Arguments
Recent Comments
Prev 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 Next
Comments 115551 to 115600:
-
CBDunkerson at 21:25 PM on 9 July 2010Hotties vs Frosties?
Baa Humbug, in addition to carrot eater's points... please note that the 1970s were FAR from "early" in the debate over human induced global warming. That started around 1900 when Arrhenius's projections of warming from industrial CO2 emissions were dismissed based on a number of assumptions (e.g. single layer readings, saturation, ocean uptake) which have each been disproved over the subsequent century. The 'middle' period would be Guy Callendar's work on atmospheric CO2 levels primarily in the 40s and 50s. The 70s and 80s were indeed the END of the period of legitimate scientific debate over whether AGW was happening. No remotely rational scientist now disputes this... only the degree of warming we can expect is still in question, and even there the scientific grounding for 'skeptic' positions (e.g. 2 C or less from a doubling of CO2) is becoming incredibly thin. -
chris at 21:25 PM on 9 July 2010Hotties vs Frosties?
Baa Humbug at 20:47 PM on 9 July, 2010 Marcus: "Anyone who is being honest knows that, over a 15 year time period, global temperatures are subject to a very high noise to signal ratio. That doesn't mean that the planet hasn't warmed in that time". Baa Humbug: "Yes that's true Marcus. But it makes me wonder, how is it that in the early 90's we were so confident that AGW was happening that we set off on protocols like Kyoto? The pre 40's warming was said to be mostly natural, but the post late 70's early 80's warming was mostly anthropogenic. Hardly 15 years and subject to signal to noise ratio indeed." Marcus gave you the answer to that Baa Humbug in the very first sentence of the comments: "Here's the problem though John-*context*." It's what distinguishes science/knowledge from superstitution/"common sense". We already knew in the early 90's what we know a little better now, that carbon dioxide is a greenhouse gas, that it is a dominant contributor to the Earth's surface temperature, that increasing atmospheric concentrations will cause the Earth temperature to evolve towards a higher "equilibrium" temperature and so on. We don't have to "see" the earth temperature rising to know with a high degree of certainty that the Earth will warm as greenhouse concentrations rise, any more than we have to see atoms to know that these exist or to see DNA mutations in somatic cells to know that cigarettes greatly increase the risk of lung cancer...... -
Donald Lewis at 21:23 PM on 9 July 2010Hotties vs Frosties?
In my opinion, the difference between a frostie and a hottie is not about reflexes in looking at ambiguous data. It is about preconceptions which are prescientific. That is why "denial" is an appropriate term, in my view. The frosties rarely present all their assumptions. Perhaps they are unaware of them. In any case, in my view, they are driven to reject a wealth of evidence by internal arguments they may never voice. As a result they scramble to vocalize arguments saying the opposing view is not really established beyond (unreasonable) doubt. They want their preconceptions to survive the onslaught of data that seems to contradict their preconceptions. In my experience, the only way preconceptions can survive the onslaught of empirical data is through ones luck of preconception, or denial of the data. I would compare the theory of anthropogenic global warming to the theory of evolution. Where I live, the polls all indicate that the majority of the population does not believe in evolution. (The general population believes, instead, in an origin of species as the result of something compatible to what is described in the Bible.) When you ask educated folks, among the sub-population that denies evolution, about their view of evolution, they may provide a long list of "reasons" not to believe the science. None of those reasons will mention the bible. The reality is they think evolution contradicts the bible, so they know evolution didn't happen, so there must be a problem with the data and/or the researchers.) Instead one hears, the data is incomplete, two scientists disagree about details, Darwin was wrong about something, a duck isn't a dinosaur, ... whatever. The preconceptions bolstering climate change frosties are just more diverse and not yet well identified by the hotties. -
carrot eater at 21:14 PM on 9 July 2010Hotties vs Frosties?
Humbug, Kyoto was adopted in 1997, not the early 1990s. It did take some time in the beginning, before people became confident that warming was indeed definitely taking place. Hansen was confident there was warming in 1988, but you must note that he was examining the trends over the past *30* years, when he said that. He then somehow estimated the chance that the warming to that point could take place through natural fluctuations. And, finally confidence comes from having basic physics on your side; people were predicting warming well before it was obvious. Now, was everybody confident by 1988 like Hansen was? No. Not at all. People were cautious. But through the 90s and 2000s, it became more and more apparent. When finally it was found that the UAH satellite team's initial findings of no warming and then limited warming were in error, then there was really no room left. There simply was warming since the 1960s/1970s. But it's bizarre to say that you won't accept that warming is happening now, just because somebody else accepted it was happening by 1990 or 1997 and gave reasonable analysis to support their position. -
JMurphy at 21:08 PM on 9 July 2010Hotties vs Frosties?
Anyone who makes claims of conspiracy, fraud, incompetence or cheating against the science or the scientists involved, but who then calls any enquiry into such accusations a white-wash, can't be treated as genuine ( a 'frostie' ?) or rational. That, however, rules out any input from all those self-proclaimed auditors and pseudo-science bloggers out there being taken seriously; which rules out 95% (at least) of the so-called skeptical noise. What's left, then ? Not a lot, especially on the anti-AGW scientific side, so who are the 'hotties' supposed to be arguing against ? It seems to me that on one side is the science; on the other is the noise of political/ideological denial; and in the middle a few isolated individuals who don't like taking sides or who prefer to be different - especially if it gives them an audience. -
CBDunkerson at 21:06 PM on 9 July 2010Hotties vs Frosties?
The overall message of the post above seems to boil down to 'perception is Truth'... which sadly is how many people approach the world, but NOT reality. 'How you look at the graph' does NOT determine whether values are increasing or decreasing. That can, and must, be determined by BASIC MATHEMATICS. No 'model' required except an acceptance of fundamental mathematical realities. That said, a temperature graph of one small location for one month tells us precisely nothing about global climate. I realize you were using it as an illustration of your 'differing perception' hypothesis, but I find that position inherently destructive. When something can be reduced to a mathematical proof the choice to 'perceive it differently' is nothing short of nihilism. -
chris at 20:56 PM on 9 July 2010Hotties vs Frosties?
John Brookes at 18:42 PM on 9 July, 2010 "No, I think there are people of ill will on both sides." In terms of the science the misrepresentation and "ill will" are hugely on one side of this issue (the "anti-science" side) as it has always been for some rather obvious reasons [*]. If we are going to pretend that there is a sort of "equivalence" then we're engaging in the same sort of self-deception that has caused so much grief and personal misery in the past [*]. I'm not sure what the answer is other than persistently to address the flaws and misrepresentations from those that deliberately distort the science or who have been suckered into thinking that posting nonsense on blogs (or attempting to winkle dodgy science into the scientific literature) is a good way to address important problems. I agree with you that much of the "frosties" impulse (where it's not brutal self-interest [*]) is ideological; e.g. your suggestion "They think that attempts to reshape our world without fossil fuels spells disaster, and think it is their duty to fight against it." One might have thought that the inherent illogic in that stance would be obvious, but apparently not. It bears a strong relation to the rather hardcore "libertarian" philosophy that's quite widespread in the US (if blogging Americans are representative!) which considers that any problem that might require collective efforts to address has to be "pretended" into non-existence by misrepresentation, since their political philosophy cannot accommodate collective efforts.... [*]e.g. D. Michaels and C. Monforton (2005) Manufacturing Uncertainty: Contested Science and the Protection of the Public’s Health and Environment Am. J. Public Health 95, S39-S48 link to full paper -
Baa Humbug at 20:47 PM on 9 July 2010Hotties vs Frosties?
This is an excellent diplomatic post. Thnx John. (Funny how I didn't connect the John Brookes posting at Novas with this Brookes) I wish you had of left out the bit about Big Oil paying notties. Marcus at 17:47 PM on 9 July, 2010 said... "Anyone who is being honest knows that, over a 15 year time period, global temperatures are subject to a very high noise to signal ratio. That doesn't mean that the planet hasn't warmed in that time". Yes that's true Marcus. But it makes me wonder, how is it that in the early 90's we were so confident that AGW was happening that we set off on protocols like Kyoto? The pre 40's warming was said to be mostly natural, but the post late 70's early 80's warming was mostly anthropogenic. Hardly 15 years and subject to signal to noise ratio indeed. Maybe if the "lunatic fringe" of the hotties side didn't jump the gun with "must do this and that or we're doomed" so early in the piece when most reasonable minded people were happy to keep an eye and an ear out, we'd now be having conversations on a different level. Maybe.' regards p.s. John, you're welcome back at Novas anytime, don't be a stranger. -
carrot eater at 20:33 PM on 9 July 2010Hotties vs Frosties?
Donald Lewis "The frosties impune the published data but typically don't collect their own. " To be fair, it's a little unreasonable to expect anybody to just set up a brand new global network of weather stations. I doubt that's what you meant here, but taken absolutely literally, that's what it looks like. -
Donald Lewis at 20:19 PM on 9 July 2010Hotties vs Frosties?
Fun posting, but there is no dispute, that I am aware of, about the temperature in Perth during September 2009. The sort of climate data under dispute is the GISS surface temp data. It doesn't look anything like the data from Perth in Sept 2009. It is absolutely irrational to assert the GISS data "show no increase in temperature." The 100 year moving average of the GISS anomaly data has increased every year for each of the 30, 100 year bins. One would expect to observe this consistent increase in temp anomoly, under the assumption of no warming trend, with a probability less than 2^(-30). My point is that your frosties simply deny the data. They either impune how the data was collected or restrict the given data set they analyze (say to Sept, 2009 in Perth) so that for that restricted set, they can argue no conclusion is statistically possible. For me, this is a generic significant difference between your frosties and the hotties. The frosties impune the published data but typically don't collect their own. The frosties aren't about advancing our empirical knowledge. -
Arkadiusz Semczyszak at 19:59 PM on 9 July 2010Hotties vs Frosties?
„... We are playing with fire ...” I think the important discussion on climate is to ignore (at least) these two phenomena as: - "claptrap" - ie those present (or ignoring “uncomfortable” data - cherry picking) that seemed irrelevant questions ... - percentage “treated” of science (that is by the "2%"), Doubts are serious (too serious). If they really did not, no business even super-rich super VIP ... Example - recently, Schwartz's work here, I quoted. His question: “We know we have to change the course of this ship, and we know the direction of the change, but we don't know how much we need to change the course or how soon we have to do it.” - has to have an answer. -
chris at 19:55 PM on 9 July 2010Hotties vs Frosties?
Berényi Péter at 19:23 PM on 9 July, 2010 That was a rather unnecessary post Peter since "looking at the big picture" means taking a broad perspective of all of the data and information that bears on an issue. It doesn't have anything to do with "pictures" in the sense that you've misconstrued it. -
daniel at 19:25 PM on 9 July 2010Sea level rise is exaggerated
Riccardo at 00:05 AM on 7 July, 2010 Ok Riccardo, I have provided a graph here using data obtained from Donnelly 2004 cited by the original article. By averaging the limits of the C14 error bars you can obtain the centres of the date ranges. The mean heights are plotted in table 1 so you can then find the centres of the uncertainty boxes. The height error limits are described in the text and also in table 1. In this graph I have tried to reconstruct the Donnelly linear fit by taking the mean height and oldest error limits for the dates of samples 4 and 11. I had to use these visual markers to reconstruct Donnelly's linear trend because I can't find any indication of what the true linear parameters are from the paper. You can see that it seems to be correct visually and rounds adequately to the 2 sig. figs. quoted by Donnelly.
You can see that I've labelled all the paleo-samples with their respective numbers and have put a linear regression line through all samples (including sample 1) spanning the entire 700 years. I have included the recent linear uptrends mentioned in the text as you asked. They both initiate from the 1mm trend as the text suggests they do. Some of the trends are extrapolated with dashed lines up to 2000AD.
I think it is fairly obvious from this graph that there is no statistically significant uptrend in the last 150 years detected by this paper.
I dare any of you to argue with me any further on that point.
-
Berényi Péter at 19:23 PM on 9 July 2010Hotties vs Frosties?
#1 Marcus at 17:47 PM on 9 July, 2010 instead of looking at the bigger picture? Science is not about pictures. It is about propositions, which can either be true or false. Pictures do not have this quality. Is the big picture below a false one?
-
omnologos at 19:22 PM on 9 July 2010Hotties vs Frosties?
This is the best climate blog I have ever disagreed with 8-) And if there's ever going to be a "best climate blog entry of 2010" it'll get my vote!! My disagreement is small but fundamental. You forgot the lukewarmers ("Warmies"?), "those who believe that we are slightly warming the planet"... -
kdkd at 19:21 PM on 9 July 2010Hotties vs Frosties?
Marcus #1. Actually the significance threshold for Pearson's R on 14 degrees of freedom at p < 0.05 is 0.497 ( two tailes), so in this case r_crit is roughly equal to 0.5. Anyway, a significance table for R clearly demonstrates what a blunt instrument correlaitons are. -
perseus at 19:06 PM on 9 July 2010Hotties vs Frosties?
Psychologists suggest that groups become gradually more polarised in their opinions as debates go on, so someone initially in the ‘don’t know’ category could be irreversibly convinced either way. Despite Kuhn’s theories, the peer review procedure, a dedication to the truth, and sometimes quite fierce competition amongst scientists should prevent ‘Warmists’ becoming over-partisan. However, the ‘Frosties’ have no such restrictions and will become more and more ideologically entrenched. There appears to be two sectors of the ‘Frosties’ camp. Those driven by political conviction and the less educated. Arguing with either camp appears to be a thankless task for different reasons. The former just insults, ridicules, or ignores you, whilst the latter are almost completely oblivious to evidence. Particularly lacking is the inability to distinguish trends from data, and the tendency to ignore anything other than what they physically perceive for themselves. These perceptions will be heavily distorted and magnified by the polarisation effects mentioned above. I have come to the view that about two thirds of the public either haven’t the time, conviction or the relevant education to participate in scientific debates, and a simple democratic vote will always be swayed by public relations manipulation and their own selfish interests, rather than hard evidence. A rather depressing picture emerges from public views of the ‘climategate’ enquiry. Despite the conclusions, this MSN poll suggests that 60% of people still believe the “scientists fabricated data to support their beliefs on man-made warming!” Hopefully more scientific polls will be yielding more hopeful figures, but this simply illustrates the magnitude of the problem. climate scientists poll -
carrot eater at 19:04 PM on 9 July 2010Hotties vs Frosties?
I don't think the ending is worded quite very well. It might be a subtle difference in wording: Sitting in the Northern Hemisphere, I know it's going to gradually get warmer from January to June. That doesn't mean I'm going to look at a single month's data like that above, and say it shows warming just because I know that seasons exist. If the single month by itself doesn't actually show warming, then I can't say that the single month by itself does show warming. Rather, I would pose it thus: There is a longer term trend (seasons), which is readily apparent when you look at the longer span of data (several months). If you only look at a couple weeks, this trend is no longer apparent because weather variability is strong enough to obscure the seasonal signal, over that time period. If they really want to (and they appear so inclined), the frosties will always and forever be able to pick out the equivalent of the couple weeks of ambiguous data, where weather obscures the longer-range pattern. There could be unambiguous warming from now until 2100, but at any given point during that span, they can always try to say that there isn't any statistically significant warming for the previous ~10 years. -
Cornelius Breadbasket at 19:02 PM on 9 July 2010Hotties vs Frosties?
I admire your diplomacy John, but one of the biggest hurdles to a truly rational debate around climate change is the division into two equal camps. This is perfectly illustrated by by the media. News isn't interesting unless you have two diametrically opposed camps thrashing it out in a TV 'debate'. But real life isn't like that - and in this case we are playing with fire. I used to spend many hours 'debating' with 'frosties'. But their camp is so tainted with political (AGW=tax) personal (I hate Gore therefore AGW is false) or religious (science = evolution and is therefore false) bias that have no place in rational scientific debate. I prefer to see the rational debate taking place between climate scientists - only 2% of whom could be described as being anything like 'frosties'. -
Arkadiusz Semczyszak at 19:01 PM on 9 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
1. E. Willis in one, however, is probably right, that the real (in the atmosphere) RF CO2 can be strongly overestimated. I recall (of the absolute latest) this paper: Why Hasn’t Earth Warmed as Much as Expected?, AMS Journals, Schwartz et al., 2010, “The observed increase in global mean surface temperature (GMST) over the industrial era is less than 40% [!!!] of that expected from observed increases in long-lived greenhouse gases together with the best-estimate equilibrium climate sensitivity given by the 2007 Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).” 2. „energy storage” in oceans Apart from that we have a considerable discrepancy between the data sets - the ocean, collect, or loses energy, another Willis (Josh) presented a map of where in recent years, the energy accumulates. Areas of the ocean where it accumulates most of the "undue" - unbalanced energy is very small - and contains most of this “extra” energy. Puzzling is that most of these fastest growing areas of the water vapor content in the atmosphere and are usually the highest concentrations of CO2 ... In contrast, large areas of the ocean (even after correction: http://www.ossfoundation.us/projects/environment/global-warming/myths/images/ocean-cooling/temperature_change.jpg) are feebly brown, without color or blue (...?). [Blue in recent decades - oceans give your energy ...] -
Marcus at 18:43 PM on 9 July 2010Hotties vs Frosties?
You know, Ian, I'd love nothing more than to believe that the "notties" are correct. Unfortunately all the evidence I see points in the opposite direction. That the planet was able to warm by an average of 0.0125 degrees per year between 2000-2009-in spite of sunspot numbers unseen since the Maunder Minimum-really doesn't leave me with much confidence that humans aren't causing Global Warming! -
John Brookes at 18:42 PM on 9 July 2010Hotties vs Frosties?
Ian @2 - Great idea! Hotties and Notties - I'll use that from now on. David @3: "John, with all due respect, do you seriously think this is a kind of academic dispute where people of goodwill are just arguing over interpretation of data?" No, I think there are people of ill will on both sides. However there is not much point talking to them, so from a pragmatic point of view, I will be assuming that I am talking to people of goodwill. Strangely enough, just thinking this brings a smile to my face. Its a bit like when I'm cycling and a car toots me. In the old days I would get infuriated, until one day I decided that if ever a car tooted me, it must be someone I know saying hello. So now if I get tooted, I give a cheery wave and continue happily on my way :-) -
David Horton at 18:22 PM on 9 July 2010Hotties vs Frosties?
John, with all due respect, do you seriously think this is a kind of academic dispute where people of goodwill are just arguing over interpretation of data? -
ian_nicolson at 18:20 PM on 9 July 2010Hotties vs Frosties?
Drat, a hottie got in first. Mind you, that's quite unusual in the blogosphere. . . Any way, to try to follow the mellow tone of John's post, which I take to be an expression of a kind of equivalent to the "what would a reasonable man understand?" position (coupled to a welcome appeal for collaborative effort to resolve a polarising issue that appears to be characterised by people taking a "whatever the other lot think means absolute doom and disaster therefore I am entitled to be as ploemic and unreasonable as possible" approach), can I suggest that the names for the camps might work better as "hotties versus "notties"? Rant over . . . ;-) -
Marcus at 17:47 PM on 9 July 2010Hotties vs Frosties?
Here's the problem though John-*context*. Whilst it might be true to say that the warming of the last 15 years is *not* statistically significant (show me anyone who claims otherwise), that represents a gross oversimplification. Anyone who is being honest knows that, over a 15 year time period, global temperatures are subject to a very high noise to signal ratio. That doesn't mean that the planet hasn't warmed in that time. For instance, if I take the temperature data of the last 15 years (1995 to 2009), I get a positive slope of +0.0149, & an R-squared value of 0.402 (where anything greater than a 0.5 is usually accepted as statistically significant). What makes this all the more damning though is that the last 5 years of that 15 year period have been dominated by a *deep solar minimum*-yet still the Frosties can provide no evidence of actual cooling. Why do the Frosties always insist on cherry-picking the dates which they *think* will give them the result they want (usually it fails, like their 1998-2008 cherry pick, which still gives a positive slope of +0.0106) instead of looking at the bigger picture? -
RSVP at 15:35 PM on 9 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
post 6 1) "On the contrary, most of the energy being stored from the increased greenhouse effect is going into the oceans:" Not "on the contrary". This is "also" true, and this energy storage in water is longer term. I was talking about the short-time energy storage captured in the atmosphere until this heat convects to the oceans. 2) "Doubling greenhouse gases causes more infrared radiation to return back to the Earth's surface." In electronics, when you double the width of a resistor, the resistance decreases by half. In other words you double the conductivity. If CO2 is absorbing energy from the ocean surface, it is taking it away, not returning it. (At some point one needs to make up their mind about which way the energy is going.) In any case, this surface heat reaches CO2 and warms the surrounding gases (N2 and O2) and thus has that "greenhouse" warming effect on the air. Yes, the rate of warming will increase with more CO2, but by "rate", I mean how "fast", not how "much". This also means that the rate of ocean cooling will also increase. So, the idea that more atmospheric CO2 warms the oceans (for me) does not pan out. 3) "The increased greenhouse effect has been directly observed by surface measurements and satellites." There seems to be a stretching of the definition of greenhouse effect. Initially it had to do with warming of the atmosphere, but here it seems to imply warming the ocean as well. -
mothincarnate at 13:34 PM on 9 July 2010Italian translation of A Scientific Guide to the 'Skeptics Handbook'
Sorry - I wasn't trying to advertise. But I hope you felt that I did your work justice.Response: Advertise away, your blog post was very relevant - I had to go searching around just to track it down so please post URLs next time :-)
I thought yours was a great post - I like how you took the very brief explanations (intentionally very brief) in the Scientific Guide and fleshed them out in further detail. -
mothincarnate at 13:06 PM on 9 July 2010Italian translation of A Scientific Guide to the 'Skeptics Handbook'
That's fair enough.. I also wrote about a post comparing both handbooks (point to point comparison) and elaborated to make it clear that she didn't survive another attack - your handbook sunk hers. :)Response: Here's a link to your blog post for those interested in a 3rd party comparison of the Skeptics Handbook vs A Scientific Guide to the Skeptics Handbook. Thanks for dropping by and letting us know about the post. -
billkerr at 12:51 PM on 9 July 2010A Scientific Guide to the 'Skeptics Handbook'
hi john, Roger Pielke snr has incorporate my comment 32 and your response into his blog post: feedback on my invitation on the three hypotheses of climate It's at the end, his blog summarises feedback received about his 3 hypotheses. He has promised to respond to the feedback in a follow up blog. -
mothincarnate at 11:57 AM on 9 July 2010Italian translation of A Scientific Guide to the 'Skeptics Handbook'
An yet Nova naively trumpets on her blog that the Scientific guide feel short. I suspect that she didn't even read it - merely saw the graph. Keep up the great work!Response: She definitely read it. I'll write a response to her response but it'll be a few days - several other tasks rank higher on the to-do list right now. -
scaddenp at 09:07 AM on 9 July 2010Tai Chi Temperature Reconstructions
Johnd. I agree. I'm all for understanding the divergence problem and what it might tell us about better selection for temperature proxies. However, whatever the answer is, the agreement of existing ring proxies with other proxies suggests that it is not going have effect on our understanding of past temperatures. Perhaps we will better proxies in the future and be able to refine existing proxies as a result of this understanding but I doubt very much if you will get a different paleoclimate. Every proxy has limitations and problems, but the concordance of them is a cause for believing that the paleoclimate record is reasonably well defined. Also, in the sense that the point of paleoclimate record is to validate climate models, having a record that has more certainties than our proxies for forcings is of limited value. The important result from paleoclimate work is that it does not invalid our current understanding of how climate works. -
johnd at 08:19 AM on 9 July 2010Tai Chi Temperature Reconstructions
scaddenp at 07:08 AM, only a quick response re "to pick trees where circumstances dictate that the growth rings will determined by primarily by temperature." If that is done, and all growth factors accounted for, then there shouldn't be such a thing as a "divergence problem" should there? -
CoalGeologist at 08:17 AM on 9 July 2010Tai Chi Temperature Reconstructions
In response to Ned @#42 You've highlighted here why it is important to separate as much as possible the discussions of four categories of issues: 1) Documentation of climate change, 2) Attribution of climate change, 3) Predictions of future climate change together with interpreted impact, and 4) Issues of response and remediation. In order to understand WHY it's so important to disengage #4 from the rest requires some understanding of the underlying factors responsible for the phenomenon of AGW Denialism. This discussion would be outside the scope of the present topic, but suffice it to say that AGW Denialism is rooted in issues related to #4, and the arguments related to #1, #2, and #3 are constructed in reverse to support a specific (often ideologically based) position. In other words, one's views related to #4 can introduce bias in how the other, ostensibly scientific, issues are treated. On the other hand, any reasonable approach regarding #4 (response and remediation) must entail probabilities, which requires some unbiased estimates of certainty regarding the first three. To the extent that contemporary climate seems to approximately resemble climate during the MWP (differences in the forcings notwithstanding), much hinges on the precision and accuracy of climate models regarding future climate change. It is exceedingly important, therefore, that climate scientists maintain credibility on this topic, which is one reason why the "hockey stick" debate has broader implications than just whether or not temperatures today are higher, lower, or the same as during the MWP. -
johnd at 08:03 AM on 9 July 2010Climate is chaotic and cannot be predicted
I should add to my post that the same principle applies when the anticipation is that negative growth will continue unabated as does also occur from time to time. OT a bit, but those who do accumulate the wealth transferred from others generally consider that it is made at the time the shares are bought, not at the time of selling. -
johnd at 07:56 AM on 9 July 2010Climate is chaotic and cannot be predicted
John Brookes at 18:35 PM, productivity growth is only an indirect driver. The direct driver is the overall consensus of the market sentiment which in turn is driven not what any individual component is valued at today, but what it is likely to be valued at at some point in the future, ie the anticipation that positive growth will continue unabated. Of course overall consensus can create a situation that often results in the market diverging from the underlying fundamental drivers until a correction takes place that catches by surprise all those who were of consensus, but not those who had been examining those relevant indicators that had been ignored by all bar a few. Generally it is those few who accumulate a disproportionate amount of the wealth over time. -
scaddenp at 07:12 AM on 9 July 2010Tai Chi Temperature Reconstructions
Whoops "It doesn't change the picture though." -
scaddenp at 07:08 AM on 9 July 2010Tai Chi Temperature Reconstructions
johnd, you dont expect a single paper to cover all the aspects in using tree rings for temperature determination. That tree rings respond to factors others than temperature is hardly news to anyone working in the field. That is the critical part of selection of trees for use in this work - to pick trees where circumstances dictate that the growth rings will determined by primarily by temperature. The fact that tree ring proxies match well with other completely independent proxies suggests to me that they that they havent got the temperature that wrong. If you think tree rings are flawed, then look at proxy reconstructions that dont use any tree ring data. It change the picture though. -
johnd at 04:41 AM on 9 July 2010Tai Chi Temperature Reconstructions
Peter Hogarth at 18:58 PM, I followed up your links regarding the divergence problem. I don't know if you have read them or not, I have only had time to read the Buntgen 2008. Buntgen 2008 is of limited use. I feel that they have gotten the whole process back to front, and that there is very little understanding of plant biology amongst those who compiled the report. Tree growth, as with all plants, is the result of a combination of complex inputs. To draw any worthwhile conclusions, not only must all those factors be understood, but must be accounted for. Once they have been accounted for, only then can any of them, including to temperature, be correlated to growth. Thus any study relating growth rings to temperature should basically be a study of tree growth, and any conclusions drawn about temperature basically a byproduct. Buntgen 2008 does virtually nothing to understand tree growth, all it basically confirms is that there is a divirgence problem by examining data, but perhaps with limited understanding of what the data represents. There is nothing about soil nutrient levels, nor about tree density. These are two major factors that affect tree growth and change over time. There was nothing about how changing CO2 levels are accounted for, it is not even referred to at all. However the most glaring omission, is that of sulphur dioxide. There is not a single mention in the entire study, yet here is perhaps the most relevant factor of all, particularly if the trees being studied are anywhere in Europe. It is this omission that would cause me to discard any such study as a useful reference. Irrespective if you have read Buntgen 2008 or not, I would recommend that you read some literature that addresses ALL the factors that affect tree growth, particularly those concerning sulphur dioxide. This may be a place to start, it is a couple of decades old but very relevant Sulfur dioxide and vegetation: physiology, ecology, and policy issues by William E. Winner, Harold A. Mooney, Robert A. Goldstein It is not enough to know that there is a divergence problem, we need to know why in order to input into any modelling that is done to reconstruct historic data. -
muoncounter at 04:08 AM on 9 July 2010Archibald’s take on world temperatures
31, 32: "highest global temperatures have been recorded during a low period in the solar cycle." "solar activity has been low for the past 40 years but is now showing signs of increasing." Are you speaking of some long-term solar cycle or the more familiar sunspot cycle? John has written on other threads that TSI is decreasing. This TSI graph from PMOD's 'Solar Constant' page supports that point.
The 11-12 year period is clearly shown; the '79 peak value seems the highest of the lot.
TSI is well-correlated with sunspot number, which has a much longer observation history. However, these short-term cycles are hardly a match for the global temperature trends, as shown below, from wikipedia.
While one can certainly see the early 20th-century temperature low in the long-term sunspot graph, the flat section (1950-1970's) in the temperature graph is a puzzler. I would love to see if a study including solar activity, atmospheric CO2 and another independent factor like atmospheric albedo (via sulphate/particulate emissions) sheds some light on that question. For example, if particulate levels rose between WW2 and the mid 70's, would that be enough to temporarily suppress the long term temperature trend?
-
Tai Chi Temperature Reconstructions
johnd at 03:23, The only way to evaluate the accuracy of a particular proxy is to compare it to other established proxies or to recent temperature measurements. The fact that all these proxies independently show the same trends and that they line up well with modern temperatures establishes that they are likely accurate representations of temperatures. -
KR at 03:40 AM on 9 July 2010Tai Chi Temperature Reconstructions
Well, johnd, I would suggest you then find additional proxy data, or re-evaluate the data currently collected, and present your findings. Write it up and publish! This is the best evidence we have, and the best conclusions that can be drawn from them. There is no solid evidence for any other conclusion than these reconstructions of temperature over the last 2000 years. I would love to see more data, in particular more proxies for the Southern hemisphere, but lacking that, and lacking any model that predicts major hemispheric differences (other than "more oceans, slower to respond", which doesn't really change the overall results), that doesn't seem to be a major problem. Hypothetical data (that which might exist) is not evidence, and hypothetical analysis errors such as you mention here are not a disproof. Or, for that matter, any reason to doubt the current conclusions. -
johnd at 03:23 AM on 9 July 2010Tai Chi Temperature Reconstructions
KR at 22:54 PM, the reconstruction is most likely an accurate representation of the proxy DATA available. It is the basically the same data available to anyone who wants to do a reconstruction. Whether or not that data is representative, or accurate has not been assessed and requires a different analysis rather than a compilation. -
MarkR at 03:10 AM on 9 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
#1: they do comment that seasonal effects will only catch 'fast' feedbacks like quick albedo changes from snow & clouds. The seasonal cycle has a wonderful advantage in that we're pretty confident about what causes it and can quantify it, whereas longer time periods (e.g. the last century) may have uncertain inputs since we don't know things like aerosol or ground albedo radiative forcings from 80 years ago. On the other hand, they do caution that regional changes are a problem and they're absolutely clear that they have to make some assumptions to get this result. However, it's the best method I can think of for teasing a figure out of the seasonal cycle. -
MarkR at 03:05 AM on 9 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
#10: I think it's in the subtext from 'Both types of clouds are part of the throttle control, reducing incoming energy'. Albedo changes are pretty efficient at controlling incoming heat. 'However, this would imply a gradual decrease in GHG forcing which exactly matched the incremental billion-year increase in solar forcing to the present value.' Demonstrates that perhaps Willis hasn't read up about the carbonate-silicate cycle, which also neatly explains why Venus is now a hothouse despite evidence for there originally being water there. If Willis' hypothesis was true for 'any' planet with water like he suggests, then Venus should be temperate today... it isn't. -
IanP at 02:00 AM on 9 July 2010How Jo Nova doesn't get past climate change
In a recent post Jo Nova thinks consensus and empirical evidence are mutually exclusive. I made the mistake of suggesting that consensus arises from the empirical evidence in the comments section. I then had "argument from authority" thrown at me when I mentioned the 97% consensus figure. Garrh the stupid, it burns! -
KR at 22:54 PM on 8 July 2010Tai Chi Temperature Reconstructions
So, johnd - you agree that the reconstructions are accurate representations of temperature variations over the last 2000 years? That the "hockey stick" shape is correct? And you're shifting the discussion over to why these changes occurred? That's good; there still seem to be lots of folks who feel that the Earth isn't warming, or that the MWP was hotter than things are now. Those are the people I would like to get to read Peter's analysis. -
philipm at 21:42 PM on 8 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
#8 MarkR: you presume wrong. Willis complete ignores albedo and in the comments on the article argues he need not consider it at all. Mind you, he also claims peer review is a modern concept and I had to look up the definition of the modern era to realise it started before the 17th century, so he probably knows some other things I don't. I like the way a totally implausible piece on another site has turned into a useful way of understanding the science here. What a pity most of the people who read the other site won't be reading this. -
Berényi Péter at 21:31 PM on 8 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
Murphy 2009 [...]includes ocean heat down to 3000 metres - the NODC OHC graph you've shown is upper ocean heat You mean between 1977 and 1990 more than 1023 J went below 700 m without increasing OHC above this level. Then it suddenly stopped going down for the next 14 years but accumulated in the upper layer. Any hint of physics behind this weird behavior? I can't see a significant change of global ocean overturning rate around that time in Marsch 2000 Fig. 12. (a).
Journal of Climate 2000; 13: 3239-3260
Volume 13, Issue 18 (September 2000)
Recent Variability of the North Atlantic Thermohaline Circulation Inferred from Surface Heat and Freshwater Fluxes
Robert Marsh
-
Ned at 21:23 PM on 8 July 2010Tai Chi Temperature Reconstructions
johnd writes: Peter's reconstruction is a determination of how temperature has changed over time, and not about why it may have varied. Thus the basic outcome was predetermined, ie the planet has and is in a warming trend. Yes, I agree that the planet is warming and that Peter's work just provides an additional demonstration of that rather than directly addressing the question of why it's warming. In an ideal world that kind of demonstration wouldn't be necessary, but most of us recognize that there are a lot of people out there who still harbor the mistaken impression that the world is cooling or that it was warmer during the MWP. So, if you are comfortable with the fact that the world has warmed rapidly over the past half-century, to a temperature that is probably higher than any in the past 2000 years, then great. You can safely ignore this thread. Others, however, might benefit from it. William Connelley has a recent post over at Stoat that explicates how he sees the situation with global warming. There are four main points that most informed people would agree on: (1) The earth is getting warmer. (2) Humans are causing most of this warming, through greenhouse gas emissions and land use. (3) If we don't cut back on emissions, the warming will continue and in fact accelerate. (4) This will be a problem and we have to do something about it. Connolley says (and I agree) that those points are listed in approximately the order of certainty, with (1), (2), and (3) being essentially undisputable but with much less agreement about (4). Given that, it would be nice if we could just take the first three points for granted and focus all our energy on resolving the questions surrounding (4). Unfortunately, even people who ought to know better keep going back to revisit the first three points. Thus, post like Peter's here, and in fact all of John Cook's work on this site, are regrettably necessary. -
MarkR at 19:36 PM on 8 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
#2: Willis' method uses hemispheres, so summer/winter is applicable. I'll rephrase the article when I get back later. #4: That was the name of the WUWT piece :P #6: I was trying to keep it as short as possible but I've clearly failed to get across my point! I'll look at rewriting it. With climate sensitivity you have 3 extra heat flows to look at. First, heat lost to space from Earth warming up (this is the temperature change), heat flow into the oceans and atmosphere (showing how close you are to equilibrium) and extra heat reflected or allowed to escape (feedbacks which can be positive or negative). These 3 must add up to the change in heating or radiative forcing you applied and they change with time. Immediately after you add heating, you have very little extra from the Earth having warmed up and lots of heat going into the atmosphere and oceans. You're nowhere near getting climate sensitivity. If you leave it for ages, eventually you'll get near equilibrium and heat in = heat out. There's very little going into the atmosphere and oceans and almost all the extra heat will be 'cancelled out' by the sum of feedbacks which control heat flow to space PLUS the extra heat being radiated because temperatures have risen. I assume Willis' argument is largely albedo based, but he's looking at too short a time and looking at regional heating probably leads to incorrect feedbacks too (e.g. there are data showing increased cloudiness in summer, but global circulation is slightly different to what you'd get with a global heating so that could once again be a regional change)
Prev 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 Next
