Arguments
Recent Comments
Prev 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 Next
Comments 115501 to 115550:
-
JMurphy at 08:12 AM on 12 July 2010An account of the Watts event in Perth
skepticstudent wrote : ...but I can't seriously believe anything this person writes... Care to be a bit more specific or do you not believe every word written ? How about the start : "The Watts climate tour appeared in Perth on Tuesday evening." What don't you believe about that ? -
Peter Hogarth at 07:20 AM on 12 July 2010Tai Chi Temperature Reconstructions
johnd at 04:43 AM on 12 July, 2010 John, I agree it is a complex subject. However much of what you say appears to be conjecture and not directly referenced to the research I have seen. I suggest that if you look at the recent references supplied, particularly the ones from the last two years, there is much to learn. There has been a lot of focus on DP and some of the correlation work with temperature is highly convincing (I previously mentioned the seasonal growth and year on year growth correlating with local temperature variations) and Buntgen 2008 for example shows temperature monitoring sites on tha map above. I suspect this would be inconsistent with CO2 as main factor. -
Riccardo at 06:08 AM on 12 July 2010Sea level rise is exaggerated
daniel, "What I am saying is that the tide gauge data points fit inside of that if it were extended over sample 1." They are inside the sedimentary data uncertainty and we expect them to stay there for a while given the difference in the slopes. Ok, but they do have a different slope. Does this tell you something? -
skepticstudent at 05:29 AM on 12 July 2010An account of the Watts event in Perth
anything this person writes either. :-) -
skepticstudent at 05:28 AM on 12 July 2010An account of the Watts event in Perth
John I respect you and I've learned some things on your blog, but I can't seriously believe anything this person rights, and I think you've damaged the respectability of your blog by allowing her to submit a guest post. I don't expect this post to stand but it was meant for you anyway. -
Paul D at 05:09 AM on 12 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
Berényi PéterOr it's not stored at all, just goes to space. After all that's the coldest heat reservoir around (2.7 K).
That's one of those junk throw away statements. As has been pointed out, the only way the energy can escape to space is via radiation in the upper atmosphere. To do that it has to be fed from below, but GHGs inhibit the provision of the energy 'feedstock' that the upper atmosphere needs.
-
johnd at 05:05 AM on 12 July 2010Sea level rise is exaggerated
Peter Hogarth at 16:21 PM, Peter, the comment you make about modern tide gauges taking measurements every 6 minutes or so interests me. Given that at some locations the time it takes for the tide to rise can be considerably longer than it takes for it to fall, just a quick look at one site showed over 15 hours rising, 9 hours falling, would taking such regular measurements introduce a bias into the average when comparing against those records where the average is that of the high and low tide measurements? -
johnd at 04:43 AM on 12 July 2010Tai Chi Temperature Reconstructions
Peter Hogarth at 02:38 AM, whilst temperature is one of the many factors that influences plant growth, and not the dominant one, it's increasingly seems to me that the selection of sites, or groups of trees, is done by finding trees that by COINCIDENCE rather than by science, seemingly track temperature sufficiently well enough for them to be considered useful indicators. I say by coincidence, because if all the other factors that are perhaps even more important in influencing tree growth were sufficiently well understood to be quantified, then all trees should be able to be used as proxy indicators. But more than that, if those factors were able to be quantified, the divergence problem would not be, well, a problem. The problem is not that the growth of trees that had been previously selected as temperature indicators began to diverge, the problem is that the reasons are not understood, and this is happening at a time when the resources and knowledge is available that should be able to identify such reasons. If those reasons are not understood well enough to be able to account for present day situations, then how can anyone be confident enough to claim that those same, still unknown factors, have not been present and an influence, either positive or negative, at other previous times. I would hope that the selection of "good" sites involved more than someone with a wooden ruler in one hand and a temperature chart in the other, but that is what it seems to come down to. The one thing that is always in the back of my mind whenever tree growth ring data is used is that what has been done to ensure that the tree growth is not tracking CO2 levels rather than temperature. With the Buntgen 2008 study, about half of the available sites were selected because of their supposed historic correlation. But those sites used in other studies where the divergence problem is now evident also were supposed to have a historic correlation, so obviously some things change over time. But that doesn't mean that they are only changing now, and haven't done so in the past. So what is there to say that perhaps the basic assumptions used to model tree growth against temperature are wrong, and that instead, the other half of the trees that were rejected are better indicators once everything has been allowed for. If we were to work backwards and select trees that today show good growth correlation with temperature, then those trees that are now showing divergence would be rejected, or else any modelling done that correlated their present day growth with temperatures would when applied to historic growth rings, present a different result. The other thought that is also always in the back of my mind is how well are the actual site conditions documented over time. Temperatures can vary widely even between close localities, so correlation should be to and with site temperatures, not regional or global. Precipitation patterns can vary widely over just a few kilometres. Given that some of the locations where the samples have been taken seem to be remote, perhaps even these most basic of all factors have not been accurately accounted for. -
Peter Hogarth at 04:30 AM on 12 July 2010Sea level rise is exaggerated
In order to also start some fresh productive discussion, hot off the press is the following from Llovel 2010
This is a new measured result from GRACE which goes at least some way to confirm explanations of seasonal variations in mean sea level, and partially answers previous points on this post and also answers some questions on the visualizing sea level post.
The further relevance is that land storage contribution to mean sea level trend and budget is slightly negative, giving -0.22 +/-0.05 mm/year, confirming modeling results for this with direct measurements for the first time.
-
Albatross at 04:22 AM on 12 July 2010Hotties vs Frosties?
Philippe @87, "You went looking for what was wrong and you found it, although what you found did not exist. That is the definition of bias. Philippe, Peter recently made the same error when raging against the lowering of pH. He assures us that he is searching for the truth, but his approach seems to be inconsistent with that. -
Peter Hogarth at 03:52 AM on 12 July 2010Sea level rise is exaggerated
daniel at 23:20 PM on 11 July, 2010 One thing slightly bugged me about my chart, the slight offset between the tide gauge data and the "centre" of the error envelopes, where we would expect the real trend to probably be. I checked the tide stations closer to the site. One (New London, CT, with a shorter record from 1938) is very local, but the other (from 1856, NY) has the longest record. I charted the NY record for this reason. I've now noticed there is a small vertical offset (not unusual between stations) between the two that (subjectively at least) neatly resolves the visible offset in the chart. -
Peter Hogarth at 02:38 AM on 12 July 2010Tai Chi Temperature Reconstructions
johnd at 10:22 AM on 11 July, 2010 No, I think you have misunderstood the methodology. We do not have controlled experimental conditions. The site selection process involves looking at older tree ring data to see if the "site" is likely to give results which are affected by temperature, rather than other factors (such as drought), by comparing pre 1934 tree rings data with pre 1934 historical climate data. If it is a "good" site, on this basis, then the later tree ring data is examined to assess more recent effects of temperature (other factors notwithstanding). No assumptions are made to pre-select on the basis of correlations in later data. This is important. The authors admit that this cannot account for changes in other factors in the meanwhile, but if the correlation with instrumental temperature continues in later data, then confidence increases. I think you see the logic of this? -
Peter Hogarth at 02:15 AM on 12 July 2010Sea level rise is exaggerated
daniel at 23:20 PM on 11 July, 2010 No, you have not said this until now. What you have argued is that extending the approx 1mm/year long term linear trend from pre-tide gauge data beyond 1856 by including point 1 gives a 1.2mm trend and error bars which can fully accomodate the total tide gauge data record anywhere inside this trends error envelope, therefore you argue this paper should not be used as evidence that the recent 2.8mm/year trend is unusual. Your case for including point 1 in an overall 1.2mm trend is invalid. Clearly, the density of tide gauge data makes any influence of point 1 marginal on the measured 2.8mm/yr trend since 1856, clearly, the recent measured trend is diverging away from the long term paleo trend. That point 1 error bars overlap the tide data possibly validates point 1, but the fact that the tide gauge data overlaps point 1 does not validate extending the pre-1856 trend. The post 1856 trend is already determined as measured fact by the tide gauge data. Point 1, statistically speaking, is on this trend. The question you are asking really, is: Can the 150 year tide gauge data trend be accomodated inside the pre 1856 error envelope, and show that the longer term trend could most likely have missed similar episodes of acceleration in the past? This is the question I address in my chart. The chart I have given shows the error envelopes based on the statistics given for each point, up to the start of the tide gauge data, which has much lower standard deviation and represents the measured data. It is not the same as a linear trend. It is likely that the envelope will follow or at least accomodate whatever the true trend was. We can only ascribe a probability to this. It is barely possible to fit the tide gauge data into the 2 sigma envelope in one pre 1800 place, but it is not a "good" statistical fit anywhere over any approx 150 year period except after 1800 (by comparing with at least three paleo points, though this is not a strong test). It is not possible to fit inside the 1 sigma envelope anywhere, and the data series deviates away in opposite directions above and below the envelope, indicating significant systematic trend error. I repeat that your suggestion is possible, but not "likely" from this data. Of course we need a reality check, and the temperature record and other work I referenced strengthens the case presented in the paper, and further weakens your hypothesis. -
Philippe Chantreau at 01:44 AM on 12 July 2010Hotties vs Frosties?
BP, you missed the point. The point was not about the data, it was about your attitude. You started with the assumption that the papers came to conclusions that were wrong. You went looking for what was wrong and you found it, although what you found did not exist. That is the definition of bias. What you found did not exist but you found it anyway because you were so eager to find it that you were going to no matter what. Then you assumed, again without anything to back it up, that the (non-existing) flaws that you found were due to an intent to deceive from the authors. Don't try to deny that, your anger and accusations are patent in many of your posts, and explicit in the acidification one. But you are yet to present ANY kind of evidence of an intent to deceive or even that a paper is wrong. You raise some valid points, but their significance is far below what you suggest (especially the fraud suggestions) and, frankly, you should drop the attitude. It is quite obvious that you need to watch your own bias way more than that which you see in others. -
DarkSkywise at 23:54 PM on 11 July 2010How Jo Nova doesn't get past climate change
Baa Humbug at 20:04 PM on 11 July, 2010: "Human nature JM. When one starts reading the thread and comes across a "hidden" comment, curiosity kicks in," In the beginning: definitely. After a while: no. I've been a mod/admin on several large forums where no post rating systems were allowed, because too many people go around "plussing and minusing" not because they think posts are good or bad, but because they want their own views in sight and others' views hidden. And most of it is being done by one side only, just like with online polls where 60% says ther earth is cooling, it's a natural cycle and AGW is a conspiracy to raise taxes. The result is not only that only one side of the argument is really shown, but it also keeps many people from the other side from posting. Some people just don't like posting anything anymore (especially when they work long and hard on their posts), if the posts will be hidden anyway. Anymoo, my experience with most forums with post rating systems is that they turn political in no time - and it's nearly always the same political side. "All sceintsist are fruads!!!!11~" +283 -12 "Research has shown that (insert lots of text here) which shows a clear trend towards warming." +7 -453 -
daniel at 23:47 PM on 11 July 2010Sea level rise is exaggerated
read above pete -
Peter Hogarth at 23:34 PM on 11 July 2010Sea level rise is exaggerated
daniel at 13:42 PM on 11 July, 2010 "Understatement of the year" "overstatement of the year" etc. Histrionics does not make up for lack of knowledge, nor does it engender respect. To put these sea level numbers into context, the sea level varies by around 1m every day close to this site, and through year seasonal and tidal variations add to this. I believe I have shown from the data that your argument (that large intersample variations containing trends similar to those of the past 150 years are "likely") is weak. -
werecow at 23:34 PM on 11 July 2010Irregular Climate podcast: episode 7
It's too bad Graham can't do the podcast anymore. I like the more natural flow of conversation that results from having a co-host. Still, this was an interesting episode. I'm reading the IPCC Assessment Assessment report now. As a Dutchie, I felt a bit queezy when one of our government officials played right into the hype. But I guess it was the appropriate political move to make, and some good has come out of it; It's good to see that, even though they provide some constructive criticisms, the conclusions are soundly reaffirmed. -
daniel at 23:20 PM on 11 July 2010Sea level rise is exaggerated
Riccardo at 18:04 PM on 11 July, 2010 No you see the error envelope on Peter's graph. They are continuous lines that extend along either side of the paleo trend. What I am saying is that the tide gauge data points fit inside of that if it were extended over sample 1. The MSL does anyway. You can see this more clearly in Donnely which uses averaged tide gauge data which lie over the sample 1 uncertainty box. Donnelly and Peter seem to think that this overlap supports their case but actually it supports mine. You can see that paleo samples do not adequately show us where the true sea level is because they have such high uncertainties. A big deal is made about the centres of the boxes but clearly the tide gauge data shows the centres aren't that important because the centre of sample box 1 does not lie directly on the averaged data point trend of the tide gauge data. The mean height of sample 1 fits the tide gauge data at 1950 rather than the center of the assigned date range which is 1975. That's directly measured data lying on the very extreme of the 95% confidence interval for the mean height estimate of sample 1 and then I'm told tbat short term deviations in the older data are unlikely to be far from the centres of the boxes or the linear model. For at least three samples 8, 10 & 11 the linear model is far from the box centres. You guys can't have it both ways. -
Baa Humbug at 20:44 PM on 11 July 2010How Jo Nova doesn't get past climate change
Thankyou for the clarification. My use of the term was taken from the article itself, hence why I put it in parantheses. From Brookes article... "I don't think there is any hope for the lunatic fringe on either side. If your starting point is that the people on the other side are evil incarnate, then you won't move from that." For what it's worth, whoever owns and operates this blog has the right to set the rules. Those who don't like or agree with the rules can please themselves.Response:"My use of the term was taken from the article itself..."
Hence the reinstatement. The comments policy here is based on behaviour, not whether the majority of readers agree with the comment, and generally works pretty well - I rarely have to overrule any action by the moderators and the discussion is IMHO of a high quality. -
Baa Humbug at 20:08 PM on 11 July 2010How Jo Nova doesn't get past climate change
John Russell at 20:01 PM on 11 July, 2010 "Unfortunately I think your last post might be removed as arguably it's a little -- how shall I say -- aggressive? I hope my response is not". John I don't keep copies of my comments but I assure you it was not aggressive nor did it contain ad homs or such. If you follow the thread, there are replies to my deleted comment. You can glean from those replies if my comment was aggressive or out of line.Response: One of the moderators removed the comment because of a line about lunatic fringes which was deemed ad hominem. I reinstated the comment as there's a recent blog post that discusses this very subject. -
Baa Humbug at 20:04 PM on 11 July 2010How Jo Nova doesn't get past climate change
JMurphy at 19:36 PM on 11 July, 2010 said... "What is not immediately on show (and needs active input from the viewer, if they can be bothered, to actually show), is not on show. Simple as that". Human nature JM. When one starts reading the thread and comes across a "hidden" comment, curiosity kicks in, A SINGLE CLICK OF THE MOUSE relieves that curiosity as to why the comment was hidden. hardly a task one can't be bothered with. As to why this function is used, I don't know. Hop over there and ask, you'll get a response. Also check out one of the lates popular threads, there are dozens and dozens of posts by people not in agreement with the host. None are deleted, none are hidden. The hide function is in the hands of the bloggers, not the host or mods. Once you are informed, then your comments about it become valid. It beats having ones comment removed without explanation like mine was here. -
John Russell at 20:01 PM on 11 July 2010How Jo Nova doesn't get past climate change
OK , Baa Humbug, I agree; they're not removed, they're hidden. So why? When I've looked at them, the majority of these hidden comments seem quite reasonable counter arguments. Three, I hope, reasonable questions: why are they hidden? Why choose to hide (your word) dissent? To any casual observer finding the site what's the result of hiding dissent? Regarding your comment that was removed on this site; are you sure it was reasonable? There's lots of dissent here; it's treated robustly but courteously (if not it's removed). Several of my own comments have previously been removed because (I assume) they strayed slightly into the political arena. So, you see, we have both been 'victimised' evenly and fairly on this site! I hope you can agree. Unfortunately I think your last post might be removed as arguably it's a little -- how shall I say -- aggressive? I hope my response is not. -
kdkd at 19:51 PM on 11 July 2010How Jo Nova doesn't get past climate change
I quite like the SS deletions policy, although I'd quite like to see a section called "the swamp" or something that contained all the deleted posts (anonymised if felt necessary). -
JMurphy at 19:36 PM on 11 July 2010How Jo Nova doesn't get past climate change
Baa Humbug wrote : Any comment that accumulates more than 30 thumbs down votes gets "hidden" not removed. However, anybody wishing to read what the fuss was about, just needs to click the words "hidden due to rating" and the comment reappears. But why are they hidden ? To all intents and purposes they do not exist because they do not appear on the screen when you are viewing comments, so John Russell is correct when he states : It's a great system -- for Jo -- it means virtually every comment in the thread is in support of her viewpoint. What is not immediately on show (and needs active input from the viewer, if they can be bothered, to actually show), is not on show. Simple as that. I ask again : Why hide them ? -
Baa Humbug at 18:45 PM on 11 July 2010How Jo Nova doesn't get past climate change
John Russell at 06:44 AM on 11 July, 2010 said... "I note that they have a voting system. If enough people give a comment the thumbs down, it's automatically removed. It's a great system -- for Jo -- it means virtually every comment in the thread is in support of her viewpoint. And it completely overwhelms any criticism." I'll assume you made this assumption out of ignorance. Any comment that accumulates more than 30 thumbs down votes gets "hidden" not removed. However, anybody wishing to read what the fuss was about, just needs to click the words "hidden due to rating" and the comment reappears. You noted in error. I note your pre concieved view and bias. p.s. I posted a comment here at the "hottie nottie" thread, comment number 16. IT WAS REMOVED with no explanation given. People in glass houses John. -
MarkR at 18:37 PM on 11 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
#14 Arkadiusz: Shwartz et al don't say that RF calculations are likely incorrect. They say that their results are most likely explained by a combination of overestimated climate sensitivity OR a negative RF from atmospheric aerosols. And I quote: "the discrepancy cannot be apportioned between these two causes primarily because of present uncertainty in aerosol forcing." plus: "the forcing by doubled CO2, is approximately 3.7 W m-2." They're not saying CO2 RF has been overestimated, but that climate sensitivity may have been (or aerosols are cooling us) -
Riccardo at 18:04 PM on 11 July 2010Sea level rise is exaggerated
daniel, could you please explain this sentence: "It clearly shows that modern swings in SLR fit inside the error envelope of a shallow, linear long term trend in paleo data". As I understand it, you're saying that the tide gauge seas level data (not trend) are within the trend error of paleo data. Comparing trends is to compare 1.0 mm/yr (+/- 0.2 mm/yr) with 2.4 mm/yr. Comparing sea level, instead, is to see if tide gauge data are within the limit of variability of sedimentary data. You're doing the latter, so you're not comparing trends. Is it possible, at least in principle, that there has been similar up swings at 2.4 mm/yr in the past? Yes, but putting physics aside. If you take the lower error bar of a point and the higher of another you might get such trends. But it's unlikely, there's nothing that make us think it's actually happened and it's hard to immagine a mechanism producing such up swings. Are you aware of a sudden increase in temperature or large land ice melt between 1300 and 1800 A.D.? Are you aware of other, higher resolution, datasets showing this swings? -
John Russell at 17:42 PM on 11 July 2010Hotties vs Frosties?
philipm at 10:35 AM on 11 July, 2010 says: "There are actually three categories, not two: 1. hotties – people who believe firmly that AGW is happening 2. frosties – people who believe firmly that AGW is not happening 3. scientists – people who believe the theory should stand up to testing against the evidence" I don't agree. What you write is elitist. I'm not a scientist, but neither am I in your group 1 or 2. About 20 years ago I was sceptical whether AGW was possible. I gradually changed my view as a result of exposure to the available information. I now trust that the majority of scientists, 'the consensus', have got it right. As far as I can understand the subject -- and I don't have to tell anyone here; it's highly complex -- the evidence stacks up to the point where I'd be a fool not to believe it. But am I certain? Definitely not; I'm old enough to have seen the scientific consensus shift on several topics before. However, do I think we should act on GHGs? You bet. Surely, any sensible person would weigh up the odds and be frightened about what the future might hold? To me anyone who is fighting (careful choice of word) AGW is either too frightened to confront the evidence or, perhaps, lacks a certain amount of imagination. Whatever the actual reason, the answer must lie in their psyche. -
daniel at 17:12 PM on 11 July 2010Sea level rise is exaggerated
KR at 14:34 PM on 11 July, 2010 "you look at the larger gaps in the paleo data from this (and only this) paper, and assert that large SLR rates could occur in the spaces between the data points?" But also the large error limits of the points which indicate a high uncertainty as to where the true sea level was. "I point out between, because the slope between 9/11 and 7/8 that you use as an example shows an average slope of ~0.9-1.0mm/year" Well you clearly misunderstood me. I was saying within the small group 9-11 and also within a small group of 3-4 data points which include 7-8 either 7-10 or 5-8. "for such a large value of SLR (derivative) to occur in that period, there would have to be a corresponding low/negative SLR in that same period in order for the integral over that period to still yield ~1mm/yr?" Yeah, so, why is that so unlikely? I don't think we have to evoke negative trends to support my analysis. -
thingadonta at 16:43 PM on 11 July 2010IPCC were wrong about Amazon rainforests
I dont know what all the fuss is about. The Amazon rainforest wont change much until the Andes Mountains wear down (groundwater runoff), the Atlantic Ocean ceases to exist, and it doesn't rain when warm, moist, tropical air rises. Despite the 'peer-reviewed literature', seasonal droughts have nothing to do with long term rainfall patterns. The warming over the 20th century has shown no trend in Amazonian rainfall, because when warm moist air rises-it rains. The Amazon rainforest will still be here in much the same manner in a 100 years, even if all the IPCC T projections turn out to be correct. -
kdkd at 16:25 PM on 11 July 2010Hotties vs Frosties?
BP #81 Indeed, we do not know why the ocean heat models and measurements are problematic, and why they are inconsistent with the bigger picture of large amounts of independently derived evidence showing that anthropogenic warming is a serious concern. Not just the various temperature datasets in case you wanted to take issue with that small part of the big picture by the way. But this is not the same as the hard reductionist argument that you have been making, which you now seem to be retreating from somewhat - given that you have not addresed the most important issue in my post, that your arguments to date are unable to address the critical issue of system interdependency... -
Peter Hogarth at 16:21 PM on 11 July 2010Sea level rise is exaggerated
daniel at 14:18 PM on 10 July, 2010 A quick chart with all of the data used by Donnelly 2004, except the tide gauge data (NY) uses monthly mean values and extends to today.
The tide gauge data consists of very frequent samples (modern readings are every six minutes or so) averaged over each month. As such errors are extremely low. The seasonal MSL variations are retained in this chart and represent measured mean sea level. The overall long term linear trend is 2.8mm/year, however in this tide gauge data the trend has gradually accelerated over the measurement period.
The sediment, pollution and pollen derived data is shown with approximate two sigma and one sigma error envelopes. However it should be noted that the variance from a straight line fit for all points is very low, and in addition a smooth curve fit is further suggested by the relatively low level of decadal and inter-annual trend variation in the 150 year tide gauge record. The accelerating trend in sea level rise is evident in the overall data set. The error bars on the sediment data overlap the actual tide measurements even when an annual MSL average or overall fitted linear trend for tide gauge data is used.
-
KR at 14:49 PM on 11 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
Actually, RSVP - the atmosphere represents only a few percent at most of the thermal mass involved in the energy retention of the greenhouse effect. The observed increase in back-radiation, and decrease in top of the atmosphere (TOA) at greenhouse gas wavelengths indicate the energy retention, while the ocean heat content (OHC), overall temperature measurements, glacial retreat, polar ice decrease, and seasonal movement (etc, etc) show the added heat in the Earth system. The increasing CO2 isn't absorbing huge amounts of energy from the ocean, it's slowing it's loss back to the atmosphere and to space. And thus the oceans heat up... For all intents and purposes you can treat the atmosphere as a thickening blanket for the land and ocean, not as a thermal mass. It only holds enough energy for it's temperature to be sufficient to radiate energy to space, and that's trivial in regards to the thermal mass of land/sea. -
KR at 14:34 PM on 11 July 2010Sea level rise is exaggerated
So, daniel - you look at the larger gaps in the paleo data from this (and only this) paper, and assert that large SLR rates could occur in the spaces between the data points? I point out between, because the slope between 9/11 and 7/8 that you use as an example shows an average slope of ~0.9-1.0mm/year, as far as I can determine with a quick examination (certainly not >2mm/year!!). You do realize that these data points for sea level show the integral of the SLR over time, and that for such a large value of SLR (derivative) to occur in that period, there would have to be a corresponding low/negative SLR in that same period in order for the integral over that period to still yield ~1mm/yr? If you recognize that, great, we're half-way there, and perhaps past arguing and back into discussion over what could cause such high variation around the 1.0mm/year mean for 1300-1850. -
daniel at 14:06 PM on 11 July 2010Sea level rise is exaggerated
"I've said it before, but it didn't seem to register - if a major upswing like the currently observed 2.4 mm/yr SLR occurred in the 1300-1850 period, the paleo data points of sea level couldn't fall anywhere close to the linear fit line for the 1.0+/-0.2 mm/year SLR trend. " ...and I've said it before KR, that's total bunkem. Provide a graph to show your claim is true. You will find yourself dissapointed by the rashness of your claims. "If there was a brief 100-150 year rise at 2.4 (as currently observed) there would be a step change in the observed paleo sea levels. That is not shown in the data. " I can see two possible points where that rate or a rate closer to 2.4mm/yr than 1.0 mm/yr. could occur. Best candidate is samples 9-11 followed by sample ranges including 7-8. " If you have a physical process for something like that, I would love to see it. " Please discuss the evidence for a lack of active drivers in detail citing the relevant papers. -
daniel at 13:56 PM on 11 July 2010Sea level rise is exaggerated
Riccardo at 04:34 AM on 11 July, 2010 " ...but you're comparing the values of sea level with sea level rise, i.e. the trend." I'm only really comparing the trends. "It doesn't matter if the recent "high" resolution sea level data fall within the uncertainty of the sedimentary trend," It clearly shows that modern swings in SLR fit inside the error envelope of a shallow, linear long term trend in paleo data that is within the rate error limits of Donnelly's 1.0mm/yr +/-0.2mm/yr. Therefore there is no evidence to suggest tjhy could not have occurred in the past or that recent swings are unusual at Barn Island. " what matters for Donnelly conclusions is that the two trends are significantly different." They have not shown to be different. Directly measured, high certainty, high res, short term data cannot be compared to it's exact opposite ie. indirectly measured, low certainty, low res, long term trends. -
daniel at 13:42 PM on 11 July 2010Sea level rise is exaggerated
Peter Hogarth at 07:48 AM on 11 July, 2010 "Several data points derived from peat sediments are given where the dating of the sediment has uncertainties." A candidate for understatement of the year. Sample 7 has a height uncertainty of +/- 10.4cm and a date range of 172 years, Sample 8 does not do much better. Sample 9 generally dates older than sample 10 despite attempts using the principle of superposition to eliminate such assignment errors and sample 11 cannot be definitively defined between two date ranges which span 123 years in total. "I argue that any variation is constrained by the error envelope of the points..." And here we have overstatement of the year. Gentlemen I will provide a graph with linear fits between small groupings of the data points if you lik and you will see that on the short term deviations fall easily within the error envelopes. But then you will claim that such 2-4 point linear trends are statistically insignificant. But that's the point! Donnelly's study can't make short term comparisons so any comparison to the recent data is invalid. Donnelly doesn't give us enough data to produce statistically significant trends on the short term. " ...and the physical processes which might cause fast variations." and "I have provided a considerable body of evidence which supports this, but you have still focused on this data from this paper and provided a simple chart (but without any statistical analysis)." Well we could discuss how well these physical processes are known and you could cite specifically which papers deal with causation but I would at least like you to acknowledge that this paper, using the data it provides only, has no case to make. Donnelly has gone to all this effort to determine a linear trend in the hope it would alone provide the evidence. He only cites other climate studies not SLR studies to support his conclusions and he admits they only roughly do so. I fear that this is the kind of study that is used to determine causation of SLR (a rough correlation to paleoclimate data) where other, as yet unknown, ocean heating or seismic factors may also be playing a role. It is often claimed that climate science is in it's infancy so you should not be surprised when others claim SLR drivers may not be properly understood. If this statistically insignificant kind of study is used to determine causation then I am very worried indeed about what we do and don't know about SLR drivers and what the known drivers were actually doing in the recent and distant past. You do realise that conceding this point and accepting the poor quality of this paper does not mean you lose the war. I would love to discuss other papers but if you can't bring yourselves to accurately critique this paper what point is there in moving on to others? You can't say that all the other papers validate this study without discussing them in detail (Donnelly doesn't). You can't use dodgy materials to build a strong house. There needs to be other studies that are of higher quality than this one in order to support this one. Citations please (I haven't read your review articles Pete, I've been busy defending an obvious and very pertinent point... amongst living my life). As to the comments about my lack of statistical analysis can you please state exactly what you want? I can do a chi squared test if you like? Can you see the R squared value in my least squares fit? Do you think these kinds of analyses are going to support your cause? They will only support mine further. If I do a chi squared test on whether the 1mm/yr trend is significant on short term collections of the paleo data do you think we will get a statistically significant trend? That pendulum swings both ways and mostly in my favour (if not completely) -
Berényi Péter at 12:20 PM on 11 July 2010Hotties vs Frosties?
#74 Dappledwater at 09:32 AM on 11 July, 2010 And what exactly would that be? Like this:
-
Berényi Péter at 12:16 PM on 11 July 2010Hotties vs Frosties?
#75 Philippe Chantreau at 10:15 AM on 11 July, 2010 you have already proven in the ocean acidification thread that you are looking for certain things in the data Not yet finished with that. I'll recompute the upper layer. However, there is a small problem with OHC and acidification trends. Either heat is sequestered easily in deep ocean (it would solve the mystery of Trenberth's missing heat) or not. In the first case dissolved carbon dioxide should go down just as easily, making serious large scale pH change impossible. In the second case Earth is simply not accumulating heat whenever it does not show up in the upper layer of oceans. As it happens for extended periods, how comes heat is not trapped as it is supposed to? -
Berényi Péter at 12:00 PM on 11 July 2010Hotties vs Frosties?
#79 kdkd at 11:23 AM on 11 July, 2010 you have to make the assumption of a perfect measurement model No. It's just correct error bars and clear statement of uncertainties I am looking for. It is also perfectly legitimate and scientifically correct to say under certain circumstances that W e d o n o t k n o w. -
Berényi Péter at 11:52 AM on 11 July 2010Hotties vs Frosties?
#76 chris at 10:34 AM on 11 July, 2010 Chris, none of your references addresses the question what's happened in 1990 that suddenly prevented heat going deeper than 700 m while global ocean overturning rate didn't show any abrupt decline. In fact of course nothing like that has happened. It was instrumentation that changed abruptly.
-
kdkd at 11:23 AM on 11 July 2010Hotties vs Frosties?
BP #66 "no, I am not advocating a pure reductionist approach here" Well you're exposing your prejudiced approach to the topic then, because it's impossible to reconcile this with your statement that "each piece of evidence should be able to stand on its own right, irrespective of any support that may or may not come from another domain" (#40). For these two statements to be consistent with each other I think you have to make the assumption of a perfect measurement model, and probably a host of other spurious things such as a lack of interdependence in the system, a lack of stochasticity, both of which are clearly false. We certainly don't see any admission of interdependence in your arguments, despite the fact that the climate system is clearly made up of highly interdependent subsystems. -
owl905 at 11:12 AM on 11 July 2010Hotties vs Frosties?
If this had appeared on a history test, the question would have been “What British Prime Minister conducted his relationship with Germany like this?” And the answer would have been Stanley Baldwin. The issue itself is presented as less important than the argument, like a child watching his parents have a fight; ‘the pro-pollutionists are just a bit misguided and protective of their standard of living.’ The science itself is sanitized and diffused with the use of the word ‘believe’ for all positions. The convoluted use of the cube example illustrates how to miss the point – there is a reality answer for the cube, just as there is one reality answer for the effect of GHG pollution increases. It’s not public v private funding, and it’s not which brand is best. The ‘proof’ duck in the comments is an example of removing reality from the issue. The response is simple - ‘Prove the Greenhouse Effect doesn’t exist’. Failing that, there is a global issue of urgent priority. Here are some existing proofs: Micro: The heat properties of GHG gases at the chemistry level; Observable: The heating rate of three (or more) beakers filled with air, exhaled breath, and CO2 gas on a tabletop (identical heat sources); General: The unsaturated nature of the effect - repeat the tabletop experiment in rooms with various levels of background CO2 (outdoor, indoor, closed office building); Macro: Variation in effect when none, weak, moderate and super-charged atmospheres are present - the four inner planets and the Moon; Historical: The growing GHG anomaly since the industrial revolution started; Analysis: The human sources of the GHG gases. Therefore, the increase in concentration of Greenhouse gases will, as a consequence, facilitate increases in global temperatures. Proof: the data trends since 1880 validate this proposition. The biggest fallacy in the article is that getting along is more important than getting something done – while the pollution-rate is accelerating. Semczyszak gave the best example of the pro-pollution bankruptcy – “Schwartz's work … “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.” That’s incorrect – that’s being diagnosed with a disease that will kill you, but you won’t do anything before you know how fast. It’s the weakest response. This article comes up very short; it implies that there is, effectively, a static problem out there and some side discussion gets everyone to eventually buy in on a right, or at least really good, answer. The problem is accelerating. The responses so far have been minimal, discredited, and sabotaged. This article forgets to actually face the problem and take a a stand. While the intent of the article is commendable, perhaps even a pinch of noble, it recommends pause. That is actually further pause - inaction and delay is turning into drift and analysis paralysis - just as it did with Stanley Baldwin's foreign policy. -
philipm at 10:35 AM on 11 July 2010Hotties vs Frosties?
There are actually three categories, not two:- hotties – people who believe firmly that AGW is happening
- frosties – people who believe firmly that AGW is not happening
- scientists – people who believe the theory should stand up to testing against the evidence
-
chris at 10:34 AM on 11 July 2010Hotties vs Frosties?
Berényi Péter at 08:21 AM on 11 July, 2010 The evidence surely supports the conclusion that "global warming is still happening", doesn't it Peter? Sea levels continue to rise at a rate that is larger than can be accounted for by the apparent mass increase (indicating continuing heat uptake), and the measures of ocean heat uptake although seemingly reduced during the period between around 2003-7/8 are positive if one includes estimates of ocean heat at depths [Murphy et al. 2009 and other direct measures of deeper ocean heat uptake (e.g. [*])]. The land ocean temperature index indicates that the Earth surface is warmer during the last 12 months than any previous 12 months in the record. So global warming is still occurring, even if there has been a short time period during which the apparent uptake of heat into the oceans may have been reduced somewhat. It might be preferable to state "The evidence supports the conclusion that global warming is still happening although there is some uncertainty in balancing the heat and sea level budget during the period 2004-2008." And there's also the rather philosophical problem relating to the progression of events (with inherent variability) into the present and future! After what period of time are we justified in stating that global warming is or isn't continuing? At the end of 2008 when there had been a short downturn in surface temperature and sea level could we conclude that "global warming is not still happening"? Not really, even though you attempted someting like that in a previous post with your fit of a truncated sea level dataset to a quadratic to infer a deceleration; 18 months later the surface temperature is near a high record, the sea level rise has recovered such that it's pretty much smack on the decadal trend, and the quadratic fit of the full record is more or less equivalent to a linear fit. So obviously we need to be careful not to jump to conclusions based on events occuring during short time periods. P.S. In a post above you asked: "Even better, show us references to the peer reviewed literature where the problem is discussed." It's discussed in Cazenave (2009) and Leuliette and Miller (2009) cited below, as well as in these papers [**](amongst others). [*] e.g. Cazenave A et al. 2009. Sea level budget over 2003–2008: A reevaluation from GRACE space gravimetry, satellite altimetry and Argo. Glob. Planet. Change 65:83–88 who estimate a 0.37 (+/- 0.1) mm.yr-1 heat uptake contribution to sea level rise during 2003-2008 based on ARGO data down to 900 metres. see also Leuliette E, Miller L. 2009. Closing the sea level rise budget with altimetry, Argo and GRACE. Geophys. Res. Lett. 36:L04608 who estimate a 0.8 (+/- 0.8) mm.yr-1 heat uptake contribution to sea level rise during 2003-2007 from ARGO data. see also papers from Johnson et al who find significant recent heat uptake in the deep oceans: Johnson GC et al. (2006) Recent western South Atlantic bottom water warming Geophys. Res. Lett. 33, L14614 Johnson GC et al. (2007) Recent bottom water warming in the Pacific Ocean J. Climate 20, 5365-5375. Johnson GC (2008) Warming and Freshening in the Abyssal Southeastern Indian Ocean J. Climate 21, 5351-5363. Johnson GC et al. (2009) Deep Caribbean Sea warming Deep Sea Research. 1 –Oceanograph. Res. 56, 827-834. [**] A. Cazenave and W. Llovel (2010) Contemporary Sea Level Rise Annu. Rev. Mar. Sci. 2010. 2,145–73 K.E Trenberth (2009) An imperative for climate change planning: tracking Earth’s global energy Curr. Op. Environ. Sustain. 1, 19–27 K. E. Trenberth and J.T. Fasullo (2010) Tracking Earth’s Energy Science 328, 316-317. -
johnd at 10:22 AM on 11 July 2010Tai Chi Temperature Reconstructions
Peter Hogarth at 10:06 AM, it's not actual numbers that is important within itself, but whether or not those numbers are representative of the whole environment under study. Hovering around 50% selection as a start is hardly representative, especially when further attrition can be found as the processing continues. As the quality and quantity of data collection advances, any modelling for reconstructions of earlier periods must be validated against the most recent data. Having done that, the earlier reconstruction data cannot then be used as validation of the later data. It's the cat chasing it's own tail. -
Philippe Chantreau at 10:15 AM on 11 July 2010Hotties vs Frosties?
BP you have already proven in the ocean acidification thread that you are looking for certain things in the data, that you will find them even if they are not there and that you will share with all your emotional response to what is not there. You're doing it again now with the "rather weird" and other comments. Yet, once again, you have only taken a superficial look, and fall far, far short of the standards to which you are willing to hold everybody else. I'm not impressed with you claiming some sort of high ground while systematically suggesting ill intentions in every piece of science that you dislike. Especially when such suggestions are based on nothing more than a biased, cursory look. Drop the accusations if you can't back them up with something really solid. -
Peter Hogarth at 10:06 AM on 11 July 2010Tai Chi Temperature Reconstructions
johnd at 09:39 AM on 11 July, 2010 That’s some back yard John!
How many trees over what sort of area would you find to be a convincing sample? I think these researchers have used sufficient numbers. Their methodology is fully explained and makes sense. Why would they use later data to validate anything when they are specifically looking for DP or late 20th century effects in the later set? surely they would use earlier (presumably less affected) data as reference?
-
johnd at 09:39 AM on 11 July 2010Tai Chi Temperature Reconstructions
Peter Hogarth at 08:21 AM, I think it is very clear that the term "site" can only refer to a collection of individual trees, trees which in this case had been predetermined as being able to reflect temperature changes. As for the number of trees per site, the average number of larch trees in a site appears to be 50, and the average number of spruce trees appears to be 26. That is not many trees nor likely a very big area. In fact my back yard would have more fully grown trees than the average spruce site and possibly the average larch site as well. However given that only about half the available sites were selected seems to indicate that there was only an 50/50 chance that the trees would adequately reflect the correlation required, so that opens up the possibility that something other than the trees has a deciding influence, perhaps something related to the site conditions rather than the tree species itself, perhaps even the divergence problem was evident at those sites not selected. Can Buntgen legitimately claim a greater than 50% confidence, a toss of a coin, in their findings based on their selection process? They should at least explain why the high rejection rate. Another factor that reduces the number of effective trees under study is their age. Using larch as an example, the trees ranged in age from 65 to 447 years, the average 210 years. Given the total period of the study was 1864-2003, 139 years, a certain proportion could only be tracked for a reduced portion of the study period. However that is diverging away from why my confidence was perhaps not as inspired as yours. It seems to me that given one set of data covered the period 1864–1933 and the other 1934–2003, it should be that the latest set of data should be what is used to validate the earlier set, not the other way around as was done in the Buntgen 2008 study.
Prev 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 Next
