At the risk of fuelling up John Quiggin and UnAustralian Ken Miles (though only with renewable energy resources), here’s a fascinating post on Aaron Oakley’s Bizarre Science summarising new research suggesting that much of the observed 20th century global warming is actually caused by variations in the activity of supernovae (rather than carbon dioxide generated by evil western capitalists).
The author of the study (and Oakley’s post) is Tim Patterson, a professor in the department of earth sciences at Ottawa’s Carleton University, who specializes in paleoclimatology (whatever that is). The paper is published by the Geological Society of America, and appears to be refereed.
Update – The UnAustralian Ken Miles has an excellent long analysis in the comment box to this item, and is apparently about to post an even more extended version on his own blog. Gummo Trotsky has also posted an excellent long analysis (but his permalinks are bloggered as usual). I’m often amused by the way self-consciously provocative posts seem to be far more successful than worthy and balanced analyses at eliciting responses, especially from thoughtful bloggers. It’s one reason why Bunyip and Blair fill such a valuable blogosphere role. Shit-stirrers rule!
The actual paper is available in pdf format at:
ftp://rock.geosociety.org/pub/GSAToday/gt0307.pdf
Global Warming is a myth. The earth itself naturally warms and cools during it’s history. So called “evidence” of GW is merely a narrow study of the weather patterns.
Patterson isn’t the author of the study (by Shaviv and Veizer) and is one of the usual suspects (Google him and see what you get). His summary is about as accurate as you would expect.
The core conclusion is “In summary, we find that with
none of the CO2 reconstructions can the
doubling effect of CO2 on low-latitude sea
temperatures be larger than ~1.9
John,
What makes someone a “usual suspect”? Daring to publish studies or articles that contradict global warming religion? Being “associated” with a right wing thinktank (as opposed to leftwing ones, as both you and Christopher Sheil are)? Or does the “association” have to be closer than merely being very frequently published by the “suspect” thinktank? Does one have to have a formal official association (as Sallie Baliunas has with one thinktank). I note that Christopher Sheil has such a formal official association with Evatt Foundation. Does that mean that we should disregard everything he says as conclusively and irredeemably biased and in bad faith? Or is this a standard we should apply only to those associated with thinktanks of a right-leaning persuasion?
Even assuming Patterson (who I erroneously credited as author of the study) is one of these, are you also suggesting that Shaviv and Veizer are “usual suspects”? If not, what is the relevance of your comment?
Turning to your oblique claim that Patterson has inaccurately summarised the sutdy’s findings, I’ve re-read his article and compared it with your above quote, and I can’t find a significant inaccuracy. Certainly he fails to mention the last qualification about uncertainty limits and what could happen if one makes “unrealistic” assumptions about “ice volume correction”. But that’s hardly the sort of thing you’d include in a short general article for general audience consumption.
I note in this regard that IPCC scientists NEVER mention the large margins of error in the Mann “hockey stick” study which they use to deny the existence of the Little Ice Age and Medieval Warm Periods, thus enabling them to claim that the last couple of decades are the “warmest on record”. Does your standard of requiring scientists writing for a general audience to include mention of such qualifications apply only to scientists who dare to oppose global warming religion?
Penultimately, I didn’t suggest that this study was “authoritative”, if by that you mean “conclusive”. What I said was that it was fascinating, which it surely is. The reason I emphasised the fact that the study was (a) published by a prestigious mainstream institute; and (b) peer reviewed; was that both you and the UnAustralian Ken Miles usually dismiss non peer reviewed studies published by “right wing thinktanks” as mere fringe ratbag propaganda that can self-evidently be ignored per se because of its source, without bothering to engage with the substantive issues the study raises. The Shaviv and Veizer study can’t be so easily dismissed, and that’s why I headlined my post by suggesting it posed a “problem” for global warming proponents like you and Ken Miles. It’s a problem for you not because it conclusively proves that global warming isn’t a real and significant issue (manifestly it doesn’t), but because you can’t get away with the usual tactic of simply dismissing the study out of hand. But of course you tried to do that anyway.
Lastly, as you know from many previous discussions, I DON’T positively assert that global warming isn’t a real and significant problem. I assert that we don’t yet know whether it is, because there remain so many areas of scientific uncertainty. I tend, however, to blog more about research that suggests global warming is less of a problem than the global warming boosters claim. I do that partly because I certainly do have a predisposition towards a sceptic position (but not a closed mind predisposition or irretrievable bias), and partly because the global warming boosters are so predominant in the mainstream media that most people would never get to hear about research that contradicts their propaganda line unless people like me highlighted it. The fact that a well-informed general reader like Jason Soon could erroneously believe that there’s a meaningful scientific ‘consensus’ about the likely extent of global warming indicates just how successful global warming propagandists have been. I notice you didn’t correct Jason’s misconception (but highlighted it instead), even though you eventually conceded when we debated the issue in detail that any such ‘consensus’ is limited to a tentative conclusion that likely warming may be a modest 1-1.5 degree c by 2100.
Of course, the significance of the Shaviv and Veizer study is that it suggests (albeit by looking at things on a very long geological time scale) that warming is likely to be somewhat more modest than that, at around 0.75 degrees C. Coincidentally or otherwise, that coincides with the results you get by extrapolating both satellite and radiosonde balloon data. Obviously none of these, either separately or combined, can be regarded as conclusive. But nor is the aggregated, averaged surface temperature record (given all its shortcomings), or the computer models (given the large number of unknown variables they estimate to make their models work). This is why my position is that we simply don’t know. In my view it’s the only honest position one can take.
Where you go from there rather depends on whether you take an extreme precautionary “henny penny” approach (let’s panic now just in case the worst case scenario turns out to be true), or a cautious “wait and see” attitude and continue with intensive scientific research in all relevant areas until we DO know enough to make more confident, accurate predictions about the likely extent of warming. Fairly obviously, I favour the latter approach.
I agree with Ken on this, as I do on most things.
I also believe that the jury is out on whether the earth is round or flat, and whether it revolves around the sun.
As for the theory of evolution ..well… I’d love to be able to tell you everything that’s wrong with that, but I’ve got to rush off to Bible study classes.
See you there, Ken
Dave,
A comment right up to your usual standard of incisiveness and intelligence. The fact that you can seriously compare the current level of scientific knowledge, understanding and confidence about global warming with either the earth’s roundness or evolution, illustrates precisely the point I’m making. Neither the IPCC nor any other serious scientist claim anything remotely like any such certainty level, as you would know if you actually bothered to read any of the research or reports. Popular misconceptions like this arise, sadly, from completely over the top simplistic greenie populist propaganda that many people now simply assume must be correct, merely because it’s repeated ad nauseum. Obviously I can’t force you either to have an open mind or to bother reading the primary sources for yourself. But maybe at least some readers might do so.
Ken, I have read the scientific literature and I am well aware of the state of knowledge on this issue
As you should know, the number of greenhouse sceptic scientists is tiny.
You ask youself why the vast majority of scientists who are qualified to have an informed opinion believe in the existence of global warming. Is it because, as your friends at Bizarre Science believe, they are left wingers with no integrity who have been corrupted by being on the scientific grant teat?
Or is it because … well, you know. … their conclusions might be actually right?
Dave,
I can only assume I must have bored you to death to such an extent that you haven’t actually bothered to read my numerusposts on global warming over the last year or so. My position is nothing like Bizarre Science (or John Daly etc). I generally accept the mainstream IPCC position that there is more probably than not a human-generated CO2 component in measured late 20th century warming.
The only sceptical components I add to that are to observe:
(a) satellite, radiosonde and now paleoclimatic data suggest that the actual temperature increase might end up being a little less than the IPCC most likely 1.5-2.0 degrees estimate; and
(b) that high end estimates of temperature increase are generated by IPCC only by making unrealistic and grossly exaggerated assumptions (e.g. that the world’s population will increase to 15 million, when UN current best estimates suggest an actual population of not much more than half that number).
There is nothing especially controversial or outrageous about either of my above points. I simply approach the issue from a standpoint of assessing evidence and probability (as is a lawyer’s wont). I think we’re only justified in taking drastic, expensive and economicaly damaging measures (which will certainly be necessary if global warming really does turn out to be a problem) if the balance of evidence clearly shows that the worst case scenarios are quite likely to happen. At the moment, the evidence simply doesn’t show that at all. In fact the balance of evidence tends to suggest that warming is most likely to be at or below low end IPCC estimates. That in turn suggests that we should be very cautious about what measures we adopt at present, while continuing to fund extensive scientific research to resolve the many areas of uncertainty.
Australians especially should know that cycles of ‘environmental time’ run long… and pointing at weather variations as portents of doom is best left to the biblical scholars at Rapture Ready.
But Australians also know that vast areas of land can be completely degraded within a generation.
So I agree with Ken, while supporting any initiatives to mitigate the effects of industry and urban development on our environment.
A myth is not necessarily a bad thing.
Ken maybe I’m wrong but you look a lot like someone who wants to have his cake and eat it too here.
You’re criticising those who believe in global warming, implicity supporting the conclusions of this study, but then when challenged you say that you believed the IPCC all along.
Ken, I’m continually amazed at your touchiness on this issue. I don’t raise a big fuss if someone describes me as, say, a ‘leftwing economist’, particularly if I’m engaged in public debate. And you’ve been happy enough to use the “usual suspects” locution yourself, to refer to people whose views on a given topic are predictable.
Given that you take the trouble to cite “Tim Patterson, a professor in the department of earth sciences at Ottawa’s Carleton University, who specializes in paleoclimatology (whatever that is).”, why don’t you mention the equally relevant fact that he’s a prominent anti-Kyoto activist?
Ken – I have rarely seen you take a more reasonable, consistent and well argued position. I largely agree with everything you’ve written. Basically, it may well be true that we’re facing man-made global warming, but the evidence of the problem isn’t sufficient to warrant drastic action at this point. More information is needed…
Very similar to my position on the Iraq war I might add. :)
As to why many scientists support global warming: (1) that is a side-track to the actual arguments; and (2) it is not uncommon for people closely involved in an issue to inclined towards over-estimating it as an issue.
On the second point, note that all teachers think there’s a school crisis, health professionals think there’s a health crisis, nearly all defence personal agreed with the war, industries think we need more industry spending, road workers insist that more roads are needed, university lecturers agree uni’s need more money, welfare workers argue for more welfare programs and money etc etc. It is very unlikely that all these people are evil or biased. It is also very unlikely that all these people are correct. It’s the nature of the beast – people get captured by what they study.
With this statement “I note in this regard that IPCC scientists NEVER mention the large margins of error in the Mann “hockey stick” study which they use to deny the existence of the Little Ice Age and Medieval Warm Periods, thus enabling them to claim that the last couple of decades are the “warmest on record”” Ken Parish carries on his long standing tradition of attacking the integrity of the IPCC while simultaneously misrepresenting what they say.
In the IPCC’s Climate Change 2001: The Scientific Basis the section on past warming over the last 1000 years, includes two diagrams (click here and here). Both of these clearly show the error bars which Ken P claims are never mentioned.
From a previous post on global warming, Ken P has made similar incorrect statements coupled with attacks on the IPCC’s objectivity, such as the IPCC doesn’t include natural gas in it’s emission scenarios (it does), that the IPCC doesn’t include oil sands in it’s scenarios (it does). These errors could have been easily spotted by reading the Emission Scenario report before attacking it.
The next time Ken P wants to accuse the IPCC of “distorting reality”, it would be best if he wasn’t guilty of exactly the same crime.
24601, since you’ve made this statement: “Basically, it may well be true that we’re facing man-made global warming, but the evidence of the problem isn’t sufficient to warrant drastic action at this point. More information is needed…”, it’s seems clear that your deeply familiar with the scientific literature behind climate change.
I was wondering if you could explain what extra evidence is needed to warrant action?
Ken,
We were talking about popularising articles like Patterson’s one which is the subject of the post. To remind you (and others) of the context, JQ suggested obliquely that Patterson had misrepresented the study in his short popular press article. I replied with an observation that his summary seemed pretty fair from what I could see, except that it omitted mention of uncertainty levels in certain respects. However, I suggested that it wasn’t necessary or usual to mention such matters of detail in a short popular press summary, nor did it make an article dishonest for failing to do so. It was in that context that I said that IPCC scientists, in their own public utterances in the popular press about the “hockey stick”, also fail to mention margins of error. Manifestly, I wasn’t talking about the deailed IPCC report itself, as would be apparent to any reader of modest comprehension. Since you’re certainly in that category at the very least, I can only assume you’ve wilfully misconstrued in order to make a cheap and silly point for reasons I fail to understand.
I must say I do wonder why, given that my approach to these issues is only very modestly sceptical. Isn’t a person permitted to deviate even slightly from the true faith? Are you suggesting that the Shaviv and Veizer research should be disregarded? Why? Let’s deal with the substance instead of straw men.
Might as well buy into this one while I’m here. First off, re 24601, who suggests that:
… all teachers think there’s a school crisis, health professionals think there’s a health crisis, nearly all defence personal agreed with the war, industries think we need more industry spending, road workers insist that more roads are needed, university lecturers agree uni’s need more money, welfare workers argue for more welfare programs and money etc etc. It is very unlikely that all these people are evil or biased. It is also very unlikely that all these people are correct.
So far so good, but then our commentator concludes that “It’s the nature of the beast – people get captured by what they study.” Nice little hop there, with no apparent connecting link. The reason these people’s views are readily (but by no means always correctly) discounted is that they have a potential conflict of interest, i.e they stand to be recipients if their views are taken up, which risks compromising their affilation with the truth.
Which brings me to Ken’s statement:
I note that Christopher Sheil has such a formal official association with Evatt Foundation. Does that mean that we should disregard everything he says as conclusively and irredeemably biased and in bad faith? Or is this a standard we should apply only to those associated with thinktanks of a right-leaning persuasion?
… which now needs to be qualified to distinguish it from the earlier case, as I receive no income or benefits whatsoever from my membership of the Evatt executive … in fact, the contrary applies, as it steals my time and allows folks who aren’t as fair-minded as Ken to cast ill-conceived but damaging aspersions. The Evatt Foundation aims to supply ideas and research that is of relevance to the labour movement, something which I’m qualified to contribute to because of my work on labour history and policy making … but to which the earlier precautionary assumptions about a potential conflict between truth and vested interest doesn’t apply … unlike in the case of many of the usual suspects in the anti-global warming cadres.
Chris,
My point was the exact opposite of what you seem to have understood. My point was that there is NO conflict of interest or compromise in having a formal association with a “thinktank”, whether it’s right-leaning or left. It’s John Quiggin who regards such associations as per se suspect, although it seems to be a standard he applies only to right wing ones. The purpose of pointing out your Evatt association, which is hardly a state secret, was to highlight the absurdity of asserting that a writer or researcher such as yourself can be written off as biased solely because they have an association with a particular thinktank.
The argument between JQ and myself on this point is longstanding, and arose from the fact that John appears to think that he disposes of the research of well-known solar scientist Sallie Baliunas purely by pointing out her association with a rght wing thinktank, and without making any attempt to grapple with the substantive points she raises about globalwarming. It’s classic “attacking the man instead of the ball” and I find it deeply objectionable. So John is certainly correct that I’m very “touchy” about the subject. That’s putting it mildly.
Ken P, I’m currently writing a bit on the Shaviv cosmic ray hypothesis, however, it takes a considerable amount of time to read up on what people have written about their work, collect my own thoughts on it etc. When I’ve finished it (hopefully sometime tonight) I’ll post it here and a more complete version on my site.
My “cheap and silly point”, has to do with what I perceive is a strong anti-IPCC bias on your part. While your skepticism towards global warming is mild, you have consistently attacked the objectivity of the IPCC. It’s fine to disagree with them, but it annoys me to see statements which attack not just the various arguments put forward by the IPCC, but the integrity of the organisation, when the errors are being made by you. Examples: “[d]espite the IPCC’s efforts at distorting reality”, and “a projection this far in excess of current mid-range estimates is downright dishonest”.
I fail to see where in this statement “I note in this regard that IPCC scientists NEVER mention the large margins of error in the Mann “hockey stick” study which they use to deny the existence of the Little Ice Age and Medieval Warm Periods, thus enabling them to claim that the last couple of decades are the “warmest on record””, is the qualifier that it is only applies to public statements. However, even if the intent was there, it’s still incorrect. From their Summary for Policy Makers (which is designed for public consumption) we have this diagram. The error bars are there. Your linking the lack of error bars to their claim of the warmest decade on earth statement is also incorrect. The determination that it is the warmest decade was made with fully knowledge, and acknowledgment of the error involved.
I’m sorry if I’ve misconstrued your thoughts on the IPCC, but my perception has been that you having consistently portrayed them as have a strong ideological bias which lead them to distort the scientific literature to amplify the likely effect of global warming. This is a portrayal that I would very strongly disagree with.
The paper, if anyone actually reads it, will tell you this is an untested hypothesis.
An untested hypothesis. An untested hypothesis. An untested hypothesis.
Note all the words devoted to an untested hypothesis by the skeptics. I wonder if that is an indication of the strength of their position.
D
Ken,
I don’t have any idea what the ideological positions of IPCC scientists might be. Commonsense suggests they probably span a considerable range of viewpoints. I think you’ve misunderstood the point I was making (probably because I didn’t express it well). I was arguing that it ISN’T dodgy, in bad faith or lacking in integrity to fail to mention margins of error in short articles in popular newspapers or magazines. There simply isn’t the space, and it’s perfectly legitimate to just summarise the main findings of a study without explaining all the qualifications, unless the extent of the error margin negates the force of the primary point being made, in which case it might well be dishonest not to state that fact. Some argue that’s the case with Mann’s “hockey stick”. I have no idea whether they’re correct.
However, to return to my point, it was that Patterson was not guilty of misleadingly summarising the Shaviv and Veizer study by failing to mention error margins, nor were IPCC scientists guilty by failing to mention them in popular magazine stories (and similar) on the “hockey stick”. Thus I wasn’t accusing the IPCC of lacking integrity; in fact quite the opposite.
As for my earlier post on the IPCC’s “scenarios”, I certainly suggested that the 40 scenario families don’t provide an even spread of coverage of likely (or even possible) future outcomes. Even if I was wrong about natural gas and oil sands (and I haven’t had time to check), that remains the case i.e. the scenarios are skewed/bunched towards the pessimistic end, because of a variety of assumptions they make.
However, again that says nothing about the IPCC’s integrity. I accept your general point (and the IPCC’s) that the actual outcome probably lies in one of the scenarios (leaving aside factors flowing from improved knowledge about solar activity, supernovae, feedbacks etc which may change the equation). The balance of probabilities, however, strongly favours one of the low emission outcomes, and that’s my point. You need to assess probabilities (so far as that can be done). It’s not enough just to dream up lots of conceivable scenarios, most of them very unlikely, and then say: “See, many of these scenarios lead to really scary temperature increases, therefore we should take drastic action to reduce CO2 emissions, despite the huge social and economic cost”. If the scenarios leading to very modest (and decidedly non-scary) temperature outcomes are by far the most likely to occur on present evidence (as is the case), that just doesn’t make sense.
Moreover, if the scenarios yielding the most favourable emission outcomes are the high growth, high technology ones (as is the case), then it makes even less sense to implement measures that would seriously handicap economic growth and technological advancement. This isn’t an argument against Kyoto, I should stress. it’s an argument against the much more drastic action that would be necessary to have any meaningful impact on CO2 levels. At least cautiously,I think Kyoto might be worth pursuing. Creating “price signal” incentives to convert to lower CO2-emitting forms of energy through a modest carbon tax and carbon credits trading seems to me to be a potentially constructive way of nudging behaviour in desirable directions without causing massive economic disruption.
I don’t think IPCC lacks integrity. As I’ve pointed out, my position is based on accepting that their report generally represents science’s current best knowledge (at least as at early 2001). I just think they oversell their case in an excess of enthusiasm, something we all do from time to time. I think 24601 makes a very good point about all professions becoming convinced that their own projects/agendas are the most important. I don’t think teachers lack integrity because they think repairing the education system is the mosy urgent priority, and I don’t think IPCC scientists lack integrity because they think global warming is the most important problem to which everything else should be subordinate.
The thesis put forward by Nir Shaviv and J Veizer have put forward is an interesting one, however, it isn’t a problem for supporters of human induced climate change as Ken P suggests.
Their study essentially finds a good correlation between galactic cosmic rays and global temperatures over the last billion years. When the variability of cosmic rays are compared with surface temperatures, the residues (unexplained variability) is low. From this, they suggest that the effect that CO2 has on global warming is also low.
What needs to be remembered is the massive uncertainties involved here. Reconstructing the earth’s past, is fraught with error (ironically this thread brings up the errors associated with Michael Mann’s reconstruction of the past 1000 years temperatures – this reconstruction is six orders of magnitude longer, and the errors tend to grow as we look further back into time).
The study relies upon the following reconstructions being accurate 1) past levels of cosmic rays 2) past temperatures 3) past levels of CO2.
The first one, I won’t question, as there is very little data available. As far as I’m aware Shaviv’s reconstruction of past cosmic ray flux is the only reconstruction.
The second reconstruction is debatable. Other studies directly contradict the reconstruction made by Veizer. The third reconstruction suffers from the same problem. There is evidence which directly contradicts it.
Shaviv has detailed the problems with the first two reconstructions in his paper in New Astronomy.
This isn’t to say that the last two reconstructions are wrong – it’s just that we don’t know. And if any of them is significantly wrong (especially 1 and 2) then the whole hypothesis falls apart. It should be noted that the authors have put forward a case for cosmic rays being a major determent of the earths climate on the geological time scales, which is at least (in my humble uniformed opinion) as strong as any existing theory.
Lets for the sake of argument, assume that the conclusions of the authors are entirely correct. When we look at what this means for the recent 20th century warming, we get a very interesting result.
Contrary to Ken P’s statement, that “new research suggesting that much of the observed 20th century global warming is actually caused by variations in the activity of supernovae (rather than carbon dioxide generated by evil western capitalists)” the solar systems transition through the galaxy isn’t the cause of the 20th century warming – simply because the solar system’s movement over the last 100 years has been next to nothing on an astronomical time-scale. Or as John Quiggin notes “All of this is based on the assumption that you can go directly from a 500 million year time scale to one of 50-100 years”
Ken, thanks for that clarification.
With the regards to the range of likely temperature increases, apparently Tom Wigley (Lomborg uses his work to suggest that Kyoto will have a small effect) has calculated that the likely warming at a 50 confidence interval is 2.4 – 3.8 degrees.
Meanwhile John Railly (who was one of the IPCC senior modelers for the 1995 report – and is quite critical of the 2001 models) has calculated that the likely warming (with a confidence interval of 90%) is 1.1 – 5.4 degrees.
I haven’t read the two papers, so I can’t make any statements on the quality of the work.
Dano, I think that the really problem with Patterson’s piece isn’t how he represents the study, but with the significance that he places on it.
I wonder if he has written such a positive article on the work of Menglin Jin and Robert Dickinson, who looked at the change in earth’s surface radiative temperature from 1982 to 1998, and found that it was warming far faster than what is expected (0.43 degrees/decade vs. the generally accepted 0.16 degrees/decade). Like the Shaviv/Veizer study it also has problems with latitude, and goes against the established view.
I would guess that he will either ignore or downplay this paper.
Ken, Baliunas is pretty much a mirror-image of Stephen Schneider. She can be counted on to deny any environmental threat, just as Schneider can be counted on to take the most alarmist possible view. Here she is, for example, on the ozone layer.
So why do you object when I mention Baliunas’ political affiliations, but feel free to do the same (and worse) with respect to Schneider?
John,
I may criticise Schneider’s ideas, and especially his overt advocacy of painting misleadingly “scary scenarios” to further a(ny given) ideological agenda. That is, I criticise his ideas and public statements on their merits. Condemning someone for their affiliations, however, and refusing even to examine their ideas because you regard them as conclusively corrupt as a result of those affiliations, is a completely different proposition and completely unacceptable IMO.
I have no problem with your criticising Baliunas’ ideas and arguments, nor even with pointing out that they consistently tend towards a “right wing agenda” (if you believe that can be demonstrated). My problem flows from your refusal even to engage minimally with the ideas of people you decide are beyond the pale, and even more the fact that you place them beyond the pale almost purely as a result of their affiliation with organisations whose ideologies you disapprove. It’s dangerous intellectual tribalism. The “enemy” isn’t necessarily corrupt and may sometimes have some good ideas. However, if we refuse even to look at them then we’ll never know.
It’s a good point, well made, Ken. This morning while browsing the NYT, I came upon an Op Ed piece on DDT and the possibilities/pitfalls scenario around a controlled reintroduction of it for mosquito control. Then I noticed that the commentator hailed from the Hoover Institute….I knew in a trice that blogging this piece would bring the Angels of my Lefter Nature hastening, lemon-lipped and unbidden to my side, to warn of the intrinsic wrong-headedness of anything that might emerge from this dark and evil place.
So I didn’t.
It’s fun to see how much fuss one paper can make. Personally, I find the whole story interesting. It began from a simple question a colleague of mine asked about the effects of supernovae on life on Earth. I didn’t have any particular interest in global warming, and like the typical laymen, was sure that it is because of us homo sapiens.
After more and more pieces of the the ice-age-epochs/cosmic ray puzzle nicely fit, one of the repercussions of the work was the Earth’s climate is not as sensitive as can be understood from the IPCC report. So, without any political agenda, it is hard for me to beleive now that IPCC claims on a large global cliamte sensitivity are correct. This implies that we are to be blamed of only about a 1/3 of the global warming over the past 100 years and 2/3s should be attributed to the increased solar activity.
Irrespectively, I think we should be wiser with the way we use fossil fuels. There are a dozen good reasons why we should use more alternative sources (such as nuclear power… those who think wind power, or other such very clean sources, is the future, should try and estimate how feasible it really is…), but global warming is not the most important one. If the global warming alarmists will continue the way they do, they will simply end up losing their credibility. Which is a shame, since most of us really care about the environment.
Anyway, a few comments regarding statements written in this thread:
a) For those who try to dismiss the cosmic ray flux / climate correlation over the past billion years. The link is quite redundant in the sense that the cosmic ray flux and the climate can each be inferred from a few indpendent sources, all agreeing with each other. For example, the cosmic ray flux was reconstructed using Iron meteorites, and independently, using a astronomical data on the galactic dynamics + a diffusion model for the cosmic rays. The climate can be reconstructed using sedimentation evidence (e.g., the book “climate modes of the phanerozoic”, frakes et al.) or using isotopic data (Veizer et al. nature, 2000?)
b) The fact that the cosmic ray flux reaching earth, over the past 100 years, does not correlate that nicely with the global temperature, is not that much of a problem. This is because the cosmic ray flux people usually compare to, is the typical 1GeV particles of the cosmic rays. However, the climate link is probably through 10 GeV particles. This is because it is at these high energies that the particles can reach low geomagnetic latitutes and penetrate the troposphere, to affect the amount of ionization at low altitudes and with it, the cloud cover. So one should compare with higher energy cosmic rays. And there, the correlation is better. Irrespectively, cosmic rays are not the only driver.
Outstanding post, Nir. Thank you. I found your idea fascinating, and not only for making me picture the Milky Way spinning with us in an arm.
Anyway, it is far, far better to read the actual words of someone than the spinmeisters and I appreciate the honesty.
D
Have you seen this expanded version of Patterson’s interpretation of the Shaviv/Veizer study:
http://www.envirotruth.org/news.cfm
Glad to be of interest. I stumbled upon your site while googling ‘Shaviv’ and ‘Veizer’ to see if anything interesting can be fished.
In any case, it amusing to see how words I write or say (when interviewed) are taken out of context, distorted or otherwise abused. It is a good lesson for us all I think. We should always make sure we go for the source when possible. For me it was a new experience, since I come from the more ‘quiet’ field of astrophysics (where media relations usually sum up as very nice pictures).
On the other side, I realized that the only way to make sure the an article comes out accurate is if its writer consults the interviewees after he writes the piece. Some writers do that, most don’t…
And of course, it is always crutial to know whether someone has a political motive behinds his words.
Thank you for your comments Dr (Prof?) Shaviv.
I was wondering if you knew of any research which tried to quantify the relationship between modern records of high energy cosmic rays, and temperatures?
I’ve read some of Fangqun Yu’s work on cosmic rays and cloud cover at different altitudes, but I’ve not seen it extended to temperatures.
Me, I’m just going to fret over whether I got the science at least half right. And possibly why anyone would already be describing a scientific paper which was only published last month as “widely misunderstood”. Among other things.
There are a few results comparing solar activity to global warming over the past century. (If cosmic rays affect the climate, so will solar activity. The reason is that a more active sun has a stronger solar wind which reduced the flux of cosmic rays reaching Earth).
One example is the work by Soon et al. Astrophys. J. 472, 891 (1996) who tried to compare the global temperature to solar activity and anthropogenic sources, and found that the best fit is obtained if somewhat less than half of the rise in the temperature originates from anthropogenic causes and somewhat more than half due to the sun. (They didn’t discuss the mechanism, and in particular the possible role of cosmic rays). The amount attributable to solar activity can be obtained from the global temperature decrease observed between 1940’s to 1970’s during which solar activity decreased as well.
As far as I know, I haven’t seen work which tried to compare directly the cosmic ray flux change at high energies to the global temperature, but it would depend on solar activity, that’s for sure. (In anycase, such a record would exist only from the 1930’s onward).