Recent Comments
Prev 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 Next
Comments 114251 to 114300:
-
Doug Bostrom at 11:32 AM on 27 July 2010It's waste heat
Actually this thread is helpful because it's serving as a remarkably clear and concise example of how so much of this "debate" is ultimately driven by complete and total intractability on the part of some of the discussants. This is a very simple situation. "AHF" is capable of adding something like 1% of the quantity of solar heat being retained by additional impedance due to C02 and knock-on effects, working from mainstream estimates of anthropogenic GHG climate sensitivity. Just to make things clearer, let's imagine for a moment that we're somebody akin to Dr. Roy Spencer, a highly-qualified scientist able to make a start on articulating an alternate hypothesis to anthropogenic warming as an explanation for recent observed temperature increases. Under our Dr. Spencer-style hat, we believe that effective AGHG forcing is only 10% of more commonly accepted figures. In this circumstance we're looking at AHF forcing still being just 10% of anthropogenic GHG forcing. Even if we assume mainstream estimates are off by a full order of magnitude, AHF still pales in significance compared to anthropogenic GHGs, is still yet another order of magnitude less. Meanwhile, as has been pointed out, heat is mindless and does not care from where or to where it's going. Whatever heat is added to the pool here on Earth whether by anthropogenic liberation or arriving from the sun or for that matter emerging from retained and radioactive decay heat from within the Earth is going to find its way to the great beyond regardless of birthright, ultimately via radiation. Nothing about the origin of heat specifies its subsequent behavior. Heat flux from energy liberated as a part of human activity by any measure appears by all accounts to be a minor constituent of Earth's radiative energy budget. Even if one looks at the thermal impedance properties of the atmosphere from various outlier perspectives, AHF still does not measure up in a significant way. There's really not much to work with here for a so-called skeptic, to the point that one is left wondering how to speak patiently in the face of arguments to the contrary, once they've been repeated several times by the same person. -
Ned at 10:58 AM on 27 July 2010The nature of authority
Berényi Péter writes: You may expect that, but unfortunately reality does not seem to conform. Can you explain, in words, what that figure shows and how precisely it contradicts the claim from chris's post? Thanks. -
Ned at 10:52 AM on 27 July 2010It's waste heat
johnd writes: Ned at 22:36 PM, part of the issue being discussed was whether waste heat accumulates or not, and whether accumulative it's effect is more than negligible. There is no magic mechanism that removes heat from the atmosphere if it originally came from radiation but lets it accumulate if it originally came from combustion or whatever. IMHO these analogies to revolving doors and traffic jams seem to have no effect other than clouding the issue. How about some actual evidence, please? Doug B. gave a reference to a paper with quantitative comparison of the two sources way back in comment #2. That was very helpful, I think. -
chris at 09:42 AM on 27 July 2010The nature of authority
not sure why I wrote "longitude" when I meant "latitude" in my post just above! -
chris at 09:38 AM on 27 July 2010The nature of authority
Berényi Péter at 09:14 AM on 27 July, 2010 "You may expect that, but unfortunately reality does not seem to conform." Careful Peter. One location does not define an entire longitudinal band. You really need to look at the paper I cited (Zhang et al., 2007; link in the post that you mined my sentence from). The 20th century has seen a decrease in rainfall in the equatorial regions from around 0 o longitude to 30 o N, and an increase in rainfall in the high latitudes. Pretty much as expected from models. X. Zhang et al. (2007) Detection of human influence on twentieth-century precipitation trends Nature 448, 461-465 -
KR at 09:34 AM on 27 July 2010It's waste heat
johnd - False distinction logic error: thermal energy is thermal energy, none of it is 'pregnant' or otherwise distinguishable from the other. This is akin to the G&T arguments where some skeptics thought that an object would somehow 'know' that certain photons came from colder objects, and would not therefore contribute to energy balances. Photons (and joules) don't carry ID cards, unlike Arizona citizens. Thermal energy gets distributed by the usual suspects - conduction, convection, latent heat, and radiation, with radiation measured to be the dominant pathway. The source of the energy is irrelevant to how it leaves. As per the thread, however, only ~1% of that thermal energy comes from energy usage, the other 99% comes from GHG entrapment of solar energy. Bad analogies don't change that. If nothing else, this thread has been a delightful example of logic errors... -
Berényi Péter at 09:14 AM on 27 July 2010The nature of authority
#101 chris at 09:17 AM on 25 July, 2010 We expect in a warming world that rainfall will decrease in the equatorial regions of the Earth You may expect that, but unfortunately reality does not seem to conform. -
johnd at 09:06 AM on 27 July 2010It's waste heat
RSVP at 06:35 AM, perhaps another analogy may help. A well designed and up to date maternity hospital has been built and access is via a revolving door that is designed to maintain an efficient environment and minimize heat losses by operating only with one person entering and one person leaving at the same time. Only 1% of those entering the hospital do so to give birth, the bulk of those entering, and leaving are visitors or staff. At what point does the hospital board have to go back to the engineers who did the original design calculations, and ask them if the assumption they made that as only 1% of those entering the hospital were pregnant, and so could be considered negligible, was a indeed a valid assumption? -
johnd at 08:34 AM on 27 July 2010It's waste heat
Ned at 22:36 PM, part of the issue being discussed was whether waste heat accumulates or not, and whether accumulative it's effect is more than negligible. Obviously if the total heat losses from your dining room, being well insulated one hopes, remains less than that being provided by the burning candles, then it is the total accumulated heat that is relevant in any quantitative comparison at any point of time. Naturally, if at some point of time someone opened a door introducing a period of increased heat loss, that is a period of cooling, then a portion or perhaps all the accumulated heat of the burning candles would be lost. -
KR at 07:21 AM on 27 July 2010It's waste heat
Also take a look at Common Sense error, strongly related to the Dunning-Kruger effect -
KR at 07:16 AM on 27 July 2010It's waste heat
RSVP - queuing theory, with its associated transition points at certain flow rates, has absolutely nothing to do with this topic, and can only be considered an (rather poor) attempt to change the subject. Your waste heat issue is 1% the effect of GHG entrapment, negligible in comparison. You have shown no evidence whatsoever to the contrary. This is a science blog site - Appeals to Belief and Red Herring logical errors really don't hold up to actual numbers or physics. -
Doug Bostrom at 07:07 AM on 27 July 2010It's waste heat
RSVP, imagine that as cars from the rock concert move down the congested highway the mayor of the local city connected to the highway announces that an asteroid is approaching and will strike the center of the city within hours. Many residents respond to the announcement by "getting out of Dodge," ironically jumping into their Dodge automobiles and hightailing it for the proverbial hills. Proportioning the public panic to the relative numbers of AHF forcing versus forcing by a doubling of C02, the highway must then cope with not only the increase of traffic from the concert but a panic stricken flood of drivers representing over 100 times more additional vehicles beyond that created by the concert traffic. Not to put too fine a point on it, you're obsessing over a very tiny number. -
Ned at 06:55 AM on 27 July 2010The nature of authority
Actually, I don't know that. It sure seems like that's the impression you're trying to convey in this thread. If not, you might want to try to write more clearly. In particular, using repeated expressions like "According to AGW" and "I am being told that ..." when referring to the basic physics of infrared spectroscopy does not convey the impression of confidence in said spectroscopy. Most people, when writing about something they genuinely believe in, don't feel the need to add a continual stream of parenthetical qualifiers. -
RSVP at 06:35 AM on 27 July 2010It's waste heat
An metaphore to "queue threoy" may help you all... There is a highway that goes into the city. The flow is constant everyday (no weekends in this theoretical land). The flow of cars depends on the amount of traffic since the channel (the highway) but in generally is usually constant and flows well. One day Road Maintenance needs to paint the lines on the side of the highway and places cones on the right lane. This slows traffic down slightly. (This might be effects of elevated CO2... perhaps). On top of this however, there is a special event that day (rock concert) and the number of cars increases, but only by 1%. (waste heat) Since the flow was basically optimal before these two occurrences came about, the traffic almost comes to a complete halt. There is now a traffic jam and cars are moving bumper to bumber. Someone in a car wants to see a huge accident to justify this inconvenience. As he passes the cones, he is dissappointed that there is nothing dramatic to see. (AGW guy, asking me for numbers to justify the effects of man made waste heat). -
KR at 06:08 AM on 27 July 2010It's waste heat
Here's another summary on this topic, with some references: Global Warming Waste Heat -
KR at 05:50 AM on 27 July 2010It's waste heat
In the medium concentrations we have for GHG's in Earth's atmosphere, a doubling of CO2 concentration increases the width of the blocked LWIR band enough that the Earth's surface must be 1oC hotter for the integrated spectrum at the top of the atmosphere to sum to the energy coming in. Increased GHG concentrations slow the escape of the LWIR energy from the atmosphere. The 10^9 collisions/second ensure that the GHG's maintain the same temperature as the rest of the air mass - you can't separate N2 and O2 temps from the air mass as a whole, and it's rather silly to claim so. Back to the point of the thread - Human energy use releases energy at a rate 2 orders of magnitude less than the GHG entrapment. Unless you provide some evidence to the contrary, which you have not done so far, waste heat is not an issue worth worrying about. -
RSVP at 05:47 AM on 27 July 2010The nature of authority
Ned "In another thread RSVP is questioning basic laboratory measurements of the spectral properties of gases that have been known since the 1850s" That is not what I am doing and you know that. -
Ned at 05:41 AM on 27 July 2010It's waste heat
Maybe this will help. RSVP, think of each individual CO2 molecule as a tiny machine, taking in fuel (IR radiation) and giving off waste heat (vibrational energy transferred by collisions with other molecules in the atmosphere). Every year, we add billions of tons of those tiny machines to the atmosphere. The waste heat they produce is two orders of magnitude greater than the heat from our clunky mechanical devices down here on the surface. Does that help? -
Ned at 05:37 AM on 27 July 2010It's waste heat
The concentration of CO2 in the atmosphere affects the absorptance of longwave IR. It doesn't particularly affect the rate at which the energy from that absorption is shared with the rest of the atmosphere. Those are two entirely different processes. You really don't understand how this works, do you? -
RSVP at 05:30 AM on 27 July 2010It's waste heat
Ned "Likewise, most of the heat from GHG absorption will also be transferred to O2 and N2 molecules, thanks to the fact that each CO2 molecule collides with N2 or O2 molecules roughly one billion times per second. " Why does GHG concentration matter? Does it go to two billion times per second as concentration doubles? My point is you make it sound like all the energy captured by CO2 goes directly into the surrounding molecules (one minute), but concentration "modulates" this process another minute when it comes to justifying the reduction of GHG emissions. -
RSVP at 05:25 AM on 27 July 2010It's waste heat
Ned "I'm confused by all the references to N2 and O2. Why do you think there's some kind of distinction there? " What makes a GHG a GHG? N2 and O2 are not greenhouse gasses by definition, otherwise the atmosphere would be 100% GHG and there would be no problem with emission of GHGs. How can you ask this question? -
RSVP at 05:23 AM on 27 July 2010It's waste heat
KR "The air mass as a whole, containing GHG's, is not transparent to IR - it heats and cools depending on the IR in/out balance. What exactly is not clear about that?!?" The crux of the AGW theory (and the campaign to control GHGs concentrations) rests on the assumption that the efficiency of "The air mass as a whole" to "emit/absorb IR" is a function of concentration. Making this kind of a blank statement about how air gets rid of heat ignores the premises upon which AGW is based on. -
Ned at 05:17 AM on 27 July 2010It's waste heat
RSVP, the point that Doug and KR and I keep emphasizing is the main one -- you need to provide some evidence here. But aside from that, I admit I'm confused by all the references to N2 and O2. Why do you think there's some kind of distinction there? Most of the waste heat from anthropogenic sources will be carried in the atmosphere by O2 and N2. Likewise, most of the heat from GHG absorption will also be transferred to O2 and N2 molecules, thanks to the fact that each CO2 molecule collides with N2 or O2 molecules roughly one billion times per second. Perhaps you're under some misimpression that when a greenhouse gas absorbs IR radiation it only raises the temperature of the GHG molecules themselves? If so, that's wrong. The atmosphere is not a mix of gases each with its own distinct temperature. -
KR at 04:55 AM on 27 July 2010It's waste heat
N2 and O2 are transparent to IR. However, the CO2 and H2O content of the air mass can and does absorb and emit IR. GHG's at air temperature will lose/gain energy as they emit/absorb IR, and through molecular collisions will cool/heat the air mass as a whole, including the N2 and O2. And that thermal exchange is very efficient, very fast. The air mass as a whole, containing GHG's, is not transparent to IR - it heats and cools depending on the IR in/out balance. What exactly is not clear about that?!? I've got nothing more to say here, unless RSVP comes up with a measurement supported number comparable to Flanner's. -
Doug Bostrom at 04:52 AM on 27 July 2010It's waste heat
I think we can conclude that this is a dead end, unless RSVP can produce a number for "AHF" more useful and much larger than Flanner's. -
RSVP at 04:47 AM on 27 July 2010It's waste heat
N2 and O2 are transparent to IR. These gases do not radiate since they are not GHGs, and therefore have a hard time loosing their heat outside of convective cooling with water and ice. The cooling of manmade heat engines raises the temperature of N2 and O2 directly. This heat is carried around the planet and is being discharged and dissipated in the cooler regions since convection requires a lower temperature for heat to be transferred. -
Ned at 04:39 AM on 27 July 2010It's waste heat
RSVP, you could simplify this whole process a lot if you would just point us to a paper, a study, or anything, really, that quantitatively shows waste heat being equal to or greater than radiative forcing from GHGs. Once we have such a source, we can debate the data, methods, interpretations, etc. But until you give us something that at least remotely resembles a shred of evidence, what's the point? -
Doug Bostrom at 04:39 AM on 27 July 2010It's waste heat
RSVP, I'm (honestly) still uncertain about what point you're making. I -think- you're saying that observed increases in global temperature are significantly affected by anthropogenic liberation of heat energy. If that's the case, your argument is stuck here Nearly all energy used for human purposes is dissipated as heat within Earth's land–atmosphere system. Thermal energy released from non-renewable sources is therefore a climate forcing term. Averaged globally, this forcing is only +0.028 W m−2... until you can provide a substitute number for Flanner's calculated result that is both much larger and more correct. If you're driving at something else, different matter of course. -
RSVP at 04:27 AM on 27 July 2010It's waste heat
CBDunkerson I have tried to answer your questions. It would seem fair that you try to answer some of mine. 1. Can energy be destroyed? 2. Where exactly does the Urban Heat go? 3. What does the word energy dissipation mean to you in this context? 4. What are the radiative properties for cooling of N2 and O2? 5. How do these properties differ from GHGs? -
Doug Bostrom at 04:23 AM on 27 July 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Those still following this topic may be interested to read a very informative post by Dirk Notz, here at RealClimate. For me it was interesting to see my intuition seconded by somebody with some expertise: Because of the very low thickness of much of the Arctic sea ice, it wasn’t too surprising that at the end of the winter, sea-ice extent decreased rapidly. This rapid loss lead up to the lowest June sea-ice extent since the beginning of reliable observations. After this rapid loss of the very thin ice that had formed late in winter, the retreat slowed down substantially but the ice extent remained well below the long-term mean. Currently, the ice covers an area that is slightly larger than the extent in late July of the record year 2007. However, this does not really allow for any reliable projections regarding the future evolution of Arctic sea ice in the weeks to come. The reason for this is mostly that sea ice in the Arctic has become very thin. Hence, in contrast to the much thicker ice of past decades, the ice now reacts very quickly and very sensitively to the weather patterns that are predominant during a certain summer. This currently limits the predictability of sea-ice extent significantly. For example, in 2007 a relatively stable high-pressure system formed above the Beaufort sea, towards the north of North America, leading to rapid melting of sea ice there. If again such stable high pressure system forms in the Arctic throughout the coming weeks, we might well experience a sea-ice minimum that is below the record minimum as observed in 2007. However, if the summer should turn out to be colder than during the previous years, a sea-ice minimum similar to that observed in 2009 would not be too surprising. Hence, at the moment all that remains is to wait – and to check again and again the latest data of Arctic sea-ice extent. Emphasis mine. Probably what many of us suspected. -
Mal Adapted at 03:48 AM on 27 July 2010The nature of authority
Thingodonta:Good quote from Charles Darwin.
I chose that quote because it was Darwin's formulation of the Dunning-Kruger Effect, 128 years before it was named. -
KR at 03:44 AM on 27 July 2010It's waste heat
Previous comment, last sentence - that should be *provided*, not *proved*; I believe that makes more sense. ...must...practice...typing... -
CBDunkerson at 03:43 AM on 27 July 2010It's waste heat
RSVP #26 1: Your answer makes no sense. Heat spreading through atmospheric Nitrogen and Oxygen does not explain why the poles are heating faster... there is not more Nitrogen and Oxygen there. 2: Your answer is clearly false. Yes, the Urban Heat Island effect (which has very little to do with waste heat) causes cities to be warmer (though nowhere near enough so to explain the GLOBAL temperature increase), but it does not result in warming of the rural areas around these urban centers as we would expect if global warming were simply the spreading out of heat from urban sources. Hence the 'island' part of the name... it is a sharply localized effect. 3: Again, your answer makes no sense. How are atmospheric Nitrogen and Oxygen responsible for a decrease in the rate of heat escape? Especially as they have not themselves changed significantly? As to 'more heating oil in Winter'... I thought you had claimed that measured warming was due to ACCUMULATED waste heat because it is magically prevented from escaping the atmosphere. Thus, when the heating oil was burned is irrelevant... the heat should still be there in the Summer. 4: Here you seem to simply deny the data. -
Ned at 03:24 AM on 27 July 2010Assessing global surface temperature reconstructions
Berényi Péter writes: It is not as simple as that. The effect of adjustments on overall GHCN trend may be negligible relative to the raw dataset, but it is not so with USHCN which is a subset of it. Even if that were the case, the US represents approximately 2% of the surface area of the Earth. There is no way that the USHCN adjustment process is going to have a detectable influence on the global temperature record. As Figure 5 shows, at the global scale you get virtually no difference using raw or adjusted data. BP continues: This difference in adjustments for the US vs. the rest of the world either does not make any sense from a scientific point of view or it has such a subtle explanation, that it has escaped all the wise people attending to this blog. Peterson & Vose 1997 make it clear that different adjustment processes are used for USHCN and non-USHCN stations. The NCDC website FAQ explains that NOAA has detailed station history information for USHCN stations that it does not have for non-USHCN stations. BP continues: An even more serious question is why to waste time and effort to adjustments that have no substantial effect whatsoever on a global scale? Maybe because they want to make individual station records as accurate as possible for local to regional-scale studies, even if those corrections largely get lost in the noise when averaging data globally? Or maybe nobody could be certain there would be no effect at the global scale until actually trying it? Or maybe there's some other explanation. -
KR at 03:09 AM on 27 July 2010Models are unreliable
Pete Ridley - I'm still interested in your response to my question on evaluating Hansen 1988 as a scientific model. I believe this is critical to the thread and the discussion. -
KR at 02:57 AM on 27 July 2010It's waste heat
RSVP - I see no no numbers in your latest post, no evidence. All you present are "it seems like it should..." statements contradictory to what we observe. The numbers, the measured values, and the physics all say you are incorrect about the importance of waste heat. A hypothesis must be congruent with the evidence. If a hypothesis is contradicted by all the evidence, it's time for a new hypothesis. Waste heat driving global warming just doesn't make sense, RSVP. And you have proved exactly zero evidence to support that hypothesis. -
Peter Hogarth at 02:55 AM on 27 July 2010Assessing global surface temperature reconstructions
Ned at 02:04 AM on 27 July, 2010 Thanks, that is indeed a clearer way of visualising the increase. I also forgot to mention I had offset the GISS data in an attempt at clarity. -
Peter Hogarth at 02:51 AM on 27 July 2010Assessing global surface temperature reconstructions
Robert Way at 23:14 PM on 26 July, 2010 "ocean trends in the last couple years have not been exceedingly positive" I suspect that was written in haste...? Thermal expansion of oceans in recent years: We have to be careful here. Cazenave 2009 was writing just after the altimeter data was showing a temporary dip in rate of MSL rise, there is something of an update in Cazenave 2010 where the recent estimate of reduction in the thermal expansion component of MSL is put into the context of other previous natural variations (see for example figure 7 in that paper) which look similar and the altimeter trend reverting back to the pre-2007 rate after 2008 (yet table 1 is a repeat of the 2009 one with data up to 2007). This is discussed briefly. There is also new (2010) evidence from Grace on increased land storage of water in Llovel 2010This first estimate based on measurement of Land storage trend contribution to mean sea level trend is slightly negative, giving -0.22 +/-0.05 mm/year. We then have factors like the 2010 reprocessing of the entire DUACS altimeter data set, though this seems to have reduced variability in global MSL terms (no real difference in estimates of MSL rise rate) it has resulted in some significant (>1mm/yr) localised differences (corrections!) between old and new datasets.
-
Berényi Péter at 02:50 AM on 27 July 2010Assessing global surface temperature reconstructions
#38 Ned at 00:01 AM on 27 July, 2010 Likewise, there are a lot of people out there who think that the GHCN adjustment process is the cause of the observed warming, and that this warming would disappear if one just went back to the "raw" data. Thus, showing that the warming signal is present in almost identical form in the raw and adjusted data helps dispel that claim. It is not as simple as that. The effect of adjustments on overall GHCN trend may be negligible relative to the raw dataset, but it is not so with USHCN which is a subset of it. On this subset 80% of warming during the lats nine decades is created by adjustments. Also, the statistics of adjustments is entirely different on this subset. This difference in adjustments for the US vs. the rest of the world either does not make any sense from a scientific point of view or it has such a subtle explanation, that it has escaped all the wise people attending to this blog. You can look up the details here and here. An even more serious question is why to waste time and effort to adjustments that have no substantial effect whatsoever on a global scale? It is also shown, that there is not much difference between "rural" and "urban" trends. But no one has explained yet why the far reaching consequences of this observation are ignored. -
RSVP at 02:24 AM on 27 July 2010It's waste heat
CBDunkerson #22 "1: Why are temperature increases most pronounced at the poles... where there is virtually no industry generating waste heat? ------------------------------ This gets back to the issue of how N2 and O2 dissipate heat. Not by radiation. Since energy cant be destroyed, it must be spreading itself everywhere. 2: Why do we not see huge spikes of increased heat around urban industrial centers gradually leveling off as you get further into non-industrial regions? ---------------------------- answer to 2.: We do. See links. http://www.epa.gov/heatisld/ http://en.wikipedia.org/wiki/Urban_heat_island http://www.concretethinker.com/Content/ImageLib/lblgraph.jpg 3: Why has warming been most pronounced at night and during Winter? That makes sense if the warming is due to decreases in the rate heat escapes... but not if it is due to increasing 'accumulated heat'. --------------------------- The idea that N2 and O2 are not good emitters of IR agrees with your statement about "decrease in the rate heat escapes". The difference here is in what we assume is causing this. In addition, for a fixed quantity of man-made heat, the lower the temperature, the higher the percentage this represents quantitatively relative to the ambient energy level, and convective heat transfer is in proportion to the difference in temperature. So this also can be applied to answering in part question 1. And I dont know about you, but I personally use more heating oil in the Winter. 4: Why is the stratosphere cooling? Again, that makes sense if heat is being prevented from escaping to the stratosphere... but not if the total heat of the planetary environment is increasing." ----------------------------- Is it really cooling? Obviously this is not based on tree ring data. ;) -
Ned at 02:20 AM on 27 July 2010It's waste heat
Yes, CBD, I think that's a useful approach for many topics here. In this case, though, RSVP hasn't offered any empirical evidence in support of his claims for waste heat. Well, I'm a skeptic. I want to see some evidence before I concede that it's even worth discussing. -
CBDunkerson at 02:09 AM on 27 July 2010It's waste heat
Ned, many deniers assume that all data which contradicts their beliefs has been faked. Thus it may help to present proofs based on basic logic in addition to those based on data. Or not. Some are impervious to both. -
Ned at 02:04 AM on 27 July 2010Assessing global surface temperature reconstructions
Albatross -- thanks! Peter Hogarth: Here's another way of visualizing this:The gray line is RSS (satellite) monthly temperatures through 2000. The pink trendline is the linear trend 1979-2000. Note that, for the past decade, temperatures have mostly been above the pre-2001 trend. In fact, about 2/3 of the months have been above the trend line, including 10 of the past 12. The one exception was the 2008 La Nina.
-
Berényi Péter at 02:02 AM on 27 July 2010The nature of authority
#133 dcwarrior at 23:57 PM on 26 July, 2010 Perhaps it's time for guest posters from the world of politics, PR or public opinion to give advice on how to turn the tide? No way, man. It is supposed to be a science blog, not a political one. Neither it is a PR device. Read the Comments Policy please. More than one of my comments even slightly touching on political issues got deleted. And I truly wish all such comments have the same fate, even if they came from the other side. In this respect moderation policy is not perfect yet, as there are also posts which have a clearcut political edge, still, they get published here. But it is a shortcoming, not a strength. If you want to turn the tide with such devices, all the authenticity earned so far is thrown into the wind. -
Ned at 01:57 AM on 27 July 2010The nature of authority
BP writes: You don't even need a laboratory thermal radiometer to see this. Well, you need either a radiometer or a mathematical model to quantify it. Since he was voicing disbelief in the model, I suggested the radiometer. I do like your visualization though. -
Albatross at 01:44 AM on 27 July 2010Assessing global surface temperature reconstructions
Excellent synthesis Ned. Thanks for taking the time and for making the effort. What you have here is a comprehensive summary of the pertinent facts about the global SAT record. I'm not surprised that those in denial about AGW are going to try and dismiss it out of hand-- the data presents a very robust (an inconvenient) picture of warming. Peter @40, you beat me to it :) -
Berényi Péter at 01:32 AM on 27 July 2010The nature of authority
#129 AWoL at 10:11 AM on 26 July, 2010 Stefan-Boltzmann says that a squ mtr of material of typical emissivity of 90-95%,at 27degC will beam out something of the order of 459 watts Yes, something like that. A perfect blackbody (e.g. a hole leading to a large cavity) would indeed radiate 459.3 W/m2 at 300 K. This 300 K is only 26.85°C, not 27°C, but that's not a big deal. And the hole's emissivity is 100%, not 90-95%. A material of 90% emissivity would radiate 414 W/m2 at 27°C. You don't even need a laboratory thermal radiometer to see this. Just imagine a ball of 56.4 cm diameter (surface area 1 m2) filled with 27°C water and left in interstellar space (temperature 2.725 K, that is less than -270°C). If you want to keep its temperature unchanged, it is entirely reasonable that more than 400 W continuous power is needed for heating. Or if interstellar space is too far for you, hang the ball in a large space filled with 0°C thermal radiation. You can apply a thin rope to a branch in a dry winter night with low clouds and temperature around freezing. The background radiation in such an environment is 315.7 W/m2 (it is 3.1 μW/m2 in interstellar space). In this case, if the emissivity/absorptivity of the ball is 90%, you only need 130 W to keep it at 27°C. Of course you'd need a bit more, because now it is surrounded by (dry) air and it also cools the ball, but heat conductivity of air is low, so in calm weather most of the losses are radiative. If it is still not personal enough, try to calculate how much do you have to eat to stay alive in such an environment naked. The surface of adult human body is about 2 m2, skin's emissivity is close to 100% and you should not let your skin temperature go too low, otherwise it dies (gets black and peels off your flesh). Tibetan monks do something like that. It is called tumo and it keeps the body warm in extreme cold. But even they need plenty of tea with yak butter to resupply the energy lost. Fat has 37 kJ/g, therefore 40-50 g butter can supply more than enough heat for an hour for a well trained body. Of course if there is also a chilly wind, more energy is needed, because a lot more air gets into contact with skin, and even if it has low specific heat and low heat conductivity, contact losses can exceed radiative ones. -
Peter Hogarth at 01:10 AM on 27 July 2010Assessing global surface temperature reconstructions
Ken Lambert at 23:17 PM on 26 July, 2010 "What is of interest is that there has been a flattening of temperatures since 1998 in all the reconstructions, and overall, the satellite reconstructions since 1975 show less warming than the GHCN charts." I am highly skeptical of this conclusion.I have added the gradients for all three in degrees/year. Now ignoring the fact you cherry pick 1998 which is an obvious peak el Nino year, and the publicly available satellite data goes back to 1978 and not 1975, and the RSS satellite data has indistinguishable gradient from GISS and other land/ocean based datasets since 1978, and the 20 year gradient since 1990 has increased over the thirty year gradient in all data sets, I ask what flattening? or less warming? I could also have added the various independent radiosonde datasets, eg gradient 0.0193 for HadAT since 1990, but no surprises here either.
-
Ned at 01:07 AM on 27 July 2010It's waste heat
CBDunkerson, those are all interesting questions. For me, though, they're secondary. Being a skeptic by nature, I'd like to see some evidence from RSVP, in the form of a paper or a study or some actual data. Until something like that is presented, why should anyone care about waste heat? Flanner 2009 calculates that it's minuscule, and RSVP hasn't given us any references to contradict that. -
CBDunkerson at 00:50 AM on 27 July 2010It's waste heat
RSVP wrote: "I personally dont think humans are better off changing the chemistry of their atmosphere." Sooo... you agree that we shouldn't be emitting all that CO2. Excellent. That said, a few things which need explaining if you want to continue running with this 'global temperature increases are being caused by waste heat' bit; 1: Why are temperature increases most pronounced at the poles... where there is virtually no industry generating waste heat? 2: Why do we not see huge spikes of increased heat around urban industrial centers gradually leveling off as you get further into non-industrial regions? 3: Why has warming been most pronounced at night and during Winter? That makes sense if the warming is due to decreases in the rate heat escapes... but not if it is due to increasing 'accumulated heat'. 4: Why is the stratosphere cooling? Again, that makes sense if heat is being prevented from escaping to the stratosphere... but not if the total heat of the planetary environment is increasing. Those are just a start. There are dozens of other things which clearly indicate that 'waste heat' is not the cause... even setting aside issues of scale.
Prev 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 Next