Knud Jahnke and Rasmus Benestad
After having watched a new documentary called the ‘Cloud Mystery’ – and especially the bit about the galaxy (approximately 2 – 4 minutes into the linked video clip) – we realised that a very interesting point has been missed in earlier discussions about ‘climate, galactic cosmic rays and the evolution of the Milky Way galaxy.
It is claimed in ‘The Cloud Mystery’, the book ‘The Chilling Stars’, and related articles that our solar system takes about 250 million years to circle the Milky Way galaxy and that our solar system crosses one of the spiral arms about every ~150 million years (Shaviv 2003).
But is this true? Most likely not. As we will discuss below, this claim is seriously at odds with astrophysical data.
Here is a little background on the Milky Way: The arms of spiral galaxies are not constant entities in time. They are results of gravitational instabilities in the disk or are induced by external companions. These instabilities are moving mass ‘overdensities’ containing old stars and gas, but also newly formed stars recently created from local collapse of the overdense gas.
Arms move around a spiral galaxy with a pattern speed that is defined by the mass distribution. This pattern speed differs from the motion of individual stars, just like the speed of an ocean wave differs from the movement of water particles. Estimating the pattern speed is difficult, as it is not coupled to the motion of individual stars but can only be inferred indirectly. For this reason it has not yet been reliably measured for our Milky Way – unlike for some other spiral galaxies, for which our clear and unobstructed view from the outside allows an estimate.
So how did Shaviv come up with this number?
Measuring the rotational velocity of stars in the Milky Way disk or other spiral galaxies is straightforward. The rotation is not rigid, but depends on the encircled mass inside the orbit of a star, including the Dark Matter, a yet unknown but solidly established source of gravitational attraction. It is easy and a standard technique to measure rotation curves of galaxies as a function of radius, and this is also possible for the Milky Way.
The two different rotating velocities of arms and stars have a different radial dependence – to first order the arms get preserved as entities while the stars further out have much smaller angular velocities than stars further inside – so the relative velocity of a star with respect to the nearest spiral arm will depend on its distance from the centre of the galaxy. At a certain radius, the radius of co-rotation, the two velocities are identical and a star at this radius has zero relative velocity with respect to the spiral arm pattern. It stays “forever” in the same spiral arm – or outside of it.
What are the best estimates for the relative velocity of the Sun with respect to the spiral arm pattern of the Milky Way? As mentioned, the pattern speed of the spiral arm in the Milky Way has not been firmly established.
When investigating other spiral galaxies, however, it was found that almost independently of the wide range of possible assumptions on which the pattern speed estimate was based, the radius of co-rotation follows a simple law: rcorot=r0 * (3.0 +/- 0.5), where r0 is the scale length of the exponential disk of the galaxy (the surface brightness of spiral galaxies drops very close to exponentially from the center to the outside, setting a characteristic size scale). This was measured by Kranz et al. 2003.
Since the Milky Way is a completely normal spiral galaxy, we can apply this result to it. The scale length of the Milky Way disk has recent estimates ranging from 2.6 kilo-parsec (kpc, 1pc=3.3 light years) from the SDSS survey (Juric et al. 2008), through 2.8 kpc (Ohja 2001) to 3.5 kpc (Larsen & Humphreys 2003).
We also know the Sun’s distance to the galactic center well, 7.9 +/- 0.4 kpc (Eisenhauer et al. 2003), which means that the range of values for rcorot=9.1 +/- 1.9kpc. In other words, from this calculation the co-rotation radius of the Milky Way is between 7 and 11 kpc, and at 8 kpc our Sun is close to or at the radius of co-rotation. It almost certainly is not 6 kpc further inside, as Shaviv (2003) claims.
Shaviv (2003) lists in his Table 3 a number of values for the pattern speed of the spiral arms, taking from publications ranging from 1969 to 2001, two years before his article. In these papers the derived relative motion of the Sun relative to the arms ranges from Omegarel=+13.5 km/s/kpc to -4km/s/kpc, and includes estimates that are close to zero (-4km/s/kpc < than Omegarel < +7), i.e. a location near the radius of co-rotation in the majority of the publications, and most of the more recent ones. However, he selectively disregards most of these results.
If we add the above evidence that the radius of co-rotation lies at 9kpc distance and not further out, and convert this to relative velocities, e.g. by using the Milky Way rotation curve by Merrifield 1992, we obtain Omegarel =+3.2 km/s/kpc with an error range from -2.5 to +7.1km/s/kpc, and including zero. Shaviv’s derived “period for spiral arm crossing” of p=134 +/- 25Myr for four spiral arms is well outside the range derived from these values.
So it seems that Shaviv’s “periodicity” estimate for crossing of spiral arms by the sun does not hold up under scrutiny when using current astronomical results as the work by Kranz et al. This comes in addition to the previously shown fact that the correlation of cosmic ray flux with paleoclimatic data proposed by Shaviv and Veizer (2003) only arises “by making several arbitrary adjustments to the cosmic ray data” (Rahmstorf et al. 2004).
Note also that the question of current climate change is quite another matter from that over time scales of many millions of years – despite Shaviv’s remarkable press-release claims that “The operative significance of our research is that a significant reduction of the release of greenhouse gases will not significantly lower the global temperature”. As we repeatedly pointed out over the years: that global warming over the past decades is not linked to cosmic rays is clear from the fact that the cosmic ray measurements over the past 50 years do not show any trend (Schiermeier 2007).
Remarkably, the poor scientific basis of the galactic cosmic ray hypothesis seems to be inversely related to the amount of media backing it is getting. At least 3 documentaries (‘The Climate Conflict’, the ‘Global Warming Swindle’, and now ‘The Cloud Mystery‘) have been shown on television – all with a strong thrust of wanting to cast doubt on the human causes of global warming.
References:
Eisenhauer et al. 2003, ApJ, 597, 121; http://adsabs.harvard.edu/abs/2003ApJ…597L.121E
Kranz et al. 2003, ApJ, 586, 143; http://www.journals.uchicago.edu/doi/abs/10.1086/367551
Juric et al. 2008, ApJ, 673, 864; http://adsabs.harvard.edu/abs/2008ApJ…673..864J
Larsen & Humphreys 2003, AJ, 125,1958; http://adsabs.harvard.edu/abs/2003AJ….125.1958L
Merrifield 1992, AJ, 103, 1552; http://adsabs.harvard.edu/abs/1992AJ….103.1552M
Ohja 2001, MNRAS, 322, 426; http://adsabs.harvard.edu/abs/2001MNRAS.322..426O
Rahmstorf, S., et al., 2004: Cosmic rays, carbon dioxide and climate. Eos, 85(4), 38, 41.
Schiermeier, Q., No solar hiding place for greenhouse skeptics. Nature, 2007. 448: p. 8-9.
Shaviv, N., 2003, NewA, 8, 39; http://adsabs.harvard.edu/abs/2003NewA….8…39S
Shaviv, N. and J. Veizer, Celestial driver of Phanerozoic climate? GSA Today, 2003. 13(7): p. 4-10.
Ray thanks, yes, old Max has a lot to answer for :-)
Ray, as you know we’ve been up and down this mountain before and are unlikely to alter each other’s near intractable views. But…reacting with outrage toward people who dispute the real truth and light as seen by some, pretty much describes a fundamental religious belief. I don’t know, maybe it’s not exclusive to them and can describe other institutions as well. You just do not accept such a characterization as I described in 195 because you have the “truth and the light” on your side, albeit supported by many others, and are therefore justified and free from any accountability for whatever form the reaction takes.
Though I would guess you disagree!
Martin, interesting stuff. I had never thought of some of this before. Since Hydrogen is in fixed supply, does that mean that the Universe can not be infinite? And that possibly long before it either drops its density to zero or re-explodes with the Big Crunch that it will in effect just die out and consist of a bunch of static white, and mostly, red and brown dwarf stars?
I recognize the holes in Hoyle’s hypothesis; I was just pointing out other plausible (however improbable) scientific Universe generating alternatives.
Though cushioned with scientific caveats, Ray’s statement “….I don’t know anyone sane who challenges that…” , e.g. does in fact sound a little like “…scientists being so cock-sure of their stuff…” Now I don’t mean to pigeon-hole all scientists; nor do I single Ray (for whom I have considerable respect) out. But it sure sounds cock-sure to me!
Ray (200), very funny! Actually some guy did predict 2.7 degrees in 1940 (I think) but it was based on scattering starlight rather than BB plasma! Also Hoyle predicted 2.7 degrees with his tiny little magnetized and ubiquitous metal rods.
Coming late this I read in a climate book that the occurance of ice age cycles matched the Sun’s orbit around the rim of the Milky Way. Both occuring every 250 million years. The theory bieng that at a certain point on the rim something causes the solar furnace to splutter.
It would provide a good explanation for the cooler temperatures for the last 2 million years. The position of the continants is a good explanation, but only accounts for part of the cooling. A weakening of the Sun could account for the other part.
A quick ps, Ray: No, I certainly do not subscribe to Congressional witch hunts, though it could be said that, as opposed to you scientists, that is what Congress does. Would you be opposed to the Congressional witch hunts going the other way, by witch hunter par excellence Henry Waxman, or, to some degree, Barbara Boxer? Or are their witch hunts, as keepers of the “truth”, really just civil exploratory exercises?
Equating strong belief with religion, as per post #202, is making me a little tired because it smacks of name calling. Religion involves supreme beings and the supernatural, by definition, which can’t be falsified. Science stands on its merits and outrage at ones opponents is natural, you just have to have the goods to back it. Stick to that. Steve
Re #192 William Astley
I have followed Real Climate for over two years. This blog is my primary source for reasoned discussion of the scientific aspects of climate change. The voluntary contributions of the climate scientists are invaluable. The signal to noise ratio in the comment threads is relatively good compared to some other climate blogs due to the scientist’s moderating efforts and the contributions of readers like Ray Bradbury, Hank Roberts, Timothy Chase, Martin Vermeer, Robert Rhode, Wayne Davidson, cce, Tamino (HB), Ike Solem, P. Lewis, Eli Rabett. These folks offer patient and comprehensive answers to many questions—some repeated over and over. Many are professional scientists with significant expertise relevant to the discussion of climate.
Mr. Astley, you have raised a few interesting questions over the past year. You have received the courtesy of inline answers from climate scientists and you have been engaged by the readers on numerous threads. You continue to raise the same points over and over supported by the same references. I will respond to some of your queries, but not with any intent to engage you on a long term basis or to encourage you to continue pursuing the same issues supported by the same literature.
My thoughts on Tinsley et al:
Dr. Tinsley seems to be a well respected climate scientist with a long record of publication on upper atmosphere effects. I agree with Hank, that you attribute to the processes he examines much more significance to global climate change than he does. Our own RC folks say his work “may have merit”—high praise indeed from this tough crowd. Dr. Tinsley’s web page summarizes his work:
http://www.utdallas.edu/physics/faculty/tinsley.html
Dr. Tinsley notes on his web page recent important work in the polar regions:
“In a recent collaboration with Dr. Gary Burns of the Australian Antarctic Division we have confirmed with high statistical significance small changes in Antarctic surface pressure with small solar wind-induced changes in Jz, which are consistent with our hypothesized effects on Jz on cloud cover. In the Arctic the Jz changes are of opposite sign, as are the correlated pressure changes. Further, there are pressure changes that correlate with Jz changes due to changes in the current output of low-latitude thunderstorm generators, that have the same sign in the Arctic as in the Antarctic, as expected from theory. The implication is that global changes in Jz produce global changes in suitable types of clouds, and in some cases changes in precipitation.”
I think the key word above is “implication”—not demonstrated or correlated or replicated but hopeful perhaps.
Yes, I have read both his review articles that you reference so often. The only uncontroversial observed correlations they make are to short term and regional processes. From Tinsley and Yu 2005:
“Clearly there is a great deal of modeling that is needed in
order to provide quantitative relationships between
atmospheric ionization and macroscopic clouds properties.
However, models of the radiative and dynamical
consequences for climate of estimated precipitation and
cloud cover changes could be made with present
capabilities. Improved cloud cover and precipitation data
covering more solar cycles would be useful for validating
the present observational results, and as more accurate
inputs into global climate models.”
From Tinsley, Burns, Zhou 2007:
“The large changes in galactic cosmic ray flux on time
scales from decades through millennia produce changes
in Jz that have the potential to account for records of
long-term climate variations that correlate with cosmic
ray flux changes. Also, changes in temperature and humidity
in the thunderstorm-generating regions of land masses
at low latitudes modulate the current density flowing everywhere
in the global circuit. This may affect cloud cover
everywhere, especially with surface temperature changes
on the longer time scales.”
You continually emphasize one aspect discussed by Tinsley, electroscavenging, which can be influenced by factors other than galactic cosmic rays though the strongest effect is from GCR changes. This, I suppose, is because you acknowledge that there has been no recent (since 1970) trend in GCR flux.
From a Hadley Center review (2005)
http://www.metoffice.gov.uk/research/hadleycentre/pubs/HCTN/HCTN_62.pdf
“There are many uncertain steps between the electroscavenging and cyclone intensification in the near-cloud mechanism, as emphasised in HS99, so progress has been made either by looking at specific microphysics (e.g. scavenging theory), or from statistical studies linking cosmic rays with cloud-related parameters, such as precipitation.”
The effect noted above is primarily correlated to GCR flux changes. I would note that Dr. Tinsley’s work seems to contribute significantly to electroscavenging theory.
From a review by none other than Marsh of Svensmark and Marsh:
http://www.spacecenter.dk/research/sun-climate/Projects/TN_WP503_DNSC_v05.pdf
“It is however more unlikely that ‘electroscavaging’ has a global effect (see Harrison Carslaw article) on cloud generation and ultimately on global climate although there is some limited observational evidence to suggest that this process can have an additional influence on atmospheric dynamics (Roldugin and Tinsley 2004).”
But now to the real nub of the problem I have with you and your search for a solar alternative to anthropogenic greenhouse gases. In # 42, cce, provides two very important references to recent work examining the ISCCP multidecadal record of cloudiness. You have not commented on either of these nor do I wish you to. I would only ask that you read them and withhold all further speculation on solar influences via GCR’s, magnetic fields or fairy dust until there is a reliable multidecalal record showing some meaningful trend in low, medium or high level clouds.
By the way, there isn’t any solar alternative to AGW. There is only the remote possibility of a short respite in the unlikely event of a new Maunder minimum. The important contribution of research in solar, magnetic and electric effects will be to narrow the uncertainty in current GCM’s due to cloud/aerosol forcing. Please look at the video cce linked in #42. Dr. Norris may not be riveting but he’s coherent and competent.
Since you asked, and for what little its worth, I agree fully with Knud that Shaviv’s analysis contains much hand waving. Your response to him is a particularly egregious form of blogsmanship. When you have received a good technical response that you don’t like, shift the discussion to something really nebulous like # 166 “What are the competing hypothesis?” You answered your own question when you ended with “The importance of that correlation depends on whether GCR/solar magnetic cycle changes actually do modulate clouds and the changes in clouds significantly affect planetary temperature.” Indeed that’s what all your speculation and that of Svensmark and Palle depends on. Let’s wait for some data.
In the meantime we might encourage our national leaders to put some priority back on monitoring the earth and measuring some things that really count.
In reply to Barton Paul Levenson’s comment #182.
“There haven’t been. [My comment, BPL is saying there have not been four ice house, in the last 500MMyr. I disagree.] I recall, there was the Huronian snowball Earth 2.3 billion years ago, the Sturtian 800 million years ago and the Varangian 630 million years ago. Are you counting episodes of glaciation to any extent? That might give you every 140 mya, though I don’t think it was that even.”
I believe there is evidence of four ice houses in the last 500 MM years. See this paper. What the authors are stating is the planetary cooling appears, to be externally forced and there is evidence of four long cold periods.
http://dx.doi.org/10.1016/j.palaeo.2006.08.008
“Millennial-scale paleoclimate cycles recorded in widespread Palaeozoic deeper water rhythmites of North America”, by Maya Elricka and Linda Hinnov
“Rhythmically interbedded limestone and shale or limestone and chert (“rhythmites”) are a common feature of many deep-water Phanerozoic carbonate marine deposits. Seventeen different Palaeozoic rhythmite successions from across North America…”
“…If our short-term paleoclimatic interpretations for the rhythmites are correct, then it is apparent that millennial-scale climate changes occurred over a very wide spectrum of paleoceanographic, paleogeographic, paleoclimatic, tectonic, and biologic conditions and over time periods from the Cambrian to the Quaternary. Given this, it is difficult to invoke models of internally driven thermohaline oceanic oscillations or continental ice sheet instabilities to explain their origin. Instead, we suggest that millennial-scale paleoclimate variability is a more permanent feature of the Earth’s ocean–atmosphere system, which points to an external driver such as solar forcing.”
Re #207 [William Astley] “What the authors are stating is the planetary cooling appears, to be externally forced and there is evidence of four long cold periods.”
Actually, there are 5 periods they indicate as “icehouse”, the first much briefer than the others, and the second and third separated only by a relatively short intermediate (i.e. neither “icehouse” nor “greenhouse”) period. To my eye, there’s no obvious periodicity. They do not comment on the origin of this long-term variation. They prefer an interpretation of the rhythmites in terms of millenial-scale temperature changes, but are pretty tentative about it – there is an alternative (“diagenetic” processes following deposition). They do say that if their interpretation is correct, “an external driver such as solar forcing” (or an 1800 year Earth-Moon tidal cycle) is probably responsible, but admit that “Presently it is not clear how very small perturbations in solar radiation could be amplified within the climate system to generate the observed significant climate changes.” All in all, an interesting paper appropriately hedged with “ifs” and “buts”, but by no means paradigm-shattering.
Rod B #202:
No, it doesn’t imply this. Conservation laws like those of baryons and leptons (which prevents H atoms to pop up out of nothing, or vanish into nothing) are valid for any closed system, like a finite closed part of an infinite universe.
Yes, and black holes, black dwarfs, cold neutron stars etc. In a very far future.
Yes. And proud of it!
Seriously, it’s the self-confidence that comes with knowing your stuff. Surely you must have yourself an area of skill and expertise, so that when some outside know-nothing comes in making an outrageous claim on something very basic, you would display that same cock-sureness… or would you suppress it for “diplomatic” reasons? And how would you react to your professional self-confidence being construed as “religious belief”?
Neither Ray nor I are climatologists, but we are both backgrounded in physics, in my case geophysics. That helps enormously with understanding climatology. Furthermore we both have a history as practicing, publishing scientists (google it up!); that gives us an inside understanding of how that works. Trust me (or rather, don’t; figure it out for yourself!), it’s no “priesthood” any more than e.g., the medical profession, or for that matter, the free software/open source community. Rather a boisterously pluralistic, cut-throat meritocracy!
Martin Vermeer writes:
[[I don’t quite agree with BPL though that Olbers is a problem for SS, at least not for the Hoyle variety: the redshift in this also expanding model does the job of eliminating the paradox.]]
It doesn’t do enough. I’ve run the calculations. If you want I’ll send you a copy of the paper I wrote about it.
William Astley writes:
[[I believe there is evidence of four ice houses in the last 500 MM years. ]]
No, there is evidence of four episodes of glaciation in the last 500 million years. You have “episodes of glaciation” confused with “icehouse Earth” or “snowball Earth.” The latter requires polar ice caps to more or less meet at the equator. Not every episode of glaciation or ice ages is a snowball Earth.
Rod, the inverse square dependence of gravitational force is consistent with every observation ever made–from table-top to galactic cluster. Moreover, every self-consistent theory of gravity predicts such a dependence. Perhaps you can suggest a characterization of someone who, with zero evidence supporting their contention and reams of evidence against, challenges such a working theory. I would contend that “nutjob” works as well as any other word.
Science does not deal with “truth and light” (except as a flavor of quark and an electromagnetic phenomenon, respectively), but rather with evidence. Now, again, perhaps you have a word that characterizes someone who knowingly distorts evidence. Here I would contend that “liar” works as well as any word in common parlance. And I would also contend that ignorance does not absolve someone of culpability for propagating a lie. If you think being outraged by liars requires religious ferocity, then so be it. All I can say is that anybody who knows me would laugh their tuckus off at such a characterization.
As to witchhunts, I’m agin’ it. No one should be hounded for doing their perfectly legal job in a manner consistent with normally accepted practices. However, again, we have to look at the behavior. If someone with insider information persistently lied about a stock to pump up its price as he is consistently selling off his shares, we would probably prescribe an extended stay at Club Fed. If a company knowingly produces an unsafe product and lies about it, the same penatly ought to apply. If a company knowingly propagates disinformation about climate to increase its profits, how are they less deserving of saction?
I agree AGW does not have a supernatural being at its head and certainly is not a religion. My point is that hard-felt religion shows justifiable (in its mind) extreme rage, intolerance and offense (including desire to arrest and incarcerate) to those who might question, and absolutely refuses to recognize, let alone accept, even the slightest uncertainty in the most obscure area of the institution. Occasionally AGW proponents (some or many, but clearly not all by any means…) display the exact same characteristics and look like a religion. Walks like a duck; talks like a duck; well… maybe it is still not a duck, but it’s not far off. (And you can easily find some who push for prosecution of skeptics, e.g.) I think it hurts the credibility of the AGW proponents.
On the other hand, moving from philosophical to practical, I can certainly understand and accept the tiredness and impatience with trying to politely answer the same questions over and over again — which is why I held my 2-3 areas of skepticism in abeyance some time ago until I improved my scientific support. But there is still no cause to nuke folks who have other questions and doubts, however kooky they appear to you, as is periodically and lately the case. Just say (as a couple have) in the worst case, “I think you’re wrong but I just don’t want to take the time to play right now” or some such.
BTW, I second Paul Middents’ 1st paragraph in 206: RC, while not perfect, is IMO easily the most professional of the climate blogs. I still can’t figure out how the moderators get it done.
Martin (209), thanks for the additional info. I don’t fundemental disagree with this post (other than maybe around some of the edges), other than one teeny clarification of your examples: as somebody quipped, “What’s the difference between God and a Doctor? For one, God doesn’t think he’s a doctor.” Also, I’ve been in software fights that clearly had a clear religious bent with no assurance at all that the most meritous would win. Though the open software community not so much.
Ray (212), you make a decent point but the difference is, despite your absolute belief, climate science does not (yet) rise to the certainty of gravitation’s inverse square law.
The problem with your three examples is that climate “misinformation” doesn’t happen to be illegal. That distinction is eminent, but makes no difference to witch hunters and, in fact, can define witch hunting.
I have used this site for a few years as a source of valuable information in climated debates, but this is my first time posting. And my last. I thought I was just shy. But I had a growing sense of feeling intimitaded about asking the wrong questions, and now this thread says it all. As I scrolled through the venom, I felt so, so sad for gusbob. I don’t agree with all he said but some things like magnetic fields weren’t wrong. I would never ever feel comfortable asking a contrary question here. I don’t even feel comfortable reading the remarks anymore.
Re 210 Barton, yes please. See name link for email.
Re # 213 Rod B “My point is that hard-felt religion shows justifiable (in its mind) extreme rage, intolerance and offense (including desire to arrest and incarcerate) to those who might question, and absolutely refuses to recognize, let alone accept, even the slightest uncertainty in the most obscure area of the institution. Occasionally AGW proponents (some or many, but clearly not all by any means…) display the exact same characteristics and look like a religion.”
Come on, Rod, one can readily find those same attitudes and behaviors among, say, politicians, and the hosts of certain cable network news shows – are you going to claim they, too, are practicing religion when they act that way? Face it, human nature is human nature, and it is not surprising to find people reacting in a similar way when someone questions their beliefs, knowledge, motives, honesty, integrity, or whatever. But, as you surely know given your educational background, religion and science are fundamentally different ways of looking at the world. Any claims that scientists vigorously defending their understanding of natural phenomena based on empiracle evidence are practicing religion is simply nonsense. And you know it.
Pauline, you needn’t be reticent; it’s not nearly that perilous (Sorry! Couldn’t help myself!) If you follow the addage illegitimus non carborundum you should be fine. You can pick up some good information. For example, one of the guys I’m currently taking to task here for the very same stuff you dislike, in fact, has a wealth of knowledge. The moderators are top-notch and play the meanie game very seldom and, in fact, edit out real egregious stuff. You do have to filter the wheat from the chaff, but there is a lot of wheat. Just don’t mention off-topic second-hand smoke or WMDs!
#215 Pauline:
There’s a world of difference between asking questions and making preposterous (i.e., kooky) claims about elementary physics. There are no wrong questions. But there are outrageous claims dishonestly packaged as “questions”, of which we’ve seen a few.
If you don’t feel comfortable posting, don’t, this is a very public place after all, and there’s enough to learn by just reading.
Why do you think Lynn Vincentnathan keeps coming to this site? She asks questions all the time, and she gets even elementary things wrong all the time, and nobody jumps on her. You have yourself a big influence on how people perceive you. The gusbob way is not it.
That being said, the no. 1 purpose of this site isn’t to make you feel comfortable — it is to make you learn. Amd the good news is that you ‘get’ that, don’t you, as you keep coming back for more :-)
Try me.
Rod B appropriately points out:
Hear hear. I find it positively amazing. And in my understanding, the scientists are the moderators, they do this by the side of their science jobs.
Note also that we only see the comments that get through; we can only guess at the filth that gets stopped (although some other blogs may educate that guess :-( ). The moderators get to see it all, which must be pretty depressing at times.
Pauline, I must have missed where gusbob was asking questions. His first several posts consist of assertions that the hypothesis of dark matter constitutes “dangerous circular reasoning”. He then hijacked the thread, advocating the most amazing pseudoscientific tripe, and still he was treated politely. It was only when the choice of diagnosis was narrowed to either “troll” or “nutjob” that he suffered anything remotely resembling abuse. To call someone ignorant when they are in fact ignorant is not an insult. Ignorance is 100% curable. Willful ignorance is incurable.
So if you have real questions, go ahead and ask them (especially if they are on-topic). There are plenty of experts to answer them, and I’ve never seen a genuine question treated here with anything but respect. If, on the other hand, your idea of a question is a diatribe about your favorite pet theory, then I would tend to agree with you that your reticence will not detract from the discussion.
Rod, You cannot treat climate science as a monolith. Some aspects remain uncertain, that is true. However, greenhouse forcing is not one of them. It is a virtual certainty: add more ghg, get more warming. The only real questions concern the balance between the positive and negative feedbacks on that forcing. So far, all indications are that the positives win in the near term.
Science is not at all ambiguous–it demands that you go with the evidence. If your assertions are contrary to evidence, they are by definition NOT scientific. So, what constitutes evidence? We’ve discussed this before–papers in peer-reviewed journals along with how those papers are received (e.g. subsequent citations in later papers, etc.). Unscientific theories don’t have to be suppressed. They die out simply because they have no predictive power, and advocates wind up with nothing to publish. That is scientific consensus. That does not bear much resemblance to religion. Although I am not religious (agnostic), I do not view it as a pejorative, as you evidently do. I know people (some of them scientists) whose life is enriched by religion. I even know people who take an empirical approach to religions (e.g. study what works for them). And while there are some religious people who decide what to believe based on evidence, the evidence in question is not limited to objective, empirical evidence.
By equating the scientific approach with religion, you do a disservice to both science and religion. Indeed, you give the impression that you don’t understand the difference.
What you seem to be uncomfortable with is inductive inference, and indeed there are extreme empiricists in the school of Mach et al. who share your discomfort. However, I would contend that the past 150 years have demonstrated that science can be very powerful. It works. That is its sole justification.
RE #213, & AGW as a religion, which “refuses to recognize, let alone accept, even the slightest uncertainty [in AGW]”
Not sure about whom you’re speaking. I’ve always maintained, along with the scientists, there is some uncertainty re AGW. I believe there is some 4% uncertainty right now (someone correct me if I’m wrong). That means there is a one-in-25 chance AGW is not happening. We live in a stochastic world, at least what we can know.
However, in 1990, well before climate science reached 95% confidence in AGW (1st studies reached it in 1995), I thought it prudent to start mitigating AGW. So did Pope Paul II in his “Peace With All Creation” statement Jan. 1, 1990. That’s all I’ve ever claimed. I also buy insurance policies with much less certainty that my roof will be blown off or my house burn down.
Of course, there are other dangers to consider re AGW, besides harm to life forms on earth, such as what eventually happens to those who refuse to mitigate, despite a high level of scientific confidence re AGW. But then I guess some just like it hot; it can never get hot enough for them :)
Rod B — The is even a science of inductive inference:
http://plato.stanford.edu/entries/logic-inductive/
http://en.wikipedia.org/wiki/Inductive_reasoning
Ray, I mostly agree. I was very careful to pigeon-hole neither science/scientists nor religion. And, yes, as Hank infers, you can find the negative traits in many institutions and walks of life. But they are not universal nor monolithic anywhere. I am familiar with (as is most everybody) religious people who arguably are the best examples of humanity going, and people who seemed to have been greatly helped by their religion, at no cost to others — actually beneficial to others. I’m also aware of (as is most everybody) evil incarnate dressed up as, and in fact patriarchs of, religion.
True, there is no uncertainty over the greenhouse effect. There is some uncertainty with some of its executable details and marginal/differential variances.
I just got the time to catch up on my old issues of Science, and the December issue has a special section on observations made by the Hinode. Alfven waves seemed to be the dominant subject and one article claimed to calculate the the energy fro Alfven waves could explain the acceleration of the solar wind. Can some one explain what an Alfven wave is exactly?
Do these Alfve waves affect cosmic rays as well?
Do they affect the earth’s magnetic field or play any part in the newly observed ion plumes reported by NASA?
http://science.nasa.gov/headlines/y2007/13nov_africa.htm
Charles Landsdown,
Alfven waves are magnetohydrodynamic waves in plasmas involving the movement of ions. You can read about them here:
http://en.wikipedia.org/wiki/Alfven_waves
They probably play a big role in transport of energy to the outer regions of the Sun. Any coupling to GCR will be weak, and the coupling to the geomagnetic field will be sporadic, via solar particle events. Interplanetary space is a very tenuous plasma.
Rod,
I am aware of no religion that makes it’s creed subordinate to objective empirical evidence. Science and religion are different. The outrage you see expressed by the scientists here is because so-called skeptics claim to be doing science while ignoring and distorting all of the evidence. It is the dishonesty that inspires outrage, not the disagreement. You will have noticed that many on this board disagree–sometimes violently–with one another, on the desirability of market-based solutions, on nuclear power, on human nature. These disagreements sometimes lead to intemperate remarks, but the dialogue usually remains mostly civil. However, it offends the honor of those of us who have made it our metier to be bound by evidence when others distort evidence while claiming to be scientists. It would not matter whether it were climate, evolution, relativity or quantum mechanics (and I have butted heads with pseudoscientists on all of the above). Ignorant laymen who talk out of orifices other than the usual one are merely annoying. People who call themselves scientists while distorting evidence threaten the integrity of science. That is the source of the outrage.
Ray, I have no fundemental disagreement with 228. I think my characterization, contention, and criticism stems from my observation that occasionally (seldom, but far too oftem) some folks here allow a disagreement to morph into their interpretation of dishonesty. The old thing we’ve discussed before: “I say A; he says B; everyone knows that A is correct; therefore B must be lying.”
Rod, the disagreement is not “I say A; he says B…,” but rather “The evidence says A. He not only says B, but says the evidence says B…” Since there are definitive ways of measuring whether evidence supports A or B and to what degree, we know that either he is ignorant of these methods and evidence or that he is lying. Some people we know are not ignorant (e.g. Lindzen), ergo…
OTOH, some scientists are ignorant–e.g. Scafetta and West, who subscribe to the Chinese Menu fallacy of climate modeling (that is, they think they can make the problem go away if they can scrape together enough heating from other sources). Their ignorance does not preclude that they are also dishonest, but it does at least give them a lesser charge to which they can plead.
It is quite possible to have an honest disagreement about what to do about anthropogenic climate change. Such a disagreement is not possible when it comes to whether it is occurring.
Re: William Astley #166/#207:
ice-houses and so on:
Dana Royer has quite recently compiled all of the paleotemperature and paleo CO2 data through the period of the last 500 MYA.
D.L. Royer (2006) CO2-forced climate thresholds during the Phanerozoic Geochimica et Cosmochimica Acta 70, 5665-5675
The supposed periodicity in glacial periods isn’t very apparent, and the cold and warm periods, respectively, match reasonably well the paleo CO2 record. So in terms of your request for an explanation for what is forcing the climate on various timeframes, variations in greenhouse gas concentrations seems a rather likely explanation.
Likewise, Shaviv’s supposed correlation of the CRF with the Phanerozoic temperature record of Veizer’s is even more questionable in the light of Veizer’s reinterpretation of some of the paleotemperature data. The apparent “correlation” of supposed CRF with temperature is certainly lost in the revision of the temperature data which now matches better with the CO2 record:
Came RE, Eiler JM, Veizer J, et al. (2007) Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era Nature 449, 198-201.
very recent work highlights a coupling of climate and CO2 levels throughout the Miocene:
The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of terrestrial ecosystems
W. M. Kürschner Z. Kvaek, and D. L. Dilcher (2008) Proc. Natl. Acad. Sci. USA 105, 449-453.
and so on…
I would have thought the increasingly good evidence for significant greenhouse gas (especially CO2)-climate coupling throughout the last 500 MYA is a pretty good alternative to the supposed CRF effect and one that has some substantive evidence in its favour! Of course the origin of the variations in greenhouse gas levels is another matter…
Ray Ladbury wrote: “I am aware of no religion that makes its creed subordinate to objective empirical evidence.”
May I direct your attention to the Kalama Sutra in which the Buddha did just that:
S.A. re:232, This passage is one of the reasons why Buddhism (as taught by Gautama, not as currently practiced) has been claimed by some not to be a religion. I do not go that far. However, since the passage appeals to one’s own experience, which is inherently subjective, I would claim that my characterization stands. Buddhism is not alone in saying that experience has a role in faith. You see similar admonitions in Judaism, Hinduism and even some Christian traditions (e.g. Quaker, and btw there is scriptural support for this). For the most part, though, the experience of faith in these traditions is subjective. In mystical traditions of many religions, there is an experiential element, and interestingly enough, there’s broad agreement about mystical experiences, even across traditions. And of course, there is Gandhi’s autobiography, titled “My Experiments with Truth”. All of these, though, still deal with the subjective experience of the relation of the individual to the divine or the cosmos. And the way religion is practiced by the masses–even Bhddhism–leaves little room for any type of empiricism.
More proof that those galactic rays are warming the earth — more antarctic shelves breaking off (see http://www.climateark.org/shared/reader/welcome.aspx?linkid=95656 )
Now I’ve heard that if we reduce our GHGs that will slow down those galactic rays. It seems there’s some new study out there that shows how CO2 and other GHGs in the atmosphere attract those rays, which then warm the earth. So let’s hop to it and reduce our GHGs :)
Ray,
Thank you for your reply. Wikipedia was actually the first place I looked to help understand Alfven waves but I am still having trouble getting my head around it all. I had never heard of Alfven waves before.
If Alven waves are the result of moving ions, and the solar wind is moving ions, why evoke Alfven waves at all? Why isn’t the solar wind just an extension of those moving ions from the sun’s convection zone.
Chales Landsdown, The Solar wind is a very tenuous plasma–density about a particle per cubic cm except during relatively rare solar particle events. There is thus a discontinuity between the solar surface (defined by equilibrium between thermal pressure and gravitational force) and interstellar space, and the Alfven waves would probably not propagate strongly into interstellar space (though you’d still have the magnetic field lines). The following two pages give a little more detail:
http://cfa-www.harvard.edu/uvcs/yb/node76.html
http://homepages.see.leeds.ac.uk/~earccf/alfven.pdf
Since the assumption of the timing of temperatures of the geological past with the passage of “galactic arms” requires fx. 1 billion years ago “an ice age of 1 billions years” (!) as I heard Svensmark say in a TV-programme, I think this discussion is futile, and only another example of how this whole climate “debate” has long ago degenerated into mud-slinging initiated by the
“scepticists” and financed by Exxon etc. I think it’s far too optimistic to believe that mankind will be able to solve it’s own pollution problems, given what we have seen over the years. I think James Lovelock is right: There’s very little chance that mankind will survive this, because homo sapiens sapiens obviously isn’t able to control it’s own impulses. The only way we differ from fx. the ants is that nature can’t stop us/limit our numbers before it’s too late.
Karsten Johansen — It is called ‘The Tragedy of the Commons”.
But it does not have to occur.
> Tragedy of the [Unmanaged] Commons
Aside, pardon the digression:
The tragic results happen because of the lack management. Hardin regretted omitting that word in the title, as his later writing makes explicit.
More here:
http://www.garretthardinsociety.org/info/links.html
which includes a pointer to this excellent page:
http://members.aol.com/trajcom/private/trajcom.htm
Network resource/geek version:
http://web.media.mit.edu/~reilly/wetice2001.html
Just spotted this on the BBC’s web site: UK researchers find at best a weak link between cosmic rays and climate. In other words, they have pretty much refuted the Svensmark hypothesis. For the curious I provide also a link to the full paper.
Why do people unconvinced that CO2 drives temperature get called names ? Is it an emotional reaction by the believers ? The scientific, logical part of my brain has serious doubt about CO2 as a driver of global temperature for many reasons, none of which have been convincingly explained. First off, why is it that from 1940 through 1975, despite the post-war industrial boom and skyrocketing CO2 emissions, did the planet cool dramatically ? Also, why is it that a through scientific review of ice core samples taken from multiple locations, shows CO2 levels lagging behind temperature by several hundred years ? This second question makes it very difficult to accept logically, CO2 as a driver of temperature. I am not at all opposed to the idea of human activities possibly affecting the climate of the planet, but why has CO2 been chosen as the catalyst, when the data is so out of phase with the hypothesis ?
Another nail:
Re Noel’s questions in 241:
First off, why is it that from 1940 through 1975, despite the post-war industrial boom and skyrocketing CO2 emissions, did the planet cool dramatically?
Sulfate pollution, aka “global dimming”.
Also, why is it that a thorough scientific review of ice core samples taken from multiple locations, shows CO2 levels lagging behind temperature by several hundred years?
It’s a feedback system. Temp increases can increase atmospheric CO2, and vice versa. The usual driver is small insolation (temp) changes due to changes in Earth’s orbit (Milankovitch cycles). Humans are now pushing on the other side of the feedback loop by dumping gigatons of carbon into the atmosphere. Same feedback, different driver.
Noel Roberts, First off, where have you been getting your information? It reads as if you have been frequenting only denialist haunts. As to the two objections you raise, they have been dealt with (ad nauseum). We saw cooling in the post-war period precisely because the consumption of fossil fuels released unprecedented amounts of sulfates into the atmosphere along with the CO2. The sulfates reflected light out of the atmosphere, so the warming effect of the CO2 was masked. The climate models reproduce this effect if you put in the sulfates. In the early ’70s, there was a raft of environmental regulation that removed the sulfates. Voila, it warmed…a lot.
WRT the canard that CO2 emissions follow warming, you need to distinguish between a driver and a feedback. The vast majority of climate change in the past has been associated with small variations in sunlight reaching Earth due to changes in orbit, axis tilt, etc. (Google Milankovitch Cycles) Naturally with such a driver, warming would precede release of CO2 (from oceans, peat bogs, permafrost…). In this case, CO2 works to reinforce and prolong the warming (about 5000 years). However, there are episodes of warming that evidently were caused by CO2. Google Paleocene-Eocene Thermal Maximum.
There are plenty of answers to your questions on this site. Please explore it a bit–this is where you get the science.
Re #241 [Noel Roberts]
“Why do people unconvinced that CO2 drives temperature get called names ?”
It’s frustration, that people keep trotting out the same old oft-refuted objections, without taking the trouble to find out why there is a scientific consensus that they are invalid. All the points you raise have been dealt with on this site. Try putting some of the phrases you use in the search tab at the top. Better still, before you do that, click on the “start here” tab. That explains the basic physics – how CO2 is known to be a greenhouse gas. If you have questions you can’t find answered, or are not satisfied with the answers, do post again. But it’s reasonable to ask you to do a little work first, especially since this site makes that work pretty straightforward.
Re Noel Roberts @ 241: “First off, why is it that from 1940 through 1975, despite the post-war industrial boom and skyrocketing CO2 emissions, did the planet cool dramatically ?”
First off, it simply is not true that the planet cooled dramatically from 1940 through 1975.
See here: http://www.globalwarmingart.com/wiki/Image:Instrumental_Temperature_Record_png
and here: http://www.cru.uea.ac.uk/cru/info/warming/
and here: http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif
Clearly there was a sharp drop in temperature between aprox 1945 and 1950, followed by a shallow upward trend until aprox 1976, followed in turn by a sharp steepening in the temperature trend through the rest of the 20C. The cooling–defined as a drop in temperature–lasted only four to five years. From aprox 1950 to 1976 temperature rose, but more slowly than before 1945 or after 1976.
Second, particulates (ash, soot) and sulfate aerosols from the combustion of fossil fuels during the post-war industrial boom are thought to be the prime causes of the 1945-1950 drop and following shallow trend, by reflecting and blocking incoming solar insolation, thus masking the greenhouse effect of accumulating CO2. The sharp steepening of the temperature trend circa 1976 followed the passage of the Clean Air Act in the US and similar anti-pollution legislation in Europe, which dramatically reduced particulate and sulfate emissions.
Noel: “Also, why is it that a through scientific review of ice core samples taken from multiple locations, shows CO2 levels lagging behind temperature by several hundred years ? This second question makes it very difficult to accept logically, CO2 as a driver of temperature.”
It is difficult if your logic is based on an erroneous premise or two, namely that CO2 can only act as either a driver or a feedback, and that the natural warming that ends a glacial period is analogous to the current warming.
First, CO2 is not a driver during the ending of a period of glaciation, it is a feedback that amplifies and adds to the initial warming caused by increased solar insolation due to changes in Earth’s orbit and axial tilt. As the increased insolation slowly warms the ocean it can hold less dissolved CO2 and thus emits CO2 into the atmosphere. The added atmospheric CO2, since it is a known greenhouse gas, then produces yet more warming, hence the word feedback, and hence the 800-1000 year lag between temperature and CO2 levels in the ice cores.
But today we are not at the end of a period of glaciation experiencing insolation changes caused by orbital and axial shifts, we are at or near the peak of an interglacial period. By injecting more CO2 into the atmosphere directly in the absence of insolation change, as we have been doing since the start of the industrial revolution, it acts not as a feedback, but as a direct forcing. In other words, depending on the circumstances, CO2 can act as either a natural feedback to some other natural warming forcing, or as a direct forcing when added to the atmosphere directly. Either way, as a known greenhouse gas it will produce warming. The data is not out of phase with the hypothesis.
Re Nick Gotts @ 254: “It’s frustration, that people keep trotting out the same old oft-refuted objections, without taking the trouble to find out why there is a scientific consensus that they are invalid. All the points you raise have been dealt with on this site.”
Nick, it is indeed frustrating that week after week, sometimes day after day, someone comes along to ignorantly proclaim the same old long-refuted canards yet again as if they were the first ones on Earth to think to bring them up on a site dedicated to discussing the science of global warming/climate change.
Fortunately ignorance is a correctable condition, although I often doubt the success of our correction efforts, especially when the poster turns out to be yet another one-off drive-by.
A couple of logical implications from the sulphate/aerosol temperature relationships: is there any relationship between the reduction of sulphates when the old Soviet Union and eastern European coal plants went down as their industrial economies imploded in the early 90s and the high temperatures of that decade; and, is there any relationship between the much increased coal usage (and, presumably, sulphate aerosols) in China over the past decade and the observed temperatures during that period?
The Tolman Test: A galactic Glitch presented by Hubble observation.
http://www.americanscientist.org/template/AssetDetail/assetid/55839?&print=yes
Sure, Gus, but you don’t have to throw out current cosmology to find a reason that can explain what shows up on the Hubble photographs.
Look it up; there’s a need to discriminate between high and low surface brightness galaxies to address the question, and it can be done. As always, look up the citations in the article and look up the work subsequently citing it. Since you point to an opinion piece there are no cites, but look for the author’s other work and follow leads therefrom.
For example: http://arxiv.org/abs/astro-ph/0701797v1