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Tom Dayton at 05:07 AM on 31 July 2010Waste heat vs greenhouse warming
Oh.... I can't let your contention go without response, RSVP, because it isn't even basic physics textbook material--it is microwave oven owner's guide material. An empty microwave oven does not refuse to emit microwaves. Instead, the emitted waves bounce around inside the oven and (potentially) feed back onto the emitter, creating havoc. Just Google "run microwave oven empty." Sheesh. -
Doug Bostrom at 04:26 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy, don't forget that the spectrum of skepticism (disregarding the actual definition of the term) includes both those who believe the globe is warming but don't agree with mainstream attribution of that warming as well as those who don't believe the globe is warming at all. This site deals with both issues, so some of the discussion here is going to touch on topics devoid of attribution, rather only to do with various signals indicative of warming. At some time we'll probably see the former group disavow the latter but for the time being it's rather a muddle; some people go as far as to say there's no way C02 can help warm the globe and there's no warming in any case, others say it can but not much, still others say the globe is not warming but C02 could help it do so, etc. Meanwhile there's the mainstream group who have a more coherent collection of thought, sometimes called a "theory." -
chris at 04:16 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy at 03:42 AM on 31 July, 2010 I believe that Berényi Péter's post (#91) is closer to the truth. Great, but what's your evidence? It's all very well to state that black carbon has a contribution to global warming. No one doubts that. However its influence has to be quantitated if we wish to have a reliable assesment of contributions to warming. This quantitation has been (and continues to be) done, and black carbon is incorporated into scientific assessments of the contribution to 20th century and contemporary warming (e.g. here and here). It's a significant but small fraction of the forcing from enhanced [CO2]. -
chris at 04:06 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy at 07:22 AM on 30 July, 2010 Geo Guy at 03:17 AM on 31 July, 2010 It's hard to believe that a Geologist would consider the Scotese graph of any value in considering the relationships between Earth temperature and atmopheric [CO2] in the deep past. You must be aware, for example, that there is zero [CO2] data presented there. The apparent [CO2] data is from Berner's model of possible [CO2] based on an analysis of weathering rates and such like. Each data point is 10 million years apart. Broad swathes of vast geological time are sketched as having a single temperature...I'm sure Dr. Scotese never meant his sketch to be used in lieu of the scientific data, to assess these relationships! It should be obvious that the relationship between atmospheric CO2 levels and paleotemperature can only be assessed at those specific time points where paleotemperature and paleoCO2 data are contemporaneous. Where we have data points for paleotemperatures and paleoCO2 levels that match in time, the evidence is rather strong for a CO2/temperature coupling. Where paleo temperatures are high paleoCO2 levels are high and cold/glacial periods are associated with low CO2 levels. There's now extremely abundant information on this dating back many hundreds of millions of years. A recent review compiles much of the data and some of this has been discussed in detail elsewhere on this site. D.L. Royer (2006) "CO2-forced climate thresholds during the Phanerozoic" Geochim. Cosmochim. Acta 70, 5665-5675. a wealth of more recent data provides additional evidence for a strong relationship between [CO2] and temperature in the deep past. See for example: R.E. Carne, J.M. Eiler, J. Veizer et al (2007) "Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era" Nature 449, 198-202 W. M. Kurschner et al (2008) “The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of the terrestrial ecosystem” Proc. Natl. Acad. Sci. USA 105, 499-453. D. L. Royer (2008) “Linkages between CO2, climate, and evolution in deep time” Proc. Natl Acad. Sci. USA 105, 407-408 Zachos JC (2008) “An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics” Nature 451, 279-283. Doney SC et al (2007) “Carbon and climate system coupling on timescales from the Precambrian to the Anthropocene” Ann. Rev. Environ. Resources 32, 31-66. Horton DE et al (2007) “Orbital and CO2 forcing of late Paleozoic continental ice sheets” Geophys. Res. Lett. L19708 (Oct. 11 2007). B. J. Fletcher et al. (2008) “Atmospheric carbon dioxide linked with Mesozoic and early Cenozoic climate change” Nature Geoscience 1, 43-48. And so on….. -
robert way at 04:05 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
I think it'd be great if someone could find this paper http://www.opticsinfobase.org/abstract.cfm?URI=FTS-2009-FWA4 Observations of Climate Radiative Forcing from Ground and Space Wayne F. Evans Abstract The observation and monitoring of the radiative forcing of climate from greenhouse gases at the top of the atmosphere and at the surface by FTS is presented. but my library doesn't have the rights to it. would be interesting for this sort of discussion. -
RSVP at 03:44 AM on 31 July 2010Waste heat vs greenhouse warming
Tom Dayton #154 Or write one, in which case you would probably be reading it. It would not say "by RSVP" of course. -
Geo Guy at 03:42 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Ned # 94 - Yes, Yes, Yes...I do know that CO2 does have characteristics similar to a greenhouse. I first learned about the greenhouse gas effect nearly 40 years ago as an undergrad in geological engineering. Hence I am a believer of the greenhouse gas effect and any geologist would certainly agree. However the greenhouse gas effect is not what is at play here. From strictly a thermodynamics perspective, a single degree increase in atmospheric temperatures is not to account for the melting of the glaciers etc. I believe that Berényi Péter's post (#91) is closer to the truth. What I fail to accept is the strength many are attributing rising atmospheric CO2 has in driving climate change - that is what I am debating. Too often those on one side argue about how the planet is warming and come to the conclusion that it is man made CO2 that is driving that warming. I have yet to see any consequential evidence to support that position, particularly given that data exists to support the contention that other factors could be at play here. Many of the indicators of climate warming, as posted in this particular blog do not in any way relate to increased CO2 as being the cause. In fact the authors of the report failed to identify the cause for the warming. -
robert way at 03:40 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
John, this was a great post and should get more coverage. I wish there were more posts like this addressing these issues at real climate and climate progress. It would be nice for a news article to step up to the plate and really discuss each of these issues and why we know that certain things are signatures of human effects. It would also be interesting to see if there is a difference between early 20th century warming versus late in terms of days warming faster than nights in the early parts if it was indeed caused by increased solar irradience and the AMO. -
Tom Dayton at 03:36 AM on 31 July 2010Waste heat vs greenhouse warming
Okay, I give up, RSVP. You are completely, hopelessly out of touch with reality. Read a physics book, please. -
RSVP at 03:32 AM on 31 July 2010Waste heat vs greenhouse warming
If watts are consumed in the microwave, its happening in the output amp. If you leave it on too long without a load it will burn out. The waves never launch. If the Universe was only a single star, and there was absolutely nothing upon which it could shine. It could not shine. If you introduced an observer to witness this, you would no longer have a Universe with only a single star. -
Tom Dayton at 03:21 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP, the microwaves are emitted anyway. You can tell because the electricity consumed by the oven is the same as it would be if the bowl contained water. -
Geo Guy at 03:17 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
CBDunkerson # 86 - It is hardly one dubious writeup that I posted the link to. It was an analysis of the approach and if you took the time to scroll down to the bottom to review the references and then followed up by reading some of the references, you will learn that what can be determined by stomata analysis is that the past amounts of atmospheric CO2 fluctuated a great deal more than has been proposed by groups such as the IPCC. I have always had a problem with ice core analysis because of the complex pressures and temperatures that any trapped gasses would undergo over time. There are valid critiques of ice core analysis available to read for those who are interested in doing so. My position is that when you look at both sides of the argument, you will find valid research to support both sides. This tells me the issue is more complex than many people seem to accept and therefore warrants further research by BOTH sides. In the end we need to focus on adapting to climate change as simply curtailing our carbon footprint (if we could ever achieve that) would not work if climate change is being driven primarily by factors beyond our control. -
Doug Bostrom at 03:17 AM on 31 July 2010Waste heat vs greenhouse warming
Trying to tune here, RSVP. Are you saying that because a microwave oven's frequency is tuned to dump RF energy into water that if no water is present in the oven the energy will bounce around until it finds its way back to the only thing sympathetic in the room, the magnetron? What's your point? -
RSVP at 03:11 AM on 31 July 2010Waste heat vs greenhouse warming
doug_bostrom #149 OK. I will make real simple. Put a glass bowl with no water in your microwave oven. Leave it on for 1 minute. See how hot it doesnt get. -
Doug Bostrom at 03:07 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP: Photons do in a sense "know" whether they can be launched "before" leaping so to speak. Microwaves for instance require source and load impedance matching. How can it "know" this before leaving? Microwave and light and IR are of the same nature, (i.e. electromagnetic radiation). That example has nothing to do with the misunderstanding you're expressing with regard to whether radiation knows of its destination. Amplifying and then retransmitting your misunderstanding with paradoxical-seeming knowledge of microwave resonances is a strangely incoherent phenomenon of emission, a sort of epistemological transponder system with severe ringing or the like. -
Pete Ridley at 03:06 AM on 31 July 2010What do you get when you put 100 climate scientists in a room?
KR, ref. #221 (was #227), I think that we’ll have to agree to disagree on how bad scientist Hansen’s model is at forecasting global temperatures. You claim that “Luboš Motl .. posts from a clear ideological framework rather than a scientific one in the climate arena… “.Lubos has the significant advantage over us in that he does at least have a track record in one of the numerous scientific disciplines involved in improving our poor understanding of global climate processes and drivers. I place you in that “ideological framework” category and have no reason to believe that you have any scientific expertise whatsoever. If I am mistaken on that then perhaps you’d like to Ref. #228 (was #234), thanks for identifying what you consider to be three independent data sets that scientists use to estimate mean global temperatures (note that I am talking about near-surface temperature estimates such as those used by The Hadley Centre scientists, - see comment #207/217 (were #213/223). I have no disagreement about the satellite data being independent (although I understand that that those data do not refer to near-surface but to lower troposphere which may or may not be comparable). It is interesting to see what those expert climate scientists Dr. Roy Spencer and Professor John Chrisy have to say. According to their assessment of global temperatures at June 2010 (2) see http://www.drroyspencer.com/latest-global-temperatures/) there has been something like 0.13C per decade increase during the past 30 years, which, if continued (and that’s a big IF), would give a mere 1.6C increase in mean global lower atmospheric temperature by 2100, not the 6-7C forecast by some scientists. Of course we mustn’t overlook the fact that this is all pure speculation, since we (including the scientists) have no idea what global mean temperatures will be in 2100. I am not convinced about the independence those GHCN and GSOD data bases from each other so will try to make time to take a closer look at them before commenting further. Meanwhile you may like to read what the Climate Sceptic said in its 2008 “Temperature Measurement” article (http://www.climate-skeptic.com/temperature_measurement/). As I’m off on a week’s holiday with my lovely grand children you’ll have to wait for my next set of comments until I’m back, around 7th August. -
Pete Ridley at 03:06 AM on 31 July 2010What do you get when you put 100 climate scientists in a room?
gallopingcamel, when I was involved with Barry Brook on Bravenewclimate a year ago I was surprised about how keen he is on nuclear power. I agree about nuclear being relatively cheap (compared with renewables like wind and solar) but it will be a long time before it is as cheat as fossil fuel and I can’t see it being viable for private transport, can you? One other thing that Brook seems to have strong feelings about is those emissions from livestock. Did you see his interview with Supreme MasterTV? The A/V of Brook’s interview used to be at http://suprememastertv.com/bbs/board.php?bo_table=sos&wr_id=511 but it now says “connect failed”. I wonder if Brook had second thoughts about the association. -
dhogaza at 03:03 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Thinking laterally, I would say if you want to convince the skeptics that it isn't the sun causing recent global warming, do more research on the sun.
Note how thingadonta reverses the normal burden of proof from the so-called skeptic to the mainstream scientific community. I can just as easily say "skyfairies are causing warming, though I have no evidence, no proposed mechanism that has withstood scrutiny, and there is no increasing trend of observed skyfairies. In order to convince me that skyfairies are *not* the cause of recent observed warming, *you* must get a grant to study skyfairies and prove that they are not the cause". And thingadonta wonders why "skeptical" blog "science" gets no respect ... -
RSVP at 02:59 AM on 31 July 2010Waste heat vs greenhouse warming
Tom Dayton #146 What exactly happens when the photons "get there", but decide they are not wanted? Do they disturb things in any way? I dont think this has ever been measured. The other alternative is to redefine atomic radius as something that goes beyond just the outermost valence shell, at least for photons. When I put out my hand to the Sun, I can "feel" it because I am in "contact" with it (or at least a little bit of it). The Universe is all one big single Thing. -
CBDunkerson at 02:52 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Another thought on snow melt... by the time Summer comes around most snow is GONE. Ergo, it is not surprising that the rate of snow decline in Summer hasn't grown as much as the rate of snow decline in Spring. 'Smoking gun' go 'poof'. -
KR at 02:49 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP - If you dont agree with me, please at least respect my "delusion". Nope. Reality is a harsh critic. Hundreds of years of science cannot be avoided by wishful thinking, 'common sense' arguments, and the like. Please - read up on the basic concepts. Roy Spencer, an AGW critic, has an excellent reference on back radiation, and how a cold object can make a nearby warm object warmer. Science of Doom has plenty of introductory material. Wikipedia has tons of useful information on greenhouse effects, climate forcings, and the like, with lots of references. But don't expect us to drop the science... -
CBDunkerson at 02:31 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
BP, you've apparently forgotten that we've discussed that snow melt graph before. Had you remembered you'd likely realize that I'd point out the same flaw in your logic that I did last time. Specifically, the minimum (i.e. greatest rate of decrease) comes a week BEFORE the Summer solstice... yet the insolation a week AFTER the Summer solstice would be just as great and falling onto snow with two more weeks of accumulated soot. Ergo, if your 'insolation + soot = cause of melt' hypothesis were accurate we should be seeing the minimum AFTER the solstice, not before it. The other thing I believe many people pointed out the last time you trotted this out was something called precipitation. There is alot of it in the form of rain in the Spring which accelerates snow retreat and alot of it in the form of snow in the Winter which decreases (and indeed reverses) snow retreat. -
Tom Dayton at 02:28 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP, I believe you are thinking of the net effect of microwave transmission followed by reflection from the destination back to the source. That process unfolds in time. It does not happen because the microwaves don't leave the source by virtue of knowing what will happen to them. -
CBDunkerson at 02:14 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP #144 writes: "If you dont agree with me, please at least respect my "delusion"." No. Sorry, but I don't respect your belief that radiation somehow magically avoids areas of higher temperature any more than I respect beliefs that the Earth is flat. Both of these 'beliefs' are provably, and frankly rather obviously, FALSE. -
Ned at 02:04 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Very often I see the better-informed skeptics expressing frustration that we don't deal with their more sophisticated and reasonable claims, instead of spending so much time correcting the same basic and obviously-wrong nonsense ("Is the greenhouse effect real? Is the CO2 increase real? Wasn't CO2 a lot higher before WWII?" etc.) I can understand that. It must be frustrating to have what seem to you to be sensible, serious questions about climate that just get drowned out in all the noise about whether CO2 is actually a greenhouse gas (it is) and whether the greenhouse effect violates the second law of thermodynamics (it doesn't). The problem is that as long as intelligent and competent skeptics can't bring themselves to stop writing things like [...] the alleged thermal radiation trapping effect of carbon dioxide [...] we're never going to get very far. Maybe there is something interesting about the role of soot in the timing of snowmelt, and the implications for climate. Maybe it would be fun to talk about it. But why would I waste my time discussing that with someone who apparently refuses to acknowledge fundamental science that has been understood since the mid-1800s? Reading BP's comment just makes me feel very discouraged about the idea of any meaningful discussion with "skeptics". Here's a serious question. Is there any "skeptic" reading this thread who is willing to categorically state that yes, CO2 is in fact a greenhouse gas? No caveats, no "allegedly", no "for the sake of argument". Just "yes". -
RSVP at 01:55 AM on 31 July 2010Waste heat vs greenhouse warming
doug_bostrom #142 "You'll need to get past that notion in order to make better progress here" I agree that we disagree on this issue. I also noticed this, but hoped it wasnt necessary to go there. I dont want to take you or anyone on a wild goose chase, or worse, have someone think that that is my intention. If you dont agree with me, please at least respect my "delusion". It might even be interesting to at least hear. Photons do in a sense "know" whether they can be launched "before" leaping so to speak. Microwaves for instance require source and load impedance matching. If the load is not matched, the energy does not transmit. How can it "know" this before leaving? Microwave and light and IR are of the same nature, (i.e. electromagnetic radiation). -
Ned at 01:32 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
BP writes: What we can see here is that snow cover trends are almost exactly in phase with insolation. As surface temperatures lag insolation by almost two months due to high heat capacity of the climate system (mostly oceans), the trend observed is not caused by temperature (that is, by trapping outgoing longwave radiation), but by increased absorption of incoming shortwave radiation. That is what in science is called a hypothesis. It is not a conclusion or a smoking gun or anything else. You really need to stop leaping to inappropriately vast conclusions based on pure speculation. -
Ned at 01:27 AM on 31 July 2010Waste heat vs greenhouse warming
There is a lot of confusion about very basic physics concepts in this thread. There are also a lot of analogies being used that aren't necessarily helpful. We could start from ground zero and go over exactly how the greenhouse effect works. But we don't really have to do that, since Science of Doom has already done a far better job of explaining it than we are likely to do. RSVP, have you visited that site? Since you seem to be hung up more on the basic principles of greenhouse gases instead of the narrow question of waste heat, you might find it helpful to do some reading over there. -
Doug Bostrom at 01:24 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP: Curiously, [radiation] tends to always want to go to the coolest place (i.e. outer space). No. It goes in the direction it's emitted which is unrelated to its future destination, does not "want" anything, has no idea of its destiny. You'll need to get past that notion in order to make better progress here. -
RSVP at 01:05 AM on 31 July 2010Waste heat vs greenhouse warming
Someone said way back that radiation does not depend on a difference in temperature. Curiously, it tends to always want to go to the coolest place (i.e. outer space). That to me sounds like the difference matters. Likewise, here on Earth, the amount of radiation will depend on the temperature of things. So you wont have radiation happening free just because, especially when things are already getting warmed. So, the GHG will diminish as a function of ambient temperatures especially where something else (like waste heat) is causing a counter force. -
Doug Bostrom at 01:02 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Not another smoking gun? It's hard to force my way out the door in the morning because of all the smoking guns laying about. In fact, thinking along Peter's lines, all the smoke from the smoking guns very well may save us yet. -
RSVP at 01:00 AM on 31 July 2010Waste heat vs greenhouse warming
#138 "This is all nonsense. Not a word of it is true. The laws of physics do not very by geography. " You mean "vary", and I never said anything about geography. The "condition" has to do with energy level or temperature, however you wish. What I am bringin up here is a question that would be actually interesting to discuss... perhaps... That is... I assume 2.9 W/m2 is the average for the entire planet. Is it higher for places that are normally cooler, or higher for place that are normally warmer, or is it the same everywhere??? -
adelady at 00:56 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP at 00:27 AM on 31 July, 2010 "GHG only warm under certain conditions, and actually cause cooling under others. If you dont believe this, go to the desert at night." GHG warm the *atmosphere* under all conditions. Humidity or the lack of it affects the temperature for a few hours or days at individual locations. But this is just the circulation of heat and moisture -within- the atmosphere and the oceans. Global warming is about the fact that energy continues to circulate within these systems instead of making orderly progress through the atmosphere and out to space. Adding more GHG to the system increases the amount of energy held and circulating within the system. That deserts are cold at night and tropical forests are warm most of the time are simple facts about particular locations on land surfaces. It says little to nothing about the whole system of atmosphere and oceans. -
Berényi Péter at 00:54 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
#87 CBDunkerson at 21:51 PM on 30 July, 2010 Yep, the 'alarmists' sure are 'cherry picking' by not concentrating on that SH sea ice OK, let's have a look at NH snow cover trends. Spring snow cover in the Northern hemisphere is declining indeed. However, it is not the end of story. NH snow cover trend for weeks of year, in km2/year units (1972-2009)
Not all "forcings" are born equal. They act on different parts of the climate system, therefore their strength expressed in W/m2 units does not fully determine their effects.
The NH snow cover annual trend graph has a sharp minimum at week 23.5 (summer solstice is week 24.5), while its maximum is at week 52 (winter solstice is week 51). What we can see here is that snow cover trends are almost exactly in phase with insolation. As surface temperatures lag insolation by almost two months due to high heat capacity of the climate system (mostly oceans), the trend observed is not caused by temperature (that is, by trapping outgoing longwave radiation), but by increased absorption of incoming shortwave radiation.
It is a big difference. One might even call it the smoking gun of climate science. It is all the more important because unlike most other climate indicators it is not lost in noise, but stands out very clearly.
Snow cover is increasing through mid October to January, when Northern Hemisphere insolation is low, decreasing otherwise. Therefore it is some immediate effect of sunshine, not a delayed one like the alleged thermal radiation trapping effect of carbon dioxide. For thermal radiation getting available to be trapped, surface temperatures have to be increased first. But that does not happen until later in the year.
The most probable candidate for increased SW absorption is decreasing snow albedo due to black carbon (i.e. soot). There is also a positive albedo feedbeck at work here. The more snow is melting, the more bare soil is exposed to the sun. This very albedo change can explain glacier and ice sheet phenomena as well.
The good news is that residence time of soot in the atmosphere is very low (around 1 week), so as soon as emissions are decreased, the effect vanishes. It is also much cheaper to reduce soot emissions than carbon dioxide, as the technology is already available and is mostly installed throughout developed countries.
What about a soot duty on Chinese products? And a ban on small Diesel engines perhaps (like those in cars). Or help to replace heavy soot generating biofuels (like dung) as cooking materials in India and Africa by natural gas or electricity? Or to introduce reasonable woods maintenance practice in North America by making removal of dead wood from managed forests compulsory (as it is done in Europe)?
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CBDunkerson at 00:50 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP #135: "Why do you only think GHG work towards warming?" As written that is asking me why this is the only thing I think. Which is obviously inaccurate. Did you intend to ask why I think GHGs cause only warming? I don't think that either... since they cool the stratosphere. Whatever, it bears no resemblance to anything I've actually said so I'm not sure where you are going. "They should emit as much as they absorb? No?" What about the pool balls aren't you understanding? Pool ball hits a blocked pocket... it bounces off and remains on the table. Photon hits a GHG molecule... it gets emitted back out and remains in the atmosphere. So yes, they emit as much as they absorb... which is precisely why the atmosphere gets warmer. They're bouncing pool balls/photons back onto the table/into the atmosphere rather than allowing them to escape to the pocket/space. "If I am in a dry desert at dusk, temperatures are bound to drop very quickly. Why?" Because water vapor is a powerful greenhouse gas. Dry deserts don't have alot of water vapor. Ergo, they cool down at dusk more quickly than regions which do. "You could have a situation where if waste heat was equal to 2.9 W/m2, then GHG wouldnt do anything." False. GHGs work on all IR regardless of its source. Thus, some of that waste heat would be 'bounced' back down towards the surface and prevented from escaping to space longer than it would have been without the GHGs. Yeesh. At least TRY to understand the analogies. "GHG only warm under certain conditions, and actually cause cooling under others. If you dont believe this, go to the desert at night." This is all nonsense. Not a word of it is true. The laws of physics do not very by geography. -
RSVP at 00:47 AM on 31 July 2010Waste heat vs greenhouse warming
One more thing... and assuming cloudless skies in two cases, desert and beach... the fact that temperatures drop faster in the desert tells you quite a bit about how water vapor acts as a GHG vs CO2. -
Doug Bostrom at 00:46 AM on 31 July 2010Waste heat vs greenhouse warming
If I am in a dry desert at dusk, temperatures are bound to drop very quickly. You're missing a GHG there, RSVP. Think about it. -
RSVP at 00:27 AM on 31 July 2010Waste heat vs greenhouse warming
CBDunkerson #131 "However, if we then block off one of the pockets (add GHGs to the atmosphere" Why do you only think GHG work towards warming? They should emit as much as they absorb? No? This needs to be established. If I am in a dry desert at dusk, temperatures are bound to drop very quickly. Why? I assume IR doesnt have to ask permission from each CO2 molecule it finds on its way upward. You know if this were the case there would no such thing as IR satellite photography. It seems like IR makes it right through for the moment, otherwise there would be no contrasting images. But moreover, here is the crux of this issue.... You could have a situation where if waste heat was equal to 2.9 W/m2, then GHG wouldnt do anything. It would be a "clipping" situation. Another example. Waste heat was 1 W/m2 and GHG in the absense of waste heat was contributing 2.9 W/m2. So in reality GHG only actually added 1.9. Do you see what I am saying? That GHG also serve to emit radiation. They dont push power where it is cant be absorbed. This all has to do with the concept of saturation and a limited amount of surface energy. GHG only warm under certain conditions, and actually cause cooling under others. If you dont believe this, go to the desert at night. -
barry1487 at 00:26 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
I would have been better quoting number 5, where a qualification has got me thinking.Satellites measure less heat escaping out to space, at the particular wavelengths that CO2 absorbs heat
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barry1487 at 00:22 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Solar radiation, on all levels and cycles, and its effects on Earth, are multiple and diverse, and poorly understood. This means one can't definitely distinguish between these two processes relating to global warming -greenhouse gases and solar variables, and therefore all of your above fingerprints could still be correct and yet greenhouse gases may still not be the main driver of global warming in the last several decades. I didn't say this, solar scientists are saying it.
Have they postulated a mechanism whereby the sun cools the stratosphere as it warms the troposphere? Stratospheric cooling is one of the main rebuttals to 'it's the sun.' The whole atmosphere should heat if the sun gets hotter. -
barry1487 at 00:18 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
I have a query about number 6.If less heat is escaping to space, where is it going? Back to the Earth's surface. Surface measurements confirm this, observing more downward infrared radiation (Philipona 2004, Wang 2009). A closer look at the downward radiation finds more heat returning at CO2 wavelengths, leading to the conclusion that "this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming." (Evans 2006).
In the picture, there is a caption, "Less heat escaping to space." But:"...the Earth must, on average, radiate the same amount of energy back to space."
AR4 Ch 1, p 115 I may be in error to equate heat with energy in this case, but if I'm not wrong... the Earth is radiating the same amount of heat back to space, but it is happening at a higher level in the atmosphere. It's not that less heat is escaping to space, but that the relatively constant temperature lapse rate through the atmosphere means that the surface warms if heat loss occurs at a higher altitude. Have I got this right? -
chris at 23:46 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
HumanityRules at 13:55 PM on 30 July, 2010 If one is interested in the polar response to global warming, it's helpful to know that we have long expected that the Antarctic response would be delayed compared to the rapid Arctic response. For example, modelling from the early 1980's predicted that enhanced greenhouse-induced warming would be focussed in the Northern polar regions leaving the Antarctic regions relatively unaffected for considerable periods. A recent review of early modelling of the ocean response to global warming described predictions from early modelling: S. Manabe and R. J. Stouffer (2007) Role of Ocean in Global Warming J. Meterolog. Soc. Jpn. 85B 385-403 Here are some excerpts from the sections of this article describing the predicted hemispheric asymmetry (much greater N. hemispheric polar warming and delayed Southern polar warming). So, discussing the early models of Schneider and Thompson (1981) to evaluate the delay in the response of the sea surface temperature to gradual increase in CO2, Manabe and Stouffer say:"Their study shows that the time-dependent response of zonal mean surface temperature differs significantly from its equilibrium response particularly in those latitude belts, where the fraction of ocean-covered area is relatively large. Based upon the study, they conjectured that the response in the Southern Hemisphere should be delayed as compared to that in the Northern Hemisphere because of the inter-hemisphere difference in the fraction of the area covered by the oceans.”
In a later model Bryan et al (1988) made the same sort of analysis, investigating the role of the oceans in modulating the response of surface warming to enhanced greenhouse gases.“They found that the increase in surface temperature is very small in the Circumpolar Ocean of the Southern Hemisphere in contrast to high latitudes of the Northern Hemisphere where the increase is relatively large.”
It’s not just the oceans per se of course. It’s also ocean and air currents, and particularly the mechanisms governing the efficiency of surface heat transfer into the deeper oceans. If this is efficient, the deep oceans will absorb heat and there might be little measured surface warming, at least for a while. So (speaking of Bryan et al (1988)) again:“However, the detailed analysis of the numerical experiment reveals that the absence of substantial surface warming in the Circumpolar Ocean is attributable not only to the large fraction of the area covered by the oceans but also to the deep penetration of positive temperature anomaly into the oceans.”
Later models predict the same hemispherical asymmetry that is seen in the real world. e.g. discussing the simulations of Manabe et al (1992):“Figure 3 also reveals that there is a large asymmetry in surface warming between the two hemispheres. In the Northern Hemisphere, the surface warming increases with increasing latitude, and is particularly large in the Arctic Ocean. This is in sharp contrast to the Southern Hemisphere, where warming is relatively large in low latitudes and decreases with increasing latitudes. It becomes small in the Circumpolar Ocean of the Southern Hemisphere, particularly in the immediate vicinity of Antarctic Continent.”
Why is this, one might ask?! Here’s what Manabe and Stouffer say:“One can ask: why the polar amplification of warming does not occur in the Southern Hemisphere, despite the existence of extensive sea ice which has a positive albedo feedback? As discussed in the following section, the absence of significant warming in the Circumpolar Ocean of the Southern hemisphere is attributable mainly to the large thermal inertia of the ocean, which results from very effective mixing between the surface layer and the deeper layers of ocean in this region. This is in sharp contrast to the Arctic Ocean, where very stable layer of halocline prevents mixing between the surface layer and the deeper layer of the ocean.” and “In view of the absence of significant surface warming, it is not surprising that the area coverage of sea ice hardly changes in the Circumpolar Ocean despite the CO2-doubling.”
(n.b. remember this is a prediction from a model; we’re nowhere near CO2 doubling yet!). However that's what we're seeing in the real world. So the delayed warming in the deep Southern oceans and Antarctic is consistent with models/predictions from more than 20 years ago. -
Ken Lambert at 23:42 PM on 30 July 2010Waste heat vs greenhouse warming
CBDunkerson #126 "Essentially, you are arguing that if 50% of all temperature measuring stations are located in the most heavily populated 7% of the globe then that 7% of the planet determines 50% of the global temperature anomaly." No I am not arguing that. I said "then it is reasonable to expect that temperatures would be affected by waste heat which roughly adds 0.9 + 0.4 = 1.3W/sq.m over those areas." "over those areas" refers to the 7% of the globe (land) releasing this waste heat. It depends on the 'tricks' used by researchers to correct this 7% of the land area which would have a relatively high number of measuring stations compared with sparsely populated areas. Yes - waste heat moves about - but it is an energy flux ie an instantaneous heating power measured in W/sq.m or Joules/sec-sq.m. A 3D thermal gradient will be established from source to any remote point. Other sources will add to the complexity and multiple sources will distribute heat from power station stacks, cooling towers, cooling lakes by evaporation, convective and radiative means driven by winds etc. -
Lou Grinzo at 23:23 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
John: Great job as always, and on all fronts. -
chris at 23:14 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
HumanityRules at 22:07 PM on 30 July, 2010 "Why does The State of the Climate 2009 document state in one line that Arctic ice multiyear ice has increased by 11% from 2008 to 2009 then move on in the next line to state that these two numbers are similar?" You're contriving confusion by imprecise precis HR. The full paragraph of which you speak is reproduced below [*]. "What does this mean?" (i.e. re data available for bona fide research purposes). The first answer is that you could enquire to the NOAA for their precise reason for that statement. However there are lots of possible reasons. In my experience that sort of statement comes up quite frequently in various contexts; e.g.: (i) Publically-funded research is specifically made available for research purposes (even if there may be some increasingly out-dated "embargos" involving commercial publishing of publically-funded research). However it shouldn't be used, for example, by commercial organisations to advance their interests (e.g. climate data used by a company selling weather forecasts). (ii) protection of intellectual property and copyright. For example as a "bona fide" researcher, I can download figures from other peoples published papers and to display these in lectures (e.g. for teaching or for scientific presentations). However I am not allowed to do this for commercial gain. etc. etc. "If your looking for reasons I express cynical statements... I get the impression that the "reasons [you] express cynical statements" may be because you like to maintain a"rolling boil" of contrived indignation about science that happens not to suit your fancy! (in the UK we call that behaviour "Daily Mail syndrome"). Thus your tendency to false precis. Generally scientists go to some efforts to state clearly what they mean. it's unfortunate when others incorrectly precis their writing in order to contrive an impression of confusion! ---------------------------------------- [*]STATE OF THE CLIMATE IN 2009 p S113-S114In the past decade, the extent of multiyear sea ice rapidly reduced at a rate of 1.5×106 km6 per decade, triple the reduction rate during the three previous decades (1970–2000). Springtime multiyear ice extent was the lowest in 2008 in the QuikSCAT data record since 2000 (Nghiem et al. 2007). QuikSCAT results in March 2009 showed a multiyear ice extent of 3.0 ± 0 .2 million km2. This was 0.3 million km2 larger (11% increase) than the multiyear ice extent on the same date in 2008, even though the total sea ice extent was similar in the spring of 2008 and 2009. While the multiyear ice extent was similar in March 2008 and 2009, its distribution was quite different. More specifically, in 2008 there was a significant amount of multiyear ice in the Beaufort Sea and in 2009 there was a large amount of multiyear ice in the central Arctic Ocean.
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Mats Frick at 23:08 PM on 30 July 2010Models are unreliable
I can recommend Paul N. Edwards (2010) "A Vast Machine: Computer Models, Climate Data, and the Politics of Global Warming". I'm just starting on the final chapter and its by far the best text on the origins and applications of modeling in climate science. Highly recommended! -
CBDunkerson at 22:29 PM on 30 July 2010Waste heat vs greenhouse warming
Hey John. Yeah, I was trying to get across the way that photons bounce around in the atmosphere, but any analogy of things trying to move through constrained exits (e.g. the dam analogy) covers the central concept. They each have benefits. The pool table simulates the 'brownian motion' of the photons, the dam has the increasing pressure at the bottom correlating to the increasing surface temperature, and the stadium crowd helps get across the vast number of individual photons involved. -
HumanityRules at 22:07 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Why does The State of the Climate 2009 document state in one line that Arctic ice multiyear ice has increased by 11% from 2008 to 2009 then move on in the next line to state that these two numbers are similar? (S113-114) Increased multiyear ice doesn't fit the complete story of unidirectional metrics. [pointless speculation about motivations deleted]Moderator Response: Please bear in mind that if you mix potentially useful questions about science with speculation about conspiracies and the like, you may end up wasting the time of other people when entire swathes of comments are removed. Try your best to stick with discussing science. -
John Russell at 21:56 PM on 30 July 2010Waste heat vs greenhouse warming
CBDunkerson at 21:16 PM on 30 July, 2010 Wow, what a truly wonderful analogy. As a analogyphile myself I admire your creativity (I'm assuming it's not a cut and paste job!). If I may, the only thing I could suggest that might improve it is to substitute a crowd in a large stand at a football match looking for one of a number of exits -- with a stream of additional spectators joining them from the tier above. This has that advantage that one doesn't have to imagine balls being self-powered. Does that work? Someone ought to collect all the analogies together! -
CBDunkerson at 21:51 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
HumanityRules #77, to be CLEAR those are results modeled based on the available measurements. Hence my calling them estimates. Also note that when IceSAT was online we DID have direct measurements of ice volume... and they matched the PIOMAS estimates very closely. Thanks to CryoSAT II we'll know in a few months whether PIOMAS has continued to be that accurate, but given the complete collapse of ice thickness and concentration (as shown even on the PIPS site you have previously preferred to cite) it is clear that ice volume has undergone a huge collapse. As to 'cherry picking' when talking about ice melt... by all means let's look at the full picture; NH sea ice: Declining NH land ice: Declining NH all ice: Declining SH sea ice: Increasing SH land ice: Declining SH all ice: Declining Global sea ice: Declining Global land ice: Declining Global all ice: Declining Yep, the 'alarmists' sure are 'cherry picking' by not concentrating on that SH sea ice.
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