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The Last Interglacial Part Five - A Crystal Ball?

Posted on 17 November 2011 by Steve Brown, jg

Note: This is the fifth and final article of a five-part series on what we can learn from the Last Interglacial time period. Understanding this period may provide clues on how the environment may respond to similar conditions in the future. In the first post, we described the conditions that exisited during the Last Interglacial. In the second post, we looked at the key factors for making it a warm period. In the third post, we looked at how sea-levels rose as a result of melting ice-sheets.  In the fourth post, we examined how the Last Interglacial oceans influenced the climate.  In this final post, we summarise what we've learnt and conclude the discussion on the value of the Last Interglacial for helping us predict the future.

Comparing the influences on the Last Interglacial climate with those assumed in future climate projections is problematic owing to fundamental differences, especially orbital forcing, seasonal warming, and greenhouse gas concentrations.  Palaeoclimate studies show that differences in the manner in which the Earth orbited the Sun during the Last Interglacial are sufficient to explain the higher temperatures over most parts of the Northern Hemisphere, particularly due to greater axial tilt and eccentricity compared with the present day orbital configuration.  This greater axial tilt provided stronger insolation (solar heating) at high latitudes and weaker insolation at low latitudes.  Perihelion, when the Earth is nearest the Sun, occurred during summer in the Northern Hemisphere, which amplified seasonal insolation, while perihelion occurs in winter during the present day.  Figure 1 shows a comparison of Eemian and Holocene summer insolation, which highlights the key differences between then and now.  If you click on Figure 1, it will show an animation to make this easier to visualise.  Peak insolation from orbital forcing will be significantly lower over the next century than what the Earth received during the peak warm period around 126,000 years ago.

Comparison of Eemian and Holocene Summer Insolation

Figure 1: Comparison of Eemian and Holocene Summer Insolation - click for animation (Illustration and animation by jg)


The Last Interglacial climate was characterised by strong seasonality with warmer summers and cooler winters, which does not compare with the outcomes of predicted future greenhouse warming where both warmer winters and summers are expected.  Warmer winters may encourage the poleward spread of coniferous forests that would accelerate snow and ice melting during the Arctic summer.

Atmospheric CO2 varied between 250 to 300 ppmv.  Atmospheric CO2 during the Last Interglacial was comparable to the pre-industrial Holocene and reasonably stable, which prevents the period being a good analogue for future climate.  Today, atmospheric CO2 is much higher; ~390 ppm and increasing by ~2 ppm yr-1, giving a higher contribution to radiative forcing than would be expected during the Last Interglacial. 

Predictions of future sea-level rise and reduction in volume of ice sheets are consistent with what the evidence indicates during the Last Interglacial.  The IPCC AR4 report suggests a complete disappearance of the Greenland Ice Sheet during the Last Interglacial, providing a contribution of up to 2 to 4 m of sea-level rise, while Cuffey and Marshall (2000) estimate that the Greenland Ice Sheet melt contributed towards 4 to 5.5 m of sea-level rise.   According to Allison et al. (2009), as much as 2 m of sea-level rise could happen by 2100 with predicted global mean warming of +2.0oC.  However, it should be recognised that the equivalent warming during the Last Interglacial occurred over thousands of years and the thermal response of ice and oceans would be much slower.  Field et al. (1994) and Seidenkrantz & Knudsen (1997) raise the possibility that predicted higher sea-level could cause warming of the North Sea and cause warmer temperatures in northern Europe due to warm water from the North Atlantic Drift to pass through the English Channel into the North Sea and opening  sea-ways between the North and Baltic Seas.  A stronger North Atlantic Drift might also increase the flow of warm water into the North Sea past northern Britain.  However, this may be mitigated if the present isostatic rebound of the northwest European crust outpaces greenhouse warming induced sea-level rise (Burman & Passe, 2008).

The dynamics of the Atlantic Meridional Overturning Circulation (AMOC) and its influence on climate is hotly debated and evidence for its behaviour during the Last Interglacial may have potential in determining how ocean circulation and related climatic effects may alter in a future warming world.  Most models that investigate increasing greenhouse gas scenarios predict that the AMOC will slow down as a result of such forcing (Driesschaert et al., 2007; Hodell et al., 2009).  However, other model results suggest that anthropogenic aerosols may have delayed a greenhouse gas induced weakening of the AMOC by reflecting inbound solar radiation and partially offsetting greenhouse gas warming (Vellinga et al., 2008)Crowley and Kim (1992) and Lisiecki et al. (2008) show that the AMOC may be sensitive to different orbital parameters, such as maxima in obliquity and precession, and link orbital eccentricity to North Atlantic Deep Water production.  

Some climate models of the Last Interglacial suggest that a high-index state of the North Atlantic Oscillation (NAO) was favoured due to the configuration of orbital parameters.  Less vigorous ocean circulation in the North Atlantic has been associated with positive phases of NAO.  If peak summer insolation during the early Last Interglacial favoured a persistent positive NAO, this may have contributed to the slow circulation from 128 to 124 ka. (Hodell et al., 2009), as well as AMOC anomalies due to heat flux and surface wind stress variability (Vellinga et al., 2008).  With a significantly different orbital configuration over the coming centuries it cannot be expected that the behaviour of the NAO and AMOC would be similar to that during the Last Interglacial.

Comparison of the behaviour of the El Nino Southern Oscillation (ENSO) during the Last Interglacial and the recent past indicate that it may be changing in response to increased greenhouse gasses.  Hughen et al. (1999) suggests a robust ENSO variability that matches ENSO behaviour in the recent past.  The similarity appears to diverge from observations of ENSO variability since the 1970's indicating that ENSO since then is anomalous to natural variability i.e. ENSO may be relatively stable during interglacials.  El Nino events have become more frequent since the 1970's compared with the warmer Last Interglacial, which prompts the hypothesis that the higher frequency may be related to the rate of greenhouse gas induced warming rather than warmer mean conditions.

Comparison of the Eemian and Holocene Interglacials 

Figure 2: Comparison of the Eemian and the Holocene Interglacials (Illustration by jg)

The difference in greenhouse gas concentration combined with significantly different orbital parameters and seasonal insolation may limit the validity of using the Last Interglacial as an analogue for predicted future changes to the climate system.  The proxy coverage of the period in the Southern Hemisphere and large parts of the Northern Hemisphere is poor, giving a bias towards Europe and the North Atlantic region.   The value of the Last Interglacial in aiding prediction of future climate change is restricted to mainly Europe and the North Atlantic.  To improve our ability to predict the potential impacts of future climate change it is essential that the search for proxy data in new locations with a more comprehensive geographical spread are sought out in order to get a more global picture of ancient climate with better resolution.

Acknowledging the problems and benefits of using the Last Interglacial as an analogue for a future warming climate begs the question of whether there may be a more suitable analogue in the past.  Loutre and Berger (2002) suggest that Marine Isotope Stage 11 (MIS 11) from 405 to 340 ka would make a better analogue for future climate than the Last Interglacial, due to it being a warmer interglacial period, but with an orbital insolation signal that correlates closely with the recent past and future, giving a much better comparison of orbital forcing.  MIS 11 also appears to have been possibly the warmest and longest interglacial of the past 5 million years and had an extended period with little or no continental ice, which is projected to occur under some future global warming scenarios.

Because the observed and predicted rate of increase in greenhouse gas concentrations and global warming is faster than seems to have happened during the Last Interglacial may mean that we are heading into uncertain territory. 

I would like to acknowledge the enormous contribution of my fellow SkS contributor, jg, towards the production of this series.  Thank you, jg!

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Comments

Comments 1 to 37:

  1. Steve Brown, jg : thank you, very clear and informative, great job!

    In the Figure 1 / animation, there seem to be a huge summer forcing during the Eemian Optimum when compared to our Holocene Optimum, due to orbital solar change. Do we know how it translate in local temperature? Does the winter forcing (much less than now) compensate for ice mass equilibrium? And concerning the melting of Greenland, can we estimate the response time to such local forcing (or temperature) during the Eemian? Something like W/m2 -> T -> mm/y
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  2. PS : I mean "mm/y" for sea level rise (due to Greenland melting under a certain local forcing), of course, but maybe I should write Gt/y for ice loss if this kind of estimation come from ice dynamic models.
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  3. Charts of the orbital induced solar variability serve to remind us of the relative insignificance of CO2 forcing. The Eemian and Holocene optimums experienced roughly constant global insolation. But look at the variance in summer insolation from peak to trough of more than 75W/m^2 and compare it to the 3W/m^2 (albeit global) of CO2 doubling.
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  4. 3, ClimateWatcher,

    Way to play with numbers. Well done.

    But, no, I'm sorry, that's a serious fail.

    The variance in summer insolation from peak to trough is 75 W/m2 with a net of... wait for it... zero. No net change in energy. No change in climate. Change in seasonal temperatures, yes, climate, no.

    Want to know something even more amazing? The variance in daytime and nighttime insolation is 1366 W/m2!!! Isn't that amazing!

    And yet global mean temperatures are relatively constant, because the net does not change.

    But if you add 3 W/m2 of CO2 doubling, where that is a net difference, and make that continuous, every minute of every day, for year after year, that makes a difference.
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  5. Sphaerica : I'm not sure what ClimateWatcher was asserting, because he says "The Eemian and Holocene optimums experienced roughly constant global insolation" (so, I guess "constant" means no global forcing, as you put it). But for Greenland Inlandsis behavior and its contribution to sea level rise, the differences in seasonal and regional forcing are probably relevant... or maybe not, precisely I don't know the year mass balance desequilibrium due to insolation in models, and it is the scope of my question.

    Hereafter, a recent Masson-Delmotte et al 2011 paper seems of interest for this question, but is unclear for me. On one hand, it says that "the IPSL-CM4 model shows similar magnitudes of Arctic summer warming and climate feedbacks in response to 2 × CO2 and orbital forcing of the last interglacial period (126 000 yr ago)". On the other hand, it observes that "Comparisons with Greenland ice core stable isotope data reveals that IPSL/LMDZiso simulations strongly underestimate the amplitude of the ice core signal during the last interglacial, which could reach +8–10 °C at fixed-elevation". So, I don't understand if the model is correct or uncorrect !
    http://www.clim-past-discuss.net/7/1585/2011/cpd-7-1585-2011-print.pdf
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  6. 5, skept.fr,

    ClimateWatcher's references to the Eemian and Holocene were a throwaway statement intended to let him say anything he wanted without seeming to be off-topic. His real intent was to carry forth the lame denier meme that since summer/winter temperatures/insolation vary so greatly within each year that CO2 variations must be comparatively negligible.
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  7. Atmospheric CO2 during the Last Interglacial was comparable to the pre-industrial Holocene and reasonably stable ...

    Is worth to draw attention - Rundgren et al., 2005. - on Figure 4 - "raw" data. Together with a possible range of deviations - fluctuations of CO2 are possible (and in a relatively short time) between 160 and c. 350 ppmv CO2. Changes in the Eemian p.CO2 may thus be significantly underestimated. These changes, however, took place in a relatively short period of time: „... centennial to millennial changes were followed by more rapid CO2 oscillations within the range of c. 255–285 ppmv between c. 2700 and 3000 years after the onset of the Eemian.” Of course these changes are smaller and slower than today, but if you can call them: „reasonably stable” ?
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  8. Solar variability. It is worth recalling how much "link to orbital eccentricity," must be amplified to explain the creation (and end) - not just the last - interglacial.
    Beer et al., 2000.,:
    “If one computes the global and annual mean of solar forcing caused by the 100 kyr period of eccentricity one gets an amplitude of in the spherical mean. This value is too small to be detected in climate records. But, despite the tiny global forcing value, we can observe the 100 kyr frequency during the last 800 kyr in most paleoclimatic records. The global mean temperature changes between glacial and interglacial periods are large: about 20C for polar (Johnsen et al., 1995) and 5 for tropical regions (Stute et al., 1995).”
    Beer et al. 2006. :
    “ Note that the mean annual global insolation changes caused by the eccentricity are very small (<2.5 Wm −2 )”
    “The existence of feedback mechanisms is illustrated by the discussed glacial-interglacial cycles that are related to a [-all caps snipped-] annual mean change in insolation.”
    “This implies that the climate system has the potential to respond significantly to even [-all caps snipped] forcings and that this response may depend strongly, not only on the amplitude, but also on the duration of the forcing with potentially larger effects for longer lasting or repeated forcings.”
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    Moderator Response: (Rob P) No more all caps please. You have commented here long enough to know the rules. Further breaches may result in your post being deleted.
  9. MIS 11 - it is worth noting that here too we have serious objections:

    Rohling et al., 2010.: “MIS-11 is often considered as a potential analogue for future climate development because of relatively similar orbital climate forcing ...” “However, there is an obvious difference in that the current interglacial (Holocene) spans a single insolation maximum (summer, 65°N), while MIS-11 spanned two (weak) astronomical precessiondriven insolation maxima separated by a minor minimum (due to coincidence of a minimum in 400-ky orbital eccentricity with a maximum in the Earth's axial tilt ...”
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  10. skept.fr #1 - If you are asking if it's possible to infer local as in specific regional temps, then no. Local temps are influenced by numerous factors such as vegetation, proximity to ocean, prevailing wind direction etc. Modelling estimates that the various forcings in play during the Eemian led to a global temp of up to 1 degree C above present day.

    Arkadiusz Semczyszak #7 - Whilst Rundgren et al (2005) provides an interesting and useful result, it needs to be taken in the context that it's based on a leaf stomatal index proxy with whopping great error bars.
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  11. Great post.
    Post like these and the ongoing handbook information make this site invaluable!
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  12. Hi Steve,

    I am away from a computer and have to resort to my phone...

    I was a bit surprised to see your comment that paleoclimate studies show that the insolation of the Eemian was sufficient to explain the higher warmth of the Eemian, when in the previous articles that was the comment I was making and you were saying that plants in the northern latitudes were respnsible. Clearly I agree that the greater 65N summer insolation was sufficient to explain the warmer NH climate during the Eemian.

    The ENSO discussion isn't usefull because comparing a 40 year period of variability to a 10,000 year period is folly.

    What I am more curious about is what is not discussed. I agree that the Eemian is the crystal ball for the future, but I reach a different conclusion.

    The 65N insolation anomaly went negative during the Eemian ~120,000 YBP. Using the EPICA ice core data, the rate of cooling in the 11,000 year period after that was -0.67C per 1,000 years. That is a very low rate of cooling, but there was a standard deviation of 0.59C over that same 11,000 year period. Meaning that any temperature within +/- 1.18C of the negative linear trend was statistically normal. The +/- 0.4C that the Earth has experienced in the past 200 years is well within a single standard deviation of the comparable insolation from ~119,000 years ago.

    Also not mentioned is that the Earth cooled for almost 10,000 years while CO2 levels remained at the 270ppm level. That temperature drop was 5C globally based on the Raymo 2005 benthic reconstruction.

    So the Earth cooled from a warm climate for thousands of years while CO2 stayed elevated at interglacial levels. In no way did the high CO2 levels appear to keep the Earth warm as the Eemian ended into the last glacial period.

    I applaud the effort you put into this series of articles. It is one of the best series this website has ever had. It does miss some important information, but I suspect that there were some challenges to the orthodoxy that you had to spend some time working through.

    I devote a few chapters to the Eemian in my book. If you ever get a chance to read it, you should as I think you would find it interesting.

    My biggest gripe with warmists is not their conclusions, but the derision they heep on anyone that reaches a different conclusion from the warming belief. It is not anti-science to reach a different conclusion, but it is anti-science to close your mind to the idea that you might be wrong.

    I remain open to that possibility, but I suspect that few readers of this website have an open mind to the idea that they might be wrong.
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    Moderator Response: [muoncounter] Incorrect. Many readers have emphatically stated they would love to be wrong about the changes we've wrought upon the environment. The evidence, however, has yet to appear that suggests substantive error. By contrast, the denial side of the argument seems to be proved wrong with regularity. As for 'derision,' you've got to be kidding. The derision shoe is on the other foot.
  13. "It is not anti-science to reach a different conclusion, but it is anti-science to close your mind to the idea that you might be wrong."
    The issue faced by the world today is the abandonment of reason and logic by the fake skeptics in their prosecution of their predetermined narrative, a narrative achievable only by ignoring multiple lines of consilient evidence inconvenient to their ideology.

    Indeed, the horror faced by those who would have us debate the existence of gravity (or if pizza is a vegetable) is not the risks derived from AGW/CAGW/(insert your climate pejorative du jour here) but the danger of keeping one's mind so open that one's brain falls out.
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  14. DB#13: The question is not whether pizza is a vegetable, it is the tomato sauce that is the vegetable. This is time-honored policy, dating to the days of the patron saint of today's Republicans.
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  15. Although the study of paleoclimate is interesting, we can derive so little of use from these studies, apart from saying that conditions were different.

    Disregarding the orbital characteristics can we even know what the TSI was in the past. It seems that nothing is coincident to todays conditions and therefore any predictions on future climate based on the past must be considered as speculation.
    We need to study the behaviour of the oceans more with regard to the present position of the land masses if we wish to gain any predictive skill.
    Nonetheless It is still very interesting for me to learn more about the paleoclimate.
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    Moderator Response:

    [DB] "Although the study of paleoclimate is interesting, we can derive so little of use from these studies, apart from saying that conditions were different."

    Actually, climate science derives a great deal of understanding of the present climate through its studies of the past, in particular the paleoclimate.

    "Disregarding the orbital characteristics can we even know what the TSI was in the past."

    Umm. no.  Essentially you are goalpost-shifting here.  This new tangent more properly belongs on the A detailed look at climate sensitivity thread.

    "It seems that nothing is coincident to todays conditions and therefore any predictions on future climate based on the past must be considered as speculation."

    Shorter version: 'Because I haven't read enough of the literature everything I don;t know is speculation.'  I.e., handwaving dismissal.

    "We need to study the behaviour of the oceans more with regard to the present position of the land masses if we wish to gain any predictive skill."

    Climate scientists are doing this very thing, in great detail.  But very much off-topic for this thread.

    Essentially, your entire comment amounts to 'It's not Bad'.  So as you were advised before, please take your concerns to the It’s not bad thread.

  16. 15, FundME,

    You are expressing a great number of false assumptions. Further study is advised. Specifically false assumptions:
    ...we can derive so little of use...
    ...can we even know what the TSI was...
    ...nothing is consistent to todays conditions...
    ...must be considered as speculation...
    We need to...
    Every one of these statements is anywhere from false to wildly false. You need to abandon every one of them and actually learn the material, and then come back and reconsider how each is wrong.

    The one true statement you made refers to the face that you need to learn more about paleoclimate.

    This isn't really a good place for you to start but to get some evidence of where your statements are wrong you might want to look at Paleoclimate Implications for Human-Made Climate Change by Hansen and Sato (2011).
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  17. Inconvenient Skeptic #12

    "I was a bit surprised to see your comment that paleoclimate studies show that the insolation of the Eemian was sufficient to explain the higher warmth of the Eemian, when in the previous articles that was the comment I was making and you were saying that plants in the northern latitudes were respnsible. Clearly I agree that the greater 65N summer insolation was sufficient to explain the warmer NH climate during the Eemian."

    It's forcings such as orbital insolation that ultimately drive long term climate changes. I did explain in earlier posts that feedback mechanisms such as ice-albedo and vegetation changes serve to magnify those forcings. But those feedbacks wouldn't be initiated without the forcings in the first place. I'm quite happy to edit the post to make the wording more explicit for you, but I fear it may provoke accusations of fiddling the books and rewriting history from some quarters. Please accept this comment as a clarification.


    "The ENSO discussion isn't usefull because comparing a 40 year period of variability to a 10,000 year period is folly."

    You're concern over a 40 year period period not being sufficient to be useful may be valid. I made reference to it as it's a very interesting hypothesis, which may or may not have legs depending on future observations. Can I assume that you are equally critical of those who attempt to make hay about "global cooling" with less than 10 years of global surface temperature trend?


    "The 65N insolation anomaly went negative during the Eemian ~120,000 YBP. Using the EPICA ice core data, the rate of cooling in the 11,000 year period after that was -0.67C per 1,000 years...."

    Peak NH insolation in the the Eemian was around 129-128,000 YBP. This series of posts has focussed mainly on the warm Eemian climatic optimum 127-124,000 YBP. Tbe climate dynamics of the cooling phase into the next glacial period are irrelevant.


    "So the Earth cooled from a warm climate for thousands of years while CO2 stayed elevated at interglacial levels. In no way did the high CO2 levels appear to keep the Earth warm as the Eemian ended into the last glacial period."

    So what? CO2 is not the only driver of climate.


    "I applaud the effort you put into this series of articles. It is one of the best series this website has ever had. It does miss some important information, but I suspect that there were some challenges to the orthodoxy that you had to spend some time working through."

    Thanks! However, I didn't realise that this series was being unorthodox. I've never considered it to be anything other than a straight literature review of mainstream climate science research. The only criticism I've received from other members of the SkS team is purely down to some earlier drafts being too technical and not being pitched at the knowledge level of the average SkS reader. The guys have been nothing but supportive and constructive.
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  18. Steve,

    I accept your comment as the proper clarification on insolation and appreciate your reply on the ENSO. :-)

    I consider this series to be unorthodox because it is so divergent from the typical article on this site. I took some heat (not surprising) for my comments about derision heaped on those that reach different conclusions, but a cursory glance at the front page of this site has plenty of articles like...

    Climate Denial Crock of the Week.

    Baked Curry

    Skeptics are anti-science

    Geologists and Climate Change Denial

    and so forth....

    Whenever a scientist presents evidence (some is good, some is not) that casts any doubt on Global Warming, then they are savaged.

    Many articles on this site are simply attack articles that use derision of the opposition as a tactic. Your article actually discusses the science in a meaningful way and that is why I find it a breath of fresh air.

    Name calling is NOT how to encourage a constructive dialog. Your article rises above that and that is part of why I consider it unorthodox.

    Global Warming is a scientific hobby for me. My full-time job (which is what kept me from responding earlier) is R&D for semiconductors. It is certain that readers of this article have parts in their computer that use films or processes that I developed and more on the way. I did not deny science in developing those processes and in fact this week I created a new and vastly more complex process that could revolutionize large portions of semiconductor processing. The idea that I am anti-science would be amusing if it wasn't so foolish.

    When Daniel Bailey (#13) makes his comments about fake skeptics (while not sure if he lumps me into that group) and their abandonment of reason and logic, it is derision. Certainly there are people that are skeptical for the wrong reasons, but there is an equally large number of people who believe in global warming and don't understand anything about the science they are choosing to believe. That you had to reduce the technical content to make it readable is evidence of that.

    Just know that I appreciate your articles and look forward to anything else you might write in the future.
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    Moderator Response: [muoncounter] Savaged? Attack articles? Really?
    You should compare (silently) the type of 'savaging' that goes on at denial sites to the comments typically seen here. You will note, if you take the time to read objectively, that comments here are about the science, the data, the work done - not the individuals who do the work. If you object to such critical discussion of science, why are you here?
  19. "Whenever a scientist presents evidence (some is good, some is not) that casts any doubt on Global Warming, then they are savaged".

    um, please give evidence for SkS "savaging" a scientist for publishing evidence contrary to conventional climate science in a peer-reviewed publication.

    What does get savaged is misinformation, cherry-picking etc practised on the naive (eg Congress, public) in forums other that peer-reviewed science journals.
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  20. 18, An Inconvenient Skeptic,
    Many articles on this site are simply attack articles that use derision...
    Would you mind identifying them, and quoting the passages that use derision?

    [Note that a catchy title does not qualify. Sorry if you don't like the titles, but there's a whole lot more to the debate than that. If you're stuck on titles, you're stuck in ignorance.]

    Please remember to distinguish between attacks on the person and attacks on the position (which, if false, disingenuous, or down right stupid, are certainly open season for derision as long as a thorough, concise and meaningful argument is presented to demonstrate the untenable nature of the position).
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  21. TIS (#18),

    Being anti-science is not a binary property. Compartmentalized belief & willful ignorance in one subject does not have to affect cognitive functioning in other areas of study.

    The existence of people who "don't understand anything about the science they are choosing to believe" does not disprove the validity of that field of study.
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  22. Bibliovermis @21,

    You took the words out of my mouth. Excellent points.

    TIS can stop insulting us here by embarking on so-called tone trolling and claiming to be a "skeptic" when he is clearly not a true skeptic at all. Instead TIS should debate the science using science and facts.

    Usually when "skeptics" start taking offense to catchy titles etc., it is an excuse for them to not debate the science, because they do not have a compelling case and/or the science does not support their view/belief.
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  23. @ The Inconvenient Skeptic
    "Whenever a scientist presents evidence (some is good, some is not) that casts any doubt on Global Warming, then they are savaged."
    Please present evidence of this very much unsupported assertion. That would be the scientific thing to do, to actually have evidence to back up assertions. Right?
    "Many articles on this site are simply attack articles that use derision of the opposition as a tactic."
    IBID. More evidence-free assertions.
    "Name calling is NOT how to encourage a constructive dialog. "
    IBID, Part Deux.
    "there is an equally large number of people who believe in global warming and don't understand anything about the science they are choosing to believe. That you had to reduce the technical content to make it readable is evidence of that. "
    You speak to the whole Raison d'être for Skeptical Science: to communicate the literature of climate science to the layperson...and to debunk the myths and dissemblings of the skeptics and fake-skeptics. You also falsely imply that those who "believe" in (the established fact of) global warming therefore do not understand the science that they are believing (thus equivocating it to belief in religion). Or do you a reference for that implication?
    "When Daniel Bailey (#13) makes his comments about fake skeptics (while not sure if he lumps me into that group) and their abandonment of reason and logic, it is derision. "
    Actually, it is my personal opinion. And it is an assessment of the breakdown of reason and logic on the part of the fake-skeptics, based on their statements and writings.

    Beyond that, I can't be bothered to take anything personally enough anymore to take the time to foment actual derision. Life's too short and my time is too valuable.
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  24. DB#23:

    A few minutes on TIS' website reveals quite a lot of name-calling, derision, accusations of fraud, etc. In general, the weaker the argument, the more the need to resort to such tactics.
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  25. @ muoncounter

    Deucedly inconvenient, that. One can hardly go placing accusations of pots being black when one has numerous black kettles of one's own.

    Shades of specks and planks...
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  26. Arkadiusz #7, you are once again caught trying to misrepresent the data presented in a paper. You're ignoring the assessment of errors and the transfer functions associated with the relevant proxies, and the assessment of the authors of Rundgren et al 2005. They talk of rapid CO2 oscillations of ~40ppm, while you inflate this to 190ppm by using the maximal ends of their error bars (and inflating one ened by 10ppm too). The assessment of Rundgren et al is in fine agreement with the mention of CO2 in this article, being between ~250 and ~300ppm, just as mentioned in the article above.

    I caught you misrepresenting the CO2 measurements of a paper in this article, so this seems to be a habit of yours. Did you think nobody would read the paper and check your statements?
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  27. I have taken great efforts to compliment Steve on a well put together series of articles that do a good job explaining the Eemian to the layperson.

    Most of what I wrote in #12 was a technical response to the article with a final bit as to why I like the series of articles. It's honest approach to the science is appreciated. Please note that I was complimentary to Steve and the series of articles.

    Most people are not responding to the technical points I brought up, but the tiny add-on that explains why I like the series of articles.

    I fully agree with the concept that this site tries to explain the science from the warmist point of view. As a concept I fully support that purpose. This series of articles is an exemplary example of that type of article.

    However, having sections of the website named; Lindzen Illusions, Spencer Slip-Ups, Christy Rocks and so forth is name calling. I am not all that impressed by Spencer's cloud theory, but I am also not impressed with Mann's tree ring work.

    Constructive dialog is not started by articles titled in such a manner. There is little difference between the treatment that SkS gives Spencer and Lindzen and the treatment that Mann and Hansen get at Watts.
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    Moderator Response: [muoncounter] Please do not try to play the innocent. The response you are now receiving is due to your unwarranted criticism of this site at #18. If you are distressed by name-calling and interested only in constructive dialog, presumably you object to such phrases as 'desperate ploy,' 'really bad science,' 'hurricane stupidity,' 'fear and misinformation,' etc; all from your website.
    Please confine your future commentary to issues of science; unsubstantiated criticism of the people who post on this site will be snipped or deleted wholesale.
  28. TIS: I see you're not actually willing to provide evidence to support your assertions, as requested by Daniel Bailey @23.

    "I fully agree with the concept that this site tries to explain the science from the warmist scientific point of view." There, fixed it for you. Funny you should resort to calling names in the same post as complaining about name-calling.

    That you compare this site to WUWT in terms of content and treatment speaks volumes about your ability to think critically, or discern abuse from scientific criticism. Spencer, Christy and Lindzen have made a great many errors, slip-ups, crocks and presented a good number of illusions too. Some articles here call them on that. 'Constructive dialogue' can only start when these people stop misinforming the public about the science of climate change, using all sorts of tired myths.

    Nobody has presented a scientific case as to why Mann is wrong, and his work has been repeatedly independently verified - do you condone the unjustified abuse heaped upon him at WUWT and elsewhere? Skeptics perpetually fail to understand the consequences of Mann being wrong: that this would mean climate sensitivity is even higher than previously thought! Oops.

    By the way, the day that a climate skeptic procides a sound scientific case for any of "CO2 isn't the main driver of global warming", "Warming isn't having negative consequences for food production, severe weather, coastal communities etc", "the oceans are not acidifying or sea level rising", then I will break out the champagne, I'd love to be wrong. But I need a sound science case for it, not all the mutually incompatible and easily-debunked myths that seem to be the best the skeptics can come up with. Despite the fact that the big hydrocarbon producers could easily fund just about any scientific study they liked, from Antarctica to the Marianas Trench, with their loose change, not to mention their logistical capabilities, and thus scientifically demonstrate that their product is not polluting the atmosphere, they haven't managed to do so. Inconvenient?
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  29. TIS - so what examples do have of Mann misrepresenting science outside the published journals? Do you think Spenser, Lindzen and Christy would say what they do to an audience of their peers?

    If a "skeptic" wants some constructive dialogue then start by publishing some reasonable science - in fact that does go on - it just get refuted in other published papers. However, I cannot see how you can constructive dialog with someone who is willing to misrepresent the truth to a non-technical audience.
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  30. TIS...
    There is little difference between the treatment that SkS gives Spencer and Lindzen and the treatment that Mann and Hansen get at Watts.


    Seriously?
    Here are SkSs 'attacks' on Spencer which, seems to me, are purely regarding the science.
    Here is a link to something discussing McIntyre & Watts latest attack on Mann.

    IMHO, not only is this more than a 'little difference' - but, I'd suggest, anyone should want to distance them selves from the latter.
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  31. @The Inconvenient Skeptic

    I do value the conversations we've had over recent months and that we share a common interest. To the untrained eye you come across as having a reasonable argument, however to the trained eye it is obvious that you are bending over backwards to ignore a massive body of evidence that we are having a negative impact through the combustion of fossil fuels. That makes you a tad disingenuous.

    If I thought the people behind SkS were anything other than sincere in portraying an honest and balanced view of the science then I wouldn't be here. I think I can safely state that everyone at SkS would be absolutely thrilled and relieved if a bunch of skeptics could formulate a convincing, coherent and evidenced based rebuttal to AGW.

    We'd all rather be spending the rest of our lives doing somehting more constructive than playing whack-a-mole in a faux debate.
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  32. TIS wrote: "I am not all that impressed by Spencer's cloud theory, but I am also not impressed with Mann's tree ring work."

    Why? Spencer's cloud 'theory' (note: it is not a scientific theory) is contradicted by numerous studies and predicated on demonstrably false assumptions. Mann's 'tree ring work' has been confirmed by multiple studies using many different methods.

    So we've got two things which both still have some uncertainties, but one is contradicted by all available evidence while the other is confirmed by it... yet you are equating the two. That is not a balanced fact based position. Ditto your claims that 'SkS and Watts are both nasty'. These are false equivalencies. In reality there is no comparison. That you see these things as being equal can only mean that you've got your thumb resting very heavily on one side of the scales.
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  33. Just to further reiterate the point. The rebuttals in links like Lindzen Illusions, Spencer Slip-Ups, Christy Crocks are not to statements they have made in published literature but to misinformation they stated in public forums.

    And since you are not impressed by Mann's tree ring data, perhaps you would like to discuss (on the correct thread) the published papers that have led you to this position. I would sincerely hope that since you respect science that your position is based on some published science and not blog commentary.
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  34. I remember an article in SKS where it was stated that the orbital forcing did not explain the warming coming up out of the last ice age. It (orbital forcing) supposedly would only explain about 10% of the warming. The rest would be positive feedbacks I assume. Loss of albedo and co2 coming up out of the oceans. I would like some help getting to that article that explains just that ratio. It helps to emphasize that a small nudge of the climate can make a much bigger response.

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  35. renewable guy - See this post by Chris Colose: Milankovitch Cycles.

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  36. renewable guy:  See also Shakun et al. Clarify the CO2-Temperature Lag.

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  37. Rob and Tom,

     

    Thanks.  :)

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