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Jesús Rosino at 21:47 PM on 19 February 2010What would happen if the sun fell to Maunder Minimum levels?
I was missing a paper like this, thanks for the summary! Fortunately it was already highlighted in this site that "The difference in solar radiative forcing between Maunder Minimum levels and current solar activity is estimated between 0.17 W/m2 (Wang 2005) to 0.23 W/m2 (Krivova 2007)", whereas "the radiative forcing of CO2 since pre-industrial times is 1.66 W/m2 (IPCC AR4), far outstripping solar influence." -
Hoskibui at 21:41 PM on 19 February 2010Skeptical Science now an iPhone app
Where can I find this new App? Didn't find it using this link: http://itunes.com/apps/skepticalscienceResponse: If going to http://itunes.com/apps/skepticalscience did nothing, the most likely explanation is you don't have iTunes installed. If you do have iTunes installed, go to the app store and search for skeptical science. -
suibhne at 21:09 PM on 19 February 2010Is CO2 a pollutant?
Philippe Chantreau The top panel gets 168 +324 The bottom panel gets 390 All units w/m2 That is if you really believe the diagram in the first place. ....... it is exactly G&T's position that not only no radiation flows from the atmosphere to the surface but that this is altogether impossible. Could you give a page number for your quote? -
70rn at 20:47 PM on 19 February 2010What would happen if the sun fell to Maunder Minimum levels?
"The IPCC claims the radiative forcing due to changes in the solar output since 1750 is +0.12 Wm-2, an order of magnitude smaller than its estimated net anthropogenic forcing of +1.66 Wm-2. A large body of research suggests that the IPCC has got it backwards, that it is the sun's influence that is responsible for the lion's share of climate change during the past century and beyond." Given that the sun has been steady or in decline over the period of 1950 - 2010 - this surely indicates that temperature increases since then cannot be attributed to it. Given the substantial change in temperature currently do not correspond to changes in solar output I fail to see how such a conclusion can be drawn. -
Arkadiusz Semczyszak at 20:33 PM on 19 February 2010What would happen if the sun fell to Maunder Minimum levels?
1. Analysis of solar activity in the Holocene (e.g. Solanki 2004, Usosskin 2007) shows that there is possible another scenario. Just as 5000 BCE to 4900 BCE (Older Peron) may wait for us being 2-3 thousand. years - warm period of with several small minima. 2. Changes in solar activity is not only the TSI, but gravity changes (LNO-LNC - effects on THC - it is really only a "ridiculous theories"?), and a system of climate feedbacks. Rahmstorf, Ganopolski, 2005: "We attribute the robust 1,470-year response time to the superposition of the two shorter cycles [87; 210 years], together with strongly NONLINEAR DYNAMICS and the long characteristic timescale of the thermohaline circulation." http://www.nipccreport.org/chapter5.html - "Solar Variability and Climate Cycles." - "The IPCC claims the radiative forcing due to changes in the solar output since 1750 is +0.12 Wm-2, an order of magnitude smaller than its estimated net anthropogenic forcing of +1.66 Wm-2. A large body of research suggests that the IPCC has got it backwards, that it is the sun's influence that is responsible for the lion's share of climate change during the past century and beyond." - "The role of solar activity in causing climate change is so complex that most theories of solar forcing must be considered to be as yet unproven." [...] We say: that without a proper assessment of the significance Millennium cycles, each evaluation of the impact of natural factors is incorrect. Claiming: that the Millennium cycles: How warms up to N - cooled on the S, is vague - "de facto" - false. 3. If current warming is (mostly) natural and we will have a transgression of the sea as the Older Peron (Australia - 2.5 to 4 meters - 8 to 13 feet) - whether it is worth spending money on CCS? -
Philippe Chantreau at 20:11 PM on 19 February 2010Is CO2 a pollutant?
As I recall, it is exactly G&T's position that not only no radiation flows from the atmosphere to the surface but that this is altogether impossible. I believe they state it quite clearly. -
Philippe Chantreau at 20:05 PM on 19 February 2010Is CO2 a pollutant?
Suibhne, if you put a solar panel between the surface and the sun, that part of the surface below the panel does not receive the solar 342 joules/s any more. I'm not sure I see how that idea of a 2 sided panel applies to anything. -
suibhne at 20:00 PM on 19 February 2010Is CO2 a pollutant?
carrot eater ...........I've seen all that. The basic point remains. In the end, G&T have a problem with radiative exchange between bodies of different temperature...... I cant believe that you think that the G&T position is that no re radiation whatsoever from the atmosphere arrives back on Earth. In Physics it is quite common to disregard trivial quantities. An electric kettle contains 1kg of water say. Before (and after) the kettle is switched on the water and the kettles element radiate to one another. When the kettle is switched on heat energy from the element is transferred to the water. The electrical energy input is precisely known as is the internal energy gained by the water by independently derived equations. If the kettle is well insulated the input energy and the internal energy gained by the water are almost exactly equal. I have never heard of anyone including the back radiation from the water to the element in such a calculation -
dhogaza at 14:00 PM on 19 February 2010Did Phil Jones really say global warming ended in 1995?
RSVP ... "What about all the water vapor that comes from combustion? When burning methane for instance, you get twice as much water vapor as CO2. Even if you assume a shorter lifetime of water vapor as compared to CO2, the immediate presence of the extra water vapor must be factoring into the current temperature readings, in which case, CO2 is having less impact than is assumed." Do you have any idea how miniscule an amount this additional water vapor is? Tropical air can contain up to 30,000 ppm water molecules in the form of water vapor. CO2 is around 380 ppm. A quick look in google would seem to indicate that air over dense urban areas can contain an extra 20-40 or so ppm CO2 (there's one reference that talks about a 100 ppm bump but that's right next to a heavily-used freeway in Dallas). The number of H2O molecules from combustion of gasoline is almost exactly the same as the number of CO2 molecules. Miniscule. As far as heat from combustion, mechanical friction in machines driven by combustion, etc ... it's computable. It's been looked at. Science is by its very nature anal. It's an extremely tiny fraction of the forcing that results from the CO2 emissions associated with that combustion, though I'm not in the mood to google it *again* (this question gets asked a lot) . -
volando at 13:33 PM on 19 February 2010Skeptical Science now an iPhone app
Man, what a great idea, I would totally download and use this if it came in Android flavor. Please port it! Thanks. -
Chris G at 13:29 PM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
@ RSVP at 00:18 AM on 19 February, 2010 In the long run, energy in equals energy out. After a CO2 molecule, or any gas molecule for that matter, absorbs a quantum of energy, it emits it at the same wavelength as it was absorbed, and it a random direction; this basically means 50% up and 50% down. So, the CO2 in the atmosphere acts like a very fuzzy reflector. The net effect of increasing the amount of CO2 is that the black body radiation emitted at the surface has to shift to a slightly higher mean wavelength to get the same amount of energy out as is coming in. Higher medium wavelength is the same as higher temperature, as far as energy emitted by a solid is concerned. -
Marcus at 09:31 AM on 19 February 2010Did Phil Jones really say global warming ended in 1995?
Wow, RSVP, way to sidestep the entire point of my previous comment. My *point*, if you were paying any attention, is that the amount of direct energy from the sun utterly dwarfs the very minuscule energy produced directly by human activity. Similarly, the amount of water vapor generated by human activity is utterly dwarfed by the amount of water vapor traveling through the atmosphere due to evapo-transpiration. Lastly, the quantity of water vapor required to enhance the greenhouse effect is more than 10 times greater than the quantity of CO2 needed to enhance the greenhouse effect by the same degree (& methane is 8 times more potent than CO2, so turning methane into CO2 & water has a net *negative* impact on radiative forcing). As much as you try & squirm, RSVP, the reality is that the only thing we're adding significantly to is atmospheric concentrations of CO2, NO2 & methane-all potent trappers of long-wave radiation & all capable of increasing the energy imbalance within our atmosphere. To try & shift the blame to our absolutely minuscule direct heat signature really displays an amazing lack of knowledge of the underlying science of energy budgets, radiative forcing & the like. I'm certainly no expert, but I suspect I'm more up-to-date than yourself! -
peri at 08:36 AM on 19 February 2010Skeptical Science now an iPhone app
Give it to me on Android! -
Peter Hogarth at 08:09 AM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
Sorry John, I've just learned Andy Jacobson from the same NOAA lab did this version of the Surface Station visualisation. Their team also has CarbonTracker on their ftp, I think this is Andys also but will check. Re 3: (nice) and SCIAMACHY on ENVISAT, worth mentioning that Bremen University have independently matched the CO2 data from Mauna Loa etc and also provided an independent reality check of CarbonTracker (which is observations plus model) as well as producing many impressive real data based images of CO2 and CH4 sources on brand new version of: iup.uni-bremen.de/.../wfmd_image_gallery_co2.html (Michael Buchwitz is the creator). This has grown into a wonderful collection of images since last I looked.Response: Thanks, have updated the text. Also updated the post with links to the original source of the two NASA animations for those who'd like to download the animations as movie files. -
carrot eater at 08:01 AM on 19 February 2010Is CO2 a pollutant?
Oh, and as for not being polemical: Thank you for the compliment, but I must admit that the strict moderation at this site forces one to be on their best behavior. So long as you are making an honest attempt to learn and assess, that is good. -
carrot eater at 07:59 AM on 19 February 2010Is CO2 a pollutant?
suibhne I've seen all that. The basic point remains. In the end, G&T have a problem with radiative exchange between bodies of different temperature. They think this violates the Second Law. This is just wrong, on the face of it. Nowhere in the diagram is heat flowing in the wrong direction. This is an example of Dunning-Kruger actually making it into a journal. G&T thought they could tear down an entire field with a single statement of undergraduate level physics. Unfortunately, they can't, but more unfortunately, some obscure journal published their rant. One wonders if the reviewers actually read it. -
Doug Bostrom at 07:27 AM on 19 February 2010Is CO2 a pollutant?
Here's an interesting report w/regard to C02 as a human artifact, where it goes and what it does: "Today, Ridgwell and Daniela Schmidt, also of the University of Bristol, are publishing a study in the journal Natural Geoscience, comparing what happened in the oceans 55 million years ago to what the oceans are experiencing today. Their research supports what other researchers have long suspected: The acidification of the ocean today is bigger and faster than anything geologists can find in the fossil record over the past 65 million years. Indeed, its speed and strength — Ridgwell estimate that current ocean acidification is taking place at ten times the rate that preceded the mass extinction 55 million years ago — may spell doom for many marine species, particularly ones that live in the deep ocean. “This is an almost unprecedented geological event,” says Ridgwell." Beyond the finding of concern, this article includes an excellent primer on the role of C02 in the oceans and is very helpful for putting this matter into context. An Ominous Warning on the Effects of Ocean Acidification
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suibhne at 06:45 AM on 19 February 2010Is CO2 a pollutant?
carrot eater Of the other contributors an this topic I feel that you have shown most flexibility and discus the topic without being too polemical. I started looking at this area with an open mind. I read the G&T article and the attempts to counter their arguments. I looked up both Arthur P Smiths site and Eli Rabbet among others. I got my old text books out to best follow the points they were making. On the Smiths and Rabbit sites I found that Fred Staples took the discussion back to Smith and Eli and seemed to cut the ground from under them. Look up these sites and follow the discussion on the 2nd law. Don't dismiss the G&T paper out of hand. You may come to a different conclusion to me but your Physics will probably be all the stronger for it. -
Dennis at 06:41 AM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
As the saying goes, a picture is worth a thousand words. These videos (I particularly like the first one with the timeline starting in 1979) should be required viewing for anyone who doubts humans are adding CO2 to the atmosphere. -
carrot eater at 06:37 AM on 19 February 2010Is CO2 a pollutant?
suibhne "The em radiation falling on top and on the bottom according to your diagram comes to 882 joules per second." I'm not sure what all you're adding up to get that, but it doesn't really matter, since I can't figure out what point you're trying to make. "On the 2nd law and Greenhouse effect I thought that I had covered that with my flow of IR radiation at the speed of light." Hardly. Your microsecond thought experiment didn't make any sense. At once point, you said the First Law was violated. Nowhere is that true. There is a balance at the earth surface, around the atmosphere, and at the top of the atmosphere. You say the Second Law is violated. Where in this diagram is net heat flowing from a cold body to a warmer body? This is exactly where G&T got hung up. I think you are incorrect: for them it was not a matter of degree; it's a matter of concept. Look at their Figure 32/Figure 3 in the manuscript. They think heat is being transferred uphill from atmosphere to surface, and this is a violation of the second law. They think that somewhere in my (Trenberth's) diagram, heat is flowing uphill. Please show where heat is flowing in the wrong direction in my diagram. If you cannot, then you have yourself refuted a central point to G&T. -
suibhne at 06:17 AM on 19 February 2010Is CO2 a pollutant?
carrot eater The em radiation falling on top and on the bottom according to your diagram comes to 882 joules per second. But the Sun only supplies 342Joules per second. What I am and have stated is the diagram is utterly stupid. On the 2nd law and Greenhouse effect I thought that I had covered that with my flow of IR radiation at the speed of light. Net heat is always from hot to cold. G&T are aware that radiated IR from CO2 can fall on the Earth; its the massive quantities that are postulated that is in disputed. The 2nd law is a statistical law and can be formulated with entropy as the point of interest. An ice cube placed in warm water will dissolve most likely but for the ice cube to reform is most unlikely. Further the main emphasis of G&T on heat transfer concerns conduction and convection wind and frictional effects such as tides and so on. There was a small residual radiative effect in the Woods experiment but it was so small that it could not possibly account for the insulating effect of the atmosphere. -
Doug Bostrom at 06:10 AM on 19 February 2010There's no empirical evidence
Argus at 00:36 AM on 19 February, 2010 Argus, you'd be comforted if you have a fuller understanding of how these models are constructed. Check here: Simple climate models General circulation models -
carrot eater at 05:31 AM on 19 February 2010Is CO2 a pollutant?
suibhne: Now it seems like you're questioning the fact that the Earth is emitting radiation, period. Is that what you're doing? Are you saying you want to absorb the IR radiation being emitted by the earth, and do useful work with it? Good luck with that. Your device would have to be much colder than the Earth's surface in order for the net heat transfer between the device and the Earth to be inwards to the device in the first place. In any case, please return to the Second Law. G&T say that this diagram is wrong by the Second Law. They say it is impossible for the atmosphere to emit radiation down towards the Earth. Do you agree with them? That is all we need here. -
suibhne at 05:05 AM on 19 February 2010Is CO2 a pollutant?
carrot eater Given that you think the diagram is accurate. You still have not answered why a solar(or IR) panel Infra Red Down ---------- Double sided solar panel ---------- Infra Red Up I don't see why given the diagram that this wouldn't work But then if the diagram is wrong........ -
carrot eater at 04:50 AM on 19 February 2010Is CO2 a pollutant?
suibhne: You are making stranger and stranger statements, to the point it really isn't worth continuing. The First Law requires that the total energy and heat flows into the surface, and out from the surface, are equal and opposite for the surface to remain at the same temperature. The diagram does exactly that, even though you tried to say it didn't. -
StormBringer at 04:45 AM on 19 February 2010Is CO2 a pollutant?
"Venus, too, like Mars, has an atmosphere of nearly pure carbon monoxide. Yet it, unlike Mars, is hellishly hot. RSVP, do you suppose, that, just maybe, distance from the sun has some slight influence here?" "And yes, I am aware that Mars only gets about half the sunshine as the Earth, however, shouldnt all that CO2 be keeping the plantet a little warmer?" I just wanted to add that not only does Mars get less sunshine, it is about half the size of Earth, and has sparser cloud cover. Venus is almost the exact analogy of Earth, being only a few hundred km smaller in diameter. The cloud cover on Venus is much greater than Earth, but that is a consequence of the vast amounts of sulpher dioxide and water vapour. The current state of Venus is much closer to the outcome of our own planet, should we fail to regulate CO2, among other things. Between the CO2 levels, thick cloud cover and strong winds in the higher atmosphere, Venus has a nearly consistent global temperature of 450C. The Earth already has relatively thick cloud cover, if the CO2 starts trapping the heat and evaporating water, that cloud cover will become thicker, leading to a runaway negative feedback loop. The conditions on Mars are not similar enough to our own to draw any conclusions. Venus is the planet we want to study if we wish to avoid the same fate. -
suibhne at 04:14 AM on 19 February 2010Is CO2 a pollutant?
carrot eater But this is all incoherent em radiation . It does not cancel out. Two equal spotlights facing one another from each side of a room do not produce darkness. Look at my example of a double sided solar panel say one metre above the surface and explain why it cant use all the radiation falling on it! -
KLR at 03:46 AM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
My initial suspicion was that the central African plume derived from gas flaring from Nigeria's oil industry - there are places in Nigeria that haven't seen darkness in decades due to the unceasing flares - and indeed this graph shows they are #2 in the Sub Sahara - but primarily due to land use change and forestry, not fossil fuel production. Of course the two can reinforce one another. Graph from Anthropogenic CO2 emissions in Africa, published March 2009. Thanks for the visuals! -
carrot eater at 03:41 AM on 19 February 2010Is CO2 a pollutant?
suibhne: So you are one-upping G&T, and claiming a violation of the First Law, and not just the Second? Wow. Please look at the diagram again. Terms coming into the surface: 168+ 324 = 492 Terms leaving the surface: 24 + 78 + 390 = 492 You appear to have missed the outgoing arrow on the 390 term, suibhne. "I think this diagram is an even bigger clanger..." If you are going to make such strong statements, do check the arithmetic first. -
suibhne at 03:33 AM on 19 February 2010Is CO2 a pollutant?
carrot eater I looked at your diagram I take it that the diagram splits out horizontally for the purposes of illustration and it shows the energy balance transfers for a representative one square metre. All units in w/m2 Well what I see is a solar input of 342 and an available energy moving near the surface of the Earth of 168+324+390 = 882 If this square meter had a double sided solar panel it could turn this into useful work. However I don't think it is possible because it clearly violates the conservation of energy. So yes G&T are absolutely correct. I think this diagram is an even bigger clanger than the disappearing 2035 Himalayan glacier -
carrot eater at 03:14 AM on 19 February 2010Is CO2 a pollutant?
suibhne: Let's stay with http://www.windows.ucar.edu/earth/Atmosphere/images/earth_rad_budget_kiehl_trenberth_1997_big.gif A central claim of G&T is that such a diagram violates the Second Law. Do you agree with G&T on this matter? This is the critical question, so please address it directly. And as for the use of Stefan-Boltzmann, again from Eli's manuscript, "A more realistic model would split the atmosphere into a much larger number of layers for integration and take into account the detailed spectral dependence of absorption and emission, as is done with line-by-line radiation codes (HITRAN)." So please discontinue saying that Eli or anybody else is not aware of the details of spectral dependence. -
suibhne at 03:03 AM on 19 February 2010Is CO2 a pollutant?
CBDunkerson ..... you seem to be forgetting the existence of all matter OTHER than GHGs. As in... some of that IR radiation which is absorbed and re-emitted by GHGs then goes back down to the lands and oceans of the planet. Making them warmer. Ditto non greenhouse gases...... If you read my post I have allowed for that the surface of the Earth(oceans etc) is a much better IR transmitter/absorber than CO2 and it is warmer. So the up flow from Earth of IR radiation is much greater than any that's returning. Whats more the non greenhouse gases seem to be better at retaining their heat than CO2 The speed of light is important and gives a boundary in which the duration of any effect can be quantified. carrot eater "It can only radiate in one of two possible IR bands and it has just lost one !" The 15 micron band is what's relevant here. CO2 is quite happy to radiate there. I don't see what the issue is....... Perhaps I am mistaken but I thought that the IR bands of CO2 corresponded to an intermolecular thermal excitation between its atoms, rather than one of the electrons moving to a higher orbit. If I am correct then in an interaction with a neighbouring molecule this energy may be transferred to that molecule as KE. The fact that Eli mentions a book on quantum mechanics in his introduction does not excuse him for ignoring it in the relevant parts, if as you say he fully realises that his diagrams are comic book then he should say so. -
carrot eater at 02:56 AM on 19 February 2010Is CO2 a pollutant?
suibhne Your thought experiment is ill-posed, and I can't discern any meaning from it. It isn't a matter of a tracing around a single photon and studying its "time delay", suibhne. It's a question of energy flows. Take this diagram as a simple illustration. windows.ucar.edu/.../earth_rad_budget_kiehl_trenberth_1997_big.gif Without greenhouse gases in the atmosphere, that back-radiation term would not be there. If you increase the concentration of greenhouse gases, the outgoing longwave radiation term would decrease, and the system would have to warm up over time until the two terms going out to space again balanced the incoming term (here, 342 W/m^2). -
CBDunkerson at 02:39 AM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
RSVP & guinganbresil, 'infrared radiation' covers a huge range of EM wavelengths. Your statements above about whether IR radiation is increasing or decreasing are faulty due to overgeneralizing; Wavelengths of infrared absorbed by GHGs have shown decreased amounts escaping the atmosphere and increased amounts radiating down to the surface. Other wavelengths of infrared have increased both in amounts escaping and warming the surface. -
Cliff Oates at 02:29 AM on 19 February 2010It's the sun
In answer to response. There is nothing to show that greenhouse gasses caused global warming except that co2 has increased concurrently with the warming. The increase in sunspot numbers during the same period could have been totally responsible. Greenhouse gasses are an over simplified solution to a complex climate phenomenon and again seems to ignore the effects of the oceans interaction.Response: There is nothing to show that greenhouse gasses caused global warming
I suggest you read through the empirical evidence for an enhanced greenhouse effect. Satellites find less infrared radiation escaping at CO2 wavelengths. Surface measurements find more infrared radiation returning back to Earth at CO2 wavelengths. This is experimental evidence for a direct causal link between increased CO2 and a build-up of heat in our climate.
I also suggest you read the article above. Sunspot numbers have shown a long term declining trend during the last few decades of global warming. -
CBDunkerson at 02:24 AM on 19 February 2010Is CO2 a pollutant?
Suibhne, you seem to be forgetting the existence of all matter OTHER than GHGs. As in... some of that IR radiation which is absorbed and re-emitted by GHGs then goes back down to the lands and oceans of the planet. Making them warmer. Ditto non greenhouse gases. Poof... away goes the 'speed of light' objection. We are literally talking about the difference between 'up' and 'down' here. Solar radiation passes through the atmosphere and heats the planet. The planet gives off infrared radiation... which travels UP and escapes into space... UNLESS it is absorbed by GHGs and emitted back DOWN towards the planet. Carrot eater correctly noted that this infrared energy can also interact with non greenhouse gases in the atmosphere... but that's true regardless of which direction the radiation is traveling. The central point is that some of the energy which was going up and away into space gets re-directed back down and remains here on Earth. The more energy that happens to the warmer the planet gets. -
SNRatio at 02:24 AM on 19 February 2010The Dunning-Kruger effect and the climate debate
TOP, 87: "I already had a grasp of the basic principles that those folks were using and haven't seen a compelling argument for the kinds of actions being proposed to combat it. Sorry, I still stick to my principles. " Then prove that you have understood it. For example by refuting the estimated 3 degC increase per CO2 doubling. Otherwise, you just provide strong indications that you haven't - that may be another example of the effect discussed in the post. The basic action, reduction of CO2 emissions, may be too simple for your taste. NOT doing that, will give some, by now, fairly well predictable effects. The biggest uncertainty is the exact time scale. -
suibhne at 02:21 AM on 19 February 2010Is CO2 a pollutant?
CBDunkerson Riccardo Lets follow both your points with a thought experiment 1,000,000 IR PHOTONS leave the surface of the Earth and lets follow CBs postulate that 500,000 return back to the surface in less than 1microsecond. These 500,000 now join the upward stream and 1microsecond 250,000 return to the surface and join the upward stream etc,etc The flow of heat is always from hot to cold as G&T say but the delay caused by the co2 is negligible and in no way explains the insulating effect of the atmosphere. I think that Carrot Eater gave the more physically realistic explanation The IR energy is stored within the co2 molecule as vibrational KE. That is it is thermalized. the CO2 is much more likely to interact with N2(80%) then O2(19%) so the thermal energy will be shared between all the atmospheric molecules and so will delay the cooling of the Earth much longer. Of course sometimes a CO2 molecule will re-radiate but the IR photon will quickly be absorbed and thermalized or it may escape completely. -
carrot eater at 02:10 AM on 19 February 2010Is CO2 a pollutant?
suibhne "It can only radiate in one of two possible IR bands and it has just lost one !" The 15 micron band is what's relevant here. CO2 is quite happy to radiate there. I don't see what the issue is. "However Eli uses in his refutation ....guess what....Stepthan Boltzman equation for atmosphere re-radiating back to Earths surface." I have already told you the context for such illustrations; they are merely illustrations for some educational purpose. In this example, he's merely showing that there is no violation of the Second Law when a cool body radiates in the direction of a warmer body, so long as the warmer body radiates more in return. This shows one of the fundamental errors of G&T (their claim that the Second Law is violated), and I wish you would address it. Please do not misrepresent things. Eli well knows about the details of the quantum mechanics and the need to keep track of wavelength-specific bands; just look at Fig 7 or read in the introduction, "In the first case quantum theory provides the theoretical background (for example, see spectroscopy textbooks such as Hollas and Bernath) and spectroscopic data base such as HITRAN provide line positions and cross sections." -
Dikran Marsupial at 01:43 AM on 19 February 2010Did Phil Jones really say global warming ended in 1995?
RSVP @ 90 The reason there is so much focus on CO2 is that it is a factor that is actually under our full control and because it is a long-lasting greenhouse gas. If we were to stop fossil fuel use tomorrow the effects of any associated water vapour would only last a matter of a few days, whereas the (elevated levels of) CO2 would be around for at least 50-250 years. The climatologists do know water vapour is a GHG, their knowledge of its interaction with other forcings and feedbacks is still rather uncertain, hence the variation in elements of climate sensitivity. But the projections made by the modellers do include such factors (even if they are only a work in progress). Ultimately the fact that so much of the discussion revolves around CO2 is not because it is the only forcing worth talking about and the others can be ignored. It is because it is the forcing of the greatest practical importance. -
theendisfar at 01:38 AM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
RSVP, It must be understood that Convection and Evaporation move far more energy from the surface of the planet to the Tropopause than does Radiation. If you actually attempt to describe the GHE as a picture, it would have a net as a roof ~10,000 meters high and no walls. There is only 1 CO2 molecule for every 2600 O2 and N2 molecules, so the atmosphere is also very transparent to IR. The GHE is a misnomer and has been grossly overestimated as to its ability to 'trap' heat, especially when taking into account the massive cooling effects of Convection and Evaporation. -
Riccardo at 01:35 AM on 19 February 2010Is CO2 a pollutant?
CBDunkerson, when G&T paper has been published on arxiv back in 2007, the very first thing i noticed was the 40 or so pages devoted to clarify that the atmospheric greenhouse gas effect does not work like a glass greenhouse! I have seen this explained in a high school textbook, the right place for it. But then came the good old 19th century physics and i got stuck. How can you force a colder object not to emit it's thermal radiation toward a warmer object? Does it have knowledge of the thermal distribution of the universe? In the end the net flux is still in the right direction and i couldn't see violation of any known (at least by me) law. Maybe i was missing something and G&T are reputable physicists after all. But how come we can routinely measure IR and even radio frequencies with detectors at room temperature? I might not be a reputable physicist like G&T but i'm quite sure that the IR radiation reaches my f**king warmer detector :D Here they lost me. -
guinganbresil at 01:26 AM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
RSVP, GHG's absorb specific bands of IR emissions. In the case of CO2 it is around 15 um (650-750 cm^-1). GHG's also EMIT IR radiation at the brightness temperature of the gas over the same band. Greenhouse warming theory is that IR that OTHERWISE would have gone straight out will be absorbed and re-emitted, with some large fraction going back down rather than up and out. So, if the Earth is warming due to less IR emissions to space (which is the theory as far as I understand it), then you would expect less IR measured by satellites. In fact, satellites have measured MORE IR emissions to space, particularly in the 800-1000 cm^-1 band (not CO2). You will find a graph (Fig 2C, Harries 2001) on this site that would give you the impression less IR is escaping to space. That is NOT THE CASE. Figure 2B shows the spectrum prior to removing the non-GHG effects. There are also many other measurements of TOTAL outgoing IR done by satellites showing INCREASING IR loss to space. Note that CO2 Greenhouse effect warming the Earth, causing more IR emissions from the surface, resulting in more loss to space does not follow the fundamental law of conservation of energy. From what I can see, CO2 CAUSING the warming is not consistent with these observations. I would happily concede that CO2 could exacerbate SOME OTHER CAUSE.Response: Harries 2001 does not find more IR escaping out to space. This is because it doesn't cover the whole spectrum - the missing part is at lower wavelengths, where there is much absorption due to CO2 and water vapour feedback. What it does find is the change in outgoing spectrum matches very closely with how we expect greenhouse gases to absorb outgoing energy which is confirmation of theory and an enhanced greenhouse effect. -
SNRatio at 01:00 AM on 19 February 2010Did Phil Jones really say global warming ended in 1995?
RSVP, 89: "What about all the water vapor that comes from combustion? When burning methane for instance, you get twice as much water vapor as CO2. Even if you assume a shorter lifetime of water vapor as compared to CO2, the immediate presence of the extra water vapor must be factoring into the current temperature readings, in which case, CO2 is having less impact than is assumed. " Perhaps you should look at and compare the long-time effects on atmospheric concentrations of water vapor and CO2 released at the surface. You might learn why treating water vapor so differently from CO2, though they have overlapping effects, is not such a hopeless idea after all. But if you had objected to the way water vapor is treated in climate modeling today, I might tend to agree with you. -
suibhne at 00:58 AM on 19 February 2010Is CO2 a pollutant?
CBDunkerson Do you still stand by your posting ...........As to your convection hypothesis... it fails because, amongst other things, greenhouse gases do not retain heat within themselves. They absorb and then immediately re-emit the infrared radiation..... Then imagine that a CO2 immediately re-radiated an IR photon and this photon underwent 100 similar interactions with "Greenhouse Gases" before escaping to space. How long would the process take at the speed of light? I would guess less than a microsecond. I prefer Carrot Eaters explanation of the IR energy being thermalized into the form of vibrational KE. -
Riccardo at 00:51 AM on 19 February 2010There's no empirical evidence
Argus, you do not need any computer model. Pick up the hypothetical forcing of you choice, take the available recent or paleo data and see if they match. You really need to do it before assuming it could be something else and stand there forever. -
suibhne at 00:47 AM on 19 February 2010Is CO2 a pollutant?
Riccardo I really do think that you are following A P Smith and getting yourself into the most amazing muddle. To you apparently Gravity and the conservation of energy are passe. I am starting to think that if I gave you a very simple problem to do you might fail to answer it-will I? -
Argus at 00:36 AM on 19 February 2010There's no empirical evidence
The beauty of climate science is that it will take at least 50 years to prove or disprove any claim that is made today, and by then most of us will be dead anyway. You cannot test a climate theory in real life, on the real globe itself, unless you allow for a time scale that is too long for a human scientist. Sure, I can build a computer model to 'test' my theory, but a computer model only yields the results I want - the results that I have built into the model, and using the parameters that I have chosen to feed it with. -
RSVP at 00:18 AM on 19 February 2010Visual depictions of CO2 levels and CO2 emissions
I have been told that greenhouse gases do not stop IR emissions, but rather only slow them down. So if the Earth is warming, shouldnt satellites in any case be detecting more IR rather than less? Since more surface heat would imply more IR energy. From what I have been told however, satellites are detecting lower IR emmisions, and thus proving CO2 is the main cause of AGW. -
Alexandre at 23:56 PM on 18 February 2010Visual depictions of CO2 levels and CO2 emissions
For some reason, none of the videos played in my Firefox, with the exception of the third, 'revolutionary' one.
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