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Helena at 11:10 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
In my message 21 "(-snip-)" = "indicate" Sorry for the all caps. -
Helena at 11:09 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Eric : We'll see, if it disappears again i'll get rid of the all caps for the word "indicate". My all caps is Tom's bold (dunnow how to get my text in bold here). Anyway, on your message 20, here we are merely discussing communication skills and scientific rigor, not the reality of warming. Anyone who looks at the temperature trend see that it is warming. I've read KR response on the other thread about linear increase or acceleration in temperature trend and exponential CO2. What he says is not entirely correct, the exponential of the CO2 is taken care of by the log of forcings, it doesnt really play there (the exponential, not the CO2 !). What matters (in a simplified version) is the relaxation time. That tells you whether the response will be linear or quadratic. But it's out of topic here. Anyway, i'll just wait a few mins see if my post stays, then gotta go. Thanks for the discussion. Cheers -
Eric (skeptic) at 11:01 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Perhaps it was your use of all-caps (tat is forbidden) -
Helena at 10:56 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Sphaerica @18 What are you talking about ? I did provide graphs (cf previous posts) Tom @19 1/ As i said, that merely shows that uncertainties on the trends are quite large. 2/ So you do agree with me that the 75yr trend goes against the picture presented of increasing trends, right ? You said yourself : "It is not necessary that the error bars be miniscule for the purported IPCC claim to be correct. It is only necessary that the measured trend be greater." Therefore, according to your own standards, i did show that the measured trend for the 75yr trend was not greater, and that had the IPCC been consistent and depicted all 25yr periods without leaving out the 75yr trend (cherrypicking ?), the IPCC assertion would not have been possible. According to my standards, all i am doing here is pointless because, as i said, comparing trends of different lengths is meaningless. You can find any result you are looking for. 3/ You challenged me by saying "it is not possible to pick arbitrary end points mimicking the IPCC graph, and to show a deceleration over the temperature record as a result. You have no counter example to the IPCC's procedure. " I found the counterexample with an arbitrary starting point (1910) and decreasing trends mimicking the IPCC graph (25, 50, 100yr trends). Again, according to your own standard and following IPCC procedure where, as you say yourself "it is only necessary that the measured trend be greater", i've succeeded. Now that you have it you seem unhappy that it exists. "The reason is that you are, fairly obviously, cherry picking artifacts of noise in an accelerating temperature trend. " Of course I am cherry picking the starting point ! You challenged me by saying that i wouldn't be able to find an arbitrary point and mimick the IPCC procedure with decelerated trends. So i looked for it and found it. Now let's get back to what it all means : what the ipcc says is that their increasing trends (-snip-) accelerated warming. Clearly that statement is wrong. Increasing trends don't (-snip-) an accelerated warming, and decreasing trends (my example) don't (-snip-) a decelerated warming. They don't (-snip-) anything. I don't understand that you guys can defend such a graph. Isn't it easier to just admit that it was not the best chosen graph to depict that warming is accelerating ?Moderator Response:[DB] Please acquaint yourself with this site's Comments Policy (link next to every comment input box). It is noted that, more than anything, you are simply being argumentative for its own sake.
Multiple usages of all-caps snipped.
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Eric (skeptic) at 10:55 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
In a previous thread about the graphic above, I basically agreed with KR"s conclusion here. I think the graphic shows a particular type of acceleration over the long term (century timescales). As I noted in that thread they left out the 75 and the 125 year trends which narrows their definition of acceleration and would add noise to the visual. The idea of noise from natural variation is an important part of the analysis of acceleration which this graphic does not attempt to provide. -
Tom Curtis at 09:58 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Helena @13: 1) Nobody who is arguing a case that depends critically on choosing just one of two available temperature indices should be talking about "arguing mere semantics". The Gistemp Land Ocean Temperature Index (LOTI) shows a trend of 0.0169576 C per year from 1981-2005, a trend of 0.0139565 C per year from 1917-1941, and a trend of 0.0134231 C per year from 1918-1942. For what it is worth, HadCRUT4 also shows a reduced trend over the 1910-1940 period, and an increased trend over the 1970-2010 interval, although obviously I do not have precise trends. 2) The 75 year trend is 0.00650795 C per year, compared to 0.00722857 C per year for the 100 year trend. The difference, less than 0.001 C per year is less than the difference in trend you dismiss as merely semantic when it suites you. It is certainly not enough to alter the visual impact of the graph, or to alter the conclusions of the IPCC. 3) The 50 year trend from 1910 is 0.00761979 C per year; the 100 year trend is 0.00749844 C per year. The difference is just over 0.0001 C per year. What was that you said about merely semantic differences again? More importantly, the pattern is not preserved in Gistemp, in which the 50 year trend is greater than the 100 year trend. Clearly, therefore, you do not have an example showing deceleration in which successive trends from the start point are less than each other by a large (although not quite statistically significant in one case) margin. The reason is that you are, fairly obviously, cherry picking artifacts of noise in an accelerating temperature trend. -
Bob Lacatena at 09:58 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Helena, Nothing you are saying makes any sense... or bears out, when I look at the actual data. Up is up, no matter how you try to stand it. Please produce a graph (use woodfortrees.org if you like) that clearly proves your point. And try to do it without cherry picking end points and ranges. -
Helena at 09:21 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
At the end of my first paragraph, replace "cooling" by "decelerating warming" -
Helena at 09:19 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
dana @14 : don't you agree that my assertion stating that, over the 1910-2010 period, the decreasing slope for the linear trends of the first 25, 50 and the full 100years *indicates* cooling is untrue ? Well, in the same way, the assertion by the IPCC that the increasing slope for the linear trends over the last 25, 50, 100 and 150 years *indicates* accelerated warming is also untrue. Moreover, as shown above, the linear trend for the last 75 years goes in the wrong direction, so at the very least it should be considered as cherry picking the trend baseline to pick only the trends that agree with what you want to assert. This has nothing to do with climate science or denying that the world is warming (it is), it's just scientific rigor. Muoncounter @15 : Sorry but i am asking for qualitative reasons, not quantitative ones. "Short" and "long" are quantitative assessments : of course there are order of magnitudes of difference between the two timescales, but that's the whole point of my example. You cannot just say that because there are orders of magnitude of difference, the system has qualitatively a different behavior. Here is an analogy : From 101°C and orders of magnitude up, water is qualitatively the same : vapor. But from 99°C to 101°C, it is qualitatively different (phase transition) even though the temperature changes very little. The underlying question is : in a complex system, how do you know the timescale (if any) over which you can say that "internal variability" (to be defined) is filtered out. But that's out of topic here. -
Riccardo at 06:11 AM on 13 May 2012Turbines in Texas mix up nighttime heat
Betz's law says that the horizontal wind velocity can not be zero downwind and that there is a theoretical maximum efficiency of 60%; hence 40% of the "input" energy is still kinetic energy of the wind. If the real efficiency is for example 50%, i.e. it's electricity to be used elsewhere, the remaining 10% goes into heat due to electricity production losses, friction and viscosity due to the increased turbulence. The latter can then be just a few percent. Even that 10%, though, could be locally significant if sustained. But once it gets diluted by natural mixing over relatively large volumes I don't see how it could produce significant warming. I too think, with Nick, that we do not have a clear explanation of the tempemperature rise. -
Bob Lacatena at 06:10 AM on 13 May 2012Increasing CO2 has little to no effect
photeki, Hint... anyone who includes lots of words and graphs and numbers, but no actual mathematics, is being lazy and trusting to common sense and "thought processes" to qualify everything while quantifying nothing. More directly... his perspective and opinions are totally worthless. Is it not peer-reviewed because he's afraid the process is flawed, or just because he's so demonstrably wrong? How often do people get to walk onto the floor of the U.S. Mint and demand their fair share of freshly printed bills, because the money-review system is flawed and unfair and they deserve more? -
muoncounter at 04:31 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Helena#13: "you cannot prove that the impossibility to go from hours to 25 years is qualitatively different than the one going from 25years to 150years. " Really? 150/25 = 6:1 25 years = 219150 hours. Your examples of comparing temperatures 12 hours apart to temperatures 25 years apart yields 219150/12 = 18262.5:1 Comparing temperatures (and temperature trends) over short time frames to long time frames is qualitatively different - and extremely misleading. -
dana1981 at 04:23 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Helena, you seem to miss the point of this post. All the IPCC is doing is saying that in recent years/decades, global warming has accelerated. That is true. It doesn't mean that there can't be prior years with similar warming trends to that in recent years. We have discussed the 1910-1940 warming here and here. There's certainly nothing "misleading" about the IPCC figure. -
Helena at 04:20 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
True, that was a 26year period. So there is a 0.0017°C/year difference in the trend. Well i guess you're right if we stick to semantics, not to science rigor as the statement seems very much sensitive to error bars and to endpoints (ironically the statement would be wrong in AR5 as 1987-2011 is 0.0155809 per year). What about the 75yr trend i was talking about ? And the 1910 thing ? "Finally, with regard to your post 5, 12 hours is not a period long enough to represent a climatology." You know as much as i do that 30yrs it nothing more than a convention. Of course daily temperatures don't define a climatology, but 25year periods don't define one either (except by convention) and you cannot prove that the impossibility to go from hours to 25 years is qualitatively different than the one going from 25years to 150years. That's the whole point i'm making : having similar time periods is the minimum required (but not sufficient) when you compare trends ! -
Tom Curtis at 03:36 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Helena @9, you are obviously grasping at straws. It is not necessary that the error bars be miniscule for the purported IPCC claim to be correct. It is only necessary that the measured trend be greater. And the last datum on the IPCC graph is 2006. However, having just checked FAQ 3.1, I notice the IPCC calculated trends terminate in 2005. So, comparing the 1981-2005 trend (0.0188397 C per year), to that for 1917-1941 (0.0171067 C per year) and 1918-1942 (0.0171202 C per year). The difference is approximately 0.002 C per year. (Please note that 1980-2005 is a 26 year period.) Finally, with regard to your post 5, 12 hours is not a period long enough to represent a climatology. Therefore your analogy is specious. -
Helena at 03:17 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Ouch still a zero missing, sorry -
Helena at 03:17 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
I meant 0.02°C/decade (and 0.0002°C per year) -
Helena at 03:16 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Tom @ 8 Uhh i didn't know you could get the raw data, nice tool. Well, then i switched to to the 1917-1942 25yr-period. slope = 0.0178289 per year For the 1980 to 2005 period : slope = 0.0180092 per year And don't tell me error bars are smaller than 0.0002 °C/decade ! PS : How can the last point on the IPCC graph be 2006 as 2005 is not even depicted ? -
Tom Curtis at 03:06 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Helena @3, the trend for 1982-2006 (the last 25 years of the temperature record used by the IPCC) is 0.0202857 C per year. That from 1915-1940 is 0.014621 C per year, which is substantially less. That from 1980-2005 is 0.0180092 C per year. Of these three trends, that from 1915-1940 is lowest. That fact could easily have been checked by examining the raw data of your own plot. So, what you have shown is not that point number 2 is wrong, but merely that you are prepared to assert that it is without properly checking the data. -
Helena at 03:06 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
To sum it up (sorry for the length of the links, i hope it's not considered as spamming) : - I did find a counterexemple, that is say if you start in 1910 you can find that the first 25yrs trend is higher than the first 50yrs trends which is also higher than the full 100yrs 1910-2010 trend. - The IPCC picture does not work if you take the 75yr trend (1930-2005) that they don't depict (they skip from the 50yrs to the 100yrs) : the 75yrs trend is smaller than the 100years trend. How is taking the 75yrs chery picking, as you are stating yourself that it is based on 25years intervals ? - But maybe you think 75yrs is cherry picked and the 25yrs of your 2nd point applies to any 25yr-period ? Then I also showed you that the past 25yrs (1980-2005) have been warming at the same rate as the 1915-1940 25yrs period. -
Helena at 02:56 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Ok here it works with a common starting point in 1910 link 1 By the way, isn't it weird that IPCC represents 25, 50, .., 100, and 150 ? They're missing 75 (and 125). Well, that's because with 75 (1930-2005), it doesn't work :). link 2Moderator Response: TC: Edited links to preserve page format. -
Helena at 02:47 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
"More importantly, your argument entirely misses the more important point that Monckton completely misrepresents the nature of the IPCC's argument premised on the graph in question." And you miss the most important point that you cannot compare trends over different time periods. It's all i aimed to show (with wrong numbers possibly, but i gave you a simple counterexample with the midnight thing). Take for endpoint today at midnight, and you'll see that you have a cooling trend over the past 12h but a warming trend of the past 30years. -
Michael Whittemore at 02:45 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
This video at 6mins in shows Monckton explain that the climate system is like a sign wave and that the IPCC are drawing the trend lines on the up ward slop of this sign wave of climate change. He seems to be changing his angle of attack and trying to trick his audience into thinking that the reason he is right and the IPCC are wrong, is that we are going to see a cooling period. -
Helena at 02:44 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
I hadn't done the precise graph. Before I answer on point 1, the tool you used allowed me show that point number 2 ""That the pace of warming over the last 25 years is greater than that in preceding years on the record."" is wrong : linkModerator Response: TC: Edited link to preserve page format. -
Tom Curtis at 01:54 AM on 13 May 2012Increasing CO2 has little to no effect
photeki @127, the linked article immediately demonstrates that Roy Clark is yet another in the long line of supposed "skeptics" who attempt to refute the theory of the greenhouse effect with out first bothering to learn what it is. Specifically, he attempts to show that the CO2 effect is saturated by discussing back radiation only. The greenhouse effect is not based on back radiation, and any discussion that assumes it is shows the author to be in complete ignorance of the theory they purport to refute. You will find a basic introduction to the greenhouse effect here. Read it carefully. Notice how the relevant factors are the Top of Atmosphere radiative balance, and that no mention of back radiation is needed. And for the record, if you work out the radiative physics for an increase of CO2 at the TOA, it does result in significant changes in radiative forcing, of 3.7 W/m^2 per doubling of CO2. -
Tom Curtis at 01:47 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
Helena @1, we would be more impressed if you did not so obviously have to cherry pick your data points to reach your conclusion. If we in fact take the first 20 years of the HadCRUT3v temperature index, ie, from 1850 to 1870, the linear trend is 0.00238824 C per year. The trend for the first 40 years (1850-1890) is 0.00309971 C per year, showing an increase, not a decrease in the trend. The trend for the first 100 years is 0.00231824 C per year, barely lower than the trend for the first twenty years, and I doubt the difference is statistically significant. Finally, the trend for the first 150 years is 0.00369995 C per year, significantly greater than any of the other three trends examined. As the longest of the start year trends is also the largest trend of those examined, the series certainly does not show deceleration. Even if I plot from the cherry picked start point of 1860, except for 1860-1880, the later the end point of the trends examined, the larger the trend. Again this clearly does not show deceleration. What is more, even the 1860-1880 trend is inconsequential. The data for that period comes almost exclusively from Europe, the North Atlantic and the Eastern US. As such it represents a regional rather than a global temperature, and regional temperatures have larger trends than global temperatures. (Note I used the period 1860-1960 for the 100 year trend to keep the cherry picking to a minimum.) So, contrary to your apparent claim, it is not possible to pick arbitrary end points mimicking the IPCC graph, and to show a deceleration over the temperature record as a result. You have no counter example to the IPCC's procedure. More importantly, your argument entirely misses the more important point that Monckton completely misrepresents the nature of the IPCC's argument premised on the graph in question. Note: trends simply cut and paste from Wood for Trees, and the number of "significant figures" in no way represents a claim of statistical significance. Graph of the trends can be found here. -
Daniel Bailey at 01:42 AM on 13 May 2012Increasing CO2 has little to no effect
As a newcomer, Welcome! Quite frankly, anyone who runs around claiming "fraud!" like Roy does is already 1 foot in wingnutville. Add to that the usual gibberish about "2nd Law" violations and he takes the next step all the way in. Also speaking frankly, your whole linked site is a Gish Gallop of epic proportions. If you would like to select the 1 specific item that you feel Roy's whole case rests upon, do so and someone here will engage you on that. On the appropriate thread. One way to best utilize this site is by looking at the argument structure via taxonomy: http://www.skepticalscience.com/argument.php?f=taxonomy Or you can just use the Search Function in the UL corner of every page. Just plug in a term like "2nd Law" and you'll get something like this. BTW, Roy is welcome to come here openly. We don't bite. -
Helena at 01:02 AM on 13 May 2012IPCC graph showing accelerating trends is misleading
I dont like Monckton, but he's right on that one .... Here are two assertions : Linear trend fits to the first 20 (1860-1880), 40 (1860-1900), 100 (1850-1950) and for the full 150 years (1860-2010)are shown. Note that for periods ending closer to us, the slope is smaller, indicating decelerated warming. The pace of warming over the full 150years (1860-2011) has been slower than during the first 20, 40, and 100 years of the instrumental record. Are those two assertions wrong ? If they are not, will we get a chance to read them in the next IPCC report ? And in the SPM which also had a sentence comparing the linear warming trend over the last 50 years with the linear trend for the last 100 years and did not put it in perspective with the first 20 years (for example). Of course you cannot compare trends on different time periods.... ! On any given day, the trend from midnight to midday is about 1°C/hour (+/-0.5), which far exceed any global warming trend over any time period you want [1]. I can give show you global cooling too if you want. [1] 1°C/hour = 87 600°C/decade "That the pace of warming over the last 25 years is greater than that in preceding years on the record." How does the trend of the last 25yrs compare with the trend between 1915 and 1940 ? (same 25yrs basis) -
photeki at 00:36 AM on 13 May 2012Increasing CO2 has little to no effect
Hello, I'm new to this place and don't really want to cause any fuss and this may have been covered elsewhere, however I am very interested in all of the topics covered so far. Not wanting to post a link to anything that may be biased whatever a persons personal belief is, I still believe scientific work deserves credit where it is due and discredit if it can be falsified. Please any input on the findings of Roy. Clark on the questioning of radiative forcing models and techniques would be much appreciated. http://venturaphotonics.com/GlobalWarming.html I realize he is very much what you would consider a skeptic but any confirmation of his observations and/or conclusions, contradictions, corrections would be handy. I am currently unaware if he has tried to submit this work for peer review as I doubt he believes the system is currently without faults or bias itself. Thanks -
Flakmeister at 23:56 PM on 12 May 2012New research from last week 18/2012
Came across this http://www.irishtimes.com/newspaper/sciencetoday/2012/0510/1224315839757.html Genetically connecting widely separated Octopus populations with insight into the history of the Western Antartic Ice Shelf... -
Kevin C at 23:10 PM on 12 May 2012Two Centuries of Climate Science: part three - Manabe to the present day, 1966-2012
Thanks John for a concise and very readable series, and also to JG for the wonderful graphics. I've always wanted to find time to read Spencer Weart in full, but never succeeded. This summary is a big contribution. -
michael sweet at 23:07 PM on 12 May 2012Turbines in Texas mix up nighttime heat
Nick, Please provide a reference that shows the wind speed is not part of the temperature. In the College chemistry textbook that I teach from, the temperature of a gas is proportional to its total kinetic energy. To me that would include the wind kinetic energy. I think you separating the wind speed from the temperature is incorrect. There is no energy liberated to convert into heat. Wind generators remove energy from the air. That cannot heat the air. A small fraction of the wind kinetic energy from the atmosphere is turned into heat which is returned to the atmosphere as molecular kinetic energy. In the absence of the generator friction would convert the wind into heat somewhere else when the wind dissipated. My calculation indicates that maximum temperature increase is 0.03C. I doubt real increase could be anywhere near 0.01C for the wind that goes through the generator (although I know little about turbulence), the rest is unaffected. Obviously most of the energy is not trapped or the wind farm would cause the wind to stop in its vicinity. The generator definitely exports 59% of the energy. The OP states that mixing of the atmosphere causes the temperature increase. Mixing can provide all the needed energy, converting wind into heat cannot. -
Nick Stokes at 22:42 PM on 12 May 2012Turbines in Texas mix up nighttime heat
Michael, Yes, I think your second calculation is more convincing. It does say that the temp rise would be less that what is observed. But I think my claim that the energy liberated would be comparable to the elec output is still OK. It sounds like a variant of the problem with the inversion layers. When the turbines are working, there's too much wind for the waste energy to create a temp rise. So for my part, I now don't know what could explain the temp rise. -
michael sweet at 21:51 PM on 12 May 2012Turbines in Texas mix up nighttime heat
Nick, The temperature of the air is related to the square of its root mean square velocity which is 1150 miles/hr for nitrogen at 25C. The kinetic energy of the wind is related to the square of its speed which is say 30 mph on a windy day (the power in the wind is related to the cube of the speed). It seems to me that if all the energy in the wind was converted into heat it would not raise the kinetic energy of the molecules significantly. Possibly a calculation of the heat capacity of the air would be more useful. The specific heat of air is about 1.0 kj/kg. 1 kg of wind at 30 mph has about 80 joules of energy in it. That comes to about .08C increase in temp if 100% of the energy is converted into heat. That means a maximum of 0.03 C temp increase if the wind generator removes 59% the energy. In addition, a wind generator only converts the wind that passes over its blades into energy, since a much larger vertical slice of the atmosphere is moving, most of the energy stays as wind. Can you provide a calculation as to how much you think converting all the wind energy into heat would raise the temperature of the atmosphere? A peer-reviewed citation would be better. Wind generators remove energy from the local atmosphere. They do not provide any energy and cannot heat the atmosphere. The wind motion is part of the measure of temperature. -
Nick Stokes at 20:35 PM on 12 May 2012Turbines in Texas mix up nighttime heat
Or, I should say, 41:59. -
Nick Stokes at 18:18 PM on 12 May 2012Turbines in Texas mix up nighttime heat
Tom and Sphaerica, You can quantify the process. The way any aerofoil generates force is by deflecting a flow. The force is proportional to the mass rate of deflection and the velocity change. The inevitable byproduct is the generation of turbulence, which decays, converting the energy to heat. Wiki has an article on Betz' Law. This says that the best a turbine can do is extract 59.3% of the kinetic energy from the wind. But the key is that in that state, the axial component of the velocity has been reduced to zero. It has been entirely converted to swirl, and can't go anywhere much. Viscosity will convert its KE to heat. Of course total removal of axial velocity is unrealistic, so practical efficiency is less. But the ratio of swirling flow energy to output energy will remain about the same, 59:41. -
SRJ at 07:20 AM on 12 May 2012New research from last week 12/2012
About the Kilifarska paper: Climate sensitivity to the lower stratospheric ozone variations - Kilifarska (2012) In my opinion this paper is very bad, and is based on bad statistical analysis. None of the equations 1-4 seems to be based on physical insight, but only on what gives a good fit (unless I have missed something). And the same variable is used several times, scaled with seemingly arbitrary constants and raised to higher powers, eg. equation 1 giving the relationship between annual NH land temperature and annual ozone level reads: LandT = b0 + b1*TOZ11^2 + b2*(TOZ11/11)^3+b3*(TOZ11/37)^4+b4*TOZ*TOZ11 + b5*(TOZ/22)^3 + b6*(TOZ/35)^4 where TOZ = total ozone level and TOZ11 = 11 years running mean of total ozone level I.e. variables smoothed with moving averages are used in the regression - according to Briggs and Tamino that is bad practice. Using a very similar model to equation 1 but for annual CO2 concentration I can get a even better fit (measured by R^2) to the NH land temp than Kilifarska does. In my model just replace TOZ with annual CO2 and TOZ11 with annual CO2 smoothed with 11 year running mean, and finally use also the annual co2 concentation as regressor. But that is just another meaningless regression, just like Kilifarska's. Unless I have missed the point and misunderstood the methods, I think that the paper is pointless -
davesouza at 03:55 AM on 12 May 2012Why Are We Sure We're Right? #2
Hi Rob, don't want to go too much offtopic here, but I think you're wrong about one thing. In commenting on an Amazon review of Mann's "The Hockey Stick and the Climate Wars" you said that "'Mike's Nature trick' was merely adding on the modern temperature record to the proxy reconstruction. Mann just happened to be the first researcher to do that. The results were published in the journal Nature." As discussed on pages 39-40 of the book, in 1993 Raymond S. Bradley and Phil Jones published a Northern Hemisphere reconstruction, using a "composite-plus-scale" method to combine the proxies and relate them to the modern instrumental record, and this featured in the IPCC SAR. It's worth looking at the SAR, the graph shows this decadal summer temperature reconstruction together with a separate curve plotting instrumental thermometer data from the 1850s onwards. As far as I can tell, Mike's "Nature Trick" was different in that he used a different methodology to relate the proxies to the instrumental record. Unfortunate phrasing by Jones, and this specific point doesn't seem to be covered by explanations as far as I can recall. -
Andy Skuce at 03:44 AM on 12 May 2012Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”?
Helena@22: The wealth that you say is generated by oil (or equivalent) requires many other inputs (materials, human effort, etc). In any case, that GDP wealth accrues to the consumer of the oil, not the producer as your argument @20 implied. Certainly, the business of producing bitumen is a profitable one at current prices and it is especially so when the negative externalities are not paid for by consumers or producers. Bitumen production is already a significant part of the Canadian economy and, if production doubles and triples over the years to come, then it will become increasingly more important. Climate issues aside, I worry about my country becoming increasingly dependent on a single resource extraction industry in a world economy that is changing so rapidly. @25 Just because nobody can say with any confidence what the ultimate substitutes for oil will be, it doesn't mean there won't be any. I'm sure the whalers didn't see Colonel Drake coming with his cheap mineral oil, nor did buggy-whip manufacturers foresee Henry Ford. -
michael sweet at 03:07 AM on 12 May 2012Turbines in Texas mix up nighttime heat
I do not understand the discussion of wind generators heating up the atmosphere. Wind is motion of molecules and is part of the atmospheres heat budget. Wind generators do not add any waste energy to the system, they remove energy from the system. Any heat in the generator came from the atmosphere in the first place and does not heat the air when it returns. They affect the atmosphere locally by converting kinetic energy into electricity that they export. Since energy is exported the local system is cooled. According to the OP they heat the surface by mixing hot air downwards during the night. Overall the atmosphere would be cooler since energy is removed. That energy would be returned to the atmosphere as waste heat when the electricity is used. The reduction of the airs' velocity is just conversion of one form of energy in the atmosphere into another. The root mean square speed of nitrogen at 25C is 1150 miles/hour (515 m/s). Adding a little bit of wind speed would make little difference in the temperature. Where have I made a mistake? -
Tom Curtis at 00:59 AM on 12 May 2012Turbines in Texas mix up nighttime heat
Sphaerica @19, I would not be so immediately dismissive of Nick's idea. Turbulence does result in reduced air velocity, and the energy of that reduced air velocity must be preserved as heat. Where Nick's hypothesis is not plausible is in assuming that if 50% of the wind's energy is captured by the turbine, the remainder of its energy will be released as heat as the result of turbulence. I suspect that a 50% efficient wind turbine captures 50% of the wind energy in the area of its blades - not the swept area of its blades meaning that most of winds energy is neither captured nor lost to turbulence. Given that, it is possible that an amount is lost to turbulence equivalent to the amount captured. Having said that, I agree that hand waving arguments are irrelevant. They need to be placed into a mathematical form to render them more precise. Should Nick desire to do so (and I know he has the mathematical ability), the relevant equations are discussed by Science of Doom, Wikipedia, and in the linked UCLA lecture notes. -
70rn at 00:58 AM on 12 May 2012Turbines in Texas mix up nighttime heat
@ Sphaerica. You may find yourself having to make that point rather regularly over coming months, I suspect. -
Composer99 at 00:46 AM on 12 May 2012Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”?
From Helena #25: On your first point, what's the alternative to oil ? Electricity ? That means massive infrastructure investments, and a complete change of paradigm. That's maybe what you wish, but the cheapest, easiest and most likely solution is that we'll stick to oil for still quite some time (even at high prices, because there is no alternative that efficient and energy dense Given the consequences of continued dependence on fossil fuel combustion, any disruption resulting from making the switch will be less significant and less destructive than sticking to oil "for quite some time". In any case, I do not see massive infrastructure investments to de-carbonize our societies as undue burdens. Rather, they are opportunities for entrepreneurial agents to make money (and such massive investments will surely require much labour, which I expect would attenuate or even outweigh unemployment resulting from declining fossil fuel exploitation). -
shoyemore at 23:47 PM on 11 May 2012Two Centuries of Climate Science: part three - Manabe to the present day, 1966-2012
I hvae a dream in which Manabe and Wetherald are awarded a Nobel Prize for their 1967 paper. It was the first model that described the greenhouse effect in an atmosphere with convection. All subsequent climate science is in their shadow. In terms of important papers, it is surely one of the highest ever written. Perhaps James Hansen, the first to publicly announce the observing of global warming, would share the award. -
Bob Lacatena at 23:46 PM on 11 May 2012Turbines in Texas mix up nighttime heat
18, Nick, I think you are grossly over-guesstimating the amount of heat released. You have broken the model into two components... wind energy converted to power, and the remnant converted to heat. Clearly this is grossly over-simplified, but more importantly it is completely unquantified. Your argument amounts to "it seems to me." The Internet is rife with such "thought experiments" which put together a few simple concepts, gloss over all of the details, and arrive at "it's obvious that..." I think that unless you are able to properly, mathematically estimate the amount of heat actually generated by each turbine, your suppositions are merely that... suppositions. Personally, the idea of a temperature inversion drawing down warmth from higher altitudes is substantially more likely than such a large amount of excess heat being generated through inefficiency. And even if it is... it's still not actual warming. The energy was already in the system. It's not a net change, just a redistribution. The whole question of the source of the heat is rather pointless (except to an engineer who is concerned with mitigating its local effects). This study says zero about climate change, or the impact of wind farms on climate change. -
Nick Stokes at 22:49 PM on 11 May 2012Turbines in Texas mix up nighttime heat
70m Night time does create a thermal stratification of a given air column - with warmer above and cooler below. Yes, on a calm night. But then how can a turbine mix? I think any wind strong enough to turn the blades would have already mixed the air. Riccardo It does not produce waste heat, the energy remains as kinetic energy of the wind. I believe it does. The drag on any aerofoil is the result of linear momentum being converted to angular and shed as vortices. Those vortices (turbulence) decay through viscous effects, releasing heat. Kevin, My understanding is that direct heat release is a big part of UHI. But I don't currently have a source for that. -
les at 18:33 PM on 11 May 2012Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”?
26 - Regarding moving to cars. From Horse Power to Horsepower, by Eric Morris is worth a read. In summary; the environmental impact from widespread horse usage neared catastrophic levels before the car became viable and, in part, drove the commercialisation of the car. Now the environmental impact from cars (etc.) will drive new innovation... and new commercial opportunities. -
Riccardo at 18:11 PM on 11 May 2012Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”?
Automobiles were not cheaper than horses, but this is irrelevant as far as the reasoning Helena is supporting (or fearing) is concerned. We should fear it because not always (at best) short term convenience is the best choice, more so when a long term global problem, like the energetic structure of our societies, is involved. -
Helena at 16:27 PM on 11 May 2012Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”?
"You would just as well argue that we should not have moved to automobiles until all the horses on the planet had died. " People moved to automobiles because they were cheaper, more convenient, and more energy dense. And horses haven't disappeared, they're just used for other less primary purposes. Like oil, if you find a better source (which is on the case yet), it will still get exploited for other uses. -
Helena at 16:19 PM on 11 May 2012Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”?
Sphaerica : On your first point, what's the alternative to oil ? Electricity ? That means massive infrastructure investments, and a complete change of paradigm. That's maybe what you wish, but the cheapest, easiest and most likely solution is that we'll stick to oil for still quite some time (even at high prices, because there is no alternative that efficient and energy dense). On your second point, good to know that, by taking the lowest of the two figures and dividing it by 100years, you stil get 50 billion $ per year and manage to say that this is a small figure. Just a reminder : Canada is about 35 million people, so if it were the US (per capita) it would be equivalent to 500 billions dollars par year. Does it look like a small figure ? 50 billions $ is 3% of their GDP and 25% of the annual government expenditures.
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