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  1. So funny how your dismissive attitude here toward the ideas expressed in the article mirror the dismissive attitude in the article toward your side. This is just the most recent example of this sort of thing.

    I am just annoyed that no one seems to be acting grown-up in their rhetoric about this on either side. Hyperbole, alarmism, and sarcasm toward opposing viewpoints prevails on both sides, at least in terms of what the public is treated to in the popular media.

    We, the non-scientist public, deserve better from both sides, if this is of such grave import.

    Comment by pk — 12 Feb 2007 @ 1:47 PM

  2. [[So funny how your dismissive attitude here toward the ideas expressed in the article mirror the dismissive attitude in the article toward your side. ]]

    Did you miss the fact that the cosmic ray people have a big fat contradiction between their theory and the evidence? Forget who is dismissive of whom, take a look at the facts.

    Comment by Barton Paul Levenson — 12 Feb 2007 @ 1:53 PM

  3. They say there are no facts Barton. Like all of that particular social persuasion, they seem to think if you just say it, that makes it true and no support is needed. Amazing. My comment there failed to post for some reason.

    Comment by Mark A. York — 12 Feb 2007 @ 2:02 PM

  4. I had commented on Nigel’s article yesterday (curously the page seems to show only 10 comments at a time) and basically pointed out three main problems with the argument he presented.

    1) Nigel claims that the ‘cooling’ of East Antarctica contradicts the theory that greenhouse gases are causing global warming. For one – and I think RealClimate has made this clear – pointing to East Antarctica is not proof that global warming is not happening (see Davis 2005). Furthermore, how can one infer that it is not greehouse gases causing the recent warming by pointing to East Antarctic cooling, especially considering what the IPCC has already had to say about this.

    2) He claims that the global temperature rise reached a plateau in 1999. So far, what I have seen shows the contrary: that it has continued to rise.

    3) The argument is based to a large degree on political arguments, rather than scientific analysis. In other words, it is purported that the claim that anthropogenic global warming in recent times is a real and dominant phenomena is weakened because it’s the orthodox position, or it’s somehow not open to new interpretations and theories, and so on. These are arguments from a given political circumstance, not from quantitaive/ qualitative analysis of data.

    Comment by Justin — 12 Feb 2007 @ 2:29 PM

  5. Now the bees are dying. Is there any link between the decline in the bee population and climate change? We need those little critters to pollinate the plants.

    Comment by Paul M — 12 Feb 2007 @ 2:31 PM

  6. >is there any link ….?
    Er, probably (wry grin). I’m commenting as another reader here (who did keep bees once), I’m not a climate scientist.

    Ask locally if you’re seeing a local problem. There are changes due to climate and weather. There are far greater risks for honeybees (one of hundreds of kinds of bees, which are among dozens if not hundreds of kinds of pollinators).

    Got pesticide spraying? Migratory beekeepers? A good bee inspection system in your state watching out for known bee diseases that enforces laws to control them? (Ohio had a very effective bee disease control, decades ago at least; I don’t know of many other good ones.)

    If you’re talking honeybees, remember they’re European imports; the natives here called them the “white man’s flies” when they arrived. And if you’re talking native pollinators, remember you’re talking about far more animals besides honeybees.

    http://www.google.com/search?q=%2Bpollinators+%2B%22climate+change%22
    http://www.google.com/search?q=%2Bpollinators+%2B%22migratory+beekeeping%22+%2Bfoulbrood
    http://www.google.com/search&q=%2Bpollinators+%2B%22migratory+beekeeping%22+%2B%22disease+control%22&btnG=Search

    Comment by Hank Roberts — 12 Feb 2007 @ 2:45 PM

  7. I’m surprised by two things in the article: 1. when he states that researchers who have contrary ideas or evidence are rewarded with impediments to their careers (is Svensmark and his basement his only evidence?), and 2. when he mentions solar physicists in general with no name or organisation or anything. I’m surprised because I would expect a former editor of a science mag to reference evidence for such statements and I’m disappointed that he didn’t.

    Comment by Steve Latham — 12 Feb 2007 @ 2:54 PM

  8. Hmm….

    So I guess that this graph, linked from the same NOAA FTP site is also a poltical ploy

    ftp://ftp.ngdc.noaa.gov/STP/SOLAR_IRRADIANCE/SOHO_VIRGO.v2.pdf

    Very good picture of how total solar energy has been increasing.

    Data does not lie

    Comment by Dennis Wingo — 12 Feb 2007 @ 2:59 PM

  9. The blogosphere is all abuzz with the reports of galactic cosmic rays. Many seem to think it’s is a new, revolutionary idea, as though we hadn’t known about this for years. What surprises me most (well, actually it doesn’t) is that skeptics are so highly critical of any perceived flaw in the IPCC AR4 SPM, but so eager to embrace (without critical appraisal, or even any appraisal at all) an alternative which has no observational support and a most flimsy theoretical basis.

    It’s also very revealing that skeptics constantly harp on the idea that alternative viewpoints are “shut out of the discussion.” Nothing could be further from the truth. Svensmark’s theory, though not really credible, still made its way to publication in the peer-reviewed literature, experiments are now scheduled to study the effect of GCRs on cloud condensation nuclei, and both the blogosphere and the media are making (much too much) a big deal of it. How is this being “shut out” of the discussion?

    Comment by tamino — 12 Feb 2007 @ 3:03 PM

  10. Re post 8 I think your link should be
    ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SOLAR_IRRADIANCE/SOHO_VIRGO.v2.PDF

    [Response: Indeed, please look at the time scale- this is just the upswing from solar minimum to solar maximum. To see how that really fits in on the longer time-period, look at the PMOD composite:
    http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant -gavin]

    Comment by gerald whyte — 12 Feb 2007 @ 3:17 PM

  11. My understanding is that the Sun has been more active magnetically for the last 150 years.

    How does a a baseline begun in 1953 disprove anything?

    The Sun was more active during the Medieval Warming and less active during the Little Ice Age. Surely, the Medieval Warming and the Little Ice Age aren’t explained by the rise and fall of green house gases. So, unless some one offers a better explanation, these events seem best explained by variations in solar output and/or the magnetic field.

    If that is right, then a more active sun would probably have SOME effect even if it does not account for all of our current warming and even if its exact mechanisms are not completely understood.

    [Response: Nobody’s saying the sun has no effect. Many of us at RC have published papers on observational and modelling evidence for solar forcing effect on climate. The point of contention which always seems to come up is whether it has anything to do with the current climate change (i.e. the last few decades). The answer there is no (or more precisely, not very much). -gavin]

    Comment by Jim Cross — 12 Feb 2007 @ 3:17 PM

  12. Dennis Wingo: data does not lie; it wants to be understood. The graph you point to shows a change from about 1365 to around 1367, with a lot of variability. If it were your average bank balance per month, or Stairmaster average steps per day, would you think you saw a trend with that kind of change and variation?
    —-
    Pollinators: honeybee colony collapse disease news:
    http://www.ento.psu.edu/MAAREC/pressReleases/ColonyCollapseDisorderWG.html

    Comment by Hank Roberts — 12 Feb 2007 @ 3:32 PM

  13. Re #11 Gavin’s comment

    Some where there was link to an article(s) that attempted to measure the effect of solar variation on recent warming. This was article that concluded it wasn’t having much of an effect. Could somebody point me to it?

    I can’t remember how the analysis was done but, given that solar variation may have accounted for much of difference between the Medieval Warming and the Little Ice Age, I wonder if it might be underestimating a little.

    Comment by Jim Cross — 12 Feb 2007 @ 3:36 PM

  14. The Antarctic sea ice numbers are misleading if not completely wrong. See http://nsidc.org/data/seaice_index/ for the specific numbers.

    The only month you can get an 8% increase since 1978 is in March. Feb, Apr, and May give you ~6%. The other months are 3% or less (and December is actually decreasing slightly).

    Meanwhile, in the Arctic, the annual mean has decreased by over 10% overall, and summers have declined by over 20%. And most importantly, while the Arctic trends are statistically significant at a 99% level, the Antarctic trends are not even significant at a 90% level.

    Comment by Walt Meier — 12 Feb 2007 @ 3:40 PM

  15. Re: #8

    Dennis, the graph you reference only covers four years — less than half a solar cycle. Have a look at this graph.

    Data does not lie. But showing only a tiny fraction of the data so that it will support your hypothesis…

    Comment by tamino — 12 Feb 2007 @ 3:41 PM

  16. PS, New Scientist’s editorial weblog — defending a recent article on a ‘reactionless drive’ — wrote:

    “… should New Scientist should have covered this story at all? The answer is a resounding yes: it is, after all, an ideas magazine. That means writing about hypotheses as well as theories….”

    http://www.newscientist.com/blog/fromthepublisher/2006/10/emdrive-on-trial.html

    Comment by Hank Roberts — 12 Feb 2007 @ 3:43 PM

  17. If I go directly to the VIRGO page (I’m a theoretical astronomer who constructs solar models) I get to

    http://www.ias.u-psud.fr/virgo/

    and I go to total solar irradiance, the relevant place is Figure 2.1 to get the variations in the solar flux.
    Nothing much is happening, although there is interesting structure even at small luminosity contrasts.
    Your link is broken, by the way; I did eventually find your image, which is taken from one small section of VIRGO data with a 3 year baseline.
    Yes, the solar luminosity does vary over a solar cycle, which is longer than 3 years. However, if you
    look over longer periods than that (as per the links above) these cycles average out and are too small.

    Data doesn’t lie, but people can either misunderstand or misinterpret data. Why did you pick a three year snippet
    instead of the more easily found 25-30 year timelines? Because the former shows a linear trend and the latter does not?

    Comment by Marc — 12 Feb 2007 @ 3:58 PM

  18. That sure is a brief commentary on Svensmark’s work. You fail to point out that the Climax Station does not measure all cosmic rays, only those in certain energy ranges, which are not the optimum ranges for cloud nuclei formation.

    [Response: We’ve done this to death, and sometimes we get bored too. If the argument is that cosmic rays are being modulated by the solar activity (which they clearly are on a 11 yr timescale), then I don’t see any reason why different energy bands will be trending differently than the ones monitored at CLIMAX. I would also point out that this is the same series used by Svensmark and others to demonstrate a cloud link in the first place. -gavin]

    Comment by jae — 12 Feb 2007 @ 4:04 PM

  19. Dennis

    Link doesn’t work.

    Comment by Gaudez Mischol — 12 Feb 2007 @ 4:09 PM

  20. Nitpicking: data -> plural; datum -> singular

    Comment by Steve Latham — 12 Feb 2007 @ 4:44 PM

  21. As an example only…

    Global warming: another experiment that demonstrates that increases in atmospheric CO2 will not have any effect on climate…

    “Researchers recently carried out an experiment that debunks the central point in the ‘theory’ of global warming. They constructed an experimental model of the atmosphere in a box, and by passing infrared light through this model, they demonstrated that the atmosphere is already saturated with respect to the absorption of infrared light by carbon dioxide. In layman’s terms, this shows conclusively that adding CO2 to the atmosphere will have no effect on the net absorption of infrared light, and thus will not increase the surface temperature of the planet. Global warming has been shown to be a hoax!”

    Hope noone takes that seriously, and decides to publish it on the front page of the Wall Street Journal…

    I suppose I should include the actual series of events related to that experiment: see http://www.aip.org/history/climate/co2.htm

    A few years after Arrhenius published his hypothesis, Knut Angstrom sent infrared radiation through a tube filled with carbon dioxide. He put in as much of the gas in total as would be found in a column of air reaching to the top of the atmosphere. The amount of radiation that got through the tube scarcely changed when he cut the quantity of gas in half or doubled it. The reason was that CO2 absorbed radiation only in specific bands of the spectrum, and it took only a trace of the gas to produce bands that were “saturated” – so thoroughly opaque that more gas could make little difference.

    This was all clarified around 1950:
    The early studies sending radiation through gases in a tube had an unsuspected logical flaw – they were measuring bands of the spectrum at sea-level pressure and temperature. Fundamental physics theory, and a few measurements made at low pressure in the 1930s, showed that in the frigid and rarified upper atmosphere, the nature of the absorption would change. The bands seen at sea level were actually made up of overlapping spectral lines, all smeared together. Improved physics theory, developed by Walter Elsasser during the Second World War, and laboratory studies during the war and after confirmed the point. At low pressure each band resolved into a cluster of sharply defined lines, like a picket fence, with gaps between the lines where radiation would get through.

    As far as the cosmic ray question, one there’s no trend, two there’s no evidence that cosmic rays would increase CCN formation in the atmosphere (as opposed to inside a smoggy box) – see http://rabett.blogspot.com/2006/10/svensmark-stumbles-into-smog-chamber.html , etc. It’s already been rebutted several times… but here we see it again! Incidentally, people were claiming that the above ‘CO2 experiment’ disproved global warming on RC threads about six months ago.

    Comment by Ike Solem — 12 Feb 2007 @ 4:53 PM

  22. Re: #10 Gerald, thanks so much for the link to those solar graphs. They will be helpful in my presentations.

    Comment by Arvella — 12 Feb 2007 @ 5:19 PM

  23. What is the current RC explanation as to why the NH is warming and Antarctica is cooling? The cloud cover theory seems to explain it. Does RC have a different explanation besides cloud cover? Do you disagree that cloud cover can explain it?

    thx

    [Response: RC search in the upper right corner of the main page is your friend here. A search on “Antarctic cooling” takes you right to our previous post Antarctic cooling, global warming. -mike]

    Comment by charlesH — 12 Feb 2007 @ 5:32 PM

  24. Re #20: “Nitpicking: data -> plural; datum -> singular”

    If you’re writing in Latin, sure. In normal English usage, though, data is a mass noun (I think that’s the correct term, though it’s been a while since I studied English grammar, or Latin), used to refer to a whole collection of stuff – like for example snow or sand. So put that nit back :-)

    Comment by James — 12 Feb 2007 @ 6:11 PM

  25. Re Nits.
    Collective is the word you are looking for. Data is a collective noun. Like sheep.

    Comment by Serinde — 12 Feb 2007 @ 6:35 PM

  26. I have seen Nigel Calder speak and I am surprised at his op-ed. As written, his op-ed inidcates he is more or less ignorant of the basis of the IPCC findings and the scientific consensus on global warming. Cherry picking at its best!

    Comment by mikek — 12 Feb 2007 @ 6:41 PM

  27. gavin: did you ever finish May discussion ( http://www.realclimate.org/index.php/archives/2006/05/thank-you-for-emitting/#comment-13470 ) with Nir Shaviv?

    Comment by jae — 12 Feb 2007 @ 6:42 PM

  28. RE#23 – There are certainly a lot of recent scientific reports on the Antarctic that you might want to look into.

    First, consider the tropical glacier record, which includes evidence of the Medieval Warm Period and the Little Ice Age as well as the last 50 years of unprecedented warming; the compilation of global tropical glacier records is discussed at:

    http://www.sciencedaily.com/releases/2006/06/060627093233.htm
    “First Compilation Of Tropical Ice Cores Shows Abrupt Global Climate Shifts” Jun 27 2006

    Thus, the warming is not confined to the Northern Hemisphere, but is a global phenomenon.

    The Antarctic cooling issue (as cited in the linked op-ed) is a good example of How Misleading Talking Points Propagate (RC) – that may be the link you’re looking for.

    Note also that overall Antarctic snowfall has not increased in 50 years.
    See also:
    http://www.sciencedaily.com/releases/2006/10/061016105739.htm
    “First Direct Evidence That Human Activity Is Linked To Antarctic Ice Shelf Collapse” Oct 16, 2006

    http://www.sciencedaily.com/releases/2001/01/010117075358.htm
    “Antarctic Ice Shelf Collapse Triggered By Warmer Summers” Jan 19 2001

    http://www.sciencedaily.com/releases/2006/03/060330181319.htm
    “Rapid Temperature Increases Above The Antarctic” Mar 30 2006

    http://www.sciencedaily.com/releases/2005/02/050224115901.htm
    “Antarctic Ice Shelf Retreats Happened Before” Feb 28, 2005

    http://www.sciencedaily.com/releases/2006/03/060302180504.htm
    “Antarctic Ice Sheet Losing Mass, Says University Of Colorado Study” Mar 2, 2006

    http://www.sciencedaily.com/releases/2006/11/061109130709.htm
    “Climate Changes Are Linked Between Greenland And The Antarctic” Nov 10 2006

    http://www.sciencedaily.com/releases/1999/04/990409073216.htm
    “Antarctic Ice Shelves Breaking Up Due To Decades Of Higher Temperatures” Apr 9 1999

    http://www.sciencedaily.com/releases/2006/03/060312210108.htm
    “Study Previews Ice Sheet Melting, Rapid Climate Change” Mar 12 2006

    And so on… the take home message seems to be that both rising ocean temperatures and summer air temperatures can have dramatic effects on ice sheets, and the Antarctic ice shelves are sensitive to ocean temperatures (which control the melting rate) and snowfall/ ice flow (the addition rate). As the shelves go away, the glaciers will flow right into the sea. The Medieval Warm Period and the Little Ice Age seem to indicate that the climate is sensitive to various forcings, and we’ve created an unprecedented and increasing atmospheric CO2 forcing due to the use of fossil fuels – estimated to be ~20X that of any potential solar forcing – so we should expect that the observed warming trends will continue. Also note that most of the above papers weren’t discussed in the 2007 IPCC report – too recent.

    Comment by Ike Solem — 12 Feb 2007 @ 6:47 PM

  29. Re New Scientist/Nigel Calder, former editor of:
    Just highlighting the difference in tone between New Scientist No 2569, 16 September 2006: GLOBAL WARMING – Will the sun come to our rescue?, and the latest issue No 2590, 10 February 2007: GOODBYE COOL WORLD – WHY OUR FUTURE WILL BE HOTTER THAN WE’VE BEEN TOLD. It may be a case of judging the book by its cover, but the second statement is a lot more assertive in its form (exclusive use of capital letters) and content (affirmative mode).

    Comment by Fabien Bulabois — 12 Feb 2007 @ 7:03 PM

  30. You will not resolve these disputes with contrasting sorts of data, because there will always be some contradictory evidence for any theory.

    Of good help is a little history, and a little meta-science, or a look at scientific method.

    Implicit in most of these articles is that because global warming has become the orthodoxy, it brooks no dissent. To prove this, every once in a while, we read some new data set that “contradicts” the whole theory.

    This happens all the time. A good example is that Newton’s theory of gravity was not able to precisely model observations of the path of Mercury beyond a certain degree of accuracy. In the end, one of the experiments seen as confirming Einstein’s theory was that it did in fact track Mercury precisely.

    But in the meantime, Newton’s theory was not thrown out in toto because of a few flaws. Instead, it was refined.

    Here, the idea that science is nothing more than a sort of pyrrhonian skepticism is simply wrong. Science accepts tested theories as a model of truth, not to be discarded without a more compelling, fully working model.

    Until the so-called skeptics of global warming can present a model that fully explains all of the observations, they have nothing.

    The best they could really hope for is to limit the anthropogenic percentage, but in the end, as long as there is any anthropogenic contribution, there needs to be man-made counter-actions.

    Another way to hit home with these (often works with evolution deniers) is to ask if they want their medicine conducted on these breaking shreds of evidence without competent review and long term study.

    Comment by Jon-Erik G. Storm — 12 Feb 2007 @ 7:12 PM

  31. Nits:
    1. I won’t debate the unpleasant subject of normal English usage, but in scholarly writing the distinction between “datum” and “data” has not disappeared, both because some of us prefer to use Latin words correctly and because it is useful to be able to differentiate between the singular and plural forms.
    2. Speaking of differentiation, “the Times” is ambiguous (yes, I know I can follow the link, but I try not to follow too many Murdoch links), especially when the author’s nationality (“group”) is unknown.
    3. (Re mike’s comment) I don’t wish to complain about the enlarged search function, since that might be viewed as volunteering for webmaster duties, but I was more inclined to scold people for not using it back when a compound search was not required to restrict the results to RC.
    4. Please give us a straight science entry soon – absence has made the heart grow quite fond enough, thank you.

    [Response: The UK Times. I’ve edited above to be clearer. If you want to volunteer for websmaster duties, I need someone to program in a branch to each search function from two radio-buttons nicely placed in the above banner. Any and all offers accepted and I’ll send you the details on request! -gavin]

    Comment by S. Molnar — 12 Feb 2007 @ 8:36 PM

  32. What seems completely implausible is that variations in solar activity have no impact on Earth’s climate whatsoever.

    They obviously do, since virtually all (99.9999%) of Earth’s climate is derived from solar energy.

    The next issue is that it is completely implausible that solar activity is a monolith, never changing amount. The Sun clearly has cycles of activity.

    The Sun clearly has an 11-year cycle. The variance is very small between those cycles but the fact remains that old Sol is a variable entity.

    What other cycles does old Sol have beyond the 11 year one. Well go back to the sunspot figures of the late 1600s if you want evidence that old Sol has more varibility than the minimal variance of the 11 year cycle.

    http://en.wikipedia.org/wiki/Image:Sunspot_Numbers.png

    What bothers me the most, is that people will go out of their way to discount the variation when the evidence is right there. No one measured total solar irradiance in the late 1600s. So we don’t really know that solar variability caused the Little Ice Age.

    We do know, however, that changes in the Earth’s orbit can translate into changes in solar energy impacting the Earth which can cause Ice Ages etc.

    What bothers me the most, is that people do not want to investigate this variability any further. And some proxies such as C-14 production indicate old Sol has alot of variability, enough to explain the Medieval Warm Period, the Little Ice Age, the Modern Warming etc.

    http://en.wikipedia.org/wiki/Image:Carbon-14_with_activity_labels.png

    [Response: Why do you think any of what you said is controversial? Look at my own papers for ample evidence that people are actively researching these issues (most recently, Shindell et al 2006). The reason we are critical here of some of the solar shennanigans is the misuse and logical fallacies that seem to abound whenever solar is discussed. Add in the sorry history of people seeing solar connections where there are none (over and again), you have a situation where, in order to be taken seriously, you have to be extremely scrupulous in doing solar research. Svensmark and colleagues haven’t been, and they have been rightly criticised for hyping their results. As a consequence, it becomes harder to take them seriously. For that, they have only themselves to blame. -gavin]

    Comment by Jeff Weffer — 12 Feb 2007 @ 8:45 PM

  33. re: your response to #23
    That link says we need to be careful about short records and instead look for long term trends. May I ask: what is long term? 50 years? 100 years, 1000? 10,000? Is ~150 years of thermometer data enough to pick a trend? Is it still enough when we know that we started in a cold period? What of the coverage? What of the accuracy? You don’t want to be fooling yourself with incomplete data, do you?

    Comment by unconvinced — 12 Feb 2007 @ 9:01 PM

  34. The good thing about the GCR theory is that it if NASA is correct about the cycle 25 slowdown,
    GCR climate impact should be very testable within 15 years:

    http://science.nasa.gov/headlines/y2006/10may_longrange.htm

    Comment by Al Bedo — 12 Feb 2007 @ 9:13 PM

  35. Re. Comment 18:

    We need to know more about Galactic CR fluxes. The CR Isotope Spectrometer aboard the ACE satellite has for instance been collecting data at the L1 Point for less than ten years.

    It may be that neutron monitoring on earth doesn’t provide the information required to establish a trend. It’s possible that a stonger solar magnetosphere preferentially shields the planet not only from certain energies but even elements & isotopes.

    Neutrons are along for the ride with the protons in their nuclei, so may or may not be a valid indicator of the charged particles that actually make it through magnetic diversion, the ionosphere & stratosphere to the lower troposphere.

    I hope the Danish team attempts to answer the questions you raised as steps in proof last year. The experimental work at CERN indicates they see the need to try in at least some cases.

    Comment by John Tillman — 12 Feb 2007 @ 9:34 PM

  36. Off Topic, quick question:

    What are your opinions (Gavin, David et al.) of Ahilleas Maurellis’ article from a few years back? I tried to research some commentary on it but could not find any…http://physicsweb.org/articles/world/16/5/7/1

    Thanks, I love your site!

    [Response: Mostly ok. There are a few odd statements (such as “Crude calculations suggest that the two effects approximately balance each other, and that water vapour does not have a strong feedback mechanism in the Earth’s climate” – don’t know where that comes from). However, the main hook, that there is ‘anomalous clear-sky absorbtion’ of solar radiation is no longer a big issue. As far as I recall, the anomaly was mostly associated with aerosol species rather than water vapour exotica. However, there are always ongoing improvements to the HITRAN database with respect to water vapour and so I wouldn’t want to be too dogmatic. -gavin]

    Comment by A Question — 12 Feb 2007 @ 10:02 PM

  37. Re 33: Like you I’m a non-climatologists getting my head around all this. It’s a very complex field being addressed by hundreds of scientists who have created a vast body of evidence and interpretation. As will become clear if you look around the articles on this site and elsewhere; readings from the network of thermometer stations around the world are but a small portion of the data being collected, interpreted and used to model the planet’s climate system. And temperature is only one of many interrelated parameters or relevance. Many of the data sets that they are working with go back thousands, hundreds of thousands or even millions of years. Such data are derived from myriad sources including the analysis of the chemistry and structure of layers in polar ice cores, lake sediments, tree rings, stalactites and many many others. The international consensus on what the climate is doing is based on all this and much more, all fitted together to create a coherent picture of what the climate has done, is doing and is likely to do. The picture is not complete and is not perfect, and there are plenty of pundits on the sidelines trying to muddy the picture. But it’s fascinating to watch the climatologists at work, as they polish their theories, incorporating and taking advantage of the flood of new data. Check out the rest of this web-site. It’s really worth trying to get your head around it all.

    Comment by Craig Allen — 12 Feb 2007 @ 10:23 PM

  38. Following the GCR debate with great interest. A few questions:

    1. Is it the RC view that Solar is essentially an 11 year cycle and that its longer cycles are essentially constant or minimal contrasted against GHG forcing?

    [Response:No. There is clearly an 11 yr cycle of small amplitude, and there may be longer term irradiance variations – but there is no positive reason to think they are much larger. In the past, solar forcing may have been important (along with volcanic) on multidecadal to century timescales, however, GHG forcing over the last 50 years dwarfs any concievable solar contribution. -gavin]

    2. Is any group trying to reconcile Milankovitch projections (which according to my limited knowlege never fully explained the data previously) in light of new understanding of GCR, i.e., Solar Attenuation?

    [Response: I have no idea how these things could be connected. Orbital variations are very well understood and there is no reason to think that GCR changes should be affected by them.]

    3. Can GCR be thought of as a stream that could have the analogy of swirls and eddies due to other solar bodies?

    Thanks,

    Comment by jd will — 12 Feb 2007 @ 10:46 PM

  39. In reply to response: [Response: We’ve done this to death, and sometimes we get bored too. If the argument is that cosmic rays are being modulated by the solar activity (which they clearly are on a 11 yr timescale), then I don’t see any reason why different energy bands will be trending differently than the ones monitored at CLIMAX. I would also point out that this is the same series used by Svensmark and others to demonstrate a cloud link in the first place. -gavin]

    Planetary cloud cover can and is being reduced by the process “electroscavenging” which can and has occurred without modulation of GCR. (i.e. No change in CLIMAX, but planetary cloud cover is reduced.)(GCR creates ions which form the nucleous for cloud particles. Electroscavenging clears the cloud of the Ion-mediated Nucleous and causes rain.)

    Electrosavenging is increasing due to an increase in the Global Electric current. The Global Electric current is increasing due to “the increased number of high speed streams of solar wind, that are occurring during the declining phase and minimum of sunspot cycle in the last decades.” (The solar southern coronal hole is moving towards the solar equator at the end of the solar cycle. The polar coronal hole is producing cyclic strong solar winds.)

    It is a fact that overalll planetary cloud cover has been reduced from 1993 to 2003. See Palle’s attached paper which notes the cloud data is consistent with process “electroscavenging” and refers to Tinsley and Yu’s paper. Palle has written a second paper which use data from earthshine (reflected off of the moon) rather than satellite data which confirms this paper.

    http://solar.njit.edu/preprints/palle1264.pdf

    (See Tinsley and Yu’s attached paper, sections 5 a-e for details concerning the Global electric current and electroscavenging.)

    http://www.utdallas.edu/physics/pdf/Atmos_060302.pdf

    Does this make sense? Two separate processes. GCR which creates ions, the ions created cloud nucleous and a separate process that clears and collects ions, hence forming rain.

    [Response: ??? Try reading the papers you cite – Palle: “However, there is no clear systematic trend [in the ionization] since the 1960s.” (figure 7 caption). This is exactly what one would expect given the lack of trend in CLIMAX. If there is no trend in the input, you can’t get a trend in the output, whatever the mechanism! – gavin]

    Comment by William Astley — 12 Feb 2007 @ 11:00 PM

  40. In reply to “2. Is any group trying to reconcile Milankovitch projections (which according to my limited knowlege never fully explained the data previously) in light of new understanding of GCR”

    Yes. The hypothesis is that earth’s magnetic field is modulate by the orbital cycle. The cyclic variations of the earth’s magnetic field cyclically modulates GCR which increases or decreases overall planetary cloud cover, which creates the ice age cycle. Also it is hypothesized that GCR cyclically changes in overall magnitude as the solar system moves through the Milky Way’s spiral arms.

    http://arxiv.org/pdf/physics/0407005

    [Response: You might want to ask yourself why this paper never made into the peer-reviewed literature. What is more likely – that the deposition 10Be is affected by climate changes associated with the ice ages (for instance Field et al, 2006 might be useful in assessing that), or that geomagnetic modulation of cosmic rays just happens to be coincident with Jun 60N insolation? (Bard and Frank, EPSL, 2006 is also another good source for why this is rubbish). -gavin]

    Comment by William Astley — 12 Feb 2007 @ 11:16 PM

  41. I do not understand your response: [Response: ??? Try reading the papers you cite – Palle: “However, there is no clear systematic trend [in the ionization] since the 1960s.” (figure 7 caption). This is exactly what one would expect given the lack of trend in CLIMAX. If there is no trend in the input, you can’t get a trend in the output, whatever the mechanism! – gavin]

    The affect is due to an increase in the Global Electric Current, not GCR. What input at Climax are you referring to? The ions are still being produced. The electroscavenging process is removing them.

    From Palle’s paper “Another explanation may be other climatic parameters are acting on cloudiness in addition to atmospheric ionization. A clear decreasing trend over approximately the past two decades is seen in both the total cloud amount … and low level cloud data. A simple linear fit to the yearly low cloud data has a slope of -0.065%/yr. If the this trend is subtracted from the low cloud data the correlation coefficient rises from 0.49 to 0.75, significant at the 99.5% level.

    [Response: No trends in cloud cover are statistically significant given the uncertainties in the data and systematic issues with the satellite measurements. Why do you think there is an increase in ‘electroscavenging’? And what do you think is driving it? -gavin]

    Comment by William Astley — 12 Feb 2007 @ 11:31 PM

  42. I don’t know if this 2004 simulation finding climate change correlations with CO2 concentrations and GCR fluxes during the Paleozoic, Mesozic & Cenozoic has been cited yet. Haven’t read the whole article, so don’t know how the author derived inputs, to include cloud cover.

    http://www.agu.org/pubs/crossref/2004/2003GC000683.shtml

    Comment by John Tillman — 12 Feb 2007 @ 11:40 PM

  43. It’s all about the muons:

    http://www2.slac.stanford.edu/vvc/cosmicrays/cratmos.html

    Comment by John Tillman — 12 Feb 2007 @ 11:47 PM

  44. Are Milankovitch Cycles and other orbital variations of the earth commonly factored in to AGW climate models? Without a better understanding of cosmic radiation, I would imagine these variables are considered statistically insignificant, yes?

    Comment by Edward Barkley — 13 Feb 2007 @ 12:13 AM

  45. Can anyone answer these questions, simply?

    The Little Ice Age – real or not?
    The lack of sunspots at the same time – real or not?
    Is it a coincidence – yes or no?

    Comment by Peter Sutton — 13 Feb 2007 @ 12:30 AM

  46. Re: #34 Al Bedo,

    Hi, I’m GW-ish.

    Comment by Jim Roland — 13 Feb 2007 @ 12:33 AM

  47. Re: Ice Ages

    There seems to be some suggestion that galactic cosmic rays are a root cause of ice ages, are modulated by earth’s orbital variations, related to Milankovitch cycles, etc.

    The climate effect of orbital cycles has to do with the amount of solar energy intercepted by earth, not the output of the sun, and says nothing at all about variations in the sun.

    Understanding the impact of astronomical cycles on paleoclimate is a rapidly advancing field, and our understanding of it is attaining a level of maturity which is very impressive. Those who know the details of the effects of orbital cycles cannot take seriously the suggestion that their impact is through modulation of GCRs. Those who suggest that such a phenomenon is real, cannot possibly have an understanding of the effect of orbital cycles on the distribution of solar energy.

    This is yet another example of throwing out an interesting idea, which seems plausible until you actually learn something about the phenomenon. It reminds me of one of the most famous pseudo-science books of all time, Velikovsky’s Worlds in Collision, which attempted to explain world-shaking biblical events (like the plagues Moses brought upon the Egyptians) by astronomical events. It all sounded extremely convincing to those who were ignorant of the topics, but to those in the know it was pure fantasy, and not even very good fantasy. Astronomers would typically say “The biblical archeology was very impressive, but the astronomy is utter nonsense,” while archeologists would typically say, “The astronomy was fascinating, but the archeology is utter nonsense.”

    For those who are interested in a few details of the effect of astronomical cycles, I’ve posted about the topic on my blog here and here.

    Comment by tamino — 13 Feb 2007 @ 12:42 AM

  48. Re: Global dimming. Does Stanhill’s Forum piece (EOS 88,p 58, 2007) require any response from RC (beyond what I was able to find in previous posts?) He’s claiming a total 20 W/m^2 for 1958-1992. He does not mention the “urban effect” reported by Alpert et al (GRL 32, L17802, 2005); is that the issue?

    Thanks

    Comment by Patrick Cassen — 13 Feb 2007 @ 12:44 AM

  49. Re: #44

    The fastest orbital (Milankovitch) cycle affecting climate is the precession cycle, with a period never shorter than about 19,000 years. That’s much to slow to affect climate significantly on century-long timescales. Therefore their effect can be safetly ignored in AGW climate models.

    Comment by tamino — 13 Feb 2007 @ 12:45 AM

  50. Are Milankovitch Cycles and other orbital variations of the earth commonly factored in to AGW climate models?

    Why no, the people doing this work are totally unaware of such things!

    Right?

    That’s your basic point, yes? That scientists trying to understand AGW are librel, perhaps even commie, conspiracy people who don’t actually pay attention to stuff that appears in undergrad science textbooks.

    Right?

    Comment by dhogaza — 13 Feb 2007 @ 12:47 AM

  51. From the Oct 16, 2006 RC (Gavin’s?) analysis of Svensmark, et al:

    “(Missing step #4). Finally, to show that cosmic rays were actually responsible for some part of the recent warming you would need to show that there was actually a decreasing trend in cosmic rays over recent decades – which is tricky, because there hasn’t been (see the figure)”

    The figure comparing CR flux vs. temperature cuts a fine figure, but the CR measurement displayed is for neutrons. Muons are the relevant form of CR, since they’re implicated in cloud formation. In Svensmark’s 1999 article, it would be possible to draw a statistically justifiable slightly downward sloping line through his muon data, as detected by ionization chambers, 1937-1994 & shown in his Figure 3. I don’t know if it could be extended to 2006 at the same inclination.

    http://www.dsri.dk/~hsv/new_sven0606.pdf

    Suffice it to say that neutron detectors & muon measuring ionization chambers or telescopes show slightly different GCR fluxes. The muons are relevant, as per my prior probably overly cryptic comment & link to discussion of muons at the SLAC site.

    However, it seems to me that Svensmark concentrates more on apparent correlation or coincidence of GCR & solar cycles than on trendlines over shorter time frames, such as 22 year cycle for the reversal of the Sun’s magnetic field, the ~11 year sunspot cycle & peak years within each cycle.

    Comment by John Tillman — 13 Feb 2007 @ 12:59 AM

  52. Re: #45

    Little Ice Age — probably real. Paleoclimate reconstructions (hockey sticks) show a cooler period from about 1450 to 1800, but the total cooling, even in the most highly-varying reconstructions (Moberg et al.), amounts to only about 0.5 deg.C, and in other reconstructions is much less. We’ve already seen more warming than that in just the last century.

    Lack of sunspots at the same time — not so. Sunspot counts only begin in earnest in the mid-1600s; there have been a number of minima in sunspots counts (most notably the “Maunder minimu”) but the record shows large variations, not only during the “little ice age” but after that as well.

    Coincidence — probably not. Solar forcing is known to be an important factor in climate change (contrary to contrarians, it is not ignored or underestimated by climate scientists), and may have been an important player in climate changes over the last few thousand years. But there are other players as well, most notably volcanic eruptions. Also, the changes in temperature in the last few thousand years are considerably smaller than what we’ve seen in the last century, and are vastly smaller than what we expect to see in the next century.

    Comment by tamino — 13 Feb 2007 @ 1:00 AM

  53. Reply to Peter’s #45, then I’ll shut up.

    The Little Ice Age – real or not?

    Real. Period before & after a low in the 1690s was remarkably cold, certainly in a good chunk of the “temperate”, subarctic & arctic NH at the very least, as you must know. Googling produces copious excellent, coherent studies from disparate proxies & actual thermometer readings of various qualities. The early 19th century dip has been associated with Tambora blowing in 1815, of course but the secular trend was in any case cool until ~1850.

    The lack of sunspots at the same time – real or not?

    Maunder Minimum is well documented, despite imperfection of sunspot record in that period, generally assessed as 1645 to 1715, confirmed by C14 & Be10 data.

    Is it a coincidence – yes or no?

    It’s definitely a coincidence, but possibly not merely so. It could be a meaningful correlation. How significant, lots of work may soon be funded to determine. Are we at the beginning of a new paradigm shift, replacing 20 years of greenhouse gas AGW consensus building? Possibly. The climate itself in coming decades will help answer that & your questions, along with experimentation & rejiggered computer simulations.

    Sunspots aren’t as scary as runaway CO2 feedback scenarios, but there should still be plenty of funding to keep paleoclimatologists, geophysicists & other climate & atmospheric scientists busy, maybe bringing more astrophysicists, statisticians & mathematicians into the fold well into the next 22 year solar magnetic cycle. Maybe by then we’ll be worrying about global cooling again, as in the 1970s, scanning the northern horizon for the advancing ice sheets.

    Perhaps unsatisfactory replies.

    Comment by John Tillman — 13 Feb 2007 @ 1:25 AM

  54. #18 Gavin comment : “we get bored too”

    Whose fault ? :D It appears there’s nothing new in Nigel Calder op-ed. So, does it deserve a discussion? And how could we expect new insights on these over-debated topics?

    Before adressing GCR-nebulosity question, I suggest it would be more useful to get correct nebulosity climatologies. An article on what we know and don’t know from current measures (e.g. ISCCP, BSRN, ERBS, HIRS, AVHRR, etc.) would be interesting. IPCC AR4 mentions it as an “important develoment since the TAR”.

    Comment by Charles Muller — 13 Feb 2007 @ 2:10 AM

  55. All the contrarian theorists seem to have missed an important point, which is that while climate certainly is affected by solar variations, volcanic activity, and so on (maybe even cosmic rays, though as mentioned it’s hard to see how a lack of variation could produce climate changes), if you want to use any of these as a complete alternative model of current climate trends, you have a twofold problem. First, you have to incorporate your theory and data into some sort of model that gives results that match actual observations. Second, you have to find a way to explain why the measured increase in CO2 is _not_ producing the effects that theory and experiment predict it should.

    As far as I can tell, very few have even tried to do the first, and almost nobody the second. Which to my way of thinking puts these theories into the same class as science-fictional “warp drives”: something thought up to get the result the author wants :-)

    Comment by James — 13 Feb 2007 @ 2:24 AM

  56. “Why no, the people doing this work are totally unaware of such things!

    That scientists trying to understand AGW are librel, perhaps even commie, conspiracy people who don’t actually pay attention to stuff that appears in undergrad science textbooks.”

    Actually, I’m generally interested in the concept of warming/cooling cycles and the variables which may drive them, as is Nigel Calder. But I’m also interested in whether of not Cognitive Dissonance is having a greater impact on bias in AGW science than hard evidence. It is my firm belief that c.d. is the greatest single psychological factor responsible for unintended bias in scientific experimentation – partially because it is as prevalent in highly educated people as it is in the common man.

    And I’d like to thank Tamino for a quick honest answer.

    Comment by Edward A. Barkley — 13 Feb 2007 @ 2:26 AM

  57. I thought that the term was GLOBAL WARMING and not LOCAL WARMING as was the MWP or LOCAL COOLING was LIA. Anyway the article is publiched in the daily telegraph (DT) here under one of the most viewed items.

    http://www.telegraph.co.uk/news/main.jhtml;jsessionid=MVR0D2TLU54GPQFIQMGSFFWAVCBQWIV0?xml=/news/2007/02/11/warm11.xml

    The DT is a well known right wing newspaper that seems to print all things climate skeptical, we remember Mr Monkston and Bob Carter don’t we. However they did print a rebuttal from Al Gore to Mr Monkston so fairs fair I suppose.

    One thing that this article does suggest however is the notion of the little knowns in climate science, ice dynamics is one area I believe especially in the area of how fast ice sheets will move but I guess that real data can help here refine the mathematics. Cloud formation is another area as well as others. I mean is the uncertainty in the projected climate temperatures from slightly differing models due to little knowns in current climate science or by chaos theory (sensitivity to initial conditions that project out after a long period of time) perhaps. 1.5 to 4.5 Deg C even after a lot more spending is not that much more accurate than climate models run 20 years ago is it ?

    Can we get more accurate climate models and if not then why not ?

    I would also like to be told why CO2 levels of 700 or 900 ppm means no greater temperatures than 550 ppm which is what we are currently heading for by around 2090.

    Comment by pete best — 13 Feb 2007 @ 5:31 AM

  58. #55

    James, nobody thinks a solar contribution to climate change implies a non-contribution of GHGs.

    Before creating new models, we may simply hope that present GCMs better cope with all climate forcings and parameters. Model intercomparisons is a good way for that. Is solar correctly implemented (even without the so hyped GCR effect, masked TSI trends, etc.)? A recent contribution of Raschke and al. (link thereafter) suggest a negative answer. I quote them :

    “A careful intercomparison of recently released data sets on the radiation climatologies as computed in the projects ISCCP-FD and GEWEX-SRB showed considerable differences of more than 20 to 50 Wm-2 in monthly averages of radiation flux products at the top of the atmosphere (TOA) and at ground for large latitudinal zones covering up to 25% of the Earth’s surface.”
    Raschke, E.; Kinne, S.; Gorgietta, M.; Uphoff, M.; Bakan, S.; Okamoto, H.
    Inconsistencies of the incoming solar radiation boundary condition in global modeling

    Abstracts at EGU General Assembly
    CL40 Climate Models Intercomparison: Dynamics and Physical Processes :
    http://www.cosis.net/members/meetings/sessions/accepted_contributions.php?p_id=237&s_id=4196&PHPSESSID=f29025fe7d71ae5f96d46ab2b26dfd6a

    Comment by Charles Muller — 13 Feb 2007 @ 6:37 AM

  59. Re 5 and 6
    Interesting question. I couldn’t find the link but I think I read that this particular die off is disease related.
    However it does beg the question if AGW is a stressor that makes individual species such as bees or corals more susceptible to disease in general.

    However if you think modeling the complexities of climate is difficult you should talk to some biologists studying interconnected ecosystems, I think they’d tell you that modeling those systems is a couple of orders of magnitude more difficult.

    Based on some of the opinions I have read here and elsewhere it seems that gleaning information from such models is probably a useless excersise since the current models are probably not sophisticated enough and there is just too much we don’t know. So let’s roll up our sleeves and get back to chopping and burning down the forests shall we.

    Comment by Fernando Magyar — 13 Feb 2007 @ 7:13 AM

  60. It’s hard to see how to reconcile the sine/cosine style pulse of the cosmic ray record with the steady increase in temps. If there’s any effect at all, it has to be real tiny because it’s getting swamped by the effect of greenhouse gases.

    Comment by Jeffrey Davis — 13 Feb 2007 @ 7:39 AM

  61. James (55). A response to your challenges is quite easy. As an experienced computer modeller (albeit not of climate), I know it is easy to produce “some sort of model” to show pretty well anything you want. The climate models (as with most computer models) are highly sensitive to the assumptions made by those who develop them. Models are not proof, although a very useful tool for those who can use them with honesty and integrity. With regard to AGW theory, this predicts an accelerating rise in temperatures. In contrast, the trend has not increased since at least 2002 (some would say 1998). While AGW advocates can come up with explanations why there is currently no rising trend (despite having the highest CO2 emission rates ever), you cannot deny that this is a mismatch to the theory.

    [Response: Maybe you’d care to point us to the publication that predicts that temperatures must increase year on year in AGW simulations? Or the model run that says that interannual variability vanishes once CO2 reaches 380ppm? The first step in testing a theory is being clear about what is predicted. -gavin]

    Comment by PHE — 13 Feb 2007 @ 7:46 AM

  62. I’ve been arguing this very story on slashdot for a day or so, thanks for tackling it head on.

    One minor but I think important point: After posting the “Taking cosmic rays for a spin” story as comment on slashdot several replies said it does not adequately state what is wrong with the CR – climate change link, and I think they have a fair point.

    A much stronger (and more civil) argument is made by this RC story. Only a suggestion but you might want to add the link to this article while it’s still fresh.

    Comment by Alan — 13 Feb 2007 @ 7:54 AM

  63. #56 Is cognitive dissonance a problem?

    The nice thing about science is that it provides a way around cognitive dissonance (the experiment). Dream up any theory you like, if it doesn’t fit the experimental data, CD won’t save you.

    If anybody has a CD problem, clearly it’s the contrarians, as they are ignoring tons of evidence. On top of that, they are (in effect) denying the basic mechanism:
    1- CO2 traps heat (known since more than a century)
    2- We are putting lots of CO2 into the atmosphere (undisputed)
    3- The temperature goes up (and lo and behold, that what we see)
    That is, warming is to be expected: we should be very surprised if there were NO warming.

    Comment by Dick Veldkamp — 13 Feb 2007 @ 8:17 AM

  64. then I don’t see any reason why different energy bands will be trending differently than the ones monitored at CLIMAX.

    Well, the lower energy GCRs should be more strongly modulated than the more energetic GCRs (since interplanetary magnetic fields in the solar wind and at the heliopause affect the former more strongly than the latter), but I agree I don’t see why the trends should be qualitatively different. If anything, the signal should be stronger in the lower energy GCRs than in the higher.

    Isotope evidence (10Be, 14C) is, I imagine, more of a proxy for the lower energy GCRs than the energetic ones that make muons that can reach low alitudes, since the flux of the former is much greater. I hope none of the contrarians are touting this evidence to support a theory that involves higher energy GCRs while dismissing the recent neutron data.

    If there really is a connection between GCRs and cloudiness, it offers the possibility of new geoengineering approaches to mitigating global warming. The total energy in cosmic rays hitting the Earth isn’t all that large (and even less in the more energetic ones), so it’s conceivable it could be artificially enhanced with accelerators in space. A whacky idea, but amusing to consider.

    Comment by Paul Dietz — 13 Feb 2007 @ 8:23 AM

  65. This is great! If true, it would mean we can expect some cooling when the rays decrease. Of course, until it’s proven to be the only cause of GW (and GHGs have no noticible impact), then we do still have to keep reducing our GHGs….in fact, it just makes economic & (other) environmental sense to reduce our GHGs whatever the situation re GW.

    As for funds to conduct research, have they tried Exxon? Or is it that even Exxon has serious doubts about their research.

    Comment by Lynn Vincentnathan — 13 Feb 2007 @ 10:24 AM

  66. Re: Dick V (62)
    I trust most readers can see the irony in the following statement by DV:

    “If anybody has a CD problem, clearly it’s the contrarians, as they are ignoring tons of evidence. On top of that, they are (in effect) denying the basic mechanism:”

    While I respect the right of AGW advocates to have their views (hopefully derived from an assessment of the arguments rather than blind faith, or the naive emotion of seeing photos of polar bears standing on melting ice), there are too many AGW zealots who happen to ignore “tons” of uncertainty, arriving at the nonsensical view that ‘the argument is settled’.
    As for ‘denying the mechanism’, I think there are very few who would deny the theory. The issue is whether the mechanism is significant. We emit many pollutants and do many things that impact on our environment, but this does not automatically mean they have a significant or devastating impact. It is my view, having followed and assesed the arguments closely for years, that the case for AGW is far from made – and I am far from alone (even if I may feel in a minority). The debate lives on!

    Comment by PHE — 13 Feb 2007 @ 10:30 AM

  67. It might seem an obvious question, but would clearer skies make for warmer weather and visa versa clouds make it cooler as Svensmark asserts?

    Comment by Jim Meldrum — 13 Feb 2007 @ 10:58 AM

  68. Simple question from the back row. If the sun and cosmic radiation have nothing to do with global warming then what exactly caused global warming in prehistory? Please email me with the answer so I can understand why climate change now has to be caused by man and cannot be caused by factors beyond our control. Does this mean that once man controls his excesses there will be no more climate change?

    Comment by Deornwulf — 13 Feb 2007 @ 11:00 AM

  69. RE # 66

    PHE you said:

    [there are too many AGW zealots who happen to ignore “tons” of uncertainty, arriving at the nonsensical view that ‘the argument is settled’.]

    That raises several questions and begs clarification.

    Do YOU really measure scientific reports and analyses “of uncertainty” in “tons”? How about a pound or two of actual peer-reviewed, published reports on uncertainty so that we can all digest their content and come to the same or similar conclusions as you? Give us links and titles so we can read what you are reading.

    As regards zealots, I hope you can differentiate zealots from scientists and well read lay persons who contribute to RealClimate. I agree that photos of stranded polar bears will not cause Texas Utilities to reassess plans to construct 11 coal-burning power plants. But Australian drought is being measured in lost economic growth for 2006 and honest scientists there are projection more of the same and worse.

    If you are a parent, you might reconsider your watch and wait attitude. Might be there are more things to take into consideration than your uneasy feeling about the preponderance of evidence that your approach spells hurt for future generations.

    Maybe the reason you feel in a minority is you lack the ability to process and act upon information that challenges your comfort level.

    Comment by John L. McCormick — 13 Feb 2007 @ 11:18 AM

  70. Lets look at it this way……If the earth was the size of a roughly a large house, a supertanker is visible as a miilimeter sized sliver moving along the ocean. Taking into effect all the stored carbon released the past 200 or so years from all the industrial revolution factories, would it impact this large ball? Decidedly, yes. If I smoke a cigar in a large room, will the people coming in an hour later detect this stench? Again, the answer is yes. The anomoly here is not this sphere with all inside it, it is the impact the human inhabitants are making on it.

    Comment by Paul M — 13 Feb 2007 @ 11:32 AM

  71. There was a book I read as a child, which had an enormous impact on me, and drove me to decide to major in Geophysics. The name of the book was “The Restless Earth.”

    Comment by Steve Sadlov — 13 Feb 2007 @ 11:38 AM

  72. Any veteran inquisitive scientist trying out a new Chinese restaurant can try out the hot and sour soup, and depending on it being to his or her liking or not, can make certain inferences about the rest of the meal. And so it is with the carbon spike in the earth’s atmosphere and what future implications one can infer from this spike. I for one am guilty of being innocent of going with my intuition, but am learning to go with the facts presented before me, and sanely and intelligently putting aside my emotions and innocent intuition and embracing the facts. Two things I know……There is no Santa Claus, and the earth is heating up due to man’s poor stewardship.

    Comment by Paul M — 13 Feb 2007 @ 11:49 AM

  73. To reply to gavin’s challenge in no. 61:
    I don’t suggest that temperatures must increase year-on-year, or that there should be no interannual variability. The theory predicts that temperature will rise as CO2 rises. We know that the rates of CO2 emissions are increasing year-on-year and that atmospheric CO2 concentrations are rising steeply now compared to the first half of 20th century (AR4 Fig SPM-1). It is difficult to reconcile this evidence with (i) the much greater IPCC certainty that AGW is significant and (ii) that the rate of temperature rise has reduced in the last 5 to 10 years (AR4 fig SPM-3) rather than giving any sense of an increasing rate to match the CO2 trend.

    Comment by PHE — 13 Feb 2007 @ 11:55 AM

  74. On the doubling (or not) of the Sun’s coronal magnetic field in the past 100 years (Lockwood, et al, 1999, from Nature, cited below), there is now a decent body of research from around the world, both confirming & denying this finding in all or part.

    http://www.nature.com/nature/journal/v399/n6735/abs/399437a0.html

    For reconstruction of early 20th Century IMF:

    http://www.springerlink.com/content/m2667x314012646h/

    For some at least partially contrary findings or analysis:

    http://adsabs.harvard.edu/abs/2001AGUSM..SH52A02L

    http://www.copernicus.org/icrc/papers/ici6227_p.pdf

    Other discussion readily Goggleable.

    Should a secular increase in IMF be shown, it would of course remain to be demonstrated what observable or plausibly reconstructible effect this had on some parts or all of our planet.

    While muon flux as measured far above, just above, at or below the earth’s surface may or may not show a downtrend globally, this could be an experimental artifact, as the record isn’t geographically complete or temporally long enough. There could be regional effects, perhaps related to the solar & terrestrial magnetic fields, like the auroras.

    As is usually the case, we need to know more. Or at least I do. Maybe someone else doesn’t.

    [Response: So what is the positive evidence that muon flux has changed in recent decades? It’s not sufficient to assert that it might have done and so there might be an unquantified effect on climate. Occam’s razor starts to come into play here…. – gavin]

    Comment by John Tillman — 13 Feb 2007 @ 12:30 PM

  75. RE: #73 – As with all systems, the bugaboo in the stability analysis is the parasitics. Do they result in an asymptotic situation, where, when you approach the “safe operating envelope,” the parasitics result in a “fold back” innately due to their increasing contribution to energy dissipation? Or are they more in the realm of something that adds to the main “control loop” and results in a “runaway” situation? The prevailing theory of the orthodoxy appears to be something like the latter, albeit on a limited scale (for example, the “runaway” in this case would not be at the total system level but only within the behavior of the parasitic terms, resulting in a new “higher equilibrium”). My own experiences with complex systems suggest that as you scale, the sorts of mechanisms that might result in a complete system runaway or even a runaway of some parasitic term across the system, become more and more implausible. That’s because with increasing scale and complexity, the opportunities for loss of efficiency and internally dissipative mechanisms increase. Consider grid lock.

    Comment by Steve Sadlov — 13 Feb 2007 @ 12:34 PM

  76. #63 DV,

    What you are saying seems to me to be a big part one of two of why there is a debate:

    Part one:

    1- CO2 traps heat (known since more than a century)
    2- We are putting lots of CO2 into the atmosphere (undisputed)
    3- The temperature goes up (and lo and behold, that what we see)
    That is, warming is to be expected: we should be very surprised if there were NO warming.

    This makes sense, but raises the question – is the AGW consensus based on assigning the observed warming to GHG’s primarily? Do I have this right?

    And, if other forcing factors are discovered, wouldn’t we have to remove some of the correlated value assigned to GHG’s? And, if the other forcing factors are cyclical and likely to turn down eventually, doesn’t this mean that some long term projections for AGW effects have to be revised?

    As to part two:

    I ask these questions because, I’m not a scientist, but I believe the recommendation is to reduce GHG emission by 50% over some period (soon). Given that fossil fuel energy is a huge driver of the global economy, I think it behooves all of us to examine the projections carefully.

    From what I can interpret in the SPM Radiative Forcing Chart, there is what looks to me to be a lot of uncertainty regarding cloud cooling and its interaction with aerosols. Does this relate to the debate over GCR or is it a separate issue? Or to rephrase that, can aerosols and GCR both be factors that when better understood will remove the uncertainty depicted in the SPM?

    Comment by jdwill — 13 Feb 2007 @ 12:49 PM

  77. Those interested in Solar contributions and cosmic rays should review the comments by Nir Shaviv and Gavin at RealClimate: http://www.realclimate.org/index.php/archives/2006/05/thank-you-for-emitting/#comment-13470

    Comment by jae — 13 Feb 2007 @ 12:54 PM

  78. Am I missing something obvious here? How can total cosmic rays be inferred from neutron monitors? A neutron is uncharged so you wouldn’t expect any variation corresponding to changes in the solar magnetic field. The charged particles obviously would be affected.

    Comment by fieldnorth — 13 Feb 2007 @ 1:19 PM

  79. A reply to PHE (#73): First, the graph you actually want to compare the temperature trend to is the calculated total forcing (made up of GHG concentrations – CO2, CH4, N2O, etc. – and aerosol forcing). CO2 may be the largest contributor to forcing, but it is not the only one. Methane at least has hit a plateau for the last decade, though it is not obvious if this is a temporary pause or a long term one. But my guess is that the total forcing will follow a roughly linear trend for the past couple decades. (And in fact, even for just CO2, because of the logarithmic relationship of concentration to forcing, you expect a linear forcing trend from an accelerating emission trend)

    Second: You are microanalyzing short term trends in what is a long term phenomena. It might be interesting for you to take said forcing graph, assume that temperature scales exactly proportionally, but then add “noise” to the temperature plot. Run this 100 times. For a decent number of cases even if the underlying equation is accelerating you’ll still get a temporary reduced rate of rise in the last few years. One outlier (like 1998) can make a large difference in any short term analysis.

    Comment by Marcus — 13 Feb 2007 @ 1:21 PM

  80. Re” #68

    I presume you’re asking about what caused global warming during the ice ages.

    Small changes in the orbit of the earth, and in the tilt of earth’s axis, can cause sizeable changes in the distribution of incoming sunlight. Greater axial tilt, for example, causes more solar energy to reach the polar regions while less reaches the tropics, and this can lead directly to the decay of ice sheets near the poles.

    When the ice sheets shrink, this reduces the earth’s overall reflectivity (ice is highly reflective but land and sea are not). This causes more incoming solar energy to be absorbed into the climate system rather than reflected back to space, and this warms the planet as a whole.

    When the planet warms, so do the oceans. Warmer oceans will hold less CO2, so that CO2 leaves the oceans and enters the atmosphere. Since CO2 is a greenhouse gas, this warms the planet even more. This causes more reduction in ice sheets, more CO2 released from ocean to atmosphere, which in turn causes more warming, etc… a classic “feedback mechanism.”

    For a few more details and some graphs, see the links in my previous post #47.

    These astronomically-related factors are very slow; the fastest cycle is precession, changes in the orientation of earth’s axis relative to perihelion (the point of closest approach to the sun), and this cycle is never less than about 19,000 years. So, they’re much to slow to explain modern global warming, which is very rapid — about twenty times faster than the warming rate during a reasonably rapid deglaciation.

    If we reverse our climate-changing activities, there will still be natural climate change. But if the past is any indication, it will be slow enough that we’ll have plenty of time to adapt.

    Comment by tamino — 13 Feb 2007 @ 1:40 PM

  81. I just read Wong et al. 2006 (thereafter). Between 1980s and 1990s, their best estimate for TOA radiative flux over Tropics (20°N-20°S) is +0,7 W/m2 for LW and -2,1 W/m2 for SW. The later number implies a significant downward trend of albedo (probably nebulosity). More insolation leads to more ocean heat content, I suppose, and more energy to be redistributed from tropics to pole. Could we expect this decadal radiative trend is involved in the 90’s warming?

    PS : if the ERBS measure is correct, it doesn’t plead in favour of Lindzen Iris effect, as Wong et al. conclude.

    Wong, T., B. A. Wielicki, R. B. Lee, III, G. L. Smith, K. A. Bush, and J. K. Willis, 2006: Re-examination of the Observed Decadal Variability of Earth Radiation Budget using Altitude-corrected ERBE/ERBS Nonscanner WFOV data. J. Climate, 19, 4028-4040.
    Downloadable at Wong page :
    http://asd-www.larc.nasa.gov/~tak/wong/f-publications.html

    Comment by Charles Muller — 13 Feb 2007 @ 1:42 PM

  82. [[It is my view, having followed and assesed the arguments closely for years, that the case for AGW is far from made – and I am far from alone (even if I may feel in a minority). ]]

    A distinct minority, especially among climatologists. Rather like those who still hold out hope for Einstein to be wrong about relativity. There are some of them, too, and they’d be quick to tell you the case for AGW is far from made.

    Comment by Barton Paul Levenson — 13 Feb 2007 @ 1:53 PM

  83. [[Simple question from the back row. If the sun and cosmic radiation have nothing to do with global warming then what exactly caused global warming in prehistory? Please email me with the answer so I can understand why climate change now has to be caused by man and cannot be caused by factors beyond our control. Does this mean that once man controls his excesses there will be no more climate change? ]]

    Nobody ever said manmade CO2 was the one and only possible cause of climate change. There are many things that have changed the climate in the past, and there are many things affecting it now. But the main item driving the present warming is manmade CO2. In short, your argument is a straw man.

    Comment by Barton Paul Levenson — 13 Feb 2007 @ 1:55 PM

  84. Reply to #78:

    As has been discussed here previously, neutrons are not the best indicator of total GCR, but more importantly are inappropriate for climatic studies. Muons are implicated in cloud formation, as shown in my SLAC link in comment #43.

    The solar coronary magnetic field (IMF) does seem to have increased in the past hundred years. I posted objections to Lockwood’s assessment of doubling, but these researchers present a graph which appears to confirm it:

    http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU2004_IAUS223%2FS1743921304006817a.pdf&code=a73460a442553c154786ecfec8f757c2

    It might not be possible to download the IAU article from this link. If not, please if interested Google “reconstruction open solar magnetic field 19th 20th centuries ivanov miletsky” or some portion of these keywords. The authors reconstruct the IMF since 1844 & 1915.

    Comment by John Tillman — 13 Feb 2007 @ 1:57 PM

  85. [[I don’t suggest that temperatures must increase year-on-year, or that there should be no interannual variability. The theory predicts that temperature will rise as CO2 rises. We know that the rates of CO2 emissions are increasing year-on-year and that atmospheric CO2 concentrations are rising steeply now compared to the first half of 20th century (AR4 Fig SPM-1). It is difficult to reconcile this evidence with (i) the much greater IPCC certainty that AGW is significant and (ii) that the rate of temperature rise has reduced in the last 5 to 10 years (AR4 fig SPM-3) rather than giving any sense of an increasing rate to match the CO2 trend. ]]

    I’d recommend a good course in statistics. You are trying to generalize from a sample of 5-10 years. The warming has been going on for over 100 years, though the most recent phase of it has lasted about 30. Mean global annual surface temperatures are a random walk around a steadily increasing mean.

    Comment by Barton Paul Levenson — 13 Feb 2007 @ 1:58 PM

  86. #89 Tamino, I agree with your description with just some questions about ocean cooling / warming link to CO2 atmospheric rise during glacial/interglacial transition. As there is no change in total solar forcing (just an orbital/regional one centered on Northern Hemisphere, not on Southern oceans) and as there’s a great thermal inertia for oceans, how do we explain the relatively high and fast increase of CO2? Shouldn’t we expect a millienium rather than secular lag between Milankovitch forcing and CO2 response?

    Comment by Charles Muller — 13 Feb 2007 @ 2:02 PM

  87. [[This makes sense, but raises the question – is the AGW consensus based on assigning the observed warming to GHG’s primarily? ]]

    The climatologists don’t arbitrarily “assign” the warming to GHGs. They calculate it on physics grounds and then see if the evidence matches the prediction.

    Comment by Barton Paul Levenson — 13 Feb 2007 @ 2:04 PM

  88. Re 61, 73

    These are both pattern-matching arguments: that the temperature curve should mimic the shape of CO2 emissions or concentrations. Even if you neglect noise, which exists on many time scales, such expectations are incorrect. They ignore both the nonlinearities (e.g. forcing is proportional to log(concentration)) and the dynamics of the system (temperature is two integrations removed from emissions: CO2 must accumulate in the atmosphere, and the heat from the resulting forcing must accumulate in the atmosphere and ocean). To make a serious claim that reality and models are diverging, one must at least account for the basic physics and forcings of the system. A suitable model could fit on a napkin – the ball is in your court.

    Comment by Tom Fiddaman — 13 Feb 2007 @ 2:05 PM

  89. Concerning New Scientist 10th Feb 2007 edition (Vol 193, No. 2590) and its alarmist out of breath “This Week: Climate Change” article by (probably) Fred Pearce : a figure on page 9 is really the culmination of “immoral” alarmism: a graphical illustration tells about “the sun versus humans” and wants to depict the difference between the “natural solar radiation” (they forget to say: the increase of …) and human caused radiative forcing. According to the SPM this is about 1.6 W/m2 to 0.12 W/m2 (lets not discuss this here), so the relationship is about 13 to 1; the illustration draws a very tiny solar disk and a huge man-made-effects disk suggesting a 269 to 1 relationship (when you draw disks, please do not expect that the visual clue is to compare the diameters! it’s the surface, stupid!). [edit]

    Comment by Francis Massen — 13 Feb 2007 @ 2:19 PM

  90. Re #66

    PHE,

    Apparently I was not clear enough in my post (apologies). What I meant was the following: suppose somebody has a theory in which phenomenon X is the cause of (most of) global warming – then clearly the burden is on him to provide an argument why the expected warming due to GHGs is NOT there, or is far less than we think it is (see post #55). If he doesn’t do that, he is in fact denying the basic greenhouse gas warming mechanism (of which we know it’s there).

    As regards to how much different things contribute: personally I am impressed by how well current theory (embodied in models) reproduces measurements quantatively. It seems to me that GHGs (+ aerosols and a few other things) pretty much explain all observed warming.

    Does that end all debate? Of course not, I just think that more than enough evidence is in to make an informed decision on mitigating policies now.

    Comment by Dick Veldkamp — 13 Feb 2007 @ 2:42 PM

  91. The Svensmark paper was interesting and innovative. However, it ignores the fact that there seems to be no measurable decrease in GCR flux in the 30 years we’ve had measures of it by satellites. I’ve looked at the GOES data myself, and the modulation over solar cycle stands out clearly, but there is no lont-term trend. Conversely, the solar-cycle modulation, which is a factor of 3-5 in GCR flux over 11 years does not seem to influence weather that much.
    Look, if someone could come up with a forcing mechanism that could explain the trends other than anthropogenic CO2, nobody would be happier than me. However, no one has proposed a mechanism that is even plausible.
    So, on the one hand, we have a mechanism that explains the trends pretty nicely and that we know is present and we have no competing hypothesis that approaches credibility. To reject a perfectly good model simply because you don’t like the implications is simply anti-scientific. If your opposition is to the policies that you think may be implemented, the place to get involved is at the policy level.

    Comment by Ray Ladbury — 13 Feb 2007 @ 2:43 PM

  92. Re #76

    JD Will,

    [This makes sense, but raises the question – is the AGW consensus based on assigning the observed warming to GHG’s primarily? Do I have this right?] I agree with Barton in #87: my understanding is that scientists don’t “assign” warming to GHGs to make predictions fit observed temperature rise: how much warming some GHG causes is determined in independent experiments.

    [Cloud cooling and aerosols] I am really not qualified to answer this one. We’ll have to ask the good folks at RC.

    Comment by Dick Veldkamp — 13 Feb 2007 @ 3:09 PM

  93. >78 “… How can total cosmic rays be inferred from neutron …”
    Here’s a start:

    http://scholar.google.com/scholar?sourceid=Mozilla-search&q=neutron+%2B%22cosmic+ray%22+%2Bmonitor

    Comment by Hank Roberts — 13 Feb 2007 @ 3:19 PM

  94. This is the wrong topic I know, but was curious about this article: http://www.sciencemag.org/cgi/content/abstract/1138478v1
    Since I can’t read Science I’m a bit curious to know what impact this have on the dynamic part of the modelling on glaciers. A step back to around 2001 or is there still evidence that the melting goes faster?

    Comment by Magnus W — 13 Feb 2007 @ 3:46 PM

  95. Calder is also making the argument that there are warming/cooling cycles in increments much smaller than 19,000 years – based on extensive historical evidence he claims is largely ignored by the AGW community. I don’t know that the book will cover such evidence, but want to read it before jumping to conclusions.

    Comment by Edward Barkley — 13 Feb 2007 @ 3:51 PM

  96. Interesting in the article about the California frost. I remember that thread about the January heatwave.In the NCDC website it said that while last month the eastern USA was a lot warmer than average the West was a lost colder. An average month?

    Comment by David Price — 13 Feb 2007 @ 4:06 PM

  97. #90
    “I just think that more than enough evidence is in to make an informed decision on mitigating policies now”

    Do we know if GHGs count for 50, 70, 90% of the last decades warming? No. Do we know if climate sensitivity is definitely constrained to 2-4,5 K and which value is really the most convincing? No.

    Precaution principle probably commits us to take policy decisions, but I don’t think policymakers are better informed in 2007 than in 2001. Just look at low and high extremes of range for 2100 projections : 1,1-2,4 K versus 2,9-6,4 K. In the first case, a not so damaging warming for which adaptation would probably be a better option. In the second case, catastrophic warming against which a drastic and urgent reduction of GHGs emissions is needed.

    Comment by Charles Muller — 13 Feb 2007 @ 4:17 PM

  98. Reply to #91:

    Ray comments that Svensmark “ignores the fact that there seems to be no measurable decrease in GCR flux in the 30 years we’ve had measures of it by satellites. I’ve looked at the GOES data myself, and the modulation over solar cycle stands out clearly, but there is no long-term trend. Conversely, the solar-cycle modulation, which is a factor of 3-5 in GCR flux over 11 years does not seem to influence weather that much.”

    What matters is muon flux in the lower atmosphere, more than overall flux in space. We don’t have a good record of that, but what we do showed an anomalous low in the ’90s followed by a lower than average high, but as Ray points out, in the regular pattern. A downtrend could be drawn through the data points. The muon series probably isn’t long enough, with adequate geographic coverage or even reliable enough upon which to base a firm conclusion.

    There does seem to be or at least arguably is a detectable or reconstructible increase in solar IMF since the mid-19th century, so it’s not unreasonable to assume some effect from this on GCR in general & muon flux in particular. We may not have the capability now & surely not in the past to measure whether such modulation actually occurred or is occurring. We may however be able to infer it from future climatic observations, in lieu of other persuasive explanations, should earth not experience the changes forecast in AGW scenarios.

    “Look, if someone could come up with a forcing mechanism that could explain the trends other than anthropogenic CO2, nobody would be happier than me. However, no one has proposed a mechanism that is even plausible.”

    I feel that GCR forcing via nebulosity is at least a plausible mechanism, more readily subject to testing than AGW.

    “So, on the one hand, we have a mechanism that explains the trends pretty nicely and that we know is present and we have no competing hypothesis that approaches credibility. To reject a perfectly good model simply because you don’t like the implications is simply anti-scientific. If your opposition is to the policies that you think may be implemented, the place to get involved is at the policy level.”

    You probably know reputable atmospheric scientists who would not agree that AGW is a perfectly good model & that there are credible competing hypotheses, if not personally, then through their work. I do.

    Few would doubt that human activity has had no effect on climate change. Ruddiman thinks it has for thousands of years. Life has had profound effect on climate, the land, sea & atmosphere for billions of years. The moot question to me is what part of observed climate change (setting aside the issue of how valid the observations, reconstructions & modeling may be) is anthropogenic & how much attributable to natural causes, which may be unknowable. Someone may be smart enough to know all of them, but I’m not.

    I’d feel more comfortable with AGW if the atmosphere had detectably warmed up before & more than the land & sea, & if other causes could not produce the same responses generally cited as proof of AGW via the greenhouse effect. Even with the most extreme adjustments to satellite & balloon data, it appears last I checked that the areas that should have warmed first & most haven’t. Please correct me if wrong.

    I am already involved on the policy level. There are good reasons to be concerned about burning fossil fuels, regardless of how much weight you give to AGW computer simulations.

    Comment by John Tillman — 13 Feb 2007 @ 4:22 PM

  99. Re JLMcC (69) ‘Tons’ was taken ironically from the words of Dick Veldkamp. A good reference on AGW uncertainties is IPCC TAR. Look at the sicence rather than the Summary [by] policymakers. As many here will tell you, one year/drought doesn’t make a rule (see gavin’s response to my comments). I have two young children, and what I recognise is that they now have the best prospects in the history of mankind – in life expectancy, healthcare, world peace, prosperity, etc. And we (in the developed world) are doing a pretty good of balancing our prosperity with environmental protection. I am what many Americans would derogatarily call a ‘liberal’. I am an environmentalist, but also a rational scientist who despairs at the distortion and misuse of science as I see in the ‘case’ for AGW.

    Re Steve Sadlov (75). I like your satire.

    Re Marcus (79) The graph I had in mind on Fig SPM-1 was the inset in the top graph which shows the rise in CO2 since about 1750. Nothing more complicated than that.

    Re BPL (82). I suppose if scientific truth was based on a vote, you’d win. [edit – no politics]. The ridiculed minority are not necessarily wrong. That’s why its important to carefully assess the facts and feel the need to be convinced ‘yourself’ rather than to go with your heart, the flow, the popular view, etc.

    Re BPL (85) You don’t need to convince me to be wary of short term data. First, direct it at all those who argue the current drought in Australia, Hurricane Katrina, the current mild winter in Europe, etc, are due to AGW. Second, try the AR4 Summary [by] Policymakers which argues the rate of sea level rise is increasing (1993-2003 compared to 1961-2003)when a look at their own Fig SPM-3 shows this is nothing more than selective statisitcs.

    Re T. Fiddaman (88) I do not expect the absence of noise. My comments were intended to be ironic. Its the AGW advocates who seem to argue that a simple correlation between CO2 rise and temperature between (just) 1976 and 1998 (just 22 years!) is sufficient to claim impending doom. The only other period of 20th century temperature rise (1910 to 45) was at a time when CO2 emissions and levels were much lower and which IPCC TAR (amongst others) claims was due to natural effects. Individual droughts, hurricanes, mild winters are the natural noise that don’t make the rule. AGW advocates have not convincingly demonstrated that the current global temperature or rising trend is anything more than long period ‘noise’.

    Re. D. Veldkamp (90) With regard to who has the burden of proof: whatever the theories, there is no convincing evidence that (i) current temperatures are exceptional in human history (ii) that the rate of rise is exceptional (almost identical to 1st half of 20th Century (iii) that the climate is currently undergoing exceptional change (though it is currently warming) (iv) that predictions of rising trends are anything more than an extrapolation of the present trend combined with the ASSUMPTION that CO2 is the cause, or (v) that rising temperatures will cause the postulated disasters. You will no doubt be convinced that all this is ‘obvious’ and proven. I recommend, however that you rely more on the science of AR4 (when it is published) and of others, than on the ‘medievel-style’ headlines of ‘the end of the world is nigh’ (Nothing new there then. While the climate continually changes, human nature changes little)

    I hate long postings. I normally get bored well before the end.

    Comment by PHE — 13 Feb 2007 @ 4:32 PM

  100. Re #95: Edward Barkley — Climate changes on many time scales. I suggest you read W.F. Ruddiman’s “Earth’s Climate: Past and Future” which is actually organized via the different time scales.

    Comment by David B. Benson — 13 Feb 2007 @ 4:47 PM

  101. Have you seen this [edited]? The part about icebergs can’t be calving and receding is pure bs. How to stamp out that book?

    Comment by ed markham — 13 Feb 2007 @ 5:26 PM

  102. Re #58: Charles, when I see results of the sort you quoted the first question I ask myself is whether the authors of the study have offered an opinion as to its significance. Since abstracts are often written with other people in the field in mind as the sole audience, often no such opinion is included. Fortunately, in the case you quoted the authors noted: “There is a need to understand and eliminate these solar irradiance inconsistencies in modeling (even though their overall impact is expected to be minor in comparison to impacts from inconsistencies introduced by the representation of clouds).” Bear in mind that there literally hundreds of papers published evey year with regard to needed improvements to the GCMs.

    Comment by Steve Bloom — 13 Feb 2007 @ 6:00 PM

  103. Magnus, the Howat article is extensively blogged over at the NYT, here:
    February 8, 2007 — Greenlandâ��s Glaciers Take a Breather –By John Tierney
    http://tierneylab.blogs.nytimes.com/2007/02/08/greenlands-glaciers-take-a-breather/#more-29

    I hoped to find a science journalist in the comments; none yet. I added links to a full text related 2005 paper from the same author, and one from Lamont-Doherty from 2006.

    Comment by Hank Roberts — 13 Feb 2007 @ 6:05 PM

  104. #56, even if there were cognitive dissonance, and somehow the whole AGW thing were overestimated or a farce, at least the error is in the right direction, bec the solutions to GW actually help the economy.

    A lethally wrong direction error would be to assume AGW is not happening, when in deed it is happening.

    So, if anyone can prove beyond a shadow of a doubt that AGW is not happening, then, well, I’ll still keep on reducing my GHGs, because it’s saving me money to do so & reducing many other harms, and, who knows, we may just need those fossil fuels when the earth starts in on a natural cooling cycle who-knows-when.

    Comment by Lynn Vincentnathan — 13 Feb 2007 @ 6:16 PM

  105. I believe the consensus of this thread is that Svensmark’s cosmic ray/climate correlation is indeed something to take into account.

    I declare “the science is settled.”

    We must now introduce a new world protocol agreement to mitigate/slow cosmic rays.

    Comment by John Lang — 13 Feb 2007 @ 6:26 PM

  106. Re:98. So what do you think drives the muon production if it isn’t the GCR–in particularly the moderate to high energy portion above the magnetic cutoff?
    As to your list of dissenting atmospheric scientists, shall we start with you naming 10 that regularly publish in relevant, peer-reviewed journals and seriously question the importance of anthropogenic mechanisms?
    The UAH group has had to backtrack quite a bit on their satellite/balloon discrepancy. It is still nonzero, but MUCH smaller. I don’t think you can view this as a serious discrepancy at this point. Moreover, why should it surprise you so much that the insulator is at a lower temperature than the source of the IR.

    Comment by Ray Ladbury — 13 Feb 2007 @ 6:30 PM

  107. RE #67 & 76, I know nothing about clouds & GW, but I think I read somewhere that some types of clouds lead to cooling and some to warming (I think the high whispy strat ones, or is it the other way around?).

    Of course, that’s during the day when the sun is shining. I imagine at night, none of the clouds would contribute to further cooling, and it seems to me they all (to various degrees) might contribute to warming — the cloud “blanket-effect,” especially the ones that look like goose-down comforters. I guess I should eventually read some books on GW.

    Comment by Lynn Vincentnathan — 13 Feb 2007 @ 6:40 PM

  108. For those, like PHE #99 who state that the recent rise in temperature is almost identical to the first half of the twentieth century, I recommend a look at today’s posting in the Nasa Earth Observatory: http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3

    Comment by Randy Ross — 13 Feb 2007 @ 6:56 PM

  109. Edward Barkley wrote

    But I’m also interested in whether of not Cognitive Dissonance is having a greater impact on bias in AGW science than hard evidence. It is my firm belief that c.d. is the greatest single psychological factor responsible for unintended bias in scientific experimentation – partially because it is as prevalent in highly educated people as it is in the common man.”

    I’d suggest people quit invoking “cognitive dissonance” when they mean something like “ignoring an inconvenient view”. Cognitive dissonance means nothing of the sort. Wikipedia has a decent summary:

    Cognitive dissonance is a psychological term which describes the uncomfortable tension that comes from holding two conflicting thoughts at the same time. More precisely, it is the perception of incompatibility between two cognitions, where “cognition” is defined as any element of knowledge, including attitude, emotion, belief, or behavior.

    When people carelessly use “cognitive dissonance” in discussions like this, they actually mean something like Piagetian assimilation. Assimilation is the process of altering or distorting perceptions of incoming stimuli in order to make the input fit into pre-existing cognitive schemata, while accommodation is the process of altering the schemata to take account of new data. Someone who systematically ignores contrary data illustrates the triumph of assimilation over accommodation, cognitive rigidity over learning.

    Comment by RBH — 13 Feb 2007 @ 7:23 PM

  110. Re 105: John, can I recommend a good dictionary for you?

    Comment by Ray Ladbury — 13 Feb 2007 @ 7:57 PM

  111. In reference to 108, that 2006 was the fifth warmest year, I note that the GISS data has diverged considerably from the HadCRUT3 data set in recent years.

    And the GISS dataset is VERY different than the raw, unadjusted GISS temperature readings.

    http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh%2Bsh/index.html

    Comment by Jeff Weffer — 13 Feb 2007 @ 8:02 PM

  112. I have a copy of Nigel Calder’s 1974 book The Weather Machine And The Threat Of Ice (BBC Books). It’s actually a good overview of the state of climate science at the time, even if it is a little sensationalist on the risks of an imminent ice age (10-1), and the suddenness of its onset (1 year).

    I’m glad to see that Nigel’s still interested in climate issues, if still perhaps a little too attracted by the wackier end of the science.

    Comment by Gareth — 13 Feb 2007 @ 8:09 PM

  113. Re #51, 60, 83, 91, 98 and original post

    It’s odd that the GW fanatic believers constantly point to short timelines as problems in the argument of ones who doubt global warming.

    Take a look at this chart:

    http://en.wikipedia.org/wiki/Image:Solar_Activity_Proxies.png

    Beryllium-10 began a dramatic decrease (sign of increased solar activity) beginning in the mid to late nineteenth century.

    However, when you look at the detail on the sunspot numbers, which parallels the beryllium-10 decrease, in this chart:

    http://en.wikipedia.org/wiki/Image:Sunspot_Numbers.png

    You see that this rise stabilizes around 1950.

    So everybody that keeps pointing to neutron counts since 1953 or other measures in the last 30 years are using too short a timeline. Based on the sunspot number and beryllium-10 proxy, we have been flat since 1950. The increase happened from the late nineteenth century until 1950. The Sun is dramatically more active now and has been since 1950 than it was in the last several hundred years.

    Comment by Jim Cross — 13 Feb 2007 @ 8:16 PM

  114. Jim Cross:
    The sunspot numbers in your two links are from the work of Hoyt & Schatten. The same work has also been used to estimate climate forcings by the IPCC, and most climate modelers. See for example this graph from the TAR, which uses an earlier Hoyt & Schatten work.

    Comment by llewelly — 13 Feb 2007 @ 8:30 PM

  115. re #103 [Tierny blog] I read through the comments there, a nice cross section of denialists, cranks and contrarians, with all the familiar canards trotted out. Under it all, woven into the bombast and protests and appeals to reason and Godliness and progress, you can sense the fear growing.

    From such fear is many a fruitful action born. Let’s see what they do next.

    Comment by cat black — 13 Feb 2007 @ 8:37 PM

  116. There is a homeless dog that was born without ears is getting surgery to get ears! I saw this on FOX news. I know this somehow fits into the scheme of this thread, but I do not know how.

    Comment by Paul M — 13 Feb 2007 @ 9:10 PM

  117. Re #115: Well, so far nobody’s proven it *isn’t* a valid climate proxy.

    Comment by Steve Bloom — 13 Feb 2007 @ 9:28 PM

  118. RBH:

    As in any science, there is disagreement over the definitions of such conditions. Our argument is primarily one of semantics. Far be it from me to differ with Wikipedia, but a better definition may be to define cognitive dissonance as the discomfort felt at a discrepancy between what one already knows or believes and new information or interpretation. It occurs when there is a need to accommodate new ideas, and it may be necessary for the belief to evolve so that one may become open to new possibilities. I chose that specific psychological effect because of the similarities I see in the AGW community to the religious groups originally studied in development of the theory. (it was meant as an indirect dig at dhogaza after comment #50). But surely, you see the dissonance that would arise when beliefs developed by some researchers over 30 years of study are challenged by potent new ideas. We may want to believe that such dissonance does not bias our work, but research into the c.g. thoery suggests it is a prime motivator of even intelligent people.

    Comment by Edward Barkley — 13 Feb 2007 @ 10:10 PM

  119. It sort of occurred to me that Nigel Calder is not a denialist or contrarian or even a skeptic. His idea sort of reminds me of “cold, chemical fusion”….and interesting idea to throw in the ring, see if anything comes of it. Science into strange and new territories for the sake of science into strange and new territories. Stir up a rather slow digging, back-breaking science in the trenches.

    The only problem is that while cold fusion would have been great (solving our GW problem!), this cosmic rays idea tends to detract from the serious need to shift focus from whether AGW is happening (which was settled enough for policy-makers back in 1990, & certainly by 1995) to actually doing something about it.

    If it weren’t for the naysayers (including the policy folks) politicizing the issue and dragging their heels kicking & screaming, the cosmic ray idea might have even been fun.

    Comment by Lynn Vincentnathan — 13 Feb 2007 @ 10:10 PM

  120. In Reply to [Response: No trends in cloud cover are statistically significant given the uncertainties in the data and systematic issues with the satellite measurements. Why do you think there is an increase in ‘electroscavenging’? And what do you think is driving it?

    The electroscavenging is modulated by changes in the ionosphere potential. (See item C from Brian Tinsley’s attached paper):

    http://www.utdallas.edu/physics/pdf/Tin_rev.pdf

    “There are at least three independent ways in which the solar wind modulates the flow of current density (Jz) in the global electric circuit. These are (A) changes in the Galactic Cosmic Rays (GCR), (B) changes in the precipation of relativistic electrons from the magnetosphere, and (C) changes in the ionospheric potential distribution in the polar caps due to magnetosphere-ionosphere coupling. The current density (Jz) flow between the ionosphere and the surface, and as … “(Tinsley follows with a desciption of the electroscavenging process which collects cloud ions, causing rain, and inhibiting or reducing the formation of clouds.)

    The changes in the ionosphere potential is due to re-occurring solar coronal holes. From the attached paper “The decreasing correlation between sunspot number and geomagnetic activity, and the deviation of global temperature trend from solar activity as expressed by sunspot index are due to the increased number of high-speed streams of solar wind on the decreasing phase and in the minimum of sunspot cycle in the last decades.”

    http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf

    Also attached is a link to the Solar Terrestrial Activity Report. The blue graph is the change which is affecting the ionospheric potential. See the massive increase for Dec. 16, 2006.

    http://www.dxlc.com/solar/

    [Response: We AGW types can take an accurately observed trend in a physical quantity (the CO2), relate it via careful laboratory measurements to a well-characterized physical process (infrared absorption), embed that process in a range of models extending from the simplest Arrhenius type models to Manabe-Strickler radiative-convective models, to full GCM’s, and out of the latter get a curve of not only temperature but patterns in space and time which agree in most important respects with the observations. We can relate predicted physical consequences to the energy imbalance of the ocean, and then go out in data and see the effects on ocean heat storage much as predicted. When GCR types can do half that, and also explain why infrared absorption plus decline of temperature with height should fail to yield the predicted warming, I’ll start to take the idea seriously. I’m still waiting to see trends in anything related to GCR that could even have a prayer of giving the recent temperature pattern, and I’m still waiting to see a first-principles derivation of the magnitude and distribution of radiative forcing purportedly due to GCR. Then there’s also the matter of the lack of a climate signal associated with the Laschamp magnetic excursion. –raypierre]

    Comment by William Astley — 13 Feb 2007 @ 10:48 PM

  121. RE#120

    Look. They’ve discovered Phlogiston. And in the nick of time too.

    Comment by Mark A. York — 14 Feb 2007 @ 12:06 AM

  122. Re #96: “Interesting in the article about the California frost…”

    Of course everyone seems to have conveniently forgotten that back in July/August California was experiencing a record-setting heat wave, and until last weekend the Sierra snowpack was as low as I can remember seeing at this time of year. Now weren’t those climate models predicting an increase in weather extremes?

    Re #118: “But surely, you see the dissonance that would arise when beliefs developed by some researchers over 30 years of study are challenged by potent new ideas.”

    What potent new ideas? The one under discussion seems more like dredging the bottom of the barrel for something, anything, that will let its supporters go on refusing to accept responsibility for the consequences of their actions. As for beliefs… Climate science can build models using known physics, put observed data into them, compare the results to what is actually happening in the world, and find that the models are a good match for the real world. Seems like there’s precious little room for belief in that process.

    So for any of you that want to put forth competing models, why not follow the same process? There are, I think, several GCMs that have publicly-available source code. (Perhaps the RC folks have links handy?) Take one of those, modify it if needed to use your theory as well, run it, and see how well it does.

    This ought to be fairly easy for the “the sun got brighter years ago, but stopped as soon as we started doing satellite measurements” theory. As mentioned earlier, the models allow varied insolation inputs. Put yours in, tell us what comes out. You might even publish a paper or two :-)

    Comment by James — 14 Feb 2007 @ 12:56 AM

  123. Reply to Gavin’s response to my comment, #74:

    “Response: So what is the positive evidence that muon flux has changed in recent decades? It’s not sufficient to assert that it might have done and so there might be an unquantified effect on climate. Occam’s razor starts to come into play here…. – gavin”

    There are two bits of evidence. One, that it would be possible to draw a statistically justifiable line with a slight down slope through the muon flux data that we have. I cited Svensmark’s graph of data from 1937-94, which could be continued forward. Only a small trend down in flux would be needed.

    Second, I cited the various studies finding an approximate doubling in solar coronal magnetic field strength in the past 100 years or so. It’s not unreasonable to assume that, if a valid observation all or in part, this phenomenon would reduce GCR flux in general & muons in particular.

    Of course I’d like much more evidence, but this is enough in my opinion to deem GCR effect on nebulosity at least a plausible explanation for any global warming that might have occurred over the past century.

    The evidentiary situation is similar to that for the greenhouse effect. Indeed, the CGR hypothesis would appear prima facie to have the stronger case. AGW advocates point to the coincidence between some global warming & an increase in CO2 & other greenhouse gases, & feel they know the mechanism whereby these gases have warmed the earth. Yet there are important problems, such as the fact that the atmosphere has apparently warmed less & later than the surface, contrary to what greenhouse theory would predict. Also, the planet has been warmer at previous times in this interglacial period & during all previous interglacials of which we have record, without benefit of elevated CO2.

    Atmospheric scientists haven’t come up with a natural explanation for current warming, so turn to an anthropogenic cause for global warming. Skeptics say we’re just coming out of another natural cold spell in the usual interglacial cycle of warmer & cooler periods, that current warmth is nothing special & doesn’t particularly need explanation any more than the Holocene Climatic Optimum, Roman or the Medieval Warm Periods.

    The correlation between climate on earth & sunspots is suggestive, just as is CO2, but presently lacking in the hard data you or I would like to see to support the hypothesis. I would also like to see more physical data supporting the greenhouse effect & fewer reruns of computer simulations testing new & scarier proposed feedback mechanisms.

    In fact, I’d like to spend more atmospheric & climatic research funds on muon telescopes & less on redundant (to me) GCM runs, unless maybe they attempt to model cloudiness. Not that I have anything against GCM models. I like those for the Last Glacial Maximum, for instance. I feel they work better at millennial & centennial time frames than for decades & years. Finer resolution requires data of higher reliability, which are largely lacking. But more significantly, they lack predictive power, while any number of questionable adjustments can make them match past data.

    Few if any theories are without problems. The history of science is replete both with problematic theories that are now objectively, undeniable true & with consensuses invalidated by once anathematized hypotheses. In my opinion, both explanations for climate change forcings are plausible.

    [Response: Changes in the IMF should modulate all GCR – as you state above. Therefore, since there is no trend in the best observed GCRs (i.e CLIMAX), that would seem to go against the idea that muon fluxes are also changing. Let me be clear – I’m not saying that muon fluxes are unchanged nor that they can’t effect climate – both things could be possible – but this idea really has some significant problems. And given that CLIMAX was taken as a proxy for GCR by Svensmark originally – I find it odd that this is now dismissed as being irrelevant. More fundamentally, we haven’t come up with GHG induced warming because of lack of other options, it is because the physical consequences of increasing GHGs actually match the obs without much trouble. – gavin]

    Comment by John Tillman — 14 Feb 2007 @ 1:02 AM

  124. Re #113 (Jim Cross): There’s a pretty poor correlation between that cycle and the behavior of climate during the Little Ice Age. If the sunspots are really confirmed by the Be10 proxy and really do correlate with solar radiance changes that in turn have such a substantial impact on climate, there should have been a very sharp climate excursion globally between 1650 and 1750, with the temperature increase between 1700 and 1750 constituting the bulk of the increase between 1700 and the present. As well, warming should have leveled off after 1950, but instead it went through a slight cooling followed by a very rapid warming. This all becomes hard to reconcile. As well, any climate scientist (really, any meteorologist) could tell you that it’s very easy to imagine all sorts of false correlations based on a fragment of a cycle such as the one you point to.

    Comment by Steve Bloom — 14 Feb 2007 @ 1:47 AM

  125. Re #118 (Edward Barkley): “But surely, you see the dissonance that would arise when beliefs developed by some researchers over 30 years of study are challenged by potent new ideas.” Actually I could, but in this case the evidence would seem to indicate that I don’t need to. See this from Rabett Run:

    “Department of there is nothing new under the sun:

    “Reviews of Geophys. and Space. Sci. 16 (1978) 400

    “Dickson [1975] suggested that solar related fluctuations in some aspect of cloudiness may connect solar activity to the meteorology of the lower atmosphere. He thought that this connection might occur via the effect of cosmic ray induced ionization on aerosol and cloud condensation nuclei and thus on the radiative properties of clouds. p403

    “Dickinson Bull Am Meteorol. Soc 56 (1975) 1240.

    “Somewhat better than Nigel Calder and the Revenge of the Killer Cosmic Rays.”

    Comment by Steve Bloom — 14 Feb 2007 @ 2:00 AM

  126. Reply to #106

    Ray responded admirably succinctly to my long comment:

    “Re:98. So what do you think drives the muon production if it isn’t the GCR–in particularly the moderate to high energy portion above the magnetic cutoff?”

    Muons are a form of GCR, modulated by the sun’s IMF. I questioned whether neutron counted at or below the surface are directly proportional to muons in the troposphere. A look at the graph I cited with data from 1937 to 1994 in the case of muons, compared with neutron flux, shows the difference. I also linked a discussion from SLAC about muon production & their effect on cloud formation. I myself don’t know all the factors that produce different patterns in the record of these & other forms of GCR, or whether particle & astrophysicists feel they do. It should suffice to know that there is a difference.

    Ray also commented: “The UAH group has had to backtrack quite a bit on their satellite/balloon discrepancy. It is still nonzero, but MUCH smaller. I don’t think you can view this as a serious discrepancy at this point. Moreover, why should it surprise you so much that the insulator is at a lower temperature than the source of the IR.”

    As you know, I commented that adjustments to the satellite & balloon data that now show warming, however less & later than the surface. The data don’t surprise me. The point is that they fly in the face of greenhouse theory prediction, & not just any prediction, but the one most essential to the hypothesis, reradiation of energy absorbed by the gases in the lower atmosphere. We can differ as to the seriousness of this discrepancy, but to me it seems critical. In my opinion, it’s not a trivial outlier to the theory, as was say Mercury’s orbit to Newtonian gravity, latter explained by Einstein.

    Ray continued, “As to your list of dissenting atmospheric scientists, shall we start with you naming 10 that regularly publish in relevant, peer-reviewed journals and seriously question the importance of anthropogenic mechanisms?”

    The peer review process for many relevant journals has become part of the problem in the AGW discussion. Many skeptics are retired, so no longer subject to retaliation for heretical departures from AGW orthodoxy. Thus I’m not sure that regularly publishing need be a criterion, if they’ve done so with distinction in the past, but I’ll comply with a ? after names that you might not find acceptable.

    For purposes of this discussion, I hope you’ll agree that the consensus view is that global warming in at least the last century is real, that it’s primarily attributed to human activity, which has increased greenhouse gases in our atmosphere via the greenhouse effect, that this warming will continue & get worse through positive feedbacks, leading to consequences ranging from negative to catastrophic by 2100. Opinions differ as to whether it’s too late or not to do anything to avert calamity, although suggestions to ameliorate the consequences previously considered bizarre are now worth considering.

    Many if not most AGW skeptics believe that humans have some effect on climate change. By “primarily”, I mean at least more than half of the warming is attributable to human activity, & probably much more, with possibly as little as 10% from natural cycles. Again consensus scientists have wiggle room to quibble on this point.

    By this definition, I don’t know to what extent satellite data collectors & analyzers John Christy & Roy Spencer, would still consider themselves AGW skeptics, since I’ve never read how much climate change either scientist now feels is natural & how much man-made. Christy recently wa quoted, “part of what has happened over the last 50 years has clearly been caused by humans.” Is “part” more or less than half?

    [edit]

    [Response: John, you are doing fine with the discussion of specific issues, but this isn’t the forum for cutting and pasting irrelevant lists of names. Please stick to the scientific points of dispute. – gavin]

    Comment by John Tillman — 14 Feb 2007 @ 3:48 AM

  127. So is the jury still out on the Suns activity being partly responsible for the current warming, not responsible at all or not responsible since the AGW signal arose from the natural background of the current climate?

    How much additional output would the Sun need to exhibit to warm the atmosphere by the 0.6 – 0.8 C that we are currently experiencing and is there any evidence of it?

    I would suggest that climate scientists have looked at the Sun in as much depth as is currently available to the from NASA/ESA and the like. How can anyone now say that the Sun is SOLELY to blame?

    Comment by pete best — 14 Feb 2007 @ 6:22 AM

  128. Re #124

    I don’t see your LIA argument at all. There is a significant increase in Be-10 during the time you mention which would be associated with reduced solar activity.

    As for the 1950s and after, the leveling of Be-10 and increased warmth can be reconciled by several factors. First, remember the leveling is already at a much higher level of solar activity than the previous several hundred years. Second, there is probably some lag time involved. Third, the Sun is not the only factor. Yes, GHG is a factor (I don’t deny that) and maybe global dimming.

    It seems to me that the offical RC position is that the Sun is certainly a factor but just not a significant one in current warming. An extreme denialist position is the warming is caused wholly by the Sun. I am closer to the official RC position but believe we may be underestimating the effects of solar activity.

    Comment by Jim Cross — 14 Feb 2007 @ 9:37 AM

  129. Wait. “… not just any prediction, but the one most essential to the hypothesis, reradiation of energy absorbed by the gases in the lower atmosphere …”

    You consider that a _prediction_? And one that if disproved, removes the basis for global warming?
    Am I understanding you correctly?

    Comment by Hank Roberts — 14 Feb 2007 @ 10:48 AM

  130. Thank you Lynn Vincentnathan /107 this is what I thought.
    Svensmark proposes that lower solar activity results in more cosmic rays penetrating the atmosphere, resulting in more cloud formation resulting in lower temperatures.
    Clouds act as a blanket keeping the heat in!
    Perhaps he should clarify this point.

    Comment by Jim Meldrum — 14 Feb 2007 @ 11:04 AM

  131. I think PK has hit the nail on the head. There is too much
    > accusatory and alarmist rhetoric in the whole
    > debate. It would be nice to
    > see an independent, or at least, philosophically
    > balanced panel take a look
    > at all of the evidence and come up with an unanimous
    > decision on the state
    > of the Global Warming debate at this time.
    >
    > The IPCC simply has too many deficiences from both a
    > scientific, and a
    > political standpoint to be the independent voice of
    > reason in this debate.

    Comment by JayMo — 14 Feb 2007 @ 11:12 AM

  132. [[You probably know reputable atmospheric scientists who would not agree that AGW is a perfectly good model & that there are credible competing hypotheses, if not personally, then through their work. I do.]]

    I know of reputable astrophysicists who still don’t buy the Big Bang. But they’re a tiny minority, just like the AGW deniers. Scientific consensus isn’t an arbitrary thing; it goes with the evidence. The deniers haven’t got a leg to stand on.

    Comment by Barton Paul Levenson — 14 Feb 2007 @ 11:20 AM

  133. [[Re BPL (82). I suppose if scientific truth was based on a vote, you’d win. [edit – no politics]. The ridiculed minority are not necessarily wrong. That’s why its important to carefully assess the facts and feel the need to be convinced ‘yourself’ rather than to go with your heart, the flow, the popular view, etc. ]]

    Your assumption that that’s where I get my information is unwarranted, pal. I got into radiation physics when I started writing radiative-convective models of planetary atmospheres. How many have you written?

    Comment by Barton Paul Levenson — 14 Feb 2007 @ 11:37 AM

  134. Re: , #129

    It would be nice to see an independent, or at least, philosophically balanced panel take a look at all of the evidence and come up with an unanimous decision on the state of the Global Warming debate at this time.

    The IPCC simply has too many deficiences from both a scientific, and a political standpoint to be the independent voice of reason in this debate.

    This is one of the reasons climate scientists sometimes get a bit “riled up.” The IPCC is exactly what was asked for: an objective, scientific evaluation of all the evidence. The conclusion they have reached doesn’t satisfy the non-believers, so they have resorted to calling it “political” and even unscientific.

    Every objection to AGW has been given serious consideration. When it is found wanting, the nonbelievers cry foul.

    Comment by tamino — 14 Feb 2007 @ 11:40 AM

  135. [[It occurs when there is a need to accommodate new ideas]]

    I keep hearing this line. AGW deniers have “new ideas” which the stodgy establishment ought to listen to.

    Heads up. The impossibility of global warming was standard doctrine from about 1900-1950, with a few brave exceptions like Hulbert and Callendar in the ’30s. AGW IS the new idea. More importantly, it has the evidence behind it.

    It isn’t whether an idea is new or old, brave or timid, progressive or reactionary, that matters. It is simply and solely whether it is true or false.

    Comment by Barton Paul Levenson — 14 Feb 2007 @ 11:45 AM

  136. [[The evidentiary situation is similar to that for the greenhouse effect. Indeed, the CGR hypothesis would appear prima facie to have the stronger case.]]

    From the rest of your post, I see you apparently don’t believe in the greenhouse effect, let alone AGW. May I ask what you think keeps the Earth from freezing over? Its emission temperature with the present albedo is 255 K, you know. Water freezes at 273 K.

    Comment by Barton Paul Levenson — 14 Feb 2007 @ 11:50 AM

  137. [[The data don’t surprise me. The point is that they fly in the face of greenhouse theory prediction, & not just any prediction, but the one most essential to the hypothesis, reradiation of energy absorbed by the gases in the lower atmosphere.]]

    The idea that greenhouse gases don’t absorb and radiate energy (they don’t “reradiate” it) has been so massively proved by so many experiments that it really does constitute pseudoscience to deny it. And again, I ask you, if the greenhouse effect doesn’t work, what keeps the Earth from freezing over? Want the math to demonstrate that it would be frozen over if not for the atmosphere’s greenhouse effect? I promise not to use anything tougher than algebra.

    Comment by Barton Paul Levenson — 14 Feb 2007 @ 11:56 AM

  138. [[Svensmark proposes that lower solar activity results in more cosmic rays penetrating the atmosphere, resulting in more cloud formation resulting in lower temperatures.
    Clouds act as a blanket keeping the heat in!
    Perhaps he should clarify this point. ]]

    Clouds are strong greenhouse agents, but they are also highly reflective (at least the ones low down are). On average the cooling from high albedo dominates over the heating from the greenhouse effect, though just slightly (I believe I’ve seen the figure 20 W/m^2).

    Comment by Barton Paul Levenson — 14 Feb 2007 @ 11:58 AM

  139. Re #98: You say “What matters is muon flux in the lower atmosphere, more than overall flux in space.” I’m having a good bit of trouble seeing why this should be so. Why should muons be the _only_ species that affects clouds, and not all the other charged particles zipping around?

    As I understand it, the premise of the GCR theory is that charged particles cause ionization which causes clouds to form. We know this mechanism works in the lab, since the cloud chambers used as early particle detectors used a variation on it, but I don’t see how it can discriminate among particle types. As long as it has a charge, it leaves a track.

    So why the claim that only muons have an effect on natural cloud formation?

    Comment by James — 14 Feb 2007 @ 12:44 PM

  140. Re #89: Sorry, there is typing error: it should be “suggesting a 169 to 1… ” (not 269 to 1).

    Comment by Francis Massen — 14 Feb 2007 @ 2:00 PM

  141. Re 126 “Muons are a form of GCR, modulated by the sun’s IMF.”
    Nice try. Muons are relatively longlived leptons that form from the weak decays of hadrons produced by the GCR. Trends in muons should follow GCR, since GCR is ultimately the driving force.

    As to the UAH results, given that they have had to revise them, what, 3 times now, and always in the direction of decreasing discrepancy, I would question how well they understand their dataset. No shame there–as anyone who has tried to parse a multi-satellite dataset would know.
    Your assertion that climate skeptics face persecution would be laughable if it were not so common. I know of no scientist who has suffered financially for denying climate change–most have been remunerated very well. The stiffest sanction I know of for a contrarian in any scientific field was that they weren’t allowed to teach their opinions as fact in graduate and undergraduate courses. Now a scientist in the pay of an organization actively trying to disseminate disinformation and subvert the scientific process–that’s a different situation entirely. They would indeed be ostracized for turning their back on the rules of scientific inquiry–not for disbelief in any specific scientic theory.

    Comment by Ray Ladbury — 14 Feb 2007 @ 5:21 PM

  142. The question of why human emissions of CO2 are invoked to explain modern warming when the climate warmed in pre industrial times is always asked in these discussions but never satisfactorily answered.

    Logically I can think of two reasons why non natural causes are put forward.

    a) Warming hasn’t occurred in the past.
    b) Warming has occurred in the past but the cause is known and now isn’t applicable.

    Which of the two is true or is there another?

    [Response: Mostly (b). -gavin]

    Comment by fieldnorth — 14 Feb 2007 @ 5:55 PM

  143. Re #142: You miss the obvious, which is

    c) Regardless of how much or little we know about past climate variation, we can be pretty darned sure it wasn’t caused by a sudden increase in CO2 due to burning large amounts of fossil fuels, because that’s never happened beforem and so in that sense discussion of past variation is irrelevant.

    Besides, you’re asking the question backwards. Climate scientists aren’t invoking human-produced CO2 to explain warming, they’re predicting that increasing CO2 produces warming. Suppose for instance we’d had fast computers and the necessary theory & data back in the mid-1800s: the climate scientists of the day could have come up with the same models, and used them to predict the warming that a given CO2 increase would cause, long before the increase or the consequent warming had started.

    Comment by James — 15 Feb 2007 @ 1:59 AM

  144. From Calders op-ed:
    “The sunâ��s magnetic field bats away many of the cosmic rays, and its intensification during the 20th century meant fewer cosmic rays, fewer clouds, and a warmer world. On the other hand the Little Ice Age was chilly because the lazy sun let in more cosmic rays, leaving the world cloudier and gloomier.”

    I am not sure if this is in the original paper or it is just Calder’s interpretation but to me it presents a problem. That is the assumption that more clouds = cooler world and less clouds = warmer world.

    Now this would only be true if the cosmic rays produced high altitude cirrus clouds that perhaps reflect more energy straight back into space than they trap long wave radiation from the Earth. Then less reflecting clouds means warming as more radiation is hitting the Earth. However if cosmic rays produce more low altitude darker clouds then these would trap more long wave radiation than reflect short wave radiation so in this case less clouds would mean cooling because there are less clouds so less long wave radiation is trapped.

    To my mind then even if the ideas presented in this paper are absolutely true there is no real way of knowing what the effect could be. I cannot think of an experiment that would nail the types of clouds that cosmic rays form more of. It may even be that the cosmic rays create equal amounts of both leading to no net effect which seems to be the observation that there is no correlation.

    Comment by Ender — 15 Feb 2007 @ 3:56 AM

  145. I want to try these questions again because I am trying to sort out as a layman how to evaluate the CRF vs. GHG debate. Can someone explain to me how increased CO2 (which I assume is fairly well measured over a long period) is correlated to observed temperature increase? Is it as simple as a theoretical projection being compared to observations?

    How is this balanced against claims that CRF (or GCR) may also be significantly responsible for the warming we are seeing? Is there a change in the last 50 yeaers of solar activity, that supports saying GCR increase can explain a significant portion of the current warming rate?

    From what I have read around, the implementation of these models on computers is very complex and requires corrective routines to deal with numerical error. Are these programs open sourced for auditing?

    Please feel free to rip to shreds any mistaken thinking I am using to phrase these questions, I am here to learn. Also, I know there are a lot of good debate archived at this site, so if a pointer is all it takes, please provide it.

    Comment by jdwill — 15 Feb 2007 @ 1:42 PM

  146. Thank you Fabien Bulabois for alluding to the fact that Nigel Calder’s comments in the Sunday Times do not reflect New Scientist’s views on climate change. Nigel Calder was editor of New Scientist from 1962 to 1966. He has written twice for New Scientist since 1997 (which is as far back as I can go in our online archive), and his views are entirely his own.

    New Scientist did indeed write about the solar activity hypothesis last year. The article made it clear that the hypothesis is highly controversial and full of holes. It concluded:

    “None of this means that we can stop worrying about global warming caused by emissions into the atmosphere. “The temperature of the Earth in the past few decades does not correlate with solar activity at all,” Solanki says. He estimates that solar activity is responsible for only 30 per cent, at most, of the warming since 1970. The rest must be the result of man-made greenhouse gases, and a crash in solar activity won’t do anything to get rid of them.
    […]
    “There is a dangerous flip side to this coin. If global warming does slow down or partially reverse with a sunspot crash, industrial polluters and reluctant nations could use it as a justification for turning their backs on pollution controls altogether, making matters worse in the long run.”

    In light of the IPCC’s fourth assessment report, Solanski’s estimate of solar radiative forcing was generous. The IPCC’s figures were cited in our coverage of the Paris release earlier this month.

    For New Scientist’s latest and on-going coverage of climate change, please visit our Environment site: http://environment.newscientist.com/

    Catherine Brahic, Online environment reporter, New Scientist

    Comment by Catherine Brahic — 15 Feb 2007 @ 1:55 PM

  147. Of the 146 comments offered so far, only one makes the salient point that the timeframe for variation needs to be examined on multi-year and multi-century bases. This is not new stuff. Look, for example, at Jan Veizer and Nir Shaviv for a particularly good demonstration of the relationship between cosmic radiation and warming. See: http://www.gsajournals.org/perlserv/?request=get-document&doi=10.1130%2F1052-5173(2003)013%3C0004:CDOPC%3E2.0.CO%3B2.

    That paper’s description of CO2 contribution tracks far better than the current IPCC estimates, and leaves CO2, at best, as a minor contribution to the variation in Global temperature.

    [Response: You make a good point, different timescales must be treated differently, and then you blow it by suggesting that correlations over the hundred million year timescale have relevance to the last few decades (even assuming that their analysis was valid, which I would not- see http://pubs.giss.nasa.gov/abstracts/2004/Rahmstorf_etal.html ). -gavin]

    Comment by David Schnare — 15 Feb 2007 @ 2:54 PM

  148. Meanwhile, in “bizarre calculus land” we’re still waiting for a single icecore showing carbon dioxide rise preceding temperature rise, rather than the other way around. You know, where cause precedes effect aka “Reality”.

    [Response: Possibly the concept of feedback doesn’t exist in your world? You, know, where one thing leads to another which leads back again…. Or maybe you have found a way to deduce a causation purely from a correlation. Do please let us know…. -gavin]

    Unlike the greenhouse hypothesis, at least Svensmark has experimental evidence whereas the Greenhouse Hypothesis has exactly zip.

    [Response: Svensmark has precisely as much experimental evidence for a GCR/climate link as Tyndall had for CO2 over 100 hundred years ago. He has a ways to go. ]

    Of course, it’s a scientific consensus so it must be “taken into consideration” despite its complete lack of testable predictions nor any paleoclimatic evidence in any meaningful timeframe.

    [Response: Lack of testable predictions? Stratospheric cooling, surface and troposphere warming, Arctic polar amplification, water vapour increases, increased precipitation intensity, more positive phases of the annular modes, decreased TOA flux at CO2 absorption lines, increased ocean heat content etc. etc. Be sure to let me know when they start giving tourist visas to visit your wonderful homeland and I’ll buy some warm clothes (presumably it must be cold since the greenhouse effect obviously doesn’t operate there….). ]

    Comment by John A — 15 Feb 2007 @ 4:09 PM

  149. Heh. The Contrarians and Denialists sure have stepped up the “our minority opinion is being repressed and therefore must be right!” rhetoric since the SPM came out. Spluttering and bombast, heat and smoke and very little light. Shortly they will have to either crawl off to vent their spleens in private chat rooms filled with others of the Michael Savage/Crichton/tinfoil hat crowd, or else change their tune to even have a place at the table with the grown ups. Must make for a hard choice.

    Comment by cat black — 15 Feb 2007 @ 6:49 PM

  150. Firstly, i’m no expert. I want people to steer my thought, so here’s a brain dump, please correct me where you see fit.

    I don’t believe we can totally discount the effects of the sun on global warming. After all there is a near 100% correlation between heating by the sun and the temperature here on earth (imagine how warm our planet would be without the sun).

    My issue with all current mainstream (if there is such a thing) thinking on global warming is that it relies almost completely on retention of heat from the sun by greenhouse gases, and kind of assumes that solar effects are constant, which clearly they are not, even if they do not present a trend.

    I’m no expert, (as you’ve probably already gathered), but one thing I do know from my limited science education is that physical systems are extremely complex. I just find the whole idea that global warming is just down to one effect (the greenhouse) difficult to believe.

    In the scheme of things the levels of change we are experiencing while extreme for earth, are tiny on a universal scale, and with such complex systems can we confidently say that we’re right?

    As for your CSI analogy (lead story today), well I kind of disagree with your sentiment. It only works if you assume that each ‘event’ is unrelated, but in fact how can they be unrelated, they are a product of the same extremely complex environmental systems, even if the mode of ‘event’ is different. Again I just see this as over simplification, how do we know for example, that one of the previous ‘event’ triggers isn’t having an influence on temperature now (no matter how subtle). Not all crimes are commited by one person or with the same motive. How about combining CSI and Cold Case?

    Comment by Jon — 15 Feb 2007 @ 6:50 PM

  151. Jon, whoever told you that “AGW theorists think that greenhouse gases are the only actor” was setting up a straw man. Search this site regarding attribution and you’ll see that ol’ Sol is considered. Finally, the IPCC states with >90% certainty that global warming is due to anthropogenic greenhouse gases. They haven’t closed their minds to other possibilities.

    Comment by Steve Latham — 15 Feb 2007 @ 7:39 PM

  152. Re: #150

    I don’t believe we can totally discount the effects of the sun on global warming. After all there is a near 100% correlation between heating by the sun and the temperature here on earth (imagine how warm our planet would be without the sun).

    My issue with all current mainstream (if there is such a thing) thinking on global warming is that it relies almost completely on retention of heat from the sun by greenhouse gases, and kind of assumes that solar effects are constant, which clearly they are not, even if they do not present a trend.

    I’m no expert, (as you’ve probably already gathered), but one thing I do know from my limited science education is that physical systems are extremely complex. I just find the whole idea that global warming is just down to one effect (the greenhouse) difficult to believe.

    You’ve been seriously misinformed! Mainstream thinking on global warming is not that it depends only on retention of heat by greenhouse gases; rather it includes the effect of reflective aerosols (both volcanic and anthropogenic), the aerosol indirect effect, black carbon soot, albedo change due to changing snow and ice patterns, land use changes, and — yes indeed — changes in solar output, as well as others. Without taking all the factors into account, calculations don’t match observation; when all factors are taken into account, the match is superb.

    When we look at the data, one of the factors is much larger than the others, and that’s greenhouse gas forcing. Since 1950, it is indeed the only forcing that’s had a potent warming effect. That is not an assumption of “global warming theory,” it’s based on actually measuring the strength of the various forcings.

    It’s like investigating why someone is suddenly gaining weight rapidly. This involves a large number of factors including diet, exercise, hormonal balance, etc., all entering into an extremely complex system. But if we have measurements of diet, exercise, kidney function, hormonal balance, etc., and only one of those factors has changed enough to affect weight, we can identify that as the cause. This doesn’t mean that the other factors aren’t important, and especially doesn’t mean that they haven’t been taken into account. But when all the other suspects have an ironclad alibi …

    Comment by tamino — 15 Feb 2007 @ 7:43 PM

  153. In #126, John Tillman wrote: “The peer review process for many relevant journals has become part of the problem in the AGW discussion. Many skeptics are retired, so no longer subject to retaliation for heretical departures from AGW orthodoxy. Thus I’m not sure that regularly publishing need be a criterion, if they’ve done so with distinction in the past…”

    This raises a point that has concerned me for some time. Without naming names, I have noticed that some of the most distinguished “skeptics” are retired, older scientists who, I would suggest, formed rigid opinions years ago and simply stick with them, even though they have not really kept up with the science. This is indicated by their heavy use of personal scientific judgement, without bothering to address the data. If they are going to challenge the conclusions of their younger peers, they should follow the rules of the game. They seem to like the attention and recognition they can get without the pesky need of publishing peer reviewed papers. It is sad, but I am of an age where I can see how easy it would be to fall into this trap. In a totally different kind of setting, I sometimes find it necessary to simply bite my tongue and avoid the ramblings of an old fool riding a wave of the past.

    Comment by Ron Taylor — 15 Feb 2007 @ 10:19 PM

  154. In Reply to “I’ll start to take the idea seriously. I’m still waiting to see trends in anything related to GCR that could even have a prayer of giving the recent temperature pattern, and I’m still waiting to see a first-principles derivation of the magnitude and distribution of radiative forcing purportedly due to GCR. ]”

    A) Trends in GCR vs Gobal Temperature
    As noted in my comment 120, modulation of GCR is not the only means in which changes in the sun, can affect cloud cover. In comment 120 there is a link to Palle’s paper that provides satellite data that shows overall planetary cloud cover decreased at 0.0165%/yr from 1993 to 2001. How can you explain the reduction in clouds that Palle notes in that paper? Palle notes the reduction in clouds is consistent with Tinsley’s electroscavenging process (A link to Tinsley’s paper is attached in my comment 120). As noted in Palle’s paper there is a 99.5% correllation between variations to GCR and variations to cloud cover up until 1993. Starting in 1993, ions are removed by the electroscavenging process, thereby blocking the GCR process.

    The increases to the electroscavenging process, is caused by an increase in global electric current. (See Tinsley and Yu’s paper which is attached in comment 120 for a diagram of the Global Electric Curcuit and a detailed explanation of the electroscavenging process.) The increase in the Global Electric Current is due the Solar south pole coronal hole moving towards the solar equator, at the end of each solar cycle. For example, the sun is currently spotless but the solar wind is high due to the coronal hole CH257. (I also included a link to the daily Solar Terrestrial report in my comment 120.)

    Attached below is a link to a second Palle paper that provides data from observing the shine of the earth on the moon, to measure planetary albedo. The earthshine data, confirms cloud cover was reduced in the 1993 to 2001 period, which supports the satellite data. Palle converts the reduction in cloud cover to a warming of 7.5 W/m3 +/- 2.4 as compared to the estimate for CO2 warming of 2.5 W/m2.

    http://solar.njit.edu/preprints/palle1266.pdf

    The proxy climatic record provides evidence of a multitude of global warmings followed by global coolings. Electroscavenging appears to be the warming mechanism. When the solar forcing function that is increasing the Global Electric Current is complete, a Maunder like minimum follows. The solar sunspot cycle is then interrupted, which causes an increase in GCR which causes an increase in cloud cover. An increase in GCR also changes cloud macroproperties. An increase in GCR increases cloud albedo.

    [Response: You’re still going around in circles, and not listening to the argument. GCR is supposed to be the forcing function, but there’s no demonstrated trend in that. Even if the earthshine analysis proves correct (there are many questions about that), at most it would have shown there is a possible correlation of cloudiness (high clouds? Low clouds? you don’t know) to solar cycle. You still wouldn’t know if this is GCR, or simply a response of cloudiness to the known effect of the short term solar cycle on temperature. You still wouldn’t have the physically demontrated quantified link between GCR and cloudiness. And you still have no trend. If, in another hundred years, all the gaps are filled, at best you’d have a theory for GCR modulating solar cycle surface temperature fluctuations. Not a theory of global warming. And besides that, it’s just alchemy to think you can throw out physics that is known and established, like the effect of CO2 on the radiation budget. That’s just not in dispute, and if you want to spin some wheels about water vapor feedback you’ve got to explain why a stabilizing water vapor feedback fails to stabilize your precious GCR idea. Gavin is a very charitable man. He thinks maybe the GCR crowd are at the point that Tyndall was at with CO2 a bit over a century ago. Sometimes I think the GCR people are more like Paracelsus groping for the philosophers’ stone — and not because they’re dumb but because, for some reason, they’re wasting their time trying to disprove global warming rather than doing the really interesting things they could do to test their theory. –raypierre]

    Comment by William Astley — 15 Feb 2007 @ 11:13 PM

  155. I find one claim of the blog to be quite disturbing:

    “Even if the evidence for solar forcing were legitimate, any bizarre calculus that takes evidence for solar forcing of climate as evidence against greenhouse gases for current climate change is simply wrong.”

    According to James Hansen the climate sensitivity employed by the models (0.5-1.0 C/W/m2) derives its claim to empirical legitimacy from the ice ages. This entire argument rests on the assumption on the notion that the sun does not vary in forcing over the course of the ice ages, neither directly nor indirectly through the svensmark effect. However, there is now empirical evidence that the sun itself does indeed vary and correlate strongly with the ice ages. This completely undermines the primary empirical evidence supporting a high climate sensitivity.

    It’s quite simple: if there is a hitherto unknown forcing causing the ice ages, it follows quite obviously that greenhouse gases account for less of the warming than previously assumed. This argument seems quite straightforward. Please tell me why it is “simply wrong.”

    [Response: It isn’t ‘simply wrong’. If there was an additional forcing that just happened to be correlated with precessional, obliquity and eccentricity cycles (all of them, mind you) that was quantifiable and significant, that would lead to a re-evaluation of the ice age evidence for climate sensitivity – (while other lines of evidence would still be valid), though not of the attribution of current changes to GHGs. However, there is a significant hurdle to demonstrating that such a forcing exists – principally you would have to show that there was no way that the causation was the other way around. That is, if you found a solar proxy that was correlated to the ice ages, you’d need to demonstrate that that the recording of that proxy was indpendent of climate itself. That is clearly not the case for any exisiting solar proxy, and the extremely low probability that solar variability would be correlated with the Earth’s orbital features (why? how?) makes it pretty clear that this is a very long shot indeed. But, in science, it is difficult to ever rule anything out completely and so the possibilty exists. But as we’ve said before, for the current changes the largest forcing is from greenhouse gases – so whatever the sensitivity, the attribution for today doesn’t change. – gavin]

    Comment by Onar Am — 15 Feb 2007 @ 11:22 PM

  156. Dear Gavin,
    The link you give in 147 doesn’t work for me.

    [fixed. – gavin]

    Dear John A (148),
    Why does ‘your side’ dump many hours and dollars into PR rather than into experiments that would address your questions?

    Comment by Steve Latham — 15 Feb 2007 @ 11:44 PM

  157. Hi chaps,
    I just had to put the cosmic ray data from the Colorado Climax station into an spreadsheet. The resultant pdf graph is year versus the monthly mean and can be found here:-

    http://putstuff.putfile.com/49019/4869140

    Hope the link works – first time I’ve done this.

    And as can be seen there’s no upward trend. Maybe a bit of a cycle. 11 year solar? I think the Times and the Telegraph owe us each a retraction, an apology and $10,000 plus expenses.

    As my mate said anything is linear if you use a log-log scale and a thick marker pen!

    Keep up the good work.

    Comment by Mike — 16 Feb 2007 @ 3:35 AM

  158. I have just noticed that in the extension of the Willson and Mordinov (ACRIM-) composite data set of TSI the previously reported trend of minima has vanished. While there has been reported a trend of +0.037% between minimas of cycle 21 and 22, the trend between minimas of cycles 21 to 23 is now a tiny 0.004%, and we have still not passed the minimum of cycle 23. See http://www.acrim.com/ACRIM%20Composite%20Graphics.htm

    Thus there is no data set anymore showing any significant trend of TSI over the last three decades. One more argument for solar induced warming over the last decades gone to Nirwana…

    Comment by Urs Neu — 16 Feb 2007 @ 5:06 AM

  159. I’m sorry but I’ll have to submit Gavin’s usual misdirections to examination:

    [Response: Actually, we are all sorry. ]

    “Meanwhile, in “bizarre calculus land” we’re still waiting for a single icecore showing carbon dioxide rise preceding temperature rise, rather than the other way around. You know, where cause precedes effect aka “Reality”.”

    [Response: Possibly the concept of feedback doesn’t exist in your world? You, know, where one thing leads to another which leads back again…. Or maybe you have found a way to deduce a causation purely from a correlation. Do please let us know…. -gavin]

    Not an answer. Does your reality include a feedback that precedes the cause by several centuries every time? Mine doesn’t. The concept of feedback still requires in climate terms THAT CARBON DIOXIDE RISE SHOULD PRECEDE TEMPERATURE RISE. Except that it doesn’t. Furthermore the witness of the icecores shows that carbon dioxide continues to rise for several centuries AFTER temperatures have begun to fall. What kind of feedback is that?

    [Response: Let me spell it out slowly. M i l a n k ov i t c h f or c i n g s lead to changes in temperature and circulation which affect CO2 and CH4 which then helps make it colder. It’s really not that complicated. But you are trying to insinuate that CO2 rises now are not anthropogenic – they are, and no amount of your posturing changes that. ]

    [edit]

    Unlike the greenhouse hypothesis, at least Svensmark has experimental evidence whereas the Greenhouse Hypothesis has exactly zip.

    [Response: Svensmark has precisely as much experimental evidence for a GCR/climate link as Tyndall had for CO2 over 100 hundred years ago. He has a ways to go. ]

    Svensmark has experimental evidence. A direct experiment showing how cosmic rays seed clouds in all depths of the atmosphere. A reproducible experiment which will shortly be reproduced. And the Greenhouse hypothesis has?

    [Response: What part of the above sentence is unclear to you? Possibly you should try reading Tyndall’s paper. Laboratory experiments showing that CO2 is a greenhouse gas have been reproduced thousands of times and are clearly documented the HITRAN database. To deny this is blindness of the highest order.]

    Of course, it’s a scientific consensus so it must be “taken into consideration” despite its complete lack of testable predictions nor any paleoclimatic evidence in any meaningful timeframe.

    [Response: Lack of testable predictions? Stratospheric cooling, surface and troposphere warming, Arctic polar amplification, water vapour increases, increased precipitation intensity, more positive phases of the annular modes, decreased TOA flux at CO2 absorption lines, increased ocean heat content etc. etc. Be sure to let me know when they start giving tourist visas to visit your wonderful homeland and I’ll buy some warm clothes (presumably it must be cold since the greenhouse effect obviously doesn’t operate there….). ]

    Here we come back to the bizarre calculus of greenhouse modelling: A prediction is supposed to explain a FUTURE event, whereas greenhouse modelling predicts what has already happened.

    So we’ll take those “evidences” in turn:

    “Stratospheric cooling”: so does the solar hypothesis
    “surface and troposphere warming”: so does the solar hypothesis
    “Arctic polar amplification”: There isn’t any. See Polyakov et al, 2004 – so Greenhouse Warming produces a failed prediction. The Arctic is warming well within the natural variation
    “water vapour increases”: so does the solar hypothesis
    “increased precipitation intensity, more positive phases of the annular modes, decreased TOA flux at CO2 absorption lines, increased ocean heat content etc. etc” so does the solar hypothesis.

    Greenhouse warming also predicts polar amplification in the Antarctic, except that the Antarctic is cooling (rather severely in places like the Dry Valleys) and not warming at all except in the area most exposed to ocean currents with attendant collapses in floating ice sheets that are downstream of an active undersea volcano. It predicts that the Southern Hemisphere should be warming (nope). It predicts (after the fact) that hurricane seasons will have more storms being forced by the increasing greenhouse gases – except that the distribution of hurricanes follows a Poisson distribution indicating that there is no trend: its a random process. It even managed to predict a slowdown in the North Atlantic Drift, whose apparent confirmation by a single measurement was rather shortlived when much longer measurements showed the natural variation of that oceanic phenomenon – no slowdown of the Gulf Stream at all.

    Greenhouse hypothesis predicts (in the sense of “explains after the fact”) many things including warming, cooling, less precipitation, more precipitation, less storminess, more storminess and so on. It “predicts” everything which means that it isn’t a scientific theory in the sense of any prediction that can be falsified.

    As I said, Greenhouse Theory appears to be unable to predict (as in the future) any phenomenon in any reasonable timeframe. It can’t even predict the next El Nino, but it does appear to be the perfect explanation after the fact. Such a flexible theory cannot be falsified. It has failed to predict any phenomenon uniquely compared to other hypotheses but it has made predictions which have failed to come about.

    [Response: Errr… where to start? Well, let’s take stratospheric cooling. Not only was this predicted as a function of greenhouse gas increases in the 1960s (Manabe and Weatherald, 1967) (years before it was observed), but all solar forcing increases would lead to a warmer stratosphere (through increased absorption by ozone). Your claims otherwise are without foundation. The rest of your claims for the ‘solar hypothesis’ fail at every turn because there is no trend in current solar forcing and thus no prediction or hindcast to show anything. And since that line of attack is worthless, you then bring up a bunch of other items that are equally bizarre – Antarctic peninsula is warming because of an undersea volcano? CO2 isn’t a forcing because it doesn’t predict El Nino? Because hurricanes follow a statistical distribution they can’t have a trend? This is nonsense (as you well know).

    To paraphrase Eric Idle – arguments should be a series of statements designed to support a contrary statement, not the automatic gainsay of anything anyone else says. To which you’ll no doubt reply ‘No it isn’t’. If instead you were a serious person, you’d move on from these tired talking points and discuss more interesting uncertainties – I won’t hold my breath. I only have 5 minutes for this, not the full half hour. -gavin]

    Comment by John A — 16 Feb 2007 @ 5:55 AM

  160. With regard to GCR theories (#154). Assume that they are correct and significant. Since cloud nucleation increases, this moves water from the vapor phase into aerosols and increases the rate of precipitation which decreases relative humidity. Unobserved.

    [Response:Far be it for me to support our reality-challenged friends, but I doubt this would be a noticeable effect. Changes in cloud nucleation can have very different effects on precipitation depending on exactly what happens – more nuclei can reduce average droplet size and make it harder for raindrops to form for instance. Also, the amount of water in vapour compared to condensate is so large that it is very difficult to make a change large enough to effect realtive humidity. I think a better line would be the prediction of increased cloud in areas of low natural aerosol content where you would expect such an effect to be more important. Also not observed. -gavin]

    Comment by Eli Rabett — 16 Feb 2007 @ 10:03 AM

  161. I have just attended a seminar by Mike Lockwood from the Rutherford labs in the UK. He specialises in Solar activity and links to Earth. He set out the ways in which the variations in Solar activity can influence our climate, via increases in radiance and in modulation of GCR.

    He then showed analysis of variation in solar activity, this rose to a maximum in around 1985, then declined. Overlaying this on the constant rise in Earth global mean temperature, his conclusions where that whilst there are now fairly good paleo records correlated with Solar activity, there is no correlation between current warming and solar activity. In fact taking solar activity into account in climate models ( I think he reffered t the HADCM3 model) increased the sensitivity of the models to anthropogenic forcing.

    Comment by John Prytherch — 16 Feb 2007 @ 12:31 PM

  162. [pointless verbiage deleted]

    [Response: Sorry to be abrupt, but the endless recycling of strawmen arguments, fake ‘predictions’ and complete inability to apply a little logic to your thinking makes any dialogue almost impossible. There are ways to be sceptical and to engage constructively (Charles Muller, Ferdinand Englebeen are two good examples) and people learn from those exchanges. But it requires a certain detachment and a willingness to refrain from questioning the motives and credibility of your interlocutors. Leave the conspiracy theories at home – We’re just not interested. gavin]

    Comment by John A — 16 Feb 2007 @ 2:34 PM

  163. Re: 161 and “influence the earth”

    Is there a estimated amount of influence that’s being bandied about? There’s a calculation of so much W/m^-2 for CO2, for methane, for soot, for aerosols, etc. If there isn’t an actual multiplier associated with GCR, shouldn’t its adherents have a bit of wit and hold their fire until they come up with one?

    Comment by Jeffrey Davis — 16 Feb 2007 @ 3:34 PM

  164. Re #155

    Gavin,

    first of all, your argument about correlation/causality applies equally well to greenhouse gases and the ice ages. We know for a fact, that 1) warming causes oceans to degas, thereby causing a strong correlation between temperature and CO2, and 2) greenhouse gases lag temperature by 4-800 years thereby relegating them at most to an intensifier of existing climate change. In an unbiased science greenhouse gas correlations and solar correlations would be on an equal footing.

    [Response: Of course. If the only evidence was the correlation that would not be sufficient. It’s the fact that the physical properties of ice sheets, greenhouse gases and vegetation changes do a good job at explaining the temperature and climate changes over the ice age cycles. -gavin]

    Second, the work by Mukul Sharma (2002) makes a strong case through spectral analysis that the correlation is not spurious.

    [Response: Not a strong case at all. Read Bard and Franks, EPSL, 2006. Sharma’s records are almost certainly contaminated by climate changes (read Field et al, 2006, JGR) to see how that might happen. -gavin]

    Third, Milankovitch theory is debunked. There is the 100 ky problem, the 400 ky problem, the unsplit peak problem, the stage 5 problem, the causality problem and the transition problem, all mounting to a thorough rejection of the theory as the driver of ice ages. Notice that the unsplit peak problem indeed shows that the eccentricity cycle is spurious. Spectral analysis of the o18 temperature proxy shows one single very sharp peak at 100 ky. This 1) is evidence against eccentricity which has TWO peaks at 95 and 120 ky respectively, and 2) is evidence for another forcing of astronomical origin. Only an external forcing could possibly create a clockwork clean peak 100 ky temperature cycle, and it’s not the weak eccentricity cycle(s).

    [Response:Milankovitch is not debunked. It’s not perfect (nor complete), but the predictions from these forcings are so well correlated with observed changes, that it is inconceivable that they are not linked – see Roe (2007) for instance. -gavin]

    [Response:The idea that the 100 kyr glacial oscillations represents a simple linear response to Milankovitch forcing is a ‘straw man’ that was discarded long ago. It is well known (e.g. the work of Saltzman and many others over the past 20 years) that a proper explanation requires, at a minimum, the model of a non-linear dynamical system that can exhibit free oscillations, but which is paced by weak Milankovitch external forcing. I myself would not point you to the specialist literature, but instead would refer you to the intro textbooks (e.g. Ruddiman’s “Earth’s Climate: Past and Future) for a basic discussion that will bring you a bit more up to speed on this. -mike]

    Fourth, why on earth couldn’t the Milankovitch cycles be correlated with solar cycles? We know for a fact that the 11-year sunspot cycle is strongly correlated with the planetary motions, strongly suggesting some kind of interplanetary resonance/synchronization effect. We know that two grandfather clocks that are placed in proximity will tend to become synchronized if the pendulum motion is sufficiently similar in frequency. Why not something similar with planetary motions wobbling the sun?

    [Response:If the dominant solar variability was going to be affected by planetary motions (for which no evidence exists), they would not be those of the Earth. If that were the case, climate on Earth would respond to the orbital parameters for Jupiter. They don’t. -gavin]

    Fifth, as it happens renowned astrophysicist Robert Erlich has modelled variations in the sun showing the existence of oscillations that could explain both the 100 ky and 41 ky solar cycle.

    http://pressesc.com/01169672696_

    [Response: He has (potentially) shown that those frequencies may exist in solar osciallations – that is not the same as showing that they exist or that they are correlated to known orbital or climatic changes. -gavin]

    Comment by Onar Åm — 16 Feb 2007 @ 8:04 PM

  165. Re #154

    Raypierre,

    you’re throwing the baby out with the bathwater here. It is perfectly possible for the observed climate change since 1940 to have been caused by something other than the sun. One possibility is increased greenhouse gases. (and another intriguing possibility is bad surface temperature reconstruction creating spurious warming) Now, as Richard Lindzen has shown, even if all the warming since 1950 is caused by increased greenhouse gases this does not in any way validate high climate sensitivities. In fact, it is perfectly consistent with a low climate sensitivity of only 0.5 C per doubling.

    In other words, if cosmic rays/the sun has caused 50% of the warming in the 20. century then *obviously* climate sensitivity for greenhouse gases must be lower.

    Comment by Onar Åm — 16 Feb 2007 @ 8:26 PM

  166. # Gavin, 159 comment
    “Well, let’s take stratospheric cooling. Not only was this predicted as a function of greenhouse gas increases in the 1960s (Manabe and Weatherald, 1967) (years before it was observed), but all solar forcing increases would lead to a warmer stratosphere (through increased absorption by ozone).”

    Sorry to insist, but if you look at HadAT2 and MSU T4 (RSS or UAH) graphs for lower stratosphere, you observe : a sustained cooling from 1979 to 1995 (except El Chichon and Pinatubo), no trend from 1995 to 2006.

    How do you explain the later point from model prediction ? IPCC SPM explained us that GHGs forcing rose by 20% during the last decade, we can reasonably think that water vapour feeback also happened in this warmest decade of instrumental records (Soden 2005)… so, for what physical reason should we expect this 11 or 12 years pause in place of a more pronounced slope toward cooler stratosphere ?

    [Response:The lower stratosphere trends from the MSU4 are mostly related to ozone depletion, not greenhouse gases. GHG related cooling occurs higher up (see http://www.realclimate.org/index.php/archives/2006/11/the-sky-is-falling/ and references there, also http://www.atmos.colostate.edu/ao/ThompsonPapers/ThompsonSolomon.pdf ). -gavin]

    Comment by Charles Muller — 16 Feb 2007 @ 8:26 PM

  167. In Reply to [Response: You make a good point, different timescales must be treated differently, and then you blow it by suggesting that correlations over the hundred million year timescale have relevance to the last few decades (even assuming that their analysis was valid, which I would not- see http://pubs.giss.nasa.gov/abstracts/2004/Rahmstorf_etal.html ).

    It is only fair to include Shaviv’s and Veizer’s response and defence of their paper, “Cosmic Rays, Carbon Dioxide, and Climate” to Rahmstorf’s attack.

    http://arxiv.org/pdf/physics/0409123

    From Shaviv’s and Veizer’s above response to Rahmstorf’s attack”

    “The estimated 1.4 +/- 0.4 W/m2 of warming attributable to the increased solar luminosity and reduced galactic ray flux since 1990 should therefore have contributed about 0.32 +/- 0.11C or roughly half of the observed global warming. …(My comment: Shaviv does not include the significant reduction in cloud levels from 1993 to 2001, which would further increase the portion of 20th century warming that is attributable to solar changes.)… The low sensitivity obtained over different time scales is clearly below the large range obtained in the Global Circulation Models (GCM). This implies that a) Earth has shown us that the GCMs do not predicted sensitivity accurately (This is most likely because of our poor understanding of cloud feedback (Cess et al 1989)

    It seems they have a scientific response to each of Rahmstorf’s questions.

    [Response: I’m puzzled as to how this article constitutes a response to the Rahmstorf et al (2004) article when it doesn’t even reference it. It certainly does not address the main criticisms raised by Rahmstorf et al. – mike]

    Comment by William Astley — 17 Feb 2007 @ 8:20 AM

  168. In reply to “Response: I’m puzzled as to how this article constitutes a response to the Rahmstorf et al (2004) article when it doesn’t even reference it. It certainly does not address the main criticisms raised by Rahmstorf et al.”

    Sorry the above was a link to the paper, Rahmstorf is criticising. The following is Shaviv and Veizer�s detailed response to Rahmstorf et al criticism.

    http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RahmstorfDebate.pdf

    [Response: This link is just a self-published thing on Shaviv’s web site, and has not been subjected to any kind of peer review. It would be fairer to refer to the arguments that actually made it into EOS. But leaving that aside, readers should be properly skeptical of just deciding an issue based on who had the last word. Editors always allow a comment/response format that allows both sides to get their two cents in, with some basic screening for respectability of the arguments. Just as on RealClimate, the lack of a further response does not mean the other side has caved in. You have to read the articles and responses, understand the arguments, and draw your conclusions. I’m sure Mr. Astley will can do this and declare that Shaviv has “won,” but among all climate scientists I know who have a publication record and have real accomplishments, those who have looked over Rahmstorf (or Damon and Laut) and the responses are of the mind that the criticisms of the GCR idea as applied by its main proponents are devastating and fatal. There are really only two alternatives to forming an opinion on something like this. Either you have to read the arguments to the point where you can understand them yourself, or you have to know who to trust. –raypierre]

    Comment by William Astley — 17 Feb 2007 @ 10:12 AM

  169. Re #164,

    Gavin & Mike,

    it requires a stretch of the wildest imagination to make the 95,120,400 ky behave like a sharp 100 ky cycle. See Muller and MacDonald for a refutation:

    http://muller.lbl.gov/papers/nature.html

    Appealing to nonlinear dynamics is the classic modelling trump card again. Essentially you are claiming that the climate is behaving like a filter that removes the 400 ky variation and dramatically amplifies the 95/120 into a sharp 100 ky cycle. That’s a neat story but where is the evidence for it? All you have is a model reconstruction tweaked in such a way as to behave like a filter that gives exactly this outcome. As the world’s best and foremost modellers (the statistical modellers in economics) can tell you, it’s extremely easy to overfit a model to fit the data with surprisingly few degrees of freedom. This truth of stock markets is most certainly also true in climate.

    I do however agree that there can be no question about the *link* between the climate and the milankovitch cycles (particularly the precession and obliquity cycles). The clockwork regularity of the ice ages means that there *must* be an external forcing of astronomical origin causing them. It is just unclear at the moment what this link is and what the causal factors involved are. Muller and MacDonald have shown that for some weird reason the 100.000 year cycle perfectly matches the orbital *inclination* cycle of the Earth, both in terms of phase and frequency. That’s also another freaky coincidence. The only problem is that the orbital inclination does not in any way influence the insolation of the sun. If this cycle is the culprit then it is likely related to the grandfather clock effect: what is causing the Earths inclination to wobble at 100 ky is also causing the sun to do the same.

    Also, you say that the sun does not respond to Jupiter’s planetary motions, but that is simply wrong. In fact, Jupiter’s orbit is 11,86 years, very close to the 11 year solar cycle. The sun’s most prominent cycle is highly correlated to the motions of the planets, including Jupiter. It is worth noting though, that the influence of the planets are nontrivial. The influence appears to be related to the frequency of syzygies, i.e. planetary *alignments* towards the sun. During these alignments the gravitational forces of the planets synergize in a way that may modulate the sun. Traditionally this line of reasoning has been discarded because it is believed that the modulation factor is far too small to have any real impact on the sun. But the primary finding in Erlich’s paper is the identification of feedbacks that are capable of dramatically amplifying internal variations and causing oscillations in the sun’s activity level. Well, what do you get if you hit the resonance frequency of a naturally oscillating system? You get a standing wave. As bridge constructors have experienced so bitterly the tiny forces of the wind is sufficient to break the bridge at just the right speed. The fact that the sun is so cyclic combined with the strong correlations with planetary motions is more than a strong suggestion that the sun varies at longer time scales via similar mechanisms.

    Comment by Onar Ã?m — 17 Feb 2007 @ 12:56 PM

  170. Onar,

    Muller and MacDonald have an interesting theory; it might even be correct, but I doubt it. For one thing, the paleoclimate response at 100,000 years does not match the inclination cycle as well as they suggest. They base their results on sediment core data from ODP 607 and the SPECMAP stack. But other records don’t show anywhere near such straightforward response. They select their data based on the incorrect statement that other records are “tuned” to the eccentricity cycle, when in fact, orbital tuning is usually done to obliquity or precession cycles, or the 65N insolation, which is not significantly affected by eccentricity.

    More important, the inclination theory of M&M doesn’t match the evolution of the instantaneous period of glaciations over the late Pleistocene. Wavelet analysis shows clearly that the period of this “cycle” has increased over the last 600,000 years, in a manner which matches extremely well the changing period of the eccentricity cycle, but does not match the inclination cycle.

    You don’t even seem to understand Muller & MacDonald’s theory very well. They don’t attribute its impact to the “grandfather clock effect” causing the sun to change, their primary suggested mechanism is an increase in interplanetary dust accumulation due to longer time spent near the solar system’s invariable plane.

    You also seem to be under the misapprehension that paleoclimate scientists attribute large-scale glacial changes since the mid-Pleistocene transition to eccentricity forcing. This hasn’t been true for some time now, which is why nonlinear phase locking, stochastic response, “cycle skipping” of obliquity forcing, and freshwater-induced deep-water overturning (the subject of the post) are current ideas for the cause of glacial terminations. New developments might actually put eccentricity back on the map, but at the moment, you’re trying to dispel what is not part of the concensus view.

    As for your offhand dismissal of nonlinear dynamics, do you really believe that glacial response to astronomical forcing is linear? If so, you are the only one. Nonlinear response is not “the classic modelling trump card,” it’s what is indicated both by the complexity of ice sheet dynamics and by the data. Appealing to the “grandfather clock effect” to argue for cyclic solar variations in response to earth’s orbital configuration — now that is some serious hand-waving.

    Comment by tamino — 17 Feb 2007 @ 2:00 PM

  171. Re #169: Onar — If you actually look at the data, the just completed ice age lasted for about 120,000 years. Similarly for the one before that. But the one just previous seems to have only lasted for 80,000 years…

    Comment by David B. Benson — 17 Feb 2007 @ 2:49 PM

  172. Re #171, #170

    David,

    take a look at this correlation. Clearly there is a 100.000 year period in the ice age data:

    http://muller.lbl.gov/papers/scicorr.htm

    Tamino,

    I understand Muller and MacDonald’s theory quite well, thank you. Their preferred explanation for the correlation was dust in the interplanetary plane, causing cloud formation and therefore cooling. This explanation failed, though, but this does not rule out a grandfather clock effect, which is a different mechanism entirely.

    The grandfather clock effect is not hand-waving. Correlations between planetary motions and solar activity has been well-established for years. It is also well-established that the sun varies at many different time scales, well-documented and undisputed up to at least the millenial time scale. Why is it such a stretch of the imagination to assume 1) that these cycles are quasi-modulated by the planets and 2) that there are solar cycles at larger time scales as well? This is no more handwaving than the claim that the feedbacks in climate must be strongly positive due to the strong fluctuations of the ice ages. We could equally well argue that there must be strong positive feedbacks in the sun amplifying the weak gravitational (and/or electromagnetic) modulation of the planets.

    Comment by Onar Ã?m — 17 Feb 2007 @ 10:04 PM

  173. Re #172: I don’t recall hearing about any bump (up or down) in the solar data in association with the very well-observed planetary alignment of 20 or 30 years ago. I think the grandfather clock idea is toast in the face of that.

    FYI, Muller abandoned the M&M hypothesis some years back.

    Comment by Steve Bloom — 17 Feb 2007 @ 10:32 PM

  174. Hmm:

    “GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L04701, doi:10.1029/2006GL028083, 2007

    “Arguments against a physical long-term trend in global ISCCP cloud amounts

    “Amato T. Evan, Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin-Madison, Madison, Wisconsin, USA

    “Andrew K. Heidinger, Office of Research and Applications, National Environmental Satellite, Data, and Information Service, NOAA, Madison, Wisconsin, USA

    “Daniel J. Vimont, Department of Atmospheric Science, University of Wisconsin-Madison, Madison, Wisconsin, USA

    “Abstract: The International Satellite Cloud Climatology Project (ISCCP) multi-decadal record of cloudiness exhibits a well-known global decrease in cloud amounts. This downward trend has recently been used to suggest widespread increases in surface solar heating, decreases in planetary albedo, and deficiencies in global climate models. Here we show that trends observed in the ISCCP data are satellite viewing geometry artifacts and are not related to physical changes in the atmosphere. Our results suggest that in its current form, the ISCCP data may not be appropriate for certain long-term global studies, especially those focused on trends.

    “Received 11 September 2006; accepted 23 January 2007; published 17 February 2007.”

    Gavin, I’d be very, very curious to know what the folks downstairs think about this.

    [Response: I doubt they’ll be surprised. They’ve been poo-pooing the idea of significant trends in the ISCCP data for years. -gavin]

    Comment by Steve Bloom — 17 Feb 2007 @ 10:40 PM

  175. Re: #172

    Correlations between planetary motions and solar activity has been well-established for years.

    Not that I’ve ever heard of. What correlations are those? References, please.

    Comment by tamino — 18 Feb 2007 @ 12:07 AM

  176. [[even if all the warming since 1950 is caused by increased greenhouse gases this does not in any way validate high climate sensitivities. In fact, it is perfectly consistent with a low climate sensitivity of only 0.5 C per doubling.]]

    No it isn’t. Show your work. Lindzen’s papers have been demolished by later papers. Climate sensitivity is around 3 K per CO2 doubling, 0.5 K isn’t even in the running.

    [[In other words, if cosmic rays/the sun has caused 50% of the warming in the 20. century then *obviously* climate sensitivity for greenhouse gases must be lower. ]]

    No, it’s not *obvious* at all. Climate forcings are independent and additive. There are positive forcings and negative forcings and they don’t generally influence one another. You’ve got a mental picture of the only effect of forcings being the 0.6 K rise since 1880. It’s more like a 1.2 K rise + a 1.5 K rise + a 0.3 K rise – a 1.2 K fall – a 1.2 K fall.

    Comment by Barton Paul Levenson — 18 Feb 2007 @ 8:09 AM

  177. Re #175

    Tamino,

    a list of work done on planetary tides can be seen here:

    http://perso.orange.fr/jpdesm/sunspots/sun2.html

    Desmoulins himself have identified excellent correlations between Venus-Earth-Jupiter syzygies and the solar cycle:

    http://perso.orange.fr/jpdesm/sunspots/sun_fig3.gif

    The green curve is the amplitude of the VeEaJu Syzygies, whereas the red curve is the signed Wolf numbers. As you can see the correlation is good.

    Everyone agrees that the influence by the planets on the sun is small, and this has normally been used to dismiss the correlations as spurious. But hey, if climate scientists can get away with appealing to nonlinear dynamics and amplifying, positive feedbacks, why not also in solar physics? The sun seems like a pretty likely candidate for funky nonlinear physics.

    Comment by Onar Ã?m — 18 Feb 2007 @ 8:11 AM

  178. [[it requires a stretch of the wildest imagination to make the 95,120,400 ky behave like a sharp 100 ky cycle.]]

    Get a graphing calculator, or write a graphing routine that can handle multiple functions at once. Create some random sine-wave functions and map them all. Then sum them and see what you get. You might be surprised.

    Comment by Barton Paul Levenson — 18 Feb 2007 @ 8:13 AM

  179. Re: #177

    Onar,

    To quote Eric Cartman, “Weak. Totally weak.”

    As the last entry in the list you referred to states:

    G. Brown made a review of these type of works in a survey paper [5] at the Meudon Symposium (SolarTerrestrial Predictions), remarking that all of these failed to establish reliable long term prediction models.

    In fact the evidence you reference to support your statement that “Correlations between planetary motions and solar activity has been well-established for years,” is so pathetic, it’s actually embarrassing.

    Your claim has no more scientific credibility than alien abduction. Here’s my theory: you will accept uncritically any and all ideas, even those backed by the most flimsy evidence, or none at all, so long as it allows you to persist in your disbelief of global warming. But you refuse to accept the reality of nonlinear dynamics and amplifying feedbacks in the climate system. I can no longer take you seriously.

    Comment by tamino — 18 Feb 2007 @ 9:58 AM

  180. Tamino, allow me to put in a semi=good word for Onar. When he was posting on sci.environment, he was one of the few antis that engaged in rational discourse. Of course he was most often wrong, but what the heck

    Comment by Eli Rabett — 18 Feb 2007 @ 11:03 AM

  181. Onar, Perso’s page says “written in 1989, revised in 1990″ and “making such simulations on a PC XT computer without floating point operator is not the ideal situation for making efficient and reliable program” — this is quite old work. Has anything more recent been published that confirms or extends this notion?

    We’ve had a handful of spacecraft that should have detected an effect, if an alignment of planets allows say the magnetotail of Earth to reach as far as and somehow boost that of Mars, or whatever effect is supposed possible.

    Not saying it isn’t so, but did this ever reach the level of publication and replication?

    Comment by Hank Roberts — 18 Feb 2007 @ 12:50 PM

  182. Re: Timeframes, GCR, and solar influence

    The beryllium-10 downward trend over the 100-150 years clearly shows that the Sun has been more active than the previous centuries. I don’t see why there is any need to invoke GCR at all as mechanism to explain anything. Isn’t the simplest explanation simply that the solar constant has not been constant and that more radiation has been coming from the Sun in the last century than the previous centuries.

    http://en.wikipedia.org/wiki/Image:Solar_Activity_Proxies.png

    It is true that this trend levels off in the graph beginning in about 1950 in the above linked graph. This is completely in line with neutron counts and other satellite observations that have shown no significant change in solar output.

    If we add together the warming effects of increased solar output with the GHG contribution and subtract the cooling effects of global dimming, wouldn’t we end up with warming in the early part of the twentieth century, followed by pauses in the warming, followed again by dramatic warming in the last decade or so as global dimming has reversed.

    I find the position of some RC posters to discount the possibility of solar variation about as bad as the denialists who discount the influence of GHG.

    We know the Sun’s output changes over an 11 year cycle. There is good reason to suspect a 1500 year cycle. Ehrich’s paper suggests a theoretical basis for a longer term 100K year cycle.

    http://arxiv.org/abs/astro-ph/0701117

    Of course, there are other influences too – the Milankovitch cycles and the CO2 feedback mechanisms – but it would seem to me to be narrow-minded to reject out of hand any possibility of solar cycles being involved in the ice ages.

    Comment by Jim Cross — 18 Feb 2007 @ 1:18 PM

  183. Re #172: Onar — Sorry, but there is only a 100 ky band in the power spectral density, or cross-correlation. There is only about 2.5 My of data total, with the 100 ky band only appearing in the records for the last 0.9 My. So there is not enough data to resolve this band into more refined portions.

    If there were, it is possible the band would resolve into an 80 ky band and a 120 ky band. There is at least one paper suggesting why this might be so.

    Comment by David B. Benson — 18 Feb 2007 @ 1:30 PM

  184. one thing, how does weathering of rocks decreace carbon in the atmosphere?

    [Response: In the presence of water, carbon dioxide reacts with minerals containing silicon (“silicates”) to form carbonates (loosely, “limestone”). The carbon goes from the air into the rocks. In the normal course of events, the rate of removal by this reaction is balanced by the rate at which CO2 is cooked out of limestone in the hot, deeper earth. There’s a good elementary description of this in Kump, Kasting and Crane’s textbook, “The Earth System,” available on Amazon. You can also have a look at David Archer’s new global warming textbook. –raypierre]

    Comment by David Price — 18 Feb 2007 @ 5:06 PM

  185. [[I find the position of some RC posters to discount the possibility of solar variation about as bad as the denialists who discount the influence of GHG. ]]

    Of course Solar output varies. But it hasn’t varied significantly in the past 50 years or so, so it can’t be driving the sharp warming now. We’ve been measuring the Solar constant from satellites for decades now.

    Comment by Barton Paul Levenson — 18 Feb 2007 @ 6:36 PM

  186. Is the argument that somewhere in the geological record are hidden the sort of very fast increase in CO2 and temperature we’re seeing right now? And that this is typical each time there’s a very tiny variation in the solar ‘constant’ like the one over the past few hundred years? So people are arguing that it’s that tiny change in the sun’s output, that has caused events like we’re experiencing now to happen, but then they’re not in the ice or sediment core record because they happened so-o-o-o briefly somehow, or were s-o-o-o quickly reversed by some other mysterious forcing? Just a blip in the layer of mud or snow but too bad, they didn’t find them so they _must_ be very temporary, wait another 30 years and it’ll cool off naturally?

    It’s like assembling a jigsaw puzzle in which most of the pieces are hypothetical and the rest are improbable, eh?

    Comment by Hank Roberts — 18 Feb 2007 @ 8:19 PM

  187. The following is a new paper by Svensmark. What are your thoughts concerning the attached paper?

    The Antarctic Climate Anomaly and GCR Svensmark�s 2006 Dec Paper

    http://arxiv.org/pdf/physics/0612145

    Svensmark’s paper concerns the Antarctic anomaly, which is also called the Polar see-saw. The Polar see-saw is the term used to describe the phenomena where when the Atlantic region warms the Antarctic cools and vice versa. While other hypothesis (such as ocean currents) have been proposed to explain the polar see-saw, they cannot explain why the change is simultaneous. (i.e. If the effect has due to ocean currents one would expect a delay from hemisphere to hemisphere, as the ocean currents take time to change) Svensmark’s paper provides data (bore hole temperatures, figure 1, and satellite data figure 2) and equations (paper (1)) to support his hypothesis that changes in global cloudiness is causing the polar see-saw.

    [rest edited out]

    [Response: Yet once again, we are faced with an exotic, highly speculative and frankly quite dubious solar mechanism to explain an observed phenomenon which already has a very plausible, physically proven mechanistic explanation (see our previous article “Antarctic Cooling, global warming?”). As we find many of the points about solar mechanisms continuing to be recycled even after we have responded to them many times, we’re going to be screening such comments out unless they introduce something that is truly new, to increase the “signal to noise” ratio of our discussion threads. -mike]

    Comment by William Astley — 18 Feb 2007 @ 9:23 PM

  188. Re #186: I don’t see how that argument could hold water. In order for there to be some sort of blip in CO2 of magnitude anywhere comparable to the current increase, there’d first have to be someplace for the CO2 to come from, then there’d have to be a sink that would quickly remove the CO2 so that it doesn’t hang around for many thousands of years.

    I don’t think there is any such source. The only possibilities I can think of that would even come remotely close are a super-Yellowstone scale volcanic eruption, or a large asteroid strike causing significant ocean heating & fires. Either of those would have left unmistakable evidence of its presence. And unless the real climate scientists have been hiding something, there’s nothing at all that would meet the requirement for a sink.

    Comment by James — 18 Feb 2007 @ 11:14 PM

  189. Re #179

    “In fact the evidence you reference to support your statement that “Correlations between planetary motions and solar activity has been well-established for years,” is so pathetic, it’s actually embarrassing.”

    But this is true. The *correlations* are well-established in peer reviewed literature. Identifying anything that resembles a plausible physical explanation has proved annoyingly elusive, however. Hence, the problems of constructing predictive schemes. We just don’t understand the sun very well, and the way the planets influence the sun — if they do — is non-trivial at best. I think it is quite likely that this matter will not be thoroughly resolved until a) we understand stellar physics better, and/or b) we have sufficient observational data from extrasolar planetary systems. We know that there are stars out there that vary considerably in strength and that some of them have orbiting planets. The more of these orbits and variations we map, the greater the chance is for finding a common denominator that eludes us when merely studying the sun.

    [Response: Incorrect. Vague numerical coincidences have been reported in the literature. For instance, Jupiter’s annual cycle of 11.86 years is not in a constant phase relation to the quasi-11 year signal in sunspots – it is therefore much more likely to be a coincidence rather than fundamental. -gavin]

    Notice that I completely agree with you that the evidence for a grandfather clock effect is flimsy at best. The reason I still emphasize this line of research is because I regard the evidence for strong positive feedbacks in climate equally flimsy. I have not seen any plausible explanation by any climate scientist why the current climate sensitivity should be 5-10 times greater than the *average* climate sensitivity. (i.e. total greenhouse warming divided by the total greenhouse effect) I would love to see one. Indeed, it would be great if any of the skilled climatologists here at RC could explain this.

    [Response:It’s because you are not comparing like with like, I might do a post on this at some point but surface fluxes divided by surface temperature changes are not appropriate metrics. – gavin]

    Until then a much more plausible explanation for me is that the empirically measured climate sensitivity of the ice ages are anomalously high, reflecting hitherto unidentified climate forcings that bring the ice age estimate down to all the other empirical estimates. One very obvious candidate for doing this is the sun. There ARE well-established and irrefutable correlations between the sun and the ice ages, and even though the direction of causality is currently disputed any reasonable, unbiased scientist *must* consider the strong possibility that the sun resolves the high climate sensitivity paradox.

    [Response: There are not ‘well-established and irrefutable correlations’ between the iceages and solar activity. There have been reports of such correlations, but there are also significant problems with them (Bard and Frank, 2006). If you wish your arguments to be taken seriously, don’t spin the literature. -gavin]

    I’d like to point to Nir Shaviv’s reasoning on climate sensitivity here:

    http://www.sciencebits.com/OnClimateSensitivity

    (see figure at the bottom)

    Without a solar/cosmic ray effect the average climate sensitivity derived from a variety of independent data sets and time scales is 2+-0.5 C. (which interestingly enough is consistent with the lower end scale of the IPCC estimate) Notice, however, how the sensitivity varies wildly with temperature. Also notice how adding cosmic rays dramatically reduces the range of variation in the estimates. If cosmic rays were just any random signal added, we would have expected the variation in the estimates to *increase*. The fact that it significantly *decreases* strongly suggests that cosmic rays are non-random, i.e. that the correlation is not spurious.

    [Response: Well, I would agree that Shaviv’s adjustments to the sensitivity calculations are non random. However, his estimates both for the radiative forcing due to GCR and the evidence of GCR changes are completely subjective and do not stand up to scrutiny. In particular his calcuations for the LGM are simply in error. Climate sensitivity from every properly done analysis gives a best estimate of near 3 deg C for a doubling. -gavin]

    Comment by Onar Åm — 18 Feb 2007 @ 11:27 PM

  190. Re: 182. Jim, I’m afraid I may not understand your argument. Are you arguing for a direct solar forcing? The problem here is that this is easily measured–even with a black rock in placed in the sun. The change in insolation is simply not large enough to explain the observed effects. Moreover, it is not clear to me why a solar mechanism would not give larger effects at the tropics and smaller effects at the poles–the opposite of what we see. The rejection of insolation is based on empirical observation.

    Comment by Ray Ladbury — 19 Feb 2007 @ 1:13 PM

  191. #166

    Thanks for the answer and links, Gavin.

    Thompson and Solomon 2005 find a strong tropical stratospheric cooling they consider as “…not evident in the simulated response to observed trends in ozone and well-mixed greenhouse gases at levels below 10 hPa. Additionally, increased concentrations of carbon dioxide favor relatively weak cooling in the tropical lower stratosphere, since increased emissivity acts on relatively low climatological mean temperatures there… ” So, they suggest in conclusion an adiabatic cooling by enhanced upwelling in the tropical stratosphere, but acknowledge themselves the speculative nature of their hypothesis.

    For the first link (RC page and ESPERE page), trends are most often estimated for 1979-2000, where there’s a clear cooling, but not for the past decade or (1995-2006), the object of my question. Concerning the level of stratosphere where most cooling is expected because of GHGs specifically, it’s still hard for me to understand.
    – GHGs absorb IR and trap heat in troposphere, and this first effect is maximum for GHGs trace in higher tropo and lower strato (where there’s not a lot of cooling in past 12 years)
    – It’s unclear for me why the GHGs second effect mentioned on ESPERE (net loss of heat) should apply to 30-50 km level rather than 20-30 km level.
    – In their recent report, Ramaswamy et al. 2006 analyzed the human/natural influence on lower stratosphere 12-22 km, not particularly trends in higher levels.

    V. Ramaswamy et al. (2006), Anthropogenic and Natural Influences in the Evolution of Lower Stratospheric Cooling, Science, 311, 1138 – 1141.
    http:// http://www.sciencemag.org/cgi/content/abstract/311/5764/1138

    Comment by Charles Muller — 19 Feb 2007 @ 2:13 PM

  192. Svensmark’s theory seems to be taken seriously enough by CERN. They are conducting their own CLOUD experiments to find if there is a link between cosmic rays and cloud formation. First results are expected in the summer of 2007.

    It will be interesting to see if Svensmark’s experiment will be replicated.

    Press release:
    http://press.web.cern.ch/press/PressReleases/Releases2006/PR14.06E.html

    Comment by ILJAY — 19 Feb 2007 @ 10:47 PM

  193. Re #189

    Gavin,

    As I have said previously the correlations are non-trivial. Jupiter is not the only planet in the solar system and it seems fairly obvious that if there is a real gravitational/electromagnetic planetary modulation effect then it involves ALL the planets, not just Jupiter. The orbital interactions of these planets are, to put it mildly, VERY complex. It is, however, worth noting that all the Milankovitch cycles are caused by precisely these planetary oscillations. According to Wikipedia:

    “The Earth’s eccentricity varies primarily due to interactions with the gravitational fields of Jupiter and Saturn.”

    Thus, if there indeed is a grandfather clock effect of gravitational/electromagnetic tides on the sun then there is every reason to expect this effect to be highly correlated with the Milankovitch cycles. Disentangling the solar and the orbital variations could therefore prove a highly complex task. The transition problem, the causality problem and the split peak problem are precisely the kind of effects we would expect if the Milankovitch cycles are merely secondary correlations to solar variations.

    Now, of course, I’m not claiming massive evidence for this, but the strong climatic correlations to the Milankovitch cycles are not evidence *against* this theory due to the above mentioned possibility of strongly entangled orbital and solar correlations.

    Think a moment what the implications of such a theory, should it prove right, really is: it means that our present understanding about climate change needs to be thoroughly revised. These implications are far too important for an objective scientist to ignore.

    I am looking forward to an article refuting the low sensitivity calculations. A nice summary of the low sensitivity view is over at Junkscience:

    http://www.junkscience.com/Greenhouse/What_Watt.htm

    Addressing these would be nice. On Shaviv’s LGM figure I cannot comment. I don’t know exactly how he arrives at the figure, but I register that his estimate varies significantly from Hansen’s. Definitely worth scrutinizing.

    Comment by Onar Ã?m — 20 Feb 2007 @ 12:21 AM

  194. Re #193: Onar, eccentricity is *one* of the Milankovitch cycles. The other two are obliquity and precession, which between them certainly dominate eccentricity and have little if any relationship to the motions of other planets. If there was a significant long-term irradiance signal of some kind thrown into the mix it would be hard to miss. Also, to repeat a point you didn’t answer above, a planetary effect on irradiance would have to be convoluted indeed for there to have been no noticable effect during the recent closely-observed planetary alignment.

    Comment by Steve Bloom — 20 Feb 2007 @ 2:32 AM

  195. Re #185

    Barton did you actually read all of my post?

    The fact that the solar output hasn’t changed in the last 50 years is in agreement with the Be-10 proxy. It is this same proxy that shows a sharp increase from the late nineteenth to mid-twentieth century and that shows solar activity at much higher (though flat) level of activity for the last 50 years than the previous several centuries.

    Comment by Jim Cross — 20 Feb 2007 @ 9:05 AM

  196. [[Barton did you actually read all of my post?

    The fact that the solar output hasn’t changed in the last 50 years is in agreement with the Be-10 proxy. It is this same proxy that shows a sharp increase from the late nineteenth to mid-twentieth century and that shows solar activity at much higher (though flat) level of activity for the last 50 years than the previous several centuries. ]]

    Right, but you don’t seem to be seeing the implications. If Solar output was flat for the last 50 years, it can’t account for the exponential curve of temperature over the past 30 years.

    Comment by Barton Paul Levenson — 20 Feb 2007 @ 9:40 AM

  197. Re #194

    As I understand it the obliquity/precession is also influenced by gravitational tides. The moon certainly influences and stabilizes it.

    As I also said previously, the planetary tides have very small effects on the sun, even during planetary alignments. Thus, if the grandfather clock is real, there is much more likely a subtle cumulative effect over several syzygies — a positive feedback of some kind that greatly amplifies the effect. I gave an example of such a correlation previously:

    http://perso.orange.fr/jpdesm/sunspots/sun_fig3.gif

    Notice here how there are typically around 6-7 syzygies during one solar cycle. One single planetary alignment doesn’t have much zap in it, but combined the cumulative effect og several in succession could modulate the oscillation of the sun.

    Comment by Onar Ã?m — 20 Feb 2007 @ 7:05 PM

  198. Re #196

    Why do expect that solar output has to increase to cause warming to increase? If you put a flame under a tea kettle, you don’t have to keep increasing the flame to cause the water to boil eventually. And where were the CO2 increases and decreases to explain the Medieval Warming or the Little Ice Age. CO2 changes do not explain the Medieval Warming or the Little Ice Age but these events do correlate well with solar output changes.

    My point is that there are lag times and that also that global dimming moderated the solar influence. And I am not a single cause proponent. I think modern warming is caused by solar output increases and CO2 increases. With global dimming diminishing, both causes are now reasserting themselves.

    Is it a coincidence that the warmest year in recent history was 1998 near the peak of the solar cycle? I would bet that the next 5-6 years leading to the next peak will be extremely warm and break previous records. However, I would also bet that the cycle following in the approximate 2015-2025 time period will be cooler than 2000-2010.

    Comment by Jim Cross — 20 Feb 2007 @ 8:19 PM

  199. Re #198: “If you put a flame under a tea kettle, you don’t have to keep increasing the flame to cause the water to boil eventually.”

    Think of the way that happens: if you turn on the heat, the kettle warms at a constant rate, not an increasing one. Likewise, if the sun’s output had increased prior to the start of satellite observations, then stayed constant since (as we know it has), we’d have seen a sharp temperature rise in the first half of the century, followed by a gradual tapering off as the new equilibrium was approached. Instead, we see just the opposite: warming that started slowly, but which keeps increasing.

    “CO2 changes do not explain the Medieval Warming or the Little Ice Age…”

    Of course. Try to understand this one simple idea: the present increase in CO2 due to humans doesn’t explain anything that has happened in the past, because it is something that has never happened before.

    Comment by James — 20 Feb 2007 @ 10:44 PM

  200. Re #198: “However, I would also bet that the cycle following in the approximate 2015-2025 time period will be cooler than 2000-2010.” Really? Then James Annan and Brian Schmidt would really like to hear from you! I’ll look forward to seeing the bets placed.

    Comment by Steve Bloom — 20 Feb 2007 @ 11:27 PM

  201. A quick look at the solar data (http://data.giss.nasa.gov/modelforce/solar.irradiance/) shows that it increased slightly from 1900-1950 and has remained stable since. It doesn’t correlate with observed temperature for the 20th century (http://zfacts.com/metaPage/lib/zFacts-global-temperature-1860-2005.gif) at all, particularly for the the 1950-2005 period.

    Calder is also misleading when he goes on about the Antarctic not warming up as quickly and suggesting that this was somehow unexpected. This was predicted in the 2001 IPCC report and is due to the buffer effect of the Southern Ocean and the general isolation of the Antarctic from global climate. But the Antarctic is also predicted to catch up…

    Comment by Bryan — 21 Feb 2007 @ 8:19 AM

  202. [[Why do expect that solar output has to increase to cause warming to increase?]]

    Because over a long period of time, the Earth radiates out as much energy as it absorbs; i.e., it’s in thermodynamic equilibrium. To raise the temperature by Solar means you have to raise the Solar input, and that hasn’t been happening.

    Comment by Barton Paul Levenson — 21 Feb 2007 @ 8:23 AM

  203. Re #200: I believe I’ve offered to bet Jim before and was met with the usual denialist silence. Jim, if I’m mistaken or if you’ve changed your mind, I accept your bet – please contact me to arrange terms.

    Comment by Brian Schmidt — 21 Feb 2007 @ 6:16 PM

  204. My apologies, I put the wrong contact info in #203. The correct one is here.

    Comment by Brian Schmidt — 22 Feb 2007 @ 3:26 PM

  205. Re #200, 203, 204

    Sure. I’ll bet. Not much. I could be wrong. Will you give 5 to 1 odds? We’ll settle up in 2026. Let me know.

    I don’t regard myself as a denialist. I believe global warming is happening and I believe GHG is a major part of it. I just think the solar influence is underestimated. Are you 100% sure it isn’t?

    The Medieval Warm Period and the Little Ice Age were both associated with solar variations. I’ve seen arguments about ocean circulation changes and that these were really regional phenonmena. With the Earth and climate, there are no regional phenonmena.

    Comment by Jim Cross — 22 Feb 2007 @ 9:17 PM

  206. This is why betting is useful. Jim has clarified his position in #205 to one where temps in 20 years are 80% likely to rise instead of fall.

    As to whether I’m 100% sure that solar influence is underestimated, I’m not, but I’m sure enough to offer bets to people who think the IPCC is wrong.

    Comment by Brian Schmidt — 23 Feb 2007 @ 6:54 PM

  207. Re #206

    To be clear, the bet is that 2015-2025 will be cooler than 2000-2010. Temperatures might be warmer in 2025 than 2000. The bet is for a 10 year average.

    Actually I would bet at least even that temperatures will fall. I’m just trying to determine how sure you are and get the best odds. So apparently you are not 100% sure temperatures will rise and seem to be hedging some at 80%. How sure are you? Maybe we’re not so far apart after all.

    Comment by Jim Cross — 25 Feb 2007 @ 11:58 AM

  208. Are you two agreeing to hold anything constant? solar output, no asteroid impact?

    Comment by Hank Roberts — 25 Feb 2007 @ 12:48 PM

  209. Re #208

    Hank, I haven’t heard back from Brian. I think I should get 5 to 1 odds since the IPCC is 90% confident in their assessment of climate change. I would think he would be at least 90% confident in the warming side of the bet.

    I’m willing to cancel the bet on asteroid strike or major volcanic eruption even though it would more likely tilt the bet in my favor.

    Solar output is what the bet is about.

    http://science.nasa.gov/headlines/y2006/10may_longrange.htm

    Comment by Jim Cross — 26 Feb 2007 @ 7:42 PM

  210. Funny, I wasn’t aware that we were in negotiation. I asked Jim to contact me as he hides his own contact information here.

    I have a standing offer, open for nearly 2 years, to bet 3:1 on temps rising in 20 years. 5:1 strikes me as high, and the IPCC overall projection of certainty doesn’t translate into a similar guarantee as to what will happen in a given time period.

    Jim’s bet translates into an over 80% certainty temperatures will increase and that’s not remotely skeptical. If Jim wants to take any of my bet offers, once again, please contact me directly.

    And finally, I’m not interested in betting token amounts.

    Comment by Brian Schmidt — 28 Feb 2007 @ 11:50 AM

  211. Regarding the graph of neutron monitor data collected at Climax Station in Colorado: Is that not local; data collected at one point, at a constant elevation, local pressure, temperature, relative also to atmospheric interactions at the point of collection? It’s my understanding that Svensmark is claiming that cosmic rays are interacting with the atmosphere, as one forcing for cloud formation that isn’t yet accounted for in any GCM. Are cosmic particles that seed cloud formation processes even detectable, and if not, was cloud formation data over the Climax Station even collected, or accounted for?

    The fact that the graph yields no obvious correlation looks to me like a straw man, given that it’s like trying to find a global correlation (for the last thirty years only, no less) based only on local data (of any kind – temperatures, tree rings, ice cores) collected from any one location.

    A GCM may have a rougher than tough time accounting for clouds, but it seems to me that a local correlation would be easy enough to find in a study where data is collected with correlations made between cosmic rays, clouds, other local atmospheric conditions. The graph cited just seems to be just one more set of data that is blind to clouds – or anything else, for that matter, other than time. Or am I missing something. Has a such a study ever been done?

    [Response: Any of neutron monitors or ion chambers would do since they are all highly correlated with each other. CLIMAX is often used becuase it has a long continuous record. Indeed, Svensmark used it when trying to show correlations with clouds. What they are measuring is something that depends on geomagnetic latitude, but since they are all being modulated by solar changes, you expect the modulation to be the similar regardless. -gavin]

    Comment by Steven Douglas — 14 Mar 2007 @ 7:39 AM

  212. Thank you for your response, Gavin. It’s the “you expect the modulation to be the similar regardless” part that still has me wondering, because, as I said, I haven’t seen any study that could substantiate or falsify this theory based on data collection that accounts for actual atmospheric conditions. Indeed, if you look at the global temperature record, similarities abound there as well. Nothing is obvious until corrections are made, sensitivities are accounted for, and all data are combined in such a way that gives us a net global warming trend.

    One last thing. When you wrote:

    [Response:…In the past, solar forcing may have been important (along with volcanic) on multidecadal to century timescales, however, GHG forcing over the last 50 years dwarfs any concievable solar contribution. -gavin]

    To state a theoretical conclusion as a factual premise (that GHG forcing over the last 50 years dwarfs any conceivable solar contribution), is begging the question, otherwise known as circular reasoning. This is combined with a larger logical fallacy, known as the False Dilemma – where it’s assumed that either claim X is true or that claim Y must be true. This is fallacious, because it does not account for the possibility that neither claim may be true.

    Climate change, and specifically recent warming trends, are hardly in question. I don’t know of many so-called ‘deniers’ where either is concerned. You can dismiss solar contributions as the primary forcing responsible for recent warming trends, but that does not automatically mean that GHG (and more specifically, CO2) are the de facto primary forcing mechanism responsible for [most? all?] of recent warming trends. This is also a theory, one that you are advancing, which is still very much in question. I am not saying that you should not believe as you do, or come to conclusions; only that it’s logically fallacious and not very scientific, IMO, to state it in such a way – especially in light that you advancing logical arguments in support of a theory.

    Comment by Steven Douglas — 14 Mar 2007 @ 8:30 AM

  213. re:212

    I may be lunatic or forgetful, but there’s a calculable addition to our energy budget due to increases in CO2. If cosmic rays also have a large effect there would be 2 vectors, GHGs and cosmic rays, and the curious Maxwell’s Demon which siphons off the GHG component while leaving the cosmic ray contribution untouched.

    Comment by Jeffrey Davis — 14 Mar 2007 @ 11:19 AM

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