled environment – is a proof that ”climatology” is a cult, religion, but most definitely not a science. .

        Climate system is sometimes chaotic, sometime cyclical – same places chaotic – other places cyclical. Using ”climatic systems”, to insert the phony ”GLOBAL” warmings / or phony GLOBAL coolings – is the mother of all crimes. On my blog it clearly states and proves that: climatic changes are a natural phenomena – GLOBAL warmings CON is a phenomenal lie!!!. Hank, you people will not be able to get away with that for much longer; people on the street will realize that climate keeps changing, will get more extreme; but phony GLOBAL warming will not happen. Then they will realize that: the laws of physics were same in the past, as they are today. So, your beliefs that: you people can make up dozens of phony global warmings – just to create career, will backfire. Some people hate me, for informing / warning them… I do the same as parent says to his children; stop doing silly things / people will notice and you will regret it.

        Then people will demand for ”sunspots & galactic dust” and any other crap; protagonist, to be brought to justice. Crime shouldn’t pay. Have in mind the ”INSTANT” shrinking / expanding of O&N, in change of temperature – and what’s the temp into the space they expand into, comparing with the ground temp = you will see that: only Hilton’s menstrual cycle can stand scrutiny; all other GLOBAL warming cycles are just an avalanche of crap. Please note: I NEVER ARGUE ABOUT LOCALIZED WARMINGS / I NEVER ARGUE ABOUT ”CLIMATIC CHANGES”

        • HankH says:

          Okay, that’s what I was missing.

          Three points of correction…

          1. You think I am a proponent of catastrophic global warming. I’m not.

          2. You think I am a climatologist. I’m not. Had you read my article you would have realized that I stated it up front. My fields of research are technology and medicine. I don’t write the climate book so I don’t take credit for what flies and doesn’t fly. I don’t get paid either way.

          3. You talk like you have a background in physics but you seem oblivious to the concept of resonance. It occurs at all temporal scales in our natural system. Why is our climate system so special that it strangely lacks a key physical property that is essential to the workings of the rest of the universe?

          #3 above is a rhetorical question. Think about it.

        • HankH says:July 14, 2012 at 11:25 pm Okay, that’s what I was missing.1. You think I am a proponent of catastrophic global warming. I’m not.”

          Hank, did you ever see me using the word ”catastrophic”?! Never. But I use the words: Warmist & Fakes have a WRONG ”STARTING” point. Both camps are barking up the SAME wrong bush; because they think that they have already abolished the laws of physics… Overlooked that: O&N regulate the temp, to be same ”OVERALL’ every day of every year and millenia; because, that’s what the laws of physics say!!! You are promoting phony GLOBAL warmings -> that promotes / justifies the Warmist crimes, I say what I see. Worse climate is ahead, worse than anybody prefers; but people are blinded by the CO2 crap

          Hank, if you want, we can discus climate, for weeks, I’m writing a post on it, now. But first, we should get to the conclusion: if it was those past climatic changes – ”GLOBAL WARMINGS, or NOT’?!?!?! If not, keep confusing yourself with all the misleading propaganda…confusion is not conclusion. Climate needs to change constantly – when is extreme = is culling the weak, to make space for diversification.

          I said many times: ”most of the genes have degenerated; but not the ones for adaptation = proof that climate NEVER stopped changing”. Lets hope that the climate will keep changing. That has nothing to do with the Warmist GLOBAL warmings ”cycles” that you promote Hank, even extreme climate; has reasons for it + has positive contributions H2O is doing it, NOT co2, or any stupid sunspots!!! SAME sunspots affect Brazil and Sahara; isn’t that proof enough; to stop blaming the sun?! WRONG STARTING POINT, CREATED ALL THE CONFUSIONS. Do you intent to go further into the WRONG direction? Think and ask yourself that question.

    • HankH says:

      …all we can do is make stuff up so we can [ call ] ourselves scientists…

  7. HankH says:July 14, 2012 at 8:57 pm…”all we can do is make stuff up so we can [ call ] ourselves scientists”

    No, Hank, there are brilliant scientists in this world; they are contributing to humanity. Unfortunately, climatology cannot be packaged and sold in the supermarket -> people involved in it are making up things / exaggerating others, ignoring real facts and all sorts of goodies

    Hank, when you have time; check if those Q&A are wrong, misleading, fantasy… or 24carat proofs
    http://globalwarmingdenier.wordpress.com/q-a/ If those Q&A are correct, can stand to any scrutiny = proofs that 99% in the global warming blogosphere is CRAP Proof is not a”rant” If you cannot cross those 2 hurdles that: one: O&N expand instantly when warmed / shrink instantly the split second they are cooled to previous temp
    Two: the hotter it gets close to the ground .-> the FASTER vertical wind becomes (hot air balloon has plenty of CO2 in; but doesn’t prevent warm O&N lifting the balloon and 500kg up. Tantrum doesn’t change the truth / reality

    • HankH says:

      Stephan, thank you for switching out of attack mode.

      I understand the physics of your “proofs.” My challenge in finding agreement with you is that we seem to have a disconnect on the concept that climate variability is not instantaneous and occurs on various time scales. My understanding is the largest heat transport on the planet is the thermohaline conveyors, not air. Then there’s all the drivers, feedback loops, coupling of subsystems, and such that interact in complex ways and on different time scales.

      If I could understand how all of the above reduces down to O&N and EC > AS > LHR then I might get it. I feel our free form discussion and hitting minute points will take ages for me to understand. I am not in the habit of dismissing other people’s ideas but being placed in an ideological box and attacked because I don’t understand your point of reference is a difficult position to work from.

      Perhaps if I were to obtain an edited full text copy of your book it might be more instructional for me. What is the title of your book and is it available in a reader format? The PDF condensed summary of your book is like reading the playbill rather than watching the play.

      Regards

  8. Jim Masterson says:

    With all of the electronics experts around here, I would think that dealing with sine waves would be a no-brainer (I’m a EE myself). Has anyone tried doing an RMS (root-mean-square) average of these waveforms? RMS is what an AC voltmeter would read. To get peak voltage (or peak-to-peak) requires an oscilloscope.

    The mathematical definition of RMS is quite precise. I would think you could get a running RMS mean of these waveforms and obtain a more meaningful average.

    Someday maybe I’ll have time to do it.

    Jim

    • HankH says:

      I forgot to put the peak to peak voltage on those sine waves. For fun, lets assume 160V. I think then it will work out to what the AC voltmeter would read if you stuck it in the wall socket (assuming you live in the U.S.A.). Working out the average… Dang, my calculator must be broke. It keeps saying zero. LOL!

      • Jim Masterson says:

        Well, it’s more like 165V, and you shouldn’t have plugged your 9V calculator into the wall receptacle.

        Jim

        • miked1947 says:

          Jim:
          As I stated before, there is not enough ACCURATE data to find a meaningful result as our measuring methods are still not up to the challenge and what we do have does not contain enough data points to get a good peek to peek reference.
          At 60 hrtz I can take ten minutes worth of data and give you an average for comparison, although I preferred to use ten hours or more as a reference point. (More meaningful)
          Even when measuring 1 Khz to 28 Khz over distance we would usually get one or two minutes of readings to find a base line for comparison.
          I think of weather events as if they represent the ripples on a water surface after a rock has struck the surface. We may be still experiencing the after effects of events that started over a billion years ago. Action and reaction on to infinity. There is always another tipping point just around the corner.
          Living through the events we are to blind to see what is coming and we can only guess at what happened in the past.

        • HankH says:

          Good catch.

          For 117V RMS you would be correct. I was doing the calcs in my head (after two glasses of Merlot) and basing on 115V RMS but dropped the 2 when writing. I should have written 162. A case of drinking and deriving. LOL

          RMSavg and Vavg yield two different results. I realize you were talking about RMSavg and I was thinking Vavg. Vavg is always zero if there’s no DC bias. If there is then Vavg = DC bias.

        • HankH says:

          Miked1947:

          I think there’s something to your concept of ripples. I like to think of it in terms of a bell ringing. Something struck the bell a long time ago and we’re still seeing the resonance going forward. There’s old theory that the moon was created when a large asteroid struck the earth back in its early formation. It may have been that impact that got things to rippling and set up the wobble and procession of the earth that Milankovitch observes. I don’t think we really know. There’s other theories too but the general concept that something struck the pond or bell makes a lot of sense. Heck, something’s always striking something out there in the universe. Lots of bells ringing and ponds rippling.

  9. Pingback: The Hockey Stick Resurrected By Marcott et al. 2012 | suyts space

  10. thallstd says:

    I noticed 2 things when comparing today’s temp to the lead up to the medieval warm period that need explanation.

    1) You start with 130 years of today’s temps (1880-2010) but when overlayed onto the 2000 year chart it covers 1720 to 2010, 290 years

    2) Today’s temps are indicated as Global, the 2000 year chart temps as Northern Hemisphere. Is this a valid comparison?

    I realize you aren’t intending to compare rate of warming now to then, just to show the cycle of warming. Still, why expand 130 years of current history to 290 and why compare global to northern?

  11. HankH says:

    Hello thallstd, thank you for visiting. When I overlaid the thermometer trend in Photoshop, I trusted that the thermometer trend should at least loosely match the trend in the reconstruction. On that basis I fitted the overlay so that the two lined up. Your spotting this issue brings me to a realization that has other implications. The thermometer trend, in no way even loosely matches the proxy reconstruction. It is generally agreed that NH has been warming at a faster rate than globally averaged trends. I would expect the reconstruction trend to then be steeper than the thermometer trend and it’s not. Ahem, I’m thinking the issue is the thermometer trend presented in Wikipedia was exaggerated. I think I’ll leave that issue alone as it wasn’t the context of the article but is an interesting problem to ponder.

    The above said, my purpose was to compare the rate of warming of the current warm period to that of the Medieval warm period. Had I just overlaid the current warm period trend in the reconstruction over the the Medieval warm period, I would have gotten the same results and made the same valid point. That or I could have gone to WFT and found a temperature series that was a better fit.

    Anyway, your observation is correct. I wasn’t concerned with making a comparison of thermometer temperatures with the reconstruction but focused on just comparing two trends by using the thermometer series as an illustration tool. Next time, I’ll pay better attention. Thanks for pointing this out.

  12. thallstd says:

    Thanks for the quick reply Hank. I wanted to cite this page and that chart as partial evidence that today’s warming is not unusual but don’t think I can now. The degree scale is also not retained in the overlay. In the original it spans -.4 to +,6 (an increase of 1 degree) and in the overlay it spans -.4 to +.1, half a degree. So when the overlay is compress the time period by ~halve and extend the temp range by double it’s current representation, it won’t fit the current or medieval warm period reconstructions at all.

    • HankH says:

      Agreed. The divergence between thermometer temperature series and proxy reconstructions is astounding. It’s like they’re taking measurements from two different planets.

      I should have simply overlaid the reconstructed trend in the Current Warm Period (CWP) with the Medieval Warm Period (MWP) and colored the overlay red for distinction. In retrospect, I think that would have made the point even better (apples to apples). Thanks again for calling it to my attention.

    • HankH says:

      thallstd, the article was updated with new images using correct scaling. I found that the HADCRUT3 NH series gave good alignment on the trends when scaled to the reconstruction. You will note that the it overshoots/undershoots the reconstruction somewhat but aligns well on the trend. This is because the temperature series has high temporal resolution whereas the reconstruction is of much lower and incapable of showing the full excursion of temperature peaks and troughs.

      Thank you again for calling the scaling issue to my attention. I’m glad we have readers that care enough about the issues to check our work.

  13. daveburton says:

    A belated comment: the literature indicates that you need about sixty years of data (bare minimum 50) to extract a robust trend from a single sea-level measurement record at a single tide gauge:
    http://www.sealevel.info/papers.html#howlong

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