Global Warming

11,000 Year Temperature Trend Study Not All It Is Claimed to Be?

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Melting less
Credit: Dreamstime

Back in early March, a team of climate researchers led by Shaun Marcott from Oregon State University published an intriguing study in Science looking at global average temperature trends using proxy data. As I reported the study found:

Our results indicate that global mean temperature for the decade 2000–2009 has not yet exceeded the warmest temperatures of the early Holocene (5000 to 10,000 yr B.P.). These temperatures are, however, warmer than 82% of the Holocene distribution as represented by the Standard5×5 stack, or 72% after making plausible corrections for inherent smoothing of the high frequencies in the stack. In contrast, the decadal mean global temperature of the early 20th century (1900–1909) was cooler than >95% of the Holocene distribution under both the Standard 5×5 and high-frequency corrected scenarios. Global temperature, therefore, has risen from near the coldest to the warmest levels of the Holocene within the past century, reversing the long-term cooling trend that began ~5000 yr B.P.

They illustrated their point using this hockey-stickesque graph:

the new hockeystick
Credit: Roger Pielke

 The National Science Foundation press release about the study stated:

Peter Clark, an OSU paleoclimatologist and co-author of the Science paper, says that many previous temperature reconstructions were regional and not placed in a global context.

"When you just look at one part of the world, temperature history can be affected by regional climate processes like El Niño or monsoon variations," says Clark.

"But when you combine data from sites around the world, you can average out those regional anomalies and get a clear sense of the Earth's global temperature history."

What that history shows, the researchers say, is that during the last 5,000 years, the Earth on average cooled about 1.3 degrees Fahrenheit–until the last 100 years, when it warmed about 1.3 degrees F.

Now it seems that the conclusion is a bit less robust than has been claimed. Various climate change watchdogs of a skeptical bent have pointed out that the the proxies used by the researchers for the more recent decades do not in fact show the big jump in temperatures in the 20th century at the end of the time series graph. in other words, their data do not produce a blade at the end of this particular hockeystick. Consequently, the researchers have backed off a bit on the claim that the proxies used in their study show that the earth has warmed 1.3 degrees Fahrenheit over the past 100 years. See, for example, their FAQ response to various critcisms over at Real Climate. In particular: 

Q: What do paleotemperature reconstructions show about the temperature of the last 100 years?

A: Our global paleotemperature reconstruction includes a so-called "uptick" in temperatures during the 20th-century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions.

The critical phrase is …

… the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions.

Somehow this subtlety got missed in the NSF press release. The researchers do, however, further note:

Our primary conclusions are based on a comparison of the longer term paleotemperature changes from our reconstruction with the well-documented temperature changes that have occurred over the last century, as documented by the instrumental record. Although not part of our study, high-resolution paleoclimate data from the past ~130 years have been compiled from various geological archives, and confirm the general features of warming trend over this time interval (Anderson, D.M. et al., 2013, Geophysical Research Letters, v. 40, p. 189-193; http://www.agu.org/journals/pip/gl/2012GL054271-pip.pdf).

The last bit is a reference to a GRL article that found that data derived from some 170 temperature proxies basically matched the upward trend in global average temperatures as measured by thermometers over the past century.

Nevertheless, it's pretty clear that the NSF press release overstated what could be concluded about recent temperature trends from the study itself. University of Colorado environmental science studies professor Roger Pielke, Jr. is recommending that the authors retract the figures showing the 20th century uptick in temperatures and issue a correction. Readers wishing to go deeper into the weeds over this particular study, please take a look at Steve McIntyre's analyses over at his Climate Audit site and Tamino's take over at his Open Mind site.

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  1. The massive snowstorms and bitter spring weather now being experienced across large parts of Europe and North America may be due to the dramatic loss of Arctic sea ice

    1. That’s funny. I just read that anthropogenic global warming is to blame for the INCREASE in Antarctic sea ice. Who’d have thought?

      http://www.bbc.co.uk/news/scie…..t-21991487

      1. When it comes to not being taken by third rate con-artists the Brits it’s seems are leaving us looking like a bunch of ignorant marks begging to be used.

  2. Would someone of reasonable climatological experience just finally come out and say “You know what? We have no idea what the temperature was 11,000 years ago, but it’s stupid to be spewing a bunch of crap in to the air when we have ways of minimizing pollution available now.”

    This whole debate could have been ended a decade ago if they just said “Global pollution is bad. Let’s figure out ways to slow it down/eliminate it.” Instead we’ve been playing this stupid game over how hot or cold the planet is.

    1. That’s because it’s not about reducing pollution, it’s about CONTROL.

      1. Labeling CO2 as “pollution” was the Big Lie.

        1. Oxygen is a corrosive, you know. And contributes to combustion.

          1. Carbon dioxide is twice as bad as carbon monoxide, and you don’t even want to be breathing carbon monoxide. It’s just science.

            1. Don’t get me started on dihydrogen monoxide.

              1. You do not want to be breathing that stuff.

            2. Um, excuse me.
              Like, Carbon trioxide?
              I mean, gag me with a spoon, you know?
              Oh my Gaaahhhhd!

            3. Ummm hello.
              Like, Carbon trioxide?
              I mean, like, Omygod.
              Gag me with a spoon.
              Like, right, you know?

          2. Precisely. Especially killer in its free radical (superoxide anion) form.

            1. And nitrogen. . .it’s used to make explosives. Also, oxygen, carbon dioxide, and nitrogen all come from nuclear fusion. Unlicensed nuclear fusion.

              1. ProL, I thought you said crossing the metaphors was bad.

              2. So, we’ll just ban stars. Or at least make them so expensive no one will be able to afford to use them.

        2. Labeling carbon dioxide as pollution is taking misanthropy way up past the next level to the hatred of all life.

    2. This is exactly right. People were generally going along with a general anti-pollution course of action until it became totally political and about control of everything.

      1. Deniers are the ones who made it political. And it was never about your precious bodily fluids or some nefarious and vaguely-defined scheme to control you, but the politicization of this particular field certainly came with an agenda. It’s utterly baffling that you guys can see a conspiracy where there isn’t one and refuse to acknowledge the obvious financial motives right in front of your face.

        1. refuse to acknowledge the obvious financial motives right in front of your face

          Who’s refusing to acknowledge that Al Gore and his ilk in and out of government is bound to make a killing on AGW?

          1. And you suppose they somehow control the world’s scientific community to those ends?

            The oil industry is the most profitable on the planet and all it managed was a few seeds of doubt planted on the political fringe. If Al Gore was so smart you’d think he’d try some less convoluted scheme. Now not even oil companies are denying the facts. Al Gore controls them too!

            1. And you suppose they somehow control the world’s scientific community to those ends?

              Who funds academic research?

              The oil industry is the most profitable on the planet

              Citation needed.

              Take a look at Venezuela: has the most oil in the world and still a hellhole.

              1. Tony is a troll. You’re wasting your time arguing with him.

                1. I know; I’m doing it as entertainment + to keep myself on my toes.

                  I tangle with worse ones on Hungarian blogs (in Hungarian); fascinating to see how memes spread worldwide.

                  1. That’s fair. He’s like a stress doll then. Throw all your rage on him and his goofy smile just gets bigger.

              2. Who funds academic research?

                Governments largely, and you readily accept scientific findings in other fields, even fields with much less solid support in evidence.

                Take a look at Venezuela

                I see a generous social safety net funded by oil profits.

                1. I see a delusional retard.

                2. Governments largely

                  QED.

                  and you readily accept scientific findings in other fields, even fields with much less solid support in evidence

                  Not me; I subscribe to Karl Popper’s falsifiability requirement. If any & every measurement or empirical observation counts as supporting proof of a theory, that theory is utterly useless: its predictive power is nil.

                  I see that you skipped the citation for your statement of the oil industry being “the most profitable”. No surprise there.

                  As far as your look at Venezuela goes, Cytotoxic made the correct observation.

                3. Tony| 4.1.13 @ 7:27PM |#
                  …”I see a generous social safety net funded by oil profits.”

                  You would, shithead. The rest of the world sees a murder rate that’s enough to keep them away.

            2. “And you suppose they somehow control the world’s scientific community to those ends?”

              Your problem is you talk about the “scientific community” as if it’s a singular entity like the borg. Typical progressive bullshit, I guess. Sort of like “America has spoken” when 51% of the 30% or so of the population that bothered to vote, voted for your guy.

              1. But it’s not 51% of scientists agreeing on something, it’s closer to 98%.

                1. CITATION NEEDED

                2. No, Tony. No, it’s not. Not a single Physics, Chemistry, or Biology professor buys into it at my school. I’d love to see a cite for it, but I know you won’t be able to.

                    1. *Lose. More loosing of the Google finger, less begging for easily found knowledge.

                    2. For those unable to read more than a few sentences: “As of 2007 . . . no scientific body of national or international standing rejected the findings of human-induced effects on climate change.”

                    3. Re: Tony,

                      “As of 2007 . . . no scientific body of national or international standing rejected the findings of human-induced effects on climate change.”

                      Again the qualifier. Actually, scientific “bodies” are not in the business of rejecting the findings made by scientists of a different discipline, so that proves nothing. If you ask a physicist if he or she trusts what the climate scientists have claimed, he or she will invariably say “uh, yeah, sure” for the simple reason that there are a million other things in his or her mind to worry about, so it is simpler to trust what scientists of other disciplines have done rather than waste time verifying their findings.

                      At one point and after the dust settles, it is very likely most of those scientists will change their minds once the climate scientists find something different.

                    4. You could be right, but it’s you vs. every scientific body of national or international standing in the world at this point. So good luck with that. I think if you apply a little thought to the matter you might appreciate that one very likely possibility is that you will end up looking like a sad fool. That never crosses your mind though does it?

                    5. Nowhere in that entire piece does it say that 98% of scientists agree that anthrpogenic global warming is real.

                      And, Tony, saying that 98% of scientists believe in climate change is not the same thing. !00% of scientists should ‘believe’ in climate change because the climate demonstrably changes.

            3. Snork! Apple and Google are the most profitable industries on the planet, their profit margins FAR exceeding anything oil companies could dream of.

              As for Al Gore controlling the oil companies, you really ought to lay off that medicinal weed.

        2. Do you just pick random sentences and mash them together? Your mad libs is weak.

        3. Deniers are the ones who made it political

          Bwahahhahhaaaa! I only read that first sentence and knew there is only one person on the planet dumb enough to have said it.

        4. Re: Tony,

          Deniers are the ones who made it political.

          “And if it wasn’t for you pesky kids, I would’ve gotten away with it!”

          Leave it to Tony to give us a Scooby Doo argument.

        5. I don’t see a conspiracy. I see religious idiocy — the religion that holds mankind and human progress is bad and Gaia is great.

          Global average temperatures may well be increasing, but the increase so far is slight and historical data is questionable, for obvious reasons.

          How much of this is human-caused is highly speculative and hard to quantify. It could be largely from solar and planetary factors.

          How much global warming, if it is occurring, actually harms the biosphere or humankind is also debatable — it may be a net positive. Past global warming periods have been.

          How effective any proposed political “solutions” may be is also highly speculative. Even if they could be effective in terms of fighting the feared temperature increase, the costs to the human economy might overwhelm the benefit.

          Yet I’m called a “denier” if I point any of this out, and “unscientific”.

          1. At this point, it is proper to compare the people who claim that our CO2 emissions will lead to catastrophic warming to those purporting an autism-MMR link.

          2. Well put.

          3. It’s not speculative or controversial among relevant experts. You just aren’t aware of the facts. Just apply some basic Occam’s Razor for Christ’s sake. What’s more likely, that the global scientific community is involved in a plot to enrich Al Gore, one so convoluted a Bond movie scriptwriter would reject it, or that oil companies–who have an obvious stake–have funded anti-GW propaganda and idiots like you have lapped it up because it appears on all your favorite rightwing bullshit websites?

            1. Tony| 4.1.13 @ 7:29PM |#
              …”idiots like you have lapped it up because it appears on all your favorite rightwing bullshit websites?”

              Shithead pegs the ad-hom meter!
              Way to go, shithead!

              1. Calling you stupid when you’re being stupid isn’t a logical fallacy.

            2. Re: Tony,

              It’s not speculative or controversial among relevant experts.

              The qualifier “relevant” is to be taken to mean “those I find agreeable.”

              Just apply some basic Occam’s Razor for Christ’s sake.

              I’m game:

              What’s more likely? That global warming is part of the natural climate cycle of the Earth, or that it is entirely driven by evolved and materialistic apes, callously driving SUV’s without a care in the world?

              1. But we know it’s not a part of the “natural climate cycle” and we know it’s caused by human activity. These are facts. Why should you have a problem with them?

                Who really has the agenda here? The scientific community or the political dogmatist?

                1. The Earth was warmer than it is now in the Cretaceous period. The Earth has been warmer in the Holocene(the current) period. That additional warmth did not destroy all life on the planet.

                  We know this because we’re here to talk about it.

                  These are facts.

                  This is not–

                  But we know it’s not a part of the “natural climate cycle” and we know it’s caused by human activity

                  Not even to those mythical 98% of scientists you love to invoke. They believe that there is warming, that it is due to human action, and that it is bad so we must do something to stop it. And they all are agrred in this opinion–but even they do not state it as fact.

            3. “It’s not speculative or controversial among relevant experts.”

              Do you even begin to understand the idiocy of that statement? What you’re saying is that all the people who agree AGW is real are experts (and relevant!), and all the people who disagree are not.

              You obviously haven’t a clue as to how science works.

              1. I’m talking about climate scientists, and it’s not controversial among scientists generally. You have no leg to stand on. What’s frustratingly baffling is that this is so easy to find out in the age of the internet.

        6. Tony| 4.1.13 @ 6:02PM |#
          …”And it was never about […] some nefarious and vaguely-defined scheme to control you,”…
          Shithead’s right! It has always been about very-defined control of the economy, and by extension, every human activity.

          1. And by strictly controlling every human activity they seize absolute dictatorial control over not just you but over all.

        7. Deniers are the ones who made it political.

          I’m not sure how anyone can be so….Tony.

          It has been political from the beginning.

    3. Tman…this isnt about climate. If they took your advice their pretense for enslaving mankind would evaporate, and they arent going to let that happen. They will keep screeching that the sky is falling until they get enough sheep in line.

  3. He said that said there was a “need for urgency” in tackling climate change.

    OK, let’s drop some thermonuclear weapons into dormant volcanoes so they spew some ash which cools the climate.

    1. Worked for the Dinosaurs!

      1. Worked for the mammals which were small furry fucks while the dinos ruled the Earth. Once the dinos were gone, the mammals had a large niche to fill.

        1. True. But I was thinking more of the series finale for this show: http://sharetv.org/images/dinosaurs-show.jpg

          1. Ah OK; I’m not familiar with the show.

            But I have to acknowledge that the K-Pg boundary affected female and baby dinos most.

          2. I only remember the earth is flat episode of that show. I remember liking it, but I’m terrified to go back and watch it lest I tarnish my memories with how bad it actually is.

            1. Ah yes, where the teen dinosaur walks around the planet to prove them wrong.

              Excellent show, and yes sometimes it’s better to leave these things be.

              1. That show sucked.

            2. At least it gave us “Not the Mama!”

              1. So many great sayings from that show. I remember the older folks used to hate when us yoots would quote it, because they were worried it was making us get “fresh.”

  4. Knowing what I know about interpolation and shit, I would consider 11,000 years of temperature estimation to be accurate to within + or – 50 degrees K.

    Has anybody ever seen the crazy “scientific” methods they come up with for measuring things in, for example, a soils or fluids lab? The precision is not very convincing.

  5. OT: Clayton Kershaw is pitching an absolute gem and just belted a home run to score the only run of the game so far. I love this game.

    1. I might have to jump on the bandwagon early this year. My parents have season tickets…

  6. Nevertheless, it’s pretty clear that the NSF press release overstated what could be concluded about recent temperature trends from the study itself.

    Right, and I’m sure there is no incentive for them to exaggerate. I mean it’s not like public opinion affects government’s desire to give them funding.

    This entire issue is tainted by politics.

  7. Since only 30 minutes have elapsed , it appears none of the above has troubled to read the lengthy Science paper or the links Ron has provided.

    1. We expect Ron to do the reading for us.

    2. I have been following this for weeks in the blogosphere. The articles debunking and supporting this paper all use quotes and figures from the paper.

      Why is it that when the temp. dropped very sharply over a few hundred years and it has to be natural, that a rapid increase over a few hundred years is not natural?

      1. Our furry friend Stoat notes :

        this is all about the “uptick” in the Marcott plot. Why oh why this is of the least interest to anyone I don’t know, because its the one bit where the proxies (which is what Marcott are using) are of no interest [*]. We already have instrumental records for this period; and while that instrumental series is not perfect, its certainly much better than the proxy record. Somehow spinning this into However, here I document the gross misrepresentation of the findings of a recent scientific paper via press release which appears to skirt awfully close to crossing the line into research misconduct is just stupid and pointless. How can you write stuff like that and have any aspirations to be an “honest broker” or even offer unsolicited advice on how to do the same?

        [*] Of no interest in reconstructing the temperature, I mean. It clearly is of interest to see how to mesh the proxies and the instrumental record, but that … isn’t what all the voluminous denialosphere whinging is about.

        1. So…why didn’t they just use instrumentals for the uptick part? Or use it AND the proxy for comparison? Could this be just more of the ‘fuck it close enough to the conclusions I wanted’ ‘research’ that the ‘voluminous denialosphere’ is whinging about?

      2. Re: Bill,

        Why is it that when the temp. dropped very sharply over a few hundred years and it has to be natural, that a rapid increase over a few hundred years is not natural?

        Because earthly man is evil and too materialistic and a fallen creature, that’w why. Haven’t you realized that the Progs want to impose a Paradise On Earth through government action? To make all us humans pious and humble by force?

  8. My temperature data from 9,000 years ago is a lot more comprehensive, but no one asked me for it.

  9. Nevertheless, it’s pretty clear that the NSF press release overstated what could be concluded about recent temperature trends from the study itself. University of Colorado environmental science studies professor Roger Pielke, Jr. is recommending that the authors retract the figures showing the 20th century uptick in temperatures and issue a correction.

    Ok, fair enough, but just to recap and so nobody forgets: Man is still evil for wanting to have nice things and is killing the planet!

    Ok? Everybody got that? Good! Let’s move on, then!

  10. I think it’s clear from this graph that we’ve halted the next ice age. So, good news, right? Champagne all around! Keep those oil wells flowing!

      1. This proves nothing.

        1. Weather that’s out of the norm disproves climate change? Nobody ever said there would be hotter temperatures than average everywhere at all times.

          1. That’s why I said it proves nothing dipshit.

            1. This made me laugh out loud.

            2. Poor shithead. Logic isn’t one of his skill sets.

              1. Too bad breathing is.

    1. Don’t you get it? COLD WEATHER PROVES AGW! It’s about..um..arctic ice. Yeah, that works. Also, warm weather, temperate weather, hurricanes, tornadoes, and lack thereof are all PROOF POSITIVE that carbon driven AGW is real! It’s such an amazingly powerful theory that EVERYTHING that happens PROVES IT! You want to argue with something that powerful, pal? HUH? DO YA?!

      1. Posted this up thread, but still worth looking at:

        http://www.numberwatch.co.uk/warmlist.htm

        1. That’s great.

    2. The Brits just may save our asses for once. Seems they have more than their fair share of what little common sense remains.

  11. What the AGW chicken littles have yet to prove to me is that, one, that the warming that is occurring (AGW or otherwise) is significantly outside normal climactic cycles and two that said warming is in fact a threat to our species.

    1. Well, Monkey, the important thing is the days of species adapting to their environment is over. It’s a new dawn, one in which our self-styled masters have declared the environment shall serve their wishes and adapt to their chosen species.

  12. Sorry if this has already been posted, but “If you torture the data long enough, it will confess.” This explains why there is so much variation in historical temperature data extrapolations. However, mainstream climate sensitivity models are trending downward (according to that far-right media outlet: the economist) so I don’t think climate change is going to be a big deal.

    But why does it seem like the weather is so extreme? Possibly confirmation bias, looking for patterns that don’t exist? Maybe. My theory is that there is simply better recognition of extreme weather events. Also expanding populations mean bigger impacts on human activities. Hard to recognize an extreme weather event when it doesn’t affect anybody (as most extreme events likely did not when the country was sparsely populated).

  13. The “Anthrocene” is going the way of Piltdown Man!

    I think I may have won a bet once this is firmly established.

  14. Ross McKitrick vivisects this POS right here. Basically, the authors and their backers say ‘but 20th cent temp data!’ but that’s wrong because the previous data set can’t resolve temp changes

  15. I can’t believe it took a few weeks for this to actually come out. If I remember correctly, they smoothed their data to 300 years (even though much of it was acquired at even longer intervals), but they show the past century on an annual scale. The problems with that are too obvious to even waste one’s time on.

    Also, why is no one pointing out the oh-so convenient starting date for their graph? It just so happened to be right after some truly extreme temperature changes:

    Big Freeze Plunged Europe Into Ice Age in Months

    How about a 22 degree spike in 50 years?

    Damn link limits…

    1. I didn’t mean that to be a reply.

      1. More links:

        or 4 degrees C in less than 14 years

        or 2-4 degrees C in 1-3 years…and there’s plenty more where these came from.

  16. Then, let’s not forget the fact that the article is looking at global temperatures. They always broadcast that fact as if it lends some greater credence to their arguments. But, if the problem is that rapid climate change may cause extirpations or population declines as species don’t have time to adapt or to shift their ranges, then global temperature is completely irrelevant. Fraser firs don’t give a shit what the temperature is in Zimbabwe or England or even in Michigan. All that matters is what the temp is within or near their current range. By looking at global temperature, the authors are hiding (or at least downplaying) any biologically relevant patterns, such as the asynchronous Holocene Thermal Maximum.

    If they want to argue that society won’t have the time to adapt their lifestyles and/or settlement patterns, then they might have a case. But that can’t pretend that we came in and instituted some unprecedented, destructive change in the environment.

  17. Could Bailey finally be waking up to the lovely aroma of Scientific Method?

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