Scafetta and West 2007

Francois O writes in:

For those interested in the role of the Sun on the climate, and how reconstructions can be used to assess it, there is an interesting paper just out in JGR by Nicola Scafetta and B J West. The paper is available here. This is a continuation of their previous work. Basically they use a phenomenological approach. So instead of taking the reconstructed TSI values, plug them into a model, and find that indeed the Sun has only a minor influence (like Ammann et al. did in their PNAS paper of March 6, 2007 | vol. 104 | no. 10 | 3713-3718 ), they make no prior assumption on the total Solar forcing. They just assume, mostly rightly, that the Sun was the main driver of climate variability. Then from the solar reconstruction and the temperature reconstruction, they deduce which model of solar forcing best matches the two together.

They have a nice discussion in the introduction about the pitfalls of the usual method. For the record, even though they use both Mann03 and Moberg05 reconstructions, they refer to MM05 and the Wegman report as pointing to the flaws of Mann03.

This is all to show that temperature reconstructions do play an important role in understanding the human role on climate.

I’ve not spent as much time on Nicola Scafetta’s work as I would like to have. I spent about an hour with him at last year’s AGU and he gave an impressive explanation of his ideas. One of the fundamental assumptions of modern models (as I understand it) is that all “forcings” are equal. “Forcings” is a useful metaphor but what if, for some reason, all forcings are not the same. For example, it doesn’t seem inconceivable to me that 1 wm-2 of solar forcing (visible wave length, high energy photons, low entropy) could have a different effect than 1 wm-2 of GHG “forcing” (infrared, low energy, high entropy). I’m not saying that they do or don’t; I haven’t studied the issue in any detail – just that I don’t see the harm in working through the assumptions of non-equal forcing “efficacy”. Mathematicians like to work through the analysis of alternative axioms to see what happens and it’s hard to see that any harm would result in this case. Arguably Scafetta finds empirical evidence suggesting that this may actually be the case.

I don’t vouch for this paper as I have merely skimmed it and have not even begun to work through the details. At this point, I am threading it for discussion.

Luboš discusses it here and Rasmus(now out of the penalty box) at RC here .

102 Comments

  1. Posted Nov 26, 2007 at 4:03 PM | Permalink

    Definitely worth a read. The Mann / Moberg comparison in the conclusion is very interesting.

  2. Steve McIntyre
    Posted Nov 26, 2007 at 4:08 PM | Permalink

    Given that there’s nothing magical about Moberg, I wonder what the impact of a Moberg variation (such as Loehle) would be.

  3. Bruce
    Posted Nov 26, 2007 at 4:08 PM | Permalink

    Under this scenario the Sun might have contributed up to approximately 50% (or more if
    ACRIM total solar irradiance satellite composite (Willson and Mordvinov, 2003) is
    implemented
    ) of the observed global warming since 1900.

    I vote for “more”.

    An 8,000 year should not be dismissed.

  4. Bruce
    Posted Nov 26, 2007 at 4:09 PM | Permalink

    Oops.

    An 8,000 year high in solar output should not be dismissed.

  5. Posted Nov 26, 2007 at 4:27 PM | Permalink

    Ref 2 That would be entertaining to find out.

  6. Posted Nov 26, 2007 at 4:50 PM | Permalink

    #3 Bruce:
    It’s a very interesting paper and seems reasonable to me.
    Your quote from the abstract is correct but speaks only of the total warming for the century. Since there is little argument regarding the effect of increased solar output through the first half of the century, it is more appropriate to look at the latter half of the century when considering AGW. For this time frame, the conclusions are not quite as exciting.

    This quote is from the discussion section and represents the largest post-1950 solar influence discussed in the paper:

    Thus the Sun could have contributed roughly [...] 50% of the global NH surface warming that occurred from 1900 to 2005. Since 1950 the Sun might have contributed ~0.05K (0.5/6 = 8% of the warming) using LEAN2000, or ~0.15K (1.5/6 = 25% of the warming) using WANG2005.

    That is, Scaffeta and West attribute between 8% and 25% of post-1950 warming to solar influence. That seems reasonable to me. Furthermore, they come up with a time constant of 6 to 12 years, implying an equilibrium temperature response from the high-but-steady TSI since ~1950 by the mid-1970s.

    Despite what you might hope, the warming since the mid-1970s is still not explained by TSI.

    • Vangel
      Posted Jul 19, 2009 at 8:14 AM | Permalink

      Re: John V. (#6),

      That is, Scaffeta and West attribute between 8% and 25% of post-1950 warming to solar influence…

      How much warming have we really seen since 1950? Everyone is talking about some massive warming by pointing to the global temperatures even though most of the warming came from adjustments to the data. If we look at the raw data where it is available we see that the warming is overstated and that NASA was right when it pointed admitted that six of the ten warmest years in the US were in the 1930s and 1940s.

  7. Posted Nov 26, 2007 at 4:53 PM | Permalink

    From the Conclusion (paragraph 34):

    Climate is relatively insensitive to solar changes if a temperature reconstruction showing little preindustrial variability is adopted. In this scenario most of the global warming since 1900 has to be interpreted as anthropogenically induced. On the other hand, if a secular temperature showing large preindustrial variability is adopted, such as MOBERG05, the climate is found to be very sensitive to solar changes and a significant fraction of the global warming that occurred during last century should be solar induced.

    I was just reading Chapter 9 of IPCC AR4 and the thought had occurred to me: The paleoclimate models are immensely important because the “fingerprint” for the natural forcings (i.e. not CO2) is calibrated based on the past temperature record.

    Now this paper says the same thing: We have to understand the climate of the past to make predictions about the future. And that means trusting the paleoclimate reconstructions.

    Steve, I’m starting to think that this website could be more important than I had guessed. I’ll stop there because my thoughts are starting to cantilever beyond what can be supported by this paper, but it’s certainly got me thinking.

  8. Posted Nov 26, 2007 at 5:14 PM | Permalink

    #7 Geoff Olynyk:
    This paper also made me more aware of the importance of temperature reconstructions.

  9. Larry
    Posted Nov 26, 2007 at 5:23 PM | Permalink

    Their usage of the word “thermodynamic” is rather unconventional. What they’re actually talking about is transient heat transport. This really doesn’t give me warm fuzzies.

    Here’s an interesting footnote, though:

    In conclusion, if we assume that the latest temperature and TSI secular reconstructions, WANG2005 and MOBERG05, are accurate, we are forced to conclude that solar changes significantly alter climate, and that the climate system responds relatively slowly to such changes with a time constant between 6 and 12 a. This would suggest that the large-scale computer models of climate could be significantly improved by adding additional Sun-climate coupling mechanisms.

    Essentially, they’re accepting the Schwartz hypothesis, with the time constant being 6-12 instead of 5 years.

  10. Larry
    Posted Nov 26, 2007 at 5:28 PM | Permalink

    This sure seems like a lot of outright conjecture that is completely out of place in that paper:

    Our argument assumes that during the preindustrial era the anthropogenic forcing is negligible compared to natural ones. We believe this is an important topic of discussion because our assumption does not exclude, in principle, the existence of a direct human contribution to past climate change, as Ruddiman [2003] suggests. In fact, it should be considered that humans too are part of the climate system and their activity might indeed be effected by climate changes. Thus there might exist a kind of
    anthropogenic positive feedback to climate change. For
    example, periods of warmer Sun might favor the rise of
    large civilizations that once organized might produce more CO2 via deforestation and agricultural activity, and this would make the climate even warmer (the Roman empire, for example, reached its maximum during the solar maximum of the first century and Vikings inhabited Greenland during the solar medieval maximum). On the contrary, a decrease of solar activity might induce a climate cooling causing periods of severe drought that might cause a civilization to suffer famine and plague and ultimately to collapse with the abandonment of agricultural activity. This collapse would favor a reforestation that would yield to the
    absorbtion of CO2 from the atmosphere and a further
    cooling of the climate (for example, the Maya empire
    collapsed because of a sequence of droughts occurred
    probably because of a solar change during the 8th and
    9 centuries [Hodell et al., 2001]). These effects, although anthropogenic in nature, may be interpreted indeed as a special kind of climate feedback to solar change. Authentic anthropogenic forcing should be the one that results from human activity that occurs despite the change of natural climate forcing, not the one that occurs because of it. Thus anthropogenic forcing might be significant during the modern age when technology overcomes nature.

    Did that really contribute anything? Don’t we have enough wild speculation as it is?

  11. Gerald Machnee
    Posted Nov 26, 2007 at 5:39 PM | Permalink

    What is significant is that all the “science is NOT in”.
    They agree that there is more work to be done in all fields.

  12. Sam Urbinto
    Posted Nov 26, 2007 at 5:40 PM | Permalink

    I think that sums it up rather nice; the climate doesn’t just exist in a void, without us; what we do that affects the climate causes us to change our behavior, I would think that’s obvious.

    But highlighting a lot of the uncertainty seems a lot more fair than making blanket statements of cause/effect over highly uncertain subjects.

  13. Francois Ouellette
    Posted Nov 26, 2007 at 5:52 PM | Permalink

    Steve,

    I don’t think it’s about forcings not being “equal”. They are already not equal. Most modellers have no problem assuming a CO2 forcing different from what the “pure” greenhouse effect would give, through the so-called “water vapor” feedback. But when it’s the Sun, they only look at the Total Solar Irradiance (TSI) and take that number as is, in W/m2. They assume that there is no “amplifying” effect for the Sun, whereas there assume one for CO2. But in fact, no one really knows how much water vapor feedback there really is. It’s just that if there is nothing to amplify the Sun’s forcing, then the water vapor feedback “must” be stronger, to account for all the warming. Scafetta and West don’t make the assumption that 1W/m2 change in TSI is “only” a 1W/m2 forcing. They make no assumption at all, except that the Sun drove the climate variability in pre-industrial times. From that they find what the “real” influence of the Sun is, and deduce that the rest of the warming is most probably anthropogenic.

    The other paper that I cited, by Amman et al., do just the opposite. They attribute a fixed value for the solar forcing, run the model with that value, and conclude that the reconstruction with the least variations is the best one, and therefore that the 20th century GHG forcing is huge, which of course makes everybody happy. So the assumption that the Sun only plays a small role influences which reconstruction must be chosen, instead of the other way around.

  14. Craig Hamilton
    Posted Nov 26, 2007 at 5:53 PM | Permalink

    Is temperature a proxy for sunlight?

    If I remember my highschool biology, trees grow by using sunlight to create
    cellulose out of water and CO2. Nothing about heat. Even at high
    elevations, I cannnot see why temperature would affect growth, other
    than a trivial change to the growing season.

    If there is a relationship between tree rings and temperature, might it
    be due to the fact that sunny summers are warmer than cloudy ones? Which may
    make the solar effect on clouds even more important than the direct irradiance.

  15. bender
    Posted Nov 26, 2007 at 6:40 PM | Permalink

    #14 For Pete’s sake READ THE BLOG before posting such ridiculous comments. The theory is that longer growing seasons leads to wider rings. This is a perfectly reasonable hypothesis. THINK before you comment.

    [I am going to be SOOO pleased when the ClimateAudit101 wiki takes off. Craig Hamilton your punishment is to go help Carl Gullans fill that site out with content on tree responses to temperature, precip and other stuff.]

  16. Sam Urbinto
    Posted Nov 26, 2007 at 6:41 PM | Permalink

    No, temperature is not a proxy for sunlight. “Temperature is the unique physical property that is shared between two otherwise entirely unlike things that happen to be in thermal equilibrium with each other”. Or “The average energy of microscopic motions of a single particle in the system per degree of freedom.” Sunlight is simply a power source for whatever the temperature is doing, taking into account all the variables that result in a certain temperature (or in our case, an averaged anomaly)

  17. Michael Jankowski
    Posted Nov 26, 2007 at 6:42 PM | Permalink

    This quote is from the discussion section and represents the largest post-1950 solar influence discussed in the paper:

    Thus the Sun could have contributed roughly […] 50% of the global NH surface warming that occurred from 1900 to 2005. Since 1950 the Sun might have contributed ~0.05K (0.5/6 = 8% of the warming) using LEAN2000, or ~0.15K (1.5/6 = 25% of the warming) using WANG2005.

    That is, Scaffeta and West attribute between 8% and 25% of post-1950 warming to solar influence.

    That’s flat-out wrong.

    Try paragraph [31] on page 7 of 10. The post-1950 percentages can go up to 20% (LEAN2000) and 42% (WANG2005).

    Despite what you might hope, the warming since the mid-1970s is still not explained by TSI.

    Where might PDO fit in?

  18. Sam Urbinto
    Posted Nov 26, 2007 at 6:42 PM | Permalink

    Or

    If a thermometer orbiting the Earth is exposed to a sunlight, then it equilibrates at the temperature at which power received by the thermometer from the Sun is exactly equal to the power radiated away by thermal radiation of the thermometer. For a black body this equilibrium temperature is about 281 K (+8 C). Earth average temperature (which is maintained by similar balance) is close to this temperature.

  19. Peter Thompson
    Posted Nov 26, 2007 at 7:11 PM | Permalink

    #8 John V, which warming are they discussing? The IPCC AR4 warming which makes use of Hansen’s discredited calculations via Brohan et al., 2006, or the corrected record, as forced into the open by our host? The corrected record puts the major warming 20 years prior to 1950 and would seem to reinforce the solar issue, would it not?

  20. Posted Nov 26, 2007 at 7:28 PM | Permalink

    #17 Michael Jankowski:
    You’re right about the 20% to 42%. My apologies.
    I followed the trail from “up to 50% … since 1900″ to the Moberg2005 comparison that I quoted. Later in the discussion an alternative TSI reconstruction shows post-1950s TSI contribution as high as 42%.

    =====
    Just thinking out loud, I wonder what effect aerosols (global dimming) would have on the percentages. The model in the paper does not consider AGW or global dimming when calculating percentages. The non-solar temperature change (58% to 80% from the 1950) can be attributed to AGW and global dimming.

  21. Carl Wolk
    Posted Nov 26, 2007 at 8:26 PM | Permalink

    Concerning the difference between Loehle 2007 and Moberg [2005], you stated in a recent blog,

    The only exceptions are the Arabian Sea G Bulloides (discussed a lot here) which is uncalibrated to local temperature (actually having an inverse relation!), the Agassiz melt percentage also uncalibrated to local temperature and the Lauritzen speleothem, digital information on which was not made available at the time.

    Does the inclusion of the excluded proxies in Loehle change the reconstruction to enhance modern warming/downplay Medieval warming? If so, does the Scafetta and West conclusion using the Moberg reconstruction lose some credibility? I suppose the real question is what would you consider to be the most accurate representation of paleoclimate stretching back into the MWP, because if Loehle is accepted as the most reliable, it seems at least visually, that the solar contribution to modern warming would be greatly enhanced.

  22. Patrick Henry
    Posted Nov 26, 2007 at 8:58 PM | Permalink

    Oceans have a huge heat capacity, and it should be expected that many decades are required to achieve steady state after an upward shift in TSI – as was seen prior to 1950. Hansen’s recent work has shown that the heat content of the oceans at depth is increasing, which is strong evidence that the oceans are not at steady state. For reference, consider that temperatures in Lake Superior are still depressed from the last ice age over 10,000 years ago.

    Attempts to split the pre and post 1950s data are flawed, because of the huge thermal buffer the oceans provide. The oceans behave as a gigantic low-pass filter.

  23. James
    Posted Nov 26, 2007 at 8:58 PM | Permalink

    S&W use the NH temperature reconstruction. I wonder what the results would be if they used a SH reconstruction, or the more robust global reconstruction by Loehle. Intuitively, I think that solar would be shown to be contributing much more than 50%. John V is probably correct, though, in saying that the difference is partly AGW.

  24. Francois Ouellette
    Posted Nov 26, 2007 at 9:04 PM | Permalink

    This is not so much about the exact percentage of warming due to the Sun or to GHG. I think it’s more about how you extract that percentage, given what we know about the climatic history of the Earth. I think Scaffeta and West use a method that makes a lot of sense. But they still need the best temperature reconstruction they can get, and the best solar reconstruction they can get. And guess what, there is no consensus on either of them. The final answer can be anywhere between 0 and 100%, depending on whether you trust Mann, Moberg, Loehle, Solanki, Muscheler, Lean, etc. In fact, for some choices of reconstructions, Scafetta and West show that you get a negative influence of the Sun on temperature, which they rightly discard because it doesn’t make physical sense.

    There is a lot of evidence out there that there are mechanisms of interaction between the Sun’s radiation and the Earth’s climate that go beyond just following the Total Solar Irradiance. Whether it’s the cosmic ray/cloud connection, or the interaction of the deep UV spectrum with the stratospheric ozone, strong correlations are strongly indicative of something more complex.

  25. Kristen Byrnes
    Posted Nov 26, 2007 at 9:24 PM | Permalink

    The first mistake they’re making is to use the surface temp record.

    Hint: Detrend volcanoes from the temperature record and you’ll get the correct signal.

  26. Sylvain
    Posted Nov 26, 2007 at 9:27 PM | Permalink

    It would be very interesting to see what would look like the Wang 2005 and Moberg 2005 (with lowell proxies) as seen here .

    This also why we need updated proxies instead of comparing the last 20 years to intrumental temp. For some reason it seems very complicated to update proxies to today or to publish the result of these update. Could it be that they don’t follow the intrumental temp.

  27. Bruce
    Posted Nov 26, 2007 at 9:43 PM | Permalink

    JohnV

    Thus the Sun could have contributed roughly 4/8 = 50% of the global NH surface warming that occurred from 1900 to 2005.

    And more if ACRIM is implimented.

    May I also suggest some of the CO2 increase claimed by the AGW crowd may have been caused by the warming of the oceans caused by the Sun. Historically CO2 increases have followed temperature rises.

    In conclusion, if we assume that the latest tempera- ture and TSI secular reconstructions, WANG2005 and MOBERG05, are accurate, we are forced to conclude that solar changes significantly alter climate, and that the climate system responds relatively slowly to such changes with a time constant between 6 and 12 a. This would suggest that the large-scale computer models of climate could be significantly improved by adding additional Sun-climate coupling mechanisms.

    May I suggest that climate models that don’t include the sun are worthless.

  28. Jon
    Posted Nov 26, 2007 at 11:50 PM | Permalink

    Just thinking out loud, I wonder what effect aerosols (global dimming) would have on the percentages. The model in the paper does not consider AGW or global dimming when calculating percentages. The non-solar temperature change (58% to 80% from the 1950) can be attributed to AGW and global dimming.

    And perhaps critically that although the US temperatures are well-adjusted, we can’t say that for sure about the ROW. Consequently there may well be a signal in the 1950-2000 temperature time-series that is indeed neither TSI nor GHG in origin.

    Given that we know the US record required substantial adjustment and that the ROW lacks those adjustments, this is quite plausible and consistent with the post-1950s divergence indicated by this study.

  29. bender
    Posted Nov 26, 2007 at 11:50 PM | Permalink

    The title post should be attributed to Francois O, not Francis O.
    Errors in attribution: gotta hate ‘em.

  30. TonyA
    Posted Nov 27, 2007 at 12:48 AM | Permalink

    Probably not the correct thread but have you all seen this at JEG’s blog?

    An open letter to Craig Loehle

  31. Paul G M
    Posted Nov 27, 2007 at 12:51 AM | Permalink

    Re 10 and the assumption of minimal AGW forcing in the preindustrial era. This may be off thread but could demonstrate one of the fundamental issues with HS and other paleoclimatic proxies for the past 1000 years in that they ignore the historical record.

    In Britain at least, about 90% of the land was once covered in trees. But with the Elizabethan boom nearly all was cut down for building particlulary for ships. The forests that survived were preserved so that the aristocracy could go hunting.

    Similarly, in the early stages of the Industrial Revolution, many of the trees that had survived were cut down to make charcoal. You can imagine the Greenpeace of the time being relieved at the discovery of the coking process to make iron.

    So you have two episodes when land use changed radically with the consequent impact on CO2 and albedo. If only the CET record went back to 1400, we could compare the effects against a temperature record.

    In the US, my rather shaky history tell me that the native indians had hunted bison to near extinction thus eliminating a huge source of methane. How does that correlate with the Bristlecones?

    Cheers

    Paul

  32. Chas
    Posted Nov 27, 2007 at 3:12 AM | Permalink

    Rasmus is working through this paper too:

    http://www.realclimate.org/index.php?p=502

  33. Stephen Richards
    Posted Nov 27, 2007 at 3:19 AM | Permalink

    From what I read, this paper concludes nothing with any usable certainty. The fits of data, Mannian et al seem to me to demonstrate EXACTLY what the pre-blog award guys on this site have been saying about proxies and how to use them or not use them, as the case maybe. And MrPete, Steve Mc and famillies work in the starbuck mountains ha

  34. Stephen Richards
    Posted Nov 27, 2007 at 3:26 AM | Permalink

    Sorry touched the wrong key again

    From what I read, this paper concludes nothing with any usable certainty. The fits of data, Mannian et al seem to me to demonstrate EXACTLY what the pre-blog award guys on this site have been saying about proxies and how to use them or not use them, as the case maybe. And MrPete, Steve Mc and famillies work in the starbuck mountains have demonstrated the complexity of the proxy issue.
    They have arrived at no firm conclusions on AGW, lots of coulds, maybes and perhaps; so the real value of this paper is a comparison of temperature series against an assumption that the sun contributes something to global temperature ! But I knew that already.

  35. Andrey Levin
    Posted Nov 27, 2007 at 3:58 AM | Permalink

    Very elegant and straightforward paper, on pair with Loehle.

    It confirms findings of Schwartz for climate inertia (due to oceans) to solar forcing at about 10 years, circumstantially confirms Svensmark hypothesis, and explains why Lockwood got decoupling of solar forcing and surface temperature in last 50 years.

    Steve, I’m starting to think that this website could be more important than I had guessed.

    This paper also made me more aware of the importance of temperature reconstructions.

    Past climate reconstruction is seemingly #1 subject of Climate Audit, but audit of modern instrumental temperature reconstructions is arguably #2 (together with Antony’s monumental efforts). If (or more precisely, when) official instrumental temperature reconstructions will be forced to abandon erroneous upward bias (as it happened with continental US temperatures), solar connection will be able to explain no less than ¾ of 20 century warming. Viva la Steve!

    Heck, simple substitution of instrumental temperature record in Fig.6b by NH troposphere temperatures from weather balloons (50 years) or satellite lower troposphere measurements (30 years) already halves the discrepancy!

    Where might PDO fit in?

    Right here in Fig.6b, Michael. Note spikes in instrumental temperatures in 1920-1945 and 1975-2000, and compare with combined PDO+AMO index presented in Fig.11 here:

    http://icecap.us/docs/change/OceanMultidecadalCyclesTemps.pdf

    Both PDO and AMO were positive in these two time periods.

  36. Ivan
    Posted Nov 27, 2007 at 3:59 AM | Permalink

    Steve, answering my earlier question about why didn’t you analyzed Jaworowski and Beck’s critique of IPCC ice core measurements, you have indicated that it was so because, ” no public policy is driven by their findings”. In other words, you analyze and audit only official IPCC theories. So far so good.

    But, obviously Scaffeta and West also are outliers. IPCC ignores entirely anyone with remotely resembling attitudes and findings. What public policy is driven by Scaffeta and West papers to qualify them for Climate Audit and climate audit?

    Let me specualte: S and W results are at least to some degree acceptable to AGW crowd, as we have seen in John V’s reactions on it. S&W argue that only thiny portion of the warming in period 1975 onwards can be attributed to solar factor, what is exactly what supporters of AGW thesis assert. You have choosen the easier way – to impose direct skepticism concerning AGW in a way that wouldn’t irritate mainstream too much. Otherwise, you could, bona fide, to “audit” Svensmark (1998, 2007), or Khilyuk nad Chilingar 2006, or Weizer and Shaviv 2003 or Shaviv 2005. Or to audit Lockwood and Froelish’s (2007) “proof” that solar variability had no influence on global warming in recent dacades, or to evaluate Shaviv’s rebuttal http://motls.blogspot.com/2007/07/nir-shaviv-why-is-lockwood-and-frohlich.html.

    All those papers, discussions and even experiments (!) cast much more doubt on AGW thesis, if your intention was to question this thesis. Thus, it turned out that you made only politically correct compromise with AGW theory (by which you also compromised your policy of auditing IPCC science, but by which you will hardly eliminate accusations of being “climate denier” by eco-fanatics among both laymen and scientists).

  37. Ivan
    Posted Nov 27, 2007 at 4:34 AM | Permalink

    One qualification to preclude potential misunderstanding. Scaffeta and West are outliers (as far as I know IPCC don’t cite their previous work and ignore much of science pointing greater solar influence on climate. You also indicate that their method is opposite to established IPCC concept of “forcing”. That was why I meant by assertion that IPCC “ignores anyone with remotely resembling findings”. I meant remotely resembling methodology and direction of inquiry), but their final conclusions are, nevertheless, close to what IPCC says about warming 1975 onwards.

  38. neither a scientist nor batman
    Posted Nov 27, 2007 at 4:41 AM | Permalink

    hi, just a layman with an interest in science stuff. read (more or less) the paper and had questions. i was wondering if someone could explain to me paragraph [29] and the differences between the mann03 and the mosberg05 models.

    from what i tried to understand, if the earth was a kettle of water and the sun was a stove, is the mann03 model saying that the kettle of water cools down almost instantly if i turn off the stove, while mosberg05 says there’s a 6-12 yr delay (big kettle, big stove)? this is probably an oversimplification, but i couldn’t think of a good analogy and wanted to strip away all of the extraneous stuff and focus on the main idea.

    hope someone could explain or correct my (mis)understanding. i don’t have a side in this issue, aside from the truth (or a reasonable facsimile). tnx!

  39. Posted Nov 27, 2007 at 4:59 AM | Permalink

    Some of my comments about the paper and comments it ignited:

    http://motls.blogspot.com/2007/11/scafetta-west-climate-phenomenology.html

  40. Will Dean
    Posted Nov 27, 2007 at 5:30 AM | Permalink

    #39 something on that link is infected with a bit of spyware which tried to install ‘WinErrorFixer’ onto my machine.

    I’d advise people not to open that link without at least disabling Javascript.

  41. Posted Nov 27, 2007 at 5:47 AM | Permalink

    Ref 38 Coming from a dabbler not a scientist, that is a good analogy. The main point is their method it totally dependent on the accuracy of the proxy reconstructions (both temperature and solar). Someone will correct me if I am wrong, but their method could be a good way to verify the “skill” of proxy reconstruction.

  42. Posted Nov 27, 2007 at 5:48 AM | Permalink

    Dear Will Dean, sorry to tell you but your WinErrorFixer has nothing to do with my website. WinErrorFixer can’t be installed by JavaScript. But you are probably infected already by this fake “antivirus” program. Read some pages on the Internet about it – how to remove it and what it is:

    http://www.google.cz/search?q=winerrorfixer

  43. MarkW
    Posted Nov 27, 2007 at 5:55 AM | Permalink

    The warming since the 70′s can be explained, in large part, by the warm cycle of the PDO.

  44. MarkW
    Posted Nov 27, 2007 at 6:00 AM | Permalink

    When calculating how much of the warming is due to the sun, don’t forget to factor out the UHI contamination of the temperature record first.

  45. Will Dean
    Posted Nov 27, 2007 at 6:10 AM | Permalink

    Re WinErrorFixer – it was a Javascript ‘alert’ message which was trying to persuade me to install WinErrorFixer, not the actual WinErrorFixer application itself – that’s certainly something a website COULD do, particularly one which includes a lot of 3rd party JS (it might have been served in a rogue advert, for example). Anyway, I can’t see it now, so Steve might as well delete all the related messages. If I see it again, I’ll let you know directly.

  46. MarkW
    Posted Nov 27, 2007 at 6:56 AM | Permalink

    From the papers I’ve seen recently, the total amount of UV radiation coming from the sun is much more variable than is visible light. When the sun’s output increases a little bit, UV output increases a lot.

    UV light is responsible for the creation of ozone, and ozone is another GHG.

    Has anyone factored this change into their calculations?

  47. Michael Jankowski
    Posted Nov 27, 2007 at 7:09 AM | Permalink

    Just thinking out loud, I wonder what effect aerosols (global dimming) would have on the percentages. The model in the paper does not consider AGW or global dimming when calculating percentages. The non-solar temperature change (58% to 80% from the 1950) can be attributed to AGW and global dimming.

    Throw in black soot as well. And then there’s any portion of AGW that would be due to gases other than CO2. But CO2 gets all the emphasis.

  48. JamesG
    Posted Nov 27, 2007 at 7:32 AM | Permalink

    Regarding that time lag (or relaxation response time) mentioned in paragraph [29], Eduardo Zorita recently wrote this on the nature blog, re. the recent Lockwood & F. paper, which is maybe interesting:
    “..in a paper by Waple, Mann and Bradley (Climate Dynamics vol 18, 563 ; 2002) a lag between solar irradiance and global mean surface temperature of about 10-15 years has been identified”.

  49. steve mosher
    Posted Nov 27, 2007 at 8:02 AM | Permalink

    re 32. Rasmus gave it an F

  50. tpguydk
    Posted Nov 27, 2007 at 8:04 AM | Permalink

    #38, I was thinking something similar.

    As an aside, it’d be nice to have a SH temperature reconstruction, even though the proxies down under are sparse.

  51. Larry
    Posted Nov 27, 2007 at 9:06 AM | Permalink

    49, interesting that they didn’t even link the original text. They rip an article without even letting the readers see what it is that they’re ripping. That site does seem to operate by the motto “I’ll do all the thin’in around here”.

  52. bender
    Posted Nov 27, 2007 at 9:17 AM | Permalink

    #35/#43
    You attribute warming trends during 1920-45 and 1975-2000 to positive phase PDO & AMO, almost as though global-scale warming would not be conducted through these primary pathways. Does this make sense to you, given the hypothesis that ENSO is a primary pathway through which global-scale warming is conducted? Or can you refute that one too? Second point: the positive end of these teleconnective circulatory pathways has a correponding negative component. It’s not as if the positive phase means warm anomalies everywhere. Have you considered this in your attempts to reconcile regional vs global temperature time-series?

  53. Posted Nov 27, 2007 at 9:30 AM | Permalink

    #27 Bruce:

    May I also suggest some of the CO2 increase claimed by the AGW crowd may have been caused by the warming of the oceans caused by the Sun.

    Absolutely. And that’s what I like about the S&W method. They determine the climate sensitivity to the sun including all feedbacks empirically. TSI is used as a proxy for the total forcing including CO2 and H2O feedback, cosmic rays, and anything else that might be affected by the sun.

    May I suggest that climate models that don’t include the sun are worthless.

    Of course such a model would be worthless. But all models include the sun. S&W suggest that the models should be “improved by adding additional Sun-climate coupling mechanisms”.

    ====
    #35 Andrey Levin:

    If (or more precisely, when) official instrumental temperature reconstructions will be forced to abandon erroneous upward bias (as it happened with continental US temperatures)

    What are you talking about? Have a look at the current USA48 temperature record from NASA, which has been confirmed by comparison with the best rural stations:

    Or, if you’re talking about the error that SteveMc found, here’s the comparison:

    =====
    #47 Michael Jankowski:

    But CO2 gets all the emphasis.

    CO2 has become a short-hand for CO2-equivalent (CO2e). The IPCC and climate scientists in general are very aware of the other GHGs and non-GHG forcings:

    http://www.gcrio.org/ipcc/ar4/wg1/faq/ar4wg1faq-2-1.pdf

  54. shs
    Posted Nov 27, 2007 at 9:33 AM | Permalink

    In re: the review at realclimate.

    I assume the Team will now paint JGR with the same brush as E&E.

  55. MarkW
    Posted Nov 27, 2007 at 9:43 AM | Permalink

    bender,

    Your prose is a little dense, I’m having trouble figuring out just what it is you are asking.

    You attribute warming trends during 1920-45 and 1975-2000 to positive phase PDO & AMO, almost as though global-scale warming would not be conducted through these primary pathways. Does this make sense to you, given the hypothesis that ENSO is a primary pathway through which global-scale warming is conducted? Or can you refute that one too?

    I’m guessing that you are trying to draw a difference between the affect of PDO/AMO and ENSO. There is a strong correlation between the positive side of anPDO and the size and frequency of ENSO events.

    Second point: the positive end of these teleconnective circulatory pathways has a correponding negative component. It’s not as if the positive phase means warm anomalies everywhere. Have you considered this in your attempts to reconcile regional vs global temperature time-series?

    This is true, but it’s affect on atmospheric temperatures depend on where the negative component is located. The mechanisms of PDO/AMO and ENSO are still the subject of much research.

    1) It’s well known that the earth’s surface is not evenly covered with temperature sensors. If the negative component exists in a place where there are few or no sensors, then it’s influence might be understated.

    2) What if the PDO/AMO serves not to distribute heat amongst different parts of the globe, but rather between layers of the ocean. IE, during a cool phase warm surface waters are drawn into the oceans deeps. In the warm phase, this stored heat is released.

  56. Larry
    Posted Nov 27, 2007 at 9:56 AM | Permalink

    53, CO2e is voodoo physics. You can’t just add the effects of the gases, and then treat the mixture as if it’s all CO2, because of the logarithmic form of concentration, and because they don’t absorb at the same wavelengths. Anyone who tries to do any serious modeling using CO2e is incompetent.

  57. Posted Nov 27, 2007 at 10:19 AM | Permalink

    #56 Larry:
    Yes, CO2e for modelling would be problematic.
    It is however a useful shorthand for describing the net effect of various GHGs to non-technical people.

  58. Michael Jankowski
    Posted Nov 27, 2007 at 10:22 AM | Permalink

    Re#53, IPCC and climate scientists (and folks like you and me), sure, but the general public and policymakers? Other than cow fart jokes, I don’t see CH4 getting much attention.

  59. Larry
    Posted Nov 27, 2007 at 10:31 AM | Permalink

    57, actually, I don’t even think it’s a good idea to tell non-technical people that there’s “455 ppm CO2″ (I’ve seen that in print). The media then picks it up and starts misinterpreting it, and claiming that we’ve increased CO2 by 62%, or even worse, that there’s been a sudden increase from 384 to 455 based on a new study. There are all kinds of wrong ways to interpret a bogus number like that, and even the right way is rather meaningless.

    The correct facts in the hands in the media are dangerous; phony unphysical variables like that are virtually guaranteed to be misconstrued.

  60. Sam Urbinto
    Posted Nov 27, 2007 at 10:35 AM | Permalink

    Even if they’re talking about equivalent CO2 (which I doubt they really are, but hey) there’s two problems with that. First, it’s misleading. “CO2″ is not “The equivalent amount of CO2″ Second, you can’t just lump them together as Larry mentioned.

    The process is both considerably more complex and considerably more easy than it seems. The issue is that we don’t know the specifics and all the interactions.

    Sunlight comes in, but we actually are talking about 3 things; visible light, ultraviolet light and infrared light. Clouds and airborne particulates can (and do) reflect various wavelengths but not others, in different ways at different altitudes. So one factor is sun intensity at these different bands.

    All the GHG absorb/transfer energy at different wavelengths and different altitudes, in different ways, and interact with each other and the clouds and particulates. http://commons.wikimedia.org/wiki/Image:Atmospheric_Transmission.png

    Liguid water, contaminated ice, and different types of materials absorb/transfer/release energy at different rates, and these also interact with everything else. Vapor water moderates and interacts, as do clouds when they melt and release liquid water.

    What is temperature, what is weather? It’s everything acting and reacting in ways at at rates we can’t really directly measure, only sample or model. (Oh, and don’t forget wind, Earth’s angle, volcanoes, cosmic rays and the magnetic field, and the molten core and the pressures in the deep ocean etc.)

    What do people do that effects the system are many. The contaminents in the air and on the ground. GHG like CO2 and CH4 and O3 and N2O. The cleared or burnt forests. Cities. Farmland. Roads. Airports. How do you quantify it all? You can’t.

    And to attribute all of this by saying “CO2″ is very misleading, at best. CO2 is only half of the GHG effect on its own as far as radiative forcing, and that doesn’t include how it acts and reacts to the rest. Add to that the GHG aren’t the entire story anyway even if you “meant” the eqivalent and do the calculations and do them correctly. As if anyone can easily explain how even the GHG react among themselves.

    Take for example this graphic and pay attention to the ranges for each component considered separately (as examples, cloud albedo effect and net anthropogenic are quiet large ranges; ozone could be equally negative and positive in its forcing):

    Take a careful note of the summary, especially the last paragraph:

    Global average radiative forcing estimates and ranges in 2005 for anthropogenic greenhouse gases and other important agents and mechanisms.

    Understanding global warming requires understanding the changes in climate forcings that have occurred since the industrial revolution. These include positive forcing from increased greenhouse gases, negative forcing from increased sulphate aerosols and poorly constrained forcings from indirect aerosol feedbacks as well as minor contributions from solar variability and other factors. The poorly constrained aerosol effects results from both limited physical understanding of how aerosols interact with the atmosphere and limited knowledge of aerosol concentrations during the pre-industrial period. This is a significant source of uncertainty in comparing modern climate forcings to past states.

    Contrary to the impression given by this figure, it is not possible to simply sum the radiative forcing contributions from all sources and obtain a total forcing. This is because different forcing terms can interact to either amplify or interfere with each other. For example, in the case of greenhouse gases, two different gases may share the same absorption bands thus partially limiting their effectiveness when taken in combination.

  61. Bruce
    Posted Nov 27, 2007 at 10:44 AM | Permalink

    JohnV

    But all models include the sun.

    AGW “scientists” go out of their way to trivialize the suns contribution to any climate change.

    From IPCC 4

    During the past 50 years, the sum of solar and volcanic forcings would likely have produced cooling.

    The IPCC models are a joke.

  62. Sam Urbinto
    Posted Nov 27, 2007 at 10:47 AM | Permalink

    That should have been “The things people do that have an affect on the system are many.”

  63. Pat Keating
    Posted Nov 27, 2007 at 11:33 AM | Permalink

    53, 61 John V, Bruce

    The models assume that CO2 + positive-feedbacks cause the warming observed, and parameterize the feedbacks so this occurs (the old “climate sensitivity” problem). What they should do now is ‘turn-off’ the CO2 sensitivity and assume that insolation + positive-feedbacks cause the warming observed, parameterizing the feedback to fit, the same as in the CO2 models.

  64. Pat Keating
    Posted Nov 27, 2007 at 11:40 AM | Permalink

    53, 63
    John V, if you have a model which you can use to do what is suggested in 63, you could then:

    a) compare the results with the CO2 assumption,
    b) carry out a further, very interesting set of runs where both CO2 and insolation are included, with the CO2 CS and the insolation CS jointly adjusted for best fit.

  65. Jon
    Posted Nov 27, 2007 at 12:12 PM | Permalink

    John V writes:

    What are you talking about? Have a look at the current USA48 temperature record from NASA, which has been confirmed by comparison with the best rural stations:

    Although I didn’t make the the remark to which you are responding; let me repeat on the applicable remark I did make: ROW temperature matters more than the USA48. We’re at the point now where we know that the best rural stations agree with the adjusted network (USA), validating the necessity of the adjustments.

    Thus the next concern should be that the ROW has not been subject to this adjustment process and is dominated by Urban sites–precisely those that our rural network indicated required adjustment.

  66. Posted Nov 27, 2007 at 12:34 PM | Permalink

    #66 Jon:
    The same urban adjustment that is applied for USA48 is also applied to ROW.

  67. Dennis Wingo
    Posted Nov 27, 2007 at 1:29 PM | Permalink

    # 65

    For all of the discussions of sunspots over the past few centuries I have found little information in the literature about the Chinese records of sunspots that are supposed to be more complete and much longer in duration than their European counterparts. Do you have any information on this that could shed some light so to speak?

  68. Boris
    Posted Nov 27, 2007 at 2:16 PM | Permalink

    I haven’t read this paper, but Rasmus does say:

    They assume the TSI reconstruction is a proxy for the total solar influence and that CO2 is part of a solar ‘feedback’

    To someone who has read it: is this accurate? This would seem to be a devastating critique.

  69. steve mosher
    Posted Nov 27, 2007 at 2:36 PM | Permalink

    I would think it fruitful to outline rasmus’s objections and go through them.
    He was a bit pissy, overblown, self absorbed and over the top. The whole scanning of the document
    and posting it with Rasmus’ F grade was not very well thought out. Better had he posted a
    YouTube video

    I give rasmus a D in english.
    An F in rhetoric.
    An F in communications.

    he raised some good points in a post that could have used a few rewrites. He was kinda
    scatter brained in his critique and did not do a good job of recapitulating their arguments
    (However weak) His exposition of their position was weak yet His questions were substantive.
    He should have taken more time and thought.

    Somebody put him under deadline and he finished in a minute.

  70. Francois Ouellette
    Posted Nov 27, 2007 at 2:39 PM | Permalink

    #69 You might want to read Kouwenberg et al., in Geology, January 2005, p.33. Here’s the abstract:

    A stomatal frequency record based on buried Tsuga heterophylla needles reveals significant centennial-scale atmospheric CO2 fluctuations during the last millenium. The record includes four CO2 minima of 260-275 ppmv (ca. A.D. 860 and A.D. 1150, and less prominently, ca. A.D. 1600 and 1800). Alternating CO2 maxima of 300-320 ppmv are present at A.D. 1000, A.D. 1300, and ca. A.D. 1700. These CO2 fluctuations parallel global terrestrial air temperature changes, as well as oceanic surface temperature fluctuations in the North Atlantic. The results obtained in this study corroborate the notion of a continuous coupling of the preindustrial atmospheric CO2 regime and climate.

  71. Larry
    Posted Nov 27, 2007 at 2:41 PM | Permalink

    72, no, that’s par for the team. They’re never been to the TQC cheerleading seminar. Barely adequate is the stuff that awards are given for. Goooo team. Rah. We’re almost ok.

  72. Jon
    Posted Nov 27, 2007 at 3:57 PM | Permalink

    #66 Jon:
    The same urban adjustment that is applied for USA48 is also applied to ROW.

    No, it isn’t. Nor is it possible, not least of which is because there are comparatively more rural stations in the USA.

  73. Andrey Levin
    Posted Nov 27, 2007 at 4:13 PM | Permalink

    Re#52, Bender:

    Oceans cover ¾ of Earth surface, and in addition have lower albedo than terrestrial part. It is quite obvious that sun heats atmosphere mostly via oceans. However, transition of heat energy from oceans to atmosphere is not stationary process, it oscillates. Considering that oceans hold 2000 more heat energy than atmosphere, even small irregularities in such heat transfer will have pronounced effect on global temperatures. Everybody knows how El Nino of 1998 affected global temperatures, but somehow longer 30-year PDO/AMO cycles are summarily dismissed.

    There is only 1 (one) observed process in 20 century climatic history which co-inside exactly with two temperature maximums of around 1940 and 2000 and temperature minimum of 1970s, and it is PDO/AMO. What I am saying is that 20 century temperature history could be almost perfectly explained by combination of two factors: underlying solar warming trend and superimposed 30-years cycle of PDO/AMO oscillations. Nothing else cut it better.

    Now, temperature proxies used in the paper are naturally smoothed, so it is no wonder that ocean oscillations are not visible in the graph at Fig.6b –until temperatures switches to instrumental record with much higher resolution. Fit is far from perfect, it is true, but the input into calculations (proxies) are far from perfection too.

  74. Posted Nov 27, 2007 at 4:36 PM | Permalink

    #75 Jon:
    GISTEMP explicitly throws out urban stations that do not have rural “neighbours” within 1200km.

  75. Darwin
    Posted Nov 27, 2007 at 5:07 PM | Permalink

    #78 — Within 750 miles? That’s almost like Chicago to New York, a quarter of the distance going coast to coast. Not a very tough test.

  76. Jon
    Posted Nov 27, 2007 at 6:33 PM | Permalink

    John V.

    #75 Jon:
    GISTEMP explicitly throws out urban stations that do not have rural “neighbours” within 1200km.

    Hansen’s “lights” methodology was applied only to stations in the USA. Thus, the rural adjusters in GISTEMP are historic classifications. i.e., we don’t know that those stations are still rural.

    Second, USHCN climate records contain TOBS, station move, and instrumentation adjustments. The unadjusted GHCN records that comprise GISTEMP predominately lack these adjustments.

  77. Posted Nov 27, 2007 at 6:49 PM | Permalink

    Ref 83, Cool, how about the last 1500 years? How about the 100 – 160 years before the Little Ice Age? I am a pragmatist. Is making realistic changes to hedge bets skepticism? Should I buy into a theory that tree rings hold the answer to our tiny part of the universe and buy carbon credits?

    Didn’t solar have a noticeable influence over climate until the 1980′s (1978 was an interesting year). At that or whatever time, man overwhelmed solar influence starting the rise to ruin. Therefore ALL warming from that time on is due to man’s activities alone, or is it?

  78. steve mosher
    Posted Nov 27, 2007 at 7:04 PM | Permalink

    RE 89. Gisstemp requires that an URBAN station have 3 rural neighbors within 1000km otherwise
    the URBAN station is dropped. If it has 3 neighbors or more then the urban station is adjusted to
    reflect the Rural trends.

  79. steve mosher
    Posted Nov 27, 2007 at 7:13 PM | Permalink

    RE 74.. Maybe we should rewrite what Rasmus had to say. He raised solid points that folks here have
    not choosen to discuss. He won’t come here and defend his attack. JohnV could do it, but it’s unfair
    to ask him.

  80. Steve McIntyre
    Posted Nov 27, 2007 at 7:32 PM | Permalink

    The discussion of this paper at RC is worth reading. Here’s a point that Rasmus and I agree on:

    blogs (like RC) may play an important role, as papers get discussed. Poor papers will be torn apart, and when authors know that they risk their paper being scrutinized and criticized, they will hopefully take more care to check their analysis. -rasmus]

    I don’t have time to follow or summarize the debate unfortunately.

  81. Michael Jankowski
    Posted Nov 27, 2007 at 8:00 PM | Permalink

    Re#94, does Rasmus explain why certain authors still use a “scrutinized,” “criticized,” and “picked-apart” PC1 years after the fact? How about collation errors? Isn’t the rain in Maine not still falling in the Seine in some circles?

    And “blogs (like RC) may play an important role” in mudding the waters when it comes to cheerleading their own works and promoting their own ideas and agenda while doing their best to belittle opposing viewpoints and works.

  82. Posted Nov 27, 2007 at 8:03 PM | Permalink

    #93 steven mosher:
    I wouldn’t dare even try re-writing a Real Climate post right now. You could do it. Extract the key points without adding your own opinion. Then let the discussion begin.

  83. Peter
    Posted Nov 27, 2007 at 11:16 PM | Permalink

    #67

    “The same urban adjustment that is applied for USA48 is also applied to ROW.”

    John V, how can that be true? I had the impression that station histories for half of Jones’ Chinese stations were missing. Is that not true? Do we really have equally detailed station histories for all the ROW stations as we have for the US ones?

    Also, have the adjustments for the ROW stations been placed in the public domain? So is it possible to do exactly the same rural/urban comparison for ROW as you did for the US?

  84. MarkW
    Posted Nov 28, 2007 at 5:50 AM | Permalink

    #92, Therein lies the problem. Many stations still listed as rural, haven’t been rural for decades.

  85. steve mosher
    Posted Nov 28, 2007 at 7:26 AM | Permalink

    RE 96. JohnV I might give it a try maybe a point at a time. it would be a good excercise

  86. steve mosher
    Posted Nov 28, 2007 at 10:02 AM | Permalink

    RE 153. Yorick, have you met Dr. Slop?

  87. Posted Nov 28, 2007 at 10:34 AM | Permalink

    #118 Peter:

    John V, how can that be true? I had the impression that station histories for half of Jones’ Chinese stations were missing. Is that not true? Do we really have equally detailed station histories for all the ROW stations as we have for the US ones?

    Also, have the adjustments for the ROW stations been placed in the public domain? So is it possible to do exactly the same rural/urban comparison for ROW as you did for the US?

    I was referring to GISTEMP (not CRU). The GISTEMP data before and after “homogenization” is available from the GISTEMP website (Google “GISTEMP” to find it).

  88. Posted Nov 28, 2007 at 10:37 AM | Permalink

    #127 MarkW:

    #92, Therein lies the problem. Many stations still listed as rural, haven’t been rural for decades.

    Just thinking out loud, somebody should survey site locations using Google Earth to determine which stations are still rural. The low resolution in many areas would make it difficult to discern very small towns, but the main concern with UHI is larger centres. I could host the images and rankings.

  89. MarkW
    Posted Nov 28, 2007 at 11:50 AM | Permalink

    Even small towns can have a noticeable UHI.

  90. Sam Urbinto
    Posted Nov 28, 2007 at 6:58 PM | Permalink

    Is that the same as Norwegian MD95-2011 being from Finnish Lake?

    Denmark, Sweden, Norway, Finland.

    110/220 60/50. Whatever it takes.
    :D

    lol

  91. Posted Nov 28, 2007 at 8:09 PM | Permalink

    219: If the reconstructions are not valid, it doesn’t matter what the math is. Now, as a purely statistical exercise one can ask if the estimates of the uncertainties are valid. That would depend on something called the “number of degrees of freedom”. Basically how many ‘independent’ data points you have. There are various ways to determinate that number. Almost all geophysical and solar parameters show a high degree of ‘conservation’, meaning that high values are usually followed by other high values and low values are usually followed by other low values. So two consecutive high values are not two independent data points, but close to only one. As a concrete example, assume that you measure the sunspot number once a day [which it is, in fact]. In an 11-year sunspot cycle you have then 11*365 = 4000 data values. Careful analysis of the ‘conservation’ property of daily sunspot numbers shows that those 4000 points only have 20 degrees of freedom. The uncertainties generally scale inversely with the square root of the number of degrees of freedom. So if you calculate the uncertainty based on 4000 data points you underestimate it by a factor of sqrt(4000/20) = 14. I don’t see any discussion of this ‘conservation’ effect in the S+W paper [maybe I missed it] so I’m suspicious that the fits are stated with a higher confidence that they actually have. After all, there is little physics in the paper, it is pure curve-fitting, which is not in itself bad, if done correctly. If it is just curve-fitting then the significance depends on how good the quality of the input material is, and if that is not good, then the whole thing is no good.

  92. Posted Nov 28, 2007 at 9:41 PM | Permalink

    224: 386 billion billion megawatt is one way of expressing it.\

    223: look at Figure 3 on page 4 of CAWSES – IMF, EUV, TSI.pdf
    The top panel shows what TSI should look like without the secular change that everybody likes. Now, the Figure is not ours. It was made by Lean and Frohlich, and used the group sunspot number to reconstruct TSI. With the group sunspot number being too low by 40% before 1850 you have to increase all the peaks before that time with that amount. If you do that, there is no correlation left with the temperature because there is no real variation of solar activity except for the ups and downs of the 11-year cycle modulated by the 100 year Gleissberg cycle. Maybe I should make a graph that shows this.

  93. Posted Nov 28, 2007 at 9:41 PM | Permalink

    One thing that is a real puzzle to me is the large variation from year to year [factors of two or more] in the amount of CO2 actually added to the atmosphere. Since human activity is the sum of millions [or billions] of emitters, E, the resulting output cannot vary by a factor of two [relative variability should be of the order of sqrt(E)/E which for E in the millions [billions] is teeny tiny]. So what causes the large variation? What other factors are involved? Bio-factors? That we do not know [or even worry about it - I did not find any analysis of this in AR4] the reason for this variability shows me that we are missing something important, but what?

    From what I understand it is the Northern hemisphere growing season, especially since the sensor in in the Northern Hemisphere in Hawaii.

  94. kim
    Posted Nov 28, 2007 at 10:13 PM | Permalink

    Isn’t the amount added each year a fairly small fraction of the intrayear biological variable, and the general trend smoothly up, arguing that it may well be biological variation each year which produces the numbers about which you wonder?
    =================================

  95. Posted Nov 28, 2007 at 10:53 PM | Permalink

    232

    Yea I know what you are talking about. I graphed the rate of change today. It would be interesting to do an overlay of this with recent temperatures. It looks to me to be an interesting correlation.

    Here is my graph

  96. EW
    Posted Nov 29, 2007 at 4:25 AM | Permalink

    And the Ahlbeck’s Co2-temp relationship at the same page

  97. Posted Nov 29, 2007 at 7:11 AM | Permalink

    Leif Svalgaard:

    Here is a table from NOAA that shows the growth of CO2 per year. The growth rate should only change very gently with time because there are millions of emitters, yet it fluctuates wildly. Why?

    Given the strong correlation with temperature, it looks to me like the variation in the growth rate is a demonstration of CO2 feedback from the ocean. If I remember correctly, the ocean is about 50% of the total CO2 sink. When the ocean surface is warm (such as during an El Nino) the solubility of CO2 is reduced, the sink is less effective, and the rate of CO2 concentration growth increases.

  98. Richard Sycamore
    Posted Dec 27, 2007 at 5:06 AM | Permalink

    #73 Andrey Levin,
    When you say:

    sun heats atmosphere mostly via oceans. However, transition of heat energy from oceans to atmosphere is not stationary process, it oscillates. Considering that oceans hold 2000 more heat energy than atmosphere, even small irregularities in such heat transfer will have pronounced effect on global temperatures. Everybody knows how El Nino of 1998 affected global temperatures, but somehow longer 30-year PDO/AMO cycles are summarily dismissed. There is only 1 (one) observed process in 20 century climatic history which co-inside exactly with two temperature maximums of around 1940 and 2000 and temperature minimum of 1970s, and it is PDO/AMO. What I am saying is that 20 century temperature history could be almost perfectly explained by combination of two factors: underlying solar warming trend and superimposed 30-years cycle of PDO/AMO oscillations.

    can you back this theory, using either arguments from the primary literature, or analyses that you have done?

  99. Mark T
    Posted Jul 20, 2009 at 4:37 PM | Permalink

    You do realize you just replied to a post that is almost two years old, correct? C’mon, try to find more recent topics to be snarky about. It’s probably been that long since John V has posted in general.

    Mark

  100. David Weisman
    Posted Aug 14, 2010 at 1:07 PM | Permalink

    Would Lindzen and Choi 2009 have any relevance to this paper? If climate sensitivity is as low as they suggest, would it be harder for solar variation to account for observed temperature variation? On the other hand, since temperature variation is indeed observed, it seems the climate must be sensitive to something.

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