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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.
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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:
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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.
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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
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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?
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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. -
Rob Painting at 09:32 AM on 11 July 2010Hotties vs Frosties?
"Furthermore, there is the (not well advertised) issue of different adjustment procedures being applied to US data and the rest of the world." - BP And what exactly would that be?. -
Berényi Péter at 09:02 AM on 11 July 2010Hotties vs Frosties?
#25 carrot eater at 22:40 PM on 9 July, 2010 Anybody can take the existing data sets and analyse them in their spare time, with no funding at all I am doing just that. Downloaded GHCN v 2.0 data, selected USHCN stations, and analysed adjustments done in v2.mean_adj.Z (relative to v2.mean.Z). The result looks like this:
The adjustment pattern is rather weird. Middle line (red) is average adjustment for each month, upper (yellow) and lower (blue) lines are 1 sigma error limits.
We can see a rather smooth adjustment trend (and two discontinuities around 1918 and 1950) with an upward slope which accounts for a good portion of 20th century warming in the US. Also, the dispersion of adjustments is huge compared to the trend. And there is a large seasonal signal of smoothly varying strength. Beyond April 2006 adjustment is zero.
With no further explanation it does not increase one's confidence in surface temperature reconstructions done by professionals.
Legitimate adjustments necessitated by instrumental bias simply can't look like this.
Furthermore, there is the (not well advertised) issue of different adjustment procedures being applied to US data and the rest of the world.
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KR at 08:47 AM on 11 July 2010Sea level rise is exaggerated
Daniel - Something you haven't really addressed (at all, and I don't count your ad hominem statements) is that the paleo data indicates sea level, not sea level rise rate. The rise rate is extrapolated by looking at multiple measurements of sea level. 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. 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. The only way a rise at those rates could occur and still fit the data (including the error bars) would be if the SLR went negative (or close to it) long enough for the long term sea levels to still average 1.0+/-0.2 mm/yr. If you have a physical process for something like that, I would love to see it. If this was measuring rate of rise, there are a lot more degrees of freedom. But these measurements are of sea level, and the long term historic rate is clearly about half the current rate. That's why I said "reversible", and why I don't feel your hypothesis of high variability and equally high rise rates in the past can hold, unless you also postulate extremely low SLR levels. The current rate of 2.4mm/yr is well established by tide gauge data, Donnelly submits evidence for ~1.0mm/yr for the 1300-1850 era - and your graph fit falls within his error bars for that rate. Sparse data or not, if a high SLR rate occurred in that period, it would have to be matched by a low SLR rate for the long term trend in sea level to still be ~1mm/yr. If you don't get that, well, end of discussion for me. I'm not going to waste my time yelling at the deaf. -
CBDunkerson at 08:33 AM on 11 July 2010Hotties vs Frosties?
gallopingcamel #55 wrote, "You folks are mostly with the IPCC that predicts a warming as high as +4.0 Kevin per doubling of CO2 concentration. IMHO +0.5 Kelvin is a much more likely figure." Radiative physics suggests a figure of just under 1 C from the CO2 alone without considering any feedbacks. Thus, to get to a 0.5 Kelvin/Celsius result we'd have to assume significant negative feedbacks. However, measured results show a very different story. We passed +0.5 Kelvin a couple of decades ago and still aren't anywhere near a doubling of CO2. Ergo, your "much more likely figure" has already been exceeded by the measured warming... which indeed is now nearly double that amount. This suggests positive feedbacks and leads to the '2 C minimum / 3 C most likely / 4.5 C possible' values now being projected. -
chris at 08:30 AM on 11 July 2010Hotties vs Frosties?
Berényi Péter at 05:43 AM on 11 July 2010 #8 perseus at 19:06 PM on 9 July, 2010 "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." I think there is some truth in that, although it would be more realistic to broaden the peer-review procedure to include all of the pre-publication peer assessment that involves (i) presentation of one’s work at group seminars; presentation at departmental seminars, (iii) presentation at scientific meetings. Published work of any importance has usually gone through an extensive peer review process of this sort before a paper is submitted, and work of any merit is generally submitted in the expectation that it will be published. Berényi Péter at 05:43 AM on 11 July 2010 "There was also a secret motive, to compensate for declining willingness of people to take personal responsibility and increasing reluctance of society to accept responsibility and conscience as assurances." I’m not sure there’s much evidence for that Peter. Peer review in its modern form is largely a means of spreading the burden of quality assurance away from journal editors in the light of a huge increase in scientific publication, and establishing a more reliable and systematic means of maintaining the quality of published work. One of the often forgotten things in these dreary times where everything is subject to “politicisation”, is that peer review is simply a good way of improving the quality of published work. It’s blindingly obvious that those with expertise in a subject are best suited to addressing real or potential flaws, inconsistencies or confusions, and generally to improve the presentation and to offer thoughts and suggestions. In my experience that’s a major element of peer review (‘though it doesn’t always work so nicely). More significantly, Perseus’s comments about “dedication to the truth”, and yours on “declining willingness of people to take personal responsibility”, are the diametrically opposed idealistic (perseus) and cynical (Peter) views of science and scientists. I believe perseus is far closer to the reality. The large majority of scientists are motivated by doing good work, finding out stuff, hopefully something quite important occasionally, and making a productive contribution to their field. It’s the inherent integrity (their “willingness to take personal responsibility”) of the large majority that make scientific publishing (and the peer review part of this) rather successful. I would say scientists recognise that they have an individual and collective responsibility to get things as right as they are able. Likewise scientists interact with a natural world that has an inherent reality (there are philosophical viewpoints that dispute that!), and their work and interpretations are constrained by that reality. Despite many efforts by pseudoscience misrepresenters it is simply not possible to maintain the deceit, for example, that smoking cigarettes doesn’t increase the risk of cancer, or that oil can’t form naturally since it’s seemingly impossible for “low chemical potential biological detritus to high chemical potential hydrocarbons with no external free energy source” (false premise)... and so on. The inherent reality of the natural world can be considered a fundamental element of peer review. Your example of the journal “Homeopathy” is another example of unnecessary cynicism. If one wishes to trash a process (like peer review) one may wish to root around for the dismal examples with which to flay the entire process. But science, and scientific publishing will survive “Homeopathy”! Much like “Energy and Environment” we can recognise it for what it very likely is. I’m not going to comment further on “Homeopathy” since I haven’t looked at the journal in detail. However it’s unlikely to be an important element of the progression of scientific knowledge since no one seems to cite the papers there (it has an Impact Factor of around 1). So not a great problem really, 'though it might be wasting rather a lot of money and effort to little effect. -
Berényi Péter at 08:21 AM on 11 July 2010Hotties vs Frosties?
#68 chris at 08:03 AM on 11 July, 2010 Who said anything about "proof" Peter? What an odd thought! You are right, it is never proof, it is picture. Is global warming still happening? "Combined with the results of Murphy 2009, we now see a picture of continued global warming" -
Peter Hogarth at 08:21 AM on 11 July 2010Tai Chi Temperature Reconstructions
johnd at 10:01 AM on 10 July, 2010 John, you may be confusing selection of sites with selection of individual trees when you state: “It relies not only the selection of species, but the selection of individual trees whose growth is considered to faithfully represent a robust relationship between growth and temperature” and you then quote a section from the abstract which refers to selecting numbers of sites? Reading past the abstract, “A dataset of 3069 larch and 1600 spruce TRW series from 124 sites (62 per species) distributed across the European Alps was compiled” We then see that 64 sites are selected from the network of 124 sites, but this is spread over a wide geographical area and each site may contain hundreds of individual trees. The methodology for site selection is discussed. I would hope this increases your confidence? I suggest you will find the later references from Esper and Buntgen very interesting, it is not that the DP has been disproven or dismissed, just found to be more prevalent at sites of high latitude or elevation (for example), and not as widespread as previously assumed. From Buntgen 2009 “Therefore, the DP should not be thought of as an endemic large-scale phenomenon with one overriding cause, but rather a local- to regional-scale phenomenon of tree-growth responses to changing environmental factors including multiple sources and species-specific modification” -
Berényi Péter at 08:11 AM on 11 July 2010Hotties vs Frosties?
#37 Lou Grinzo at 23:56 PM on 9 July, 2010 I don't see how anyone can escape the conclusion that further delay in reducing our CO2 emissions would put us on an almost unimaginably bad path Are you advocating quick development and en masse deployment of either uranium or thorium based breeder reactors? If carbon dioxide is such an evil thing, there is no other commercially viable alternative. Just do the math. Am . J. Phys. 51(1), Jan. 1983 Breeder reactors: A renewable energy source Bernard L. Cohen Department of Physics. University of Pittsburgh, Pittsburgh, Pennsylvania 15260 -
chris at 08:03 AM on 11 July 2010Hotties vs Frosties?
Berényi Péter at 07:41 AM on 11 July 2010 "Until that time stop citing this paper as proof of warming...." Who said anything about "proof" Peter? What an odd thought! Is there a problem with Murphy 2009 and Levitus 2009 etc? Well yes, they're very unlikely to be fully correct are they? That's the nature of science in the delightful areas of uncertainties. In this particular arena there are some confusing uncertainties especially during a rather short period where the apparent OHC is seemingly incompatible with TOA radiative imbalance and the sea level rise doesn't quite match the apparent independently determined thermal and mass contributions. So it's a little bit of a mess right now wouldn't you say? But what is to be gained by continually pointing this out and prodding it like a sore tooth? Why not simply embrace this little uncertainty, and wait for the interesting developments that are sure to shed light on it in due course. However much one redisplays the graphs and fiddles around with the numbers we're probably not going to come with the answers on this blog. Of course you might come up with some interesting theories, and that can be quite entertaining. Otherwise I would suggest avoiding using uncertainties in sub-issues (however delicious these often are) to support dubious brutalist deductive "logic" whereby one chooses one's conclusions and then rummages around in the uncertainties to construct premises that support these. It isn't very scientific. -
Berényi Péter at 07:53 AM on 11 July 2010Hotties vs Frosties?
#48 e at 02:36 AM on 10 July, 2010 This is a blog, we aren't performing the scientific method here I see. -
Berényi Péter at 07:49 AM on 11 July 2010Hotties vs Frosties?
#52 kdkd at 09:00 AM on 10 July, 2010 The only people who claim that pure reductionism is a valid approach for studying complex systems are those who have not had to think deeply about the problem. I have done my share of work in studying complex systems. And no, I am not advocating a pure reductionist approach here. But the fact you may have emergent phenomena in complex systems does not justify a sloppy approach. It is imperative to have all the basics right. -
Peter Hogarth at 07:48 AM on 11 July 2010Sea level rise is exaggerated
daniel at 14:18 PM on 10 July, 2010 To summarise: The original paper provides evidence used to suggest a relatively recent acceleration in sea level rise. The recent trend is taken from tide gauge data. This is accurate and errors small. We can take this as the "real" local relative sea level rise since 1856. The question is, what was the local sea level doing before 1856? Several data points derived from peat sediments are given where the dating of the sediment has uncertainties. Two more points are derived from heavy metal polution and pollen. A linear trend is fitted to these points which is less than half of the tide gauge trend, hence, acceleration. You argue that the longer term trend fitted to the sparser points may be hiding short term variations and other possible periods of acceleration. I argue that any variation is constrained by the error envelope of the points and the physical processes which might cause fast variations. 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). I'll see about a chart with the actual tide data etc. -
Berényi Péter at 07:41 AM on 11 July 2010Hotties vs Frosties?
#43 chris at 02:00 AM on 10 July, 2010 there is a limit to how much we can productively "gnaw over" these [OHC issues] on a blog such as this Why? I have already shown you there is a problem with Murphy 2009.
It is inconsistent with the NODC OHC history reconstruction.
At least if both accounts are considered to be roughly correct, it follows between 1977 and 1990 about 4×1022 J of heat was sequestered in the deep ocean (below 700 m) without ever touching the upper layer. Then this process was interrupted, after that date all heat kept staying up.
In the meantime, as documented in Marsch 2000 Fig. 12. (a). there was no any abrupt change in total ocean overturning. The whole thing looks next to impossible.
The reason I keep gnawing over this issue is Google shows 152 references to this paper at the moment at skepticalscience.com. Therefore it must be pretty important from your point of view.
But until the strange discrepancy is explained, either Murphy 2009 or Levitus 2009 should be considered wrong (or both).
I do not want you to solve this particular problem, it is, as you say, a blog after all. Just acknowledge the problem exists. Even better, show us references to the peer reviewed literature where the problem is discussed. Or explain why is it ignored.
Until that time stop citing this paper as proof of warming, because with no further details supplied, the most probable explanation is that prior to mid 2003 (large scale deployment of ARGO) global OHC measurement is simply unreliable.
-
John Russell at 06:44 AM on 11 July 2010How Jo Nova doesn't get past climate change
I looked at the comments on Jo Nova's site and got fed up after a few minutes of all the repetitive -- and meaningless -- "good on ya' Jo, you really showed them scientists a thing or too!" (or similar). 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. -
muoncounter at 06:27 AM on 11 July 2010Hotties vs Frosties?
"The hotties look at the data in the light of their models, and see something different. The point of difference is not that they see different things, it is the presence or absence of an underlying model of what they see." Unfortunately, the discussion often devolves into stylistic debates. There seem to be some who want to find models that fit data and others who suggest that models should tell data where to go. As an easy example -- Model: everyone knows human activity can't be causing global warming; Conclusion: any data that shows warming is invalid. But what happens when the discussion is merely "your data doesn't look like I think it should"? Or more insidiously, "your data doesn't look like my model results say it should"? I'm with Conan-Doyle on this: "It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, rather than theories to suit facts." -
Berényi Péter at 05:43 AM on 11 July 2010Hotties vs Frosties?
#8 perseus at 19:06 PM on 9 July, 2010 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 Come on. There is a peer reviewed journal of Homeopathy on ScienceDirect. Does it make homeopathy a valid branch of science? Do you think those folks do not insist on being dedicated to truth? Is there no fierce competition in that field? The anonymous peer review process as it is practiced recently is an invention introduced after WWII in America then spread like wildfire all over the world. It was to ensure taxpayer's money went into sound research, not crap and also to keep up the prestige of popular journals. There was also a secret motive, to compensate for declining willingness of people to take personal responsibility and increasing reluctance of society to accept responsibility and conscience as assurances. Read some more on the subject. Michael Nielsen Three myths about scientific peer review January 8, 2009 at 2:18 pm · Filed under The future of science The New York Times THE DOCTOR'S WORLD When Peer Review Produces Unsound Science By LAWRENCE K. ALTMAN, M.D. Published: June 11, 2002 Unfortunately people all too often mix up the very different concepts being dedicated to truth vs. to a noble cause. -
Riccardo at 04:34 AM on 11 July 2010Sea level rise is exaggerated
daniel, i see your point, but you're comparing the values of sea level with sea level rise, i.e. the trend. It doesn't matter if the recent "high" resolution sea level data fall within the uncertainty of the sedimentary trend, what matters for Donnelly conclusions is that the two trends are significantly different. -
JMurphy at 04:31 AM on 11 July 2010Hotties vs Frosties?
johnd wrote : I wonder what odds Mr. Annan would consider a fair bet? Well, let's see : If Lindzen believes the earth will be cooling over the next 20 years (from 2005) and Annan believes it will continue to warm, then it's a straight bet of one man's money against the other's. Who needs odds...unless you're not confident of winning and want to put the other person off ? -
chris at 03:27 AM on 11 July 2010Hotties vs Frosties?
gallopingcamel at 15:21 PM on 10 July, 2010 "It is clear that increasing levels of CO2 in the atmosphere will cause warming. You folks are mostly with the IPCC that predicts a warming as high as +4.0 Kevin per doubling of CO2 concentration. IMHO +0.5 Kelvin is a much more likely figure. It is a shame that nobody is likely to be able to measure this quantity with any accuracy in my lifetime." That's an odd set of comments if you don't mind me saying so gallopingcamel. What evidence lends you to believe that climate sensitivty is so low? On the contrary, there seems to be a very large amount of evidence that supports a climate sensitivity between 2 - 4.5 oC (per doubling of [CO2]), which is quite well constrained at the low end (little likelihood of climate sensitivity below 2 oC[*]), but poorly constrained at the high end (scientifically poor basis for rejecting higher climate sensitivities). See for example Knutti and Hegerl’s recent review. R. Knutti and G. C. Hegerl (2008) The equilibrium sensitivity of the Earth's temperature to radiation changes Nature Geoscience 1, 735-743 [*] In fact it's increasingly difficult to see how climate sensitivity could be below around 2 oC (per doubling of [CO2]. For example, the Earth has warmed by around 0.8-0.9 oC since the middle of the 19th century, while [CO2] has risen from around 286 ppm then to 386 ppm now. A climate sensitivity of 2 oC should then give an equilibrium warming of: ln(386/286)*2/ln(2) = 0.85 oC We know that the Earth can't come instantly to equilibrium with the enhanced greenhouse forcing: we have a significant amount of warming to come from the greenhouse gas levels already attained. Likewise we know that some of the warming from the existing greenhouse gas levels has been offset by enhanced anthropogenic aerosols which are counteracting greenhouse induced warming. On the other hand some of the warming is due to non-CO2 sources (man-made methane, nitrous oxides, tropospheric ozone, black carbon). Non greenhouse gas contributions to this warming (solar, volcanic) are known to be small [**]. Overall if we've already had the warming expected from a 2 oC climate sensitivity, and we still have some warming still to come, and some of the warming has been offset by atmospheric aerosols, the likelihood of a climate sensitivty below 2 oC is really rather small (something extremely large must be missing from the known physics). What's your explanation gallopingcamel? [**] see for example: Knutti and Hegerl (see above), Murphy et al. (2009), Rind and Lean, 2008, Hansen et al (2005), etc. -
Sean A at 02:24 AM on 11 July 2010Hotties vs Frosties?
GC provides an example of the denialist tactics: exaggerate, spin, and disregard evidence. There is good evidence that indicate climate sensitivity for doubling CO2 is at least 1.5 and at most 5 degrees C, so 2 to 4 is a good estimate. This is a reasonable conclusion from looking at all the science that's been done on the subject (which is what IPCC does). Yet here Mr. GC says all us warmers believe it's on the high end (we don't), while he asserts (with no evidence) that the value is much lower than the low end of the reasonable estimate. Because even 2°C is not good news for human society. Yet somehow pure wishful thinking is supposed to trump what the accumulation of scientific evidence is telling us. As usual, Real Climate provides excellent guidance on this subject: The certainty of uncertainty "The bottom line is that climate sensitivity is uncertain, but we can pretty much rule out low values that would imply there is nothing to worry about. The possibility of high values will be much harder to rule out." -
daniel at 22:53 PM on 10 July 2010Sea level rise is exaggerated
Sorry Riccardo, to answer your question more directly, I don't think this particular comparison is valid at all. You also say that the tide gauge data has more deviation than 0.2mm/yr. Could you explain what you mean by that? Donnelly believes his long term trend may deviate overall by 0.2mm/yr over a ~550 year period. You can't compare that to the deviations in the tide gauge data and say that the tide gauge data is more noisy. There are no error limits placed on the short term linear trends discussed by Donnelly for the tide gauge data. You cannot compare visual non-quantified scatter to statistically determined error limits of a linear trend. Even if there were error limits on the proposed short term trends you should be able to see that I have shown that the tide gauge data can lie on a shallow long term trend of paleo data (samples 1-11) with a rate (1.2mm/yr) within the error limits proposed by Donnelly (1.0 +/- 0.2mm/yr).. -
DarkSkywise at 21:42 PM on 10 July 2010Hotties vs Frosties?
johnd #58: "That means he doesn't believe that warming is virtually certain to use IPCC terminology." Why? Somebody who's only prepared to put up £200 if you're willling to pay $10,000 is deliberately making the stakes too high, so the other will back down. "I'm sure, you're sure, but I'll let you run all the risks." I'm not a betting person, but even if I was, I wouldn't bet against somebody who wouldn't be willing to run any risks himself. ;) -
johnd at 19:40 PM on 10 July 2010Hotties vs Frosties?
John Russell at 18:35 PM, it is telling that Dr. Annan wasn't prepared to accept odds of 50-1. That means he doesn't believe that warming is virtually certain to use IPCC terminology. Based on IPCC defined likelihood of an outcome, the betting odds should be as follows:- "Virtually certainty" of warming occurring would roughly equate to odds of 100-1. "Extremely likely" of warming occurring, probability > 95%, would roughly equate to odds of 20-1. "Very likely", probability > 90% equates to roughly 10-1. I wonder what odds Mr. Annan would consider a fair bet? IPCC REPORT DEFINITIONS Likelihood of an outcome or result Virtually certain > 99% probability of occurrence Extremely likely > 95% Very likely > 90% Likely > 66% More likely than not > 50% Very unlikely < 10% Extremely unlikely < 5%. -
daniel at 19:26 PM on 10 July 2010Sea level rise is exaggerated
Riccardo, you have been absent from the discussion and it may pay for you to back track a little. I do not dispute any of the trends discussed or proposed by anyone I only dispute the argument made against me that significant deviations from the long term trend are impossible, highly unlikely or have been shown to not exist at Barn Island. Such short term deviant trends in the paleo data set would undermine any conclusiom of an unusual modern uptrend. I also have gone so far as to say that this is a good example of poor science swallowed by people who should know better but are blinded by fear of impending doom. -
CBDunkerson at 19:19 PM on 10 July 2010Hotties vs Frosties?
Baa Humbug #29, can you even NAME a scientist who says that AGW does not exist? Not that it might not be as bad as projected, but that it actually is not happening. I've seen a few, but in each case they've been pushing COMPLETE nonsense which flies in the face of basic physics (e.g. 'infrared radiation is magically prevented from traveling from a colder atmosphere down to a warmer planet'), mathematics (e.g. 'If we take a derivative to factor out the ongoing rise in temperatures then they correlate to natural process XYZ - ergo there is no ongoing rise'), and/or logic (e.g. 'CO2 levels go up and down all the time because 70 year old records taken outside factory districts show wild fluctuations'). Thus, if you think there ARE rational scientists who claim AGW is not happening at all I'd love to see their work. If not, then why can't we be done with a claim which NO ONE can provide support for and concentrate on the question of degree? Yes, I believe even there 'sceptics' are out on a VERY long limb, but they've still got SOME rational foundation for doubt. The biggest problem I see with their position is that IF they were right about all of the negative feedbacks in the climate system we ought to have seen those effects showing up by now. Yet MEASURED warming is on pace with 3 C per doubling of CO2 projections. -
John Russell at 18:35 PM on 10 July 2010Hotties vs Frosties?
Galloping Camel says, "...we could make some wagers." This is the crunch. If we 'warmists' are willing to take on the deniers directly by asking them to bet on outcomes, I think the reality would strike very quickly. And I can assure everyone it's a great way to shut someone up. The following is from an article in the Guardian "The bet is the latest in an increasingly popular field of scientific wagers, and comes after a string of climate change sceptics have refused challenges to back their controversial ideas with cash. Dr Annan first challenged Richard Lindzen, a meteorologist at the Massachusetts Institute of Technology who is dubious about the extent of human activity influencing the climate. Professor Lindzen had been willing to bet that global temperatures would drop over the next 20 years. No bet was agreed on that; Dr Annan said Prof Lindzen wanted odds of 50-1 against falling temperatures, so would win $10,000 if the Earth cooled but pay out only £200 if it warmed. Seven other prominent climate change sceptics also failed to agree betting terms. In May, during BBC Radio 4's Today programme, the environmental activist and Guardian columnist George Monbiot challenged Myron Ebell, a climate sceptic at the Competitive Enterprise Institute, in Washington DC, to a £5,000 bet. Mr Ebell declined, saying he had four children to put through university and did not want to take risks." So are we going to set up a really big fund to take on the deniers, with a handsome payout if they're proved right? I tell you; you won't see them for dust!
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