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Alexandre at 04:47 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Bob #26 Yes, it does help. Thanks. I think I can put the pieces together a bit better, now, putting you post in the context, btw. It was a good basic explanation. Thanks Spaceman Spiff too. -
Rob Honeycutt at 04:44 AM on 2 December 2010We're heading into an ice age
NQuestofApollo says... "why should I assume that CO2 CAUSES global warming?" Because it's basic physics? Actually, the globe has not been warming for the past 10,000 years. If you look at the Holocene optimum we've been slightly cooling over that period. It's only in the past 100 years that we've reversed that trend. Honestly, this site provides information that responds to everything you've said here much better than I can in a short post. I would urge you to take some time to read some of the articles and follow the cited sources. -
JMurphy at 04:37 AM on 2 December 2010We're heading into an ice age
NQuestofApollo, your post gives lots of opportunity for everyone here to point out your misunderstandings, but I would like to start with your first assertion : "Remember Michael Mann's "hockey stick graph" - the one trotted out by Al Gore and the IPCC as proof positive that AGW exists? If in fact the Earth is warming - why did Mann feel the need to concatenate two different data sets?" You should read further on this website (by using the 'Search' box in the top left) but I will start you out : Go here, here, here and here. If no-one else can be bothered to point you in the right direction for your other misinformed points (and I wouldn't blame anyone else for not wanting to go over all this again), I will return to this later. -
Rob Honeycutt at 04:37 AM on 2 December 2010We're heading into an ice age
NQuestofApollo... You've posted such a long list of baseless information that it's a little hard to respond. Let me take the "31,000 scientists" issue first. We are all aware of the Oregon Petition. What you are ignoring about it is that figure requires a denominator to have any meaning at all. The petition defines "scientist" as anyone with a BS or equivalent. That encompasses nearly 30,000,000 people in the US alone. You can likely double that number or more looking outside the US. So, even at best you are presenting a figure that is about 1/10th of one percent. If you poll actual working climate scientist who are currently working in this field you get quite the opposite number. Doran 2009 shows that 97% of climate scientists believe that climate change is real. -
Spaceman Spiff at 04:27 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio @28: It is possible that the following may be an important consideration here: most of the stratosphere, unlike most of the troposphere, is not in local thermodynamic equilibrium (LTE). i.e., the rates of collisional processes do not exceed greatly spontaneous decay rates of energetically excited molecules, as they do within gases for which LTE is an excellent approximation. The heating rate within the stratosphere should be dominated by ozone dissociation via solar photons from above. However, by increasing the CO2 content of the stratosphere, you mostly increase the rate of that gas' ability to radiate energy away via collisional excitation followed by spontaneous photon emission. This tips the heating-cooling balance to lower temperatures. I know I've a few technical papers on the subject sitting on my laptop at home, and I'll try to remember to read them tonight. -
NQuestofApollo at 04:18 AM on 2 December 2010We're heading into an ice age
scaddenp - obliviously diamonds are not emissions, but then neither is Carbon. I was being sarcastic to make the point that any reference to "Carbon" emissions is disingenuous. Unfortunately, this short hand is causing (otherwise intelligent people) to claim that "carbon emissions from cars are combining with ozone and causing a depletion in the ozone layer". Daniel, I appreciate all of the information you provided here and would like to challenge you on your definition of a "competent scientist". Remember Michael Mann's "hockey stick graph" - the one trotted out by Al Gore and the IPCC as proof positive that AGW exists? If in fact the Earth is warming - why did Mann feel the need to concatenate two different data sets? If I wanted to prove that sports scores have been increasing over the last 100 years and I take baseball scores for the first sixty years and plot them - then I take basketball scores for the last 40 years and tack them on the end of my graph, would my graph be taken seriously? Supporting articles here and here. Distressingly, this is the same IPCC that "misread" the year the Himalayan glaciers were "likely to disappear" due to global warming: Mr Cogley says it is astonishing that none of the 10 authors of the 2007 IPCC report could spot the error and "misread 2350 as 2035". IPCC error Equally distressing is the suggestion that they may have done so on purpose. IPCC error intentional Here's a question I literally cannot find an answer to: How many scientist work for the IPCC and what are their names? I've heard 1000, I've heard 2000 - yet, I cannot find a comprehensive list of the people involved in promoting AGW. On the other hand, here is a list of over 31,000 scientist that think AGW is a bunch of bunk. All their names are listed - right there. (I know, I know - they were ALL bought off by Big Oil.) Petition Project There has been some chatter on this site about not looking at thermometer reading to assess the global warming situation (too bad nobody mentioned that to Michael Mann) - I've been told to look at the sea ice extent. So, I have - it has increase for the last three years. The counter to this point is that the ice is thin - but, of course young ice is thin. The point is that the extent has NOT receded in the last three years. Now, how can that be with all of that accumulated, globe warming carbon? Sea Ice Extent Also, if accumulated CO2 definitively causes the globe to warm, why did they think the globe was cooling for the 30 years prior to the 1970s? But, this, I think, is the primary question: since CO2 will increase as the globe warms (due to melting, CO2 containing glaciers), why should I assume that CO2 CAUSES global warming? Sure the globe has been warming (for the last 10,000 years), sure there is more CO2, but what if you have your cause and effect relationship inversed? -
Bob Guercio at 04:15 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Albatross - 30 That's a fantastic writeup from RealClimate which is the cadillac of Climatology sites. If it's there, you can believe it. In any case, it's going to take me at least another reading to digest that. Did you look at Part II! It gets very heavy. Thanks for that recommendation. Bob -
Spaceman Spiff at 04:00 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio @27: Of course, it wasn't my intent not to add something substantial to understanding. However, the concept of an increasing emissivity of the stratosphere hadn't been mentioned in the above discussion. My post did not ignore the role of the absorption bands (or the complementary atmospheric window in your example) -- in fact they are key in describing the spectrum of radiation emerging from the troposphere and thereby the means by which the heating rate within the stratosphere changes. However, I should have clarified my point that the tropospheric emission diminishes within the C02 absorption band region center on 667 cm^{-1}. And, apparently, the increased emission arising from below the stratosphere over wavelengths corresponding to the ozone absorption band (centered on 1050 cm^{-1}) doesn't add enough to the heating rate budget of the stratosphere to offset the decreased heating rate there due to the diminished intensity of radiation within the main C02 band emerging from below. But it looks as though your example didn't want to consider this complication (?). In any case, I do appreciate your efforts! -
muoncounter at 03:57 AM on 2 December 2010A basic overview of Antarctic ice
#80: "one of the objections against Rignot et al. 2008 was: “Corr and Vaughn report that volcanic activity beneath the Antarctic ice may have increased the flow rate of some of the region's largest glaciers.”" Ouch. You've quoted directly from the SPPI denial site. Unfortunately for that objection and any credibility that SPPI may once have had, the layer depth dates the eruption at 207 BC±240 years. Hardly a factor in ice loss in thisdecade,century,milleniumor any other relevant time period. -
Albatross at 03:53 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Hi Bob, You mentioned Gavin Schmidt, and that reminded me of this informative post over at RealClimate. Some of the content is relevant here. -
Albatross at 03:47 AM on 2 December 2010A basic overview of Antarctic ice
And the goal post shift, again (re #80 and #81). From the main post (first sentence): "Skeptic arguments that Antarctica is gaining ice frequently hinge on an error of omission, namely ignoring the difference between land ice and sea ice." And later, "All the sea ice talk aside, it is quite clear that really when it comes to Antarctic ice, sea ice is not the most important thing to measure." And then, "There is of course uncertainty in the estimations methods but multiple different types of measurement techniques (explained here) all show the same thing, Antarctica is losing land ice as a whole, and these losses are accelerating quickly." Now we have people talking about volcanoes explaining the loss of land ice, a swipe at the AOGCMS, a link to the questionable SPPI (the much debunked Monckton is their chief policy adviser), talk of how droughts in Australia is explained by changes in snowfall over portions of the EAIS (which is misleading and cherry picking as I will demonstrate below), and the old-time favourite "X can be explained by internal climate modes/variability" (which is also refuted by the study below). It is relevant that at least one prominent "skeptic"/contrarian (McIntyre) thinks that teleconnections are "voodoo science"...I digress. If someone, especially a “skeptics” makes claims about a paper, it is always best to go to the source. Here , again, we have an example of “skeptics” distorting the results from a paper to suite their means. From the abstract from a recent paper in Nature by van Ommen and Morgan (not et al.). “Here we report a significant inverse correlation between the records of precipitation at Law Dome, East Antarctica and southwest Western Australia [edit—not all of Australia] over the instrumental period, including the most recent decades. This relationship accounts for up to 40% of the variability on interannual to decadal timescales [edit-- not all of the variability], and seems to be driven by the meridional circulation south of Australia that simultaneously produces a northward flow of relatively cool, dry air to southwest Western Australia and a southward flow of warm, moist air to East Antarctica. This pattern of meridional flow is consistent with some projections of circulation changes arising from anthropogenic climate change. The precipitation anomaly of the past few decades in Law Dome is the largest in 750 years and lies outside the range of variability for the record as a whole, suggesting that the drought in Western Australia may be similarly unusual.” So on the one hand we have Arkadiusz @80 quoting the researcher to state that the southwestern Australian drought was well outside the range of natural variability, and then another "skeptic" (BP) in the next post is claiming that multi-decadal natural variability is at play. Please do make up you minds guys. This is just yet another example of the incoherence and inconsistency of arguments made by "skeptics". In fact, the usual suspects on this thread seem to be trying to fling as much mud as they can and hope that something sticks, and to try and distract us all from the science and issue at hand. Well that might work at WUWT, but not here. -
Bob Guercio at 03:42 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Guys, I'm doing a lot of talking here but let it be known that although I am educated in Physics, I am not an expert at what we are talking about. In fact, I have never been a scientist. I'm hoping that someone jumps in to corroborate all of this because I don't want to mislead. This is what I actually hate about the Internet. Often it's hard to tell fact from fiction and I find myself somewhat doing now what I always rail against. Bob -
Bob Guercio at 03:32 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Spaceman Spiff - 25 With respect to Gavin's comment on emissivity and absorptivity, I think Gavin is saying that until the steady state is reached, the emissivity of the stratosphere is greater than the absorptivity because it is emitting more than it is absorbing. When the steady state is reached, the emissivity equals the absorptivity. -
Bob Guercio at 03:18 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Spaceman Spiff - 25 I'm not 100% sure but I think you are saying only what other explanations on the web say. You must consider the absorption spectrum which includes the absorption band and the atmospheric window. Bob -
Bob Guercio at 03:12 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Alexandre - 24 In keeping with my ridiculously simple model: In the steady state the amount of IR entering the stratosphere equals the amount leaving it. Now CO2 molecules are constantly gaining and losing energy. Some gain, some lose, this goes back and forth etc. In the steady state, the number gaining at any instant equals the number losing. Now suddenly there is less IR energy coming into the stratosphere from the troposphere. At this time, energy at the initial rate is still leaving the stratosphere going into space but less is coming in. Not all the molecules that have lost energy can get replenished because the necessary energy is no longer there. The energy leaving must diminish to equal that coming in for the steady state. Does this help? Bob -
Rob Honeycutt at 03:12 AM on 2 December 2010Renewable Baseload Energy
With all due respect to the great moderators here, I don't think a conversation regarding baseload power can be carried on without also discussing nuclear. It's a little like having one hand tied behind your back. Peter @ 187 said, "They are not viable and probably never can be (at more than about 10% of the total generation)." Did you miss the part where Steven Chu just stated that China is going to be 20% renewables by 2020? -
Spaceman Spiff at 02:50 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
As Gavin Schmidt mentioned above, by increasing the CO2 content of the atmosphere (in the stratosphere as well as the troposphere), the emissivity of the stratosphere (which is rather low due its low column density of gases) increases. The heating rate of the stratosphere depends on what energy it is able to absorb from below (the troposphere) and above (the Sun) in wavelength bands that its gases (mainly O3 and CO2) can efficiently absorb. From the point of view of the stratospheric gases that can absorb radiation from below, they see less radiation emerging from below due to the enhanced tropospheric opacity there (the effective emitting layer moves to higher altitudes where the T and thus thermal emission are lower). At the same time, the stratosphere can emit more efficiently with the enhanced CO2 content (the C02 column density there is small enough that very few wavelength bands are "saturated"). Thus the stratosphere T drops to re-establish heating(photo-absorption rate)--cooling(photo-emission rate) balance. I might be missing some of the details, but I think the above captures the gist of what happens. -
Alexandre at 02:45 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Bob #23 That part also helps me understand. More energy is now outside the absorption band of the stratosphere, and goes right through it. But that's that other part, about CO2 emiting more than absorbing, that I do not understand. I've seen this already somewhere else. In a similar version of the explanation, they say the CO2 absorption/re-emission helps "conduct" the heat upwards in the stratosphere, instead of trapping it. This part is frankly beyond my reach. Maybe it's something that's only fully understandable if you put together all the relevant physics and run the model... :-) In this case, we could only partially understand it with intuitive conceptual explanations. -
Berényi Péter at 02:42 AM on 2 December 20102nd law of thermodynamics contradicts greenhouse theory
#243 KR at 01:46 AM on 2 December, 2010 that would be cherry-picking If OHC is supposed to be the true indicator of global warming and we have only seven years of reliable OHC data, then it is not cherry-picking to use what we have, is it? What is more (and it is independent of MEPP), even if we assume heat is accumulating in the climate system on an annual rate of 1.45×1022 J, it takes more than 300 years to warm the ocean up by 1°C. It is clearly inconsistent with a 2+°C warming by the end of this century. -
Tom Dayton at 02:34 AM on 2 December 20102nd law of thermodynamics contradicts greenhouse theory
damorbel, like CBDunkerson (his last three paragraphs), I am pleased to see your agreement that photons from a cooler source are indeed absorbed by a warmer target. So you agree that the greenhouse gas effect does not violate the second law of thermodynamics, which is the topic of this thread, right? -
archiesteel at 02:29 AM on 2 December 2010Renewable Baseload Energy
@moderator: so sorry, I only now saw your requests (that's what happens when you go through "Recent Comments" instead of the actual threads...). I'll refrain from pushing the subject further here. Anyway, I've pretty much said everything I needed to say about Peter's aggressive sales pitch. I can't stand his not-so-veiled insults towards those who *dare* think renewables also have a place in the future energy mix. As for their links, at this point it should be considered blogspam for Brave New Climate. When pretty much all of one's references come from a couple of web sites, it's usually a sign you're pushing some sort of agenda... -
archiesteel at 02:23 AM on 2 December 2010Renewable Baseload Energy
"I'll just add that renewables cannot do the job at any cost and are unlikely to ever be able to." This is other examples of why we can't take you seriously. Renewables are already providing significant amounts of power to the grid, and their large-scale deployment has barely begun. We're not even talking about technologies that might be feasible 20-30 years from now, such as Orbital Solar. When you speak in such absolutist terms you make it clear this isn't a rational argument on your part, but a sales pitch that exaggerates the benefits of nuclear and the drawbacks of renewables. -
archiesteel at 02:19 AM on 2 December 2010Renewable Baseload Energy
@Peter Lang: "Talk about ideological - what is more ideological than anti-N and pro-renewables at any cost?" Peter, I think one of the reasons people here are reacting negatively to you Nuclear sales pitch is that, according to you, anyone who's not 100% behind Nuclear as the *only* solution is anti-nuclear. That is propagandist rhetoric at its ugliest. It seems to me you would have much more success by advocating for nuclear alongside renewables. It may go against your ideals/mission, but which is best: sticking to your guns and losing, or making compromises and achieving partial success? Think about it. -
Berényi Péter at 02:19 AM on 2 December 2010A basic overview of Antarctic ice
#80 Arkadiusz Semczyszak at 01:21 AM on 2 December, 2010 [drought - Australia, the increase in snowfall - Antarctica] If Snowfall increase in coastal East Antarctica is linked with Australian drought indeed and Australian drought has nothing to do with AGW, then East Antarctic snowfall is also due to multi-decadal variability alone, isn't it? -
2nd law of thermodynamics contradicts greenhouse theory
In my previous post, "degrees of freedom will override climate forcings to maintain the status quo" is not a quote, but rather my interpretation of a number of postings on this subject. My apologies - I don't mean to put words into other peoples mouths. -
2nd law of thermodynamics contradicts greenhouse theory
Berényi - You are correct, I should have used the term "steady-state", rather than "thermodynamic equilibrium". However - the essential I extract from your post is your statement that "...there is a strong tendency to counteract climatic effects of CO2, but MEPP would not allow any change which would amplify it". In other words, you claim that there is only negative feedback, not positive feedback to a CO2 forcing. Sorry to say, the data proves this not to be the case. Feedback is positive, your assertion is quite simply not supportable. MEPP is either not a correct description or it does not have the effects you claim. You have been pointed to before, and have failed to address this issue with your MEPP claims. You keep saying that "degrees of freedom will override climate forcings to maintain the status quo", and that is observationally, patently not the case. As to your claim that the last 7 years disprove CO2 forcing, that would be cherry-picking - if this holds for 20-30 years, and acquires statistical significance, then we have something worth discussing. -
Bob Guercio at 01:39 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Let me add something to all this. The following passage came from: http://www.atmosphere.mpg.de/enid/20c.html _________________________________________________________________ Cooling due to the greenhouse effect The second effect is more complicated. Greenhouse gases (CO2, O3, CFC) absorb infra-red radiation from the surface of the Earth and trap the heat in the troposphere. If this absorption is really strong, the greenhouse gas blocks most of the outgoing infra-red radiation close to the Earth's surface. This means that only a small amount of outgoing infra-red radiation reaches carbon dioxide in the upper troposphere and the lower stratosphere. On the other hand, carbon dioxide emits heat radiation, which is lost from the stratosphere into space. In the stratosphere, this emission of heat becomes larger than the energy received from below by absorption and, as a result, there is a net energy loss from the stratosphere and a resulting cooling. Other greenhouse gases, such as ozone and chlorofluorocarbons (CFC's), have a weaker impact because their concentrations in the troposphere are smaller. They do not entirely block the whole radiation in their wavelength regime so some reaches the stratosphere where it can be absorbed and, as a consequence, heat this region of the atmosphere. _________________________________________________________________ This passage absolutely drove me crazy because I didn't understand it. I now understand it because I know that it is only part of the story. What bothered me was with regard to what happens after the earth heats up and reaches a steady state with a higher tropospheric temperature. Of course, this presumes stabilization of greenhouse gases but nevertheless, in the steady state the same amount of IR energy is going to be entering the stratosphere as before the CO2 concentration increased which caused the temperature to increase. This is necessary because conservation of energy requires that the solar energy entering the troposphere from the sun must equal the IR energy leaving the troposphere since the solar energy entering did not change. If the same amount of IR energy is entering the stratosphere from the troposphere, why doesn't the temperature of the stratosphere return to what it was before all this started. The reason is that more of this energy is in the atmospheric window which does not react with CO2 and less is in the absorption band which does react with CO2. So less in the absorption band than before means less energy reacting with the CO2 and a permanent lowered temperature. The stratosphere is also cooler because of the thinning of the ozone layer but this is relatively easy to understand and is explained in the referenced website. Bob __________________ -
Bob Guercio at 01:35 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Alexandre, That's because, in my opinion, they try to make it too simple. They made it so simple that all they did was "handwaving". I sent my thoughts to RealClimate for confirmation and here is the email that I received from Gavin. Gavin's comment would have made my simple model more complex so I stayed with the simple model. Bob mostly right. You miss two key facts. First, all GHGs emit as well as absorb, and whether you will get warming or cooling in a region depends on the ratio of the change in absorption and the change in emittence. Second, the troposphere has many IR absorbers, the stratosphere only two (CO2 and O3 - everything else is minor). So the impact of CO2 above the tropopause is amplified. Otherwise you are spot on! Gavin > Hi, > > I've searched for an explanation of the reason that the Stratosphere cools > due to Global Warming and have not found a satisfactory answer. There > does seem to be quite a bit of hand waving though. > > I think that I now understand it but would like the confirmation of a > professional. If my understanding is correct, I would like to write a > blog on this most misunderstood subject. > > Please confirm if this is correct. > > Thank you, > > Robert Guercio > > The earth radiates Infrared Radiation in accordance with Black Body > theory. Most of the IR energy absorbed by CO2 has wave numbers of > approximately 650 and 1050. There is CO2 in both the troposphere and the > stratosphere so frequencies associated with these wave numbers emanating > from the heated earth heat up both the troposphere and the stratosphere. > Frequencies of all other wave numbers simply sail on through without > effecting either layer. > > If there is more CO2 in the troposphere, more of a chunk of the spectrum > is going to be taken out around these two wave numbers in heating up the > troposphere. Therefore, there is less energy in these two IR bands to heat > up the CO2 in the stratosphere and thus the stratosphere cools. > -
Bob Guercio at 01:30 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Tarcisio, I kept it ridiculously simple in order to explain a concept. I thought about bringing ozone into it which is also responsible for stratospheric cooling but for a different reason which is easy to understand. Incoming solar radiation interacts with the ozone causing the stratosphere to heat up. The ozone has thinned recently so less solar energy is reacting with ozone, thus cooling the stratosphere. However, by bringing ozone into the picture, it gets more complicated. Bob -
Bob Guercio at 01:25 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Ville, This could be the case if the temperature was at absolute zero where the spectrum is being measured and total saturation occurred. However, were that to happen, hypothetically of course, the temperature of the planet would increase allowing more IR energy to be in the atmospheric window. The area under that curve would still be the same or that of the energy of the incoming solar radiation. Just a minor point for precision. The graphs we are talking about represent energy but the y axis is actually power/meter squared wavenumber. Bob -
Alexandre at 01:24 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Thanks Bob, this is a brave attempt to explain a surprisingly complex subject. As I understood it, the post is coherent with the simplified version of the explanation that can be found in the NOAA Global Warming FAQ: An enhanced greenhouse effect is expected to cause cooling in higher parts of the atmosphere because the increased "blanketing" effect in the lower atmosphere holds in more heat, allowing less to reach the upper atmosphere. I've seen other competent guys try to explain the concept before, with limited success: Gavin Schmidt at RealClimate and Science of Doom. -
Arkadiusz Semczyszak at 01:21 AM on 2 December 2010A basic overview of Antarctic ice
At the well ..., it is worth - this very interesting discussion, supplemented about the significant facts. At the beginning: I recall that one of the objections against Rignot et al. 2008 was: “Corr and Vaughn report that volcanic activity beneath the Antarctic ice may have increased the flow rate of some of the region's largest glaciers.” In addition, I will add that Monaghan et al., 2008., write: “Annual Antarctic snowfall accumulation trends in the GCMs agree with observations during 1960–1999, and the sensitivity of snowfall accumulation to near-surface air temperature fluctuations is approximately the same as observed, about 5% K −1 . Thus if Antarctic temperatures rise as projected, snowfall increases may partially offset ice sheet mass loss by mitigating an additional 1 mm y −1 of global sea level rise by 2100.” Why have not increased snow in the Antarctic? „However, 20th century (1880–1999) annual Antarctic near-surface air temperature trends in the GCMs are about 2.5-to-5 times larger-than-observed [!], possibly due to the radiative impact of UNREALISTIC increases in water vapor.” Also missing in this discussion, reference is made to this latest work: van Ommen et al., 2010. Commenting on his work van Ommen said: “Over the past 30 years, the cores indicated there had been a significant increase in snowfall in that area [coastal East Antarctica] ...” "The snowfall increase we see in the last 30 years lies well outside the natural range recorded over the past 750 years," In paper writes: “A range of factors [drought - Australia, the increase in snowfall - Antarctica], such as natural variability and changes in land use, ocean temperatures and atmospheric circulation, have been implicated in this drought, but the ultimate cause and the relative importance of the various factors remain unclear.” For me, "unclear" is at the same time: whether the (eventual) decrease in Antarctic ice mass is a sign of warming, or maybe, rather, its absence? -
Tarcisio José D at 01:19 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio This post provides one deserves a true science because it does not translate or approaches the climatic reality of our planet's atmosphere to exclude of the study, the most important component, "steam". The water vapor is part of the mechanism of convective transport of heat from the sun. He is able to pierce the "blanket" of greenhouse gases, leading over 50% of heat to the top of the troposphere, above this "blanket called CO2." Change the heat from troposphere to the stratosphere See:
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Paul D at 01:13 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Actually oamoe, if you think about it. If the trough did go down to zero, it would mean no IR was escaping the planet. The graphs are of emissions, so if a part of the spectrum dropped to zero, then it would mean that part of the spectrum was being absorbed by the planet but never emitted, which wouldn't be very nice! -
muoncounter at 01:13 AM on 2 December 2010A basic overview of Antarctic ice
#78: "Just because a trend line fits this short data set doesn't mean it contains any meaning." It the trend fits, it fits. The meaning is in the eye of the beholder. If you choose to disagree, fine. But then how do you take such meaning out of the 'blip', which is a far shorter time sample than the data presented by Velicogna. This is akin to the 'it hasn't warmed since 1998' nonsense. "this is a completely separate question" Not really, especially in a thread that starts off "Skeptic arguments that Antarctica is gaining ice". One thing these data do not show is a gain in ice. So your criticism must therefore be directed at those who make conclusions using no data whatsoever. -
Bob Guercio at 00:53 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Everything we are talking about except "Why the stratosphere is cooler" is explained in the videotaped course given by David Archer at http://geoflop.uchicago.edu/forecast/docs/lectures.html The two blackbody levels, band saturation, CO2 weathering is all there. I recommend it highly. I also recommend the book although it has quite few typos. Bob -
Bob Guercio at 00:44 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Oamoe, My understanding is that the bandwidth, if I could use this word, is not precisely defined. At 1000 ppm the width is wider than at 100 ppm and the center of these two bands with different bandwidths is saturated in both cases. Bob -
muoncounter at 00:44 AM on 2 December 2010Naomi Oreskes' Merchants of Doubt Australian tour
#116: "the main contender is clouds moderated by sun's magnetic atmosphere?" I'm not sure what you mean, but this might be a more appropriate thread. -
Paul D at 00:42 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
oamoe: I assume you mean the trough should be at zero?? No. The trough bottoms out at an imaginary curve (not shown) that represents the temperature at the top of the atmosphere. Effectively you would have two upper and lower limit curves, the higher one represents T at ground level, the other T at the top of atmosphere. The spectrum curve (for someone observing the planet from space and looking down) will be something in between the two, depending on what gases you include, with chunks taken out at different wave lengths. It would have been useful if Bob had shown the upper (ground) and lower (TOA) limits. -
Bob Guercio at 00:39 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
CBDunkerson The frequencies of the IR in the atmospheric window do not react at all with CO2. It's like light going through glass. Yes. In one case you have extra energy in the atmospheric window (higher tropospheric temperature/lower stratospheric temperature) and in the other case you have extra energy in the absorption band (lower tropospheric temperature/higher stratospheric temperature). If you had IR energy only in the atmospheric window, it would not heat up the CO2 at all. Bob -
Berényi Péter at 00:15 AM on 2 December 20102nd law of thermodynamics contradicts greenhouse theory
#220 KR at 02:59 AM on 1 December, 2010 However, when you say that "...Earth is a system very far from thermodynamic equilibrium", I would like to point out that as far as we can tell (again from Trenberth 2009, although I'm sure there are slightly different estimates out there) the balance sheet is currently tipped only about 0.9 W/m^2 from dynamic equilibrium. If we can reduce or prevent further GHG emissions, we can reduce that imbalance, and the resulting shift in global temperatures. Thermodynamic equilibrium and steady state are very different concepts. Earth is not in thermodynamic equilibrium in any sense of the word, because its environment is not in thermal equilibrium. About one part in 184,801 of the skies around it has an effective temperature of 5777 K, while the rest is at 2.725 K. In first, second and third approximation there is only radiative coupling between Earth and its cosmic environment. In spite of the fact the Sun occupies only a tiny portion of the sky, due to the T4 dependence of thermal radiation flux, in excess of a hundred million times more radiative energy comes from it than from CMB (Cosmic Microwave Background). What you call dynamic equilibrium has nothing to do with thermal equilibrium proper, when entropy of the system is supposed to be at its maximum. Quite the contrary. The overall entropy content of the climate system (which includes at least the atmosphere and hydrosphere of Earth, probably the biosphere as well) is kept at the smallest possible value by continuously getting rid of the entropy produced inside the system (OLR has a much higher entropy flux than ASR). This low entropy state can only be maintained by working as hard as possible, that is, producing entropy at the highest possible rate (then radiating it away into outer space as soon as possible). This is what MEPP (Maximum Entropy Production Principle) is about. Obviously an energy balance has to hold in the long run and on average, otherwise sooner or later the system would enter some absolutely crazy state (contrary to observations). But this balance is best described by the concept of steady state, not as a dynamic equilibrium, because it's only too easy to mix up the latter one with thermal equilibrium. It is easy to show that whenever the climate system is in a MEP state, increasing the opacity of the atmosphere in thermal IR (that's what so called GHGs do) decreases rate of entropy production if all else is held unchanged. At the same time entropy content of the system goes up. That's what is described as warming, because warmer stuff has higher entropy in general. BTW, if the climate system were in some suboptimal state by having less IR opacity in the atmosphere than required by MEPP, adding GHGs would increase overall entropy production and decrease entropy content, hence temperature. Saying the addition of some more GHG causes warming is equivalent to insist current IR opacity is already at or above the value implied by MEPP. The fictitious value of 0.9 ± 0.15 W/m2 TOA energy flux imbalance from Trenberth 2009 has nothing to do with reality. What is actually measured by ERBE and CERES satellites, is 6.4 W/m2 (which is obviously wrong beyond repair). Therefore they apply all kinds of adjustments to the measured dataset so as to match computational model projections and this is how they arrive at the value which was assumed to be the correct one from start. The logic behind this exploit surely makes one's head spinning. J. Climate, 2008, 21, 2297–2312. doi: 10.1175/2007JCLI1935.1 The Annual Cycle of the Energy Budget. Part I: Global Mean and Land–Ocean Exchanges. Fasullo, John T., Kevin E. Trenberth J. Climate, 2008, 21, 2313–2325. doi: 10.1175/2007JCLI1936.1 The Annual Cycle of the Energy Budget. Part II: Meridional Structures and Poleward Transports. Fasullo, John T., Kevin E. Trenberth The only measurement having a chance to shed some light on the true value of energy imbalance at TOA is ARGO Ocean Heat Content data, and only after mid 2003, not before (because OHC measuring network before that date was far too sparse, with serious undersampling as a result).
An energy imbalance of 0.9 W/m2 is equivalent to a heat accumulation rate of 1.45×1022 J/annum. In seven years (between mid 2003 and mid 2010) it would be more than 10×1022 J. The NOAA/NODC figure above shows somewhat less than zero J went into the upper 700 m of oceans, so more than 1023 J had to go somewhere else. But there is no place on Earth where such a huge quantity could possibly hide, therefore it is not hiding anywhere, but has left the terrestrial climate system by crossing TOA (as outgoing thermal radiation). In other words, there is no energy imbalance whatsoever, Trenberth's speculations are falsified along with the computational climate model calculations they were based on (which means Trenberth's famous "missing heat" is nowhere to be found at the moment, but it used to be in the oceans earlier, unobserved by the much less reliable XBT/MBT system, making steep parts of the NOAA/NODC OHC graph wanting). Present climate is as close to a steady state as it can possibly be. It is as simple as that.
And now back to theory. The most lucid point to have is that Earth is not getting any heat from the Sun, just short wave EM radiation. This radiation is turned into heat when and if it is absorbed by either the atmosphere or the surface (accompanied by a huge increase in entropy).
Concerning the effect of GHG addition, the "if all else is held unchanged" clause above is an all-important one. Of course there is no one there to hold things unchanged as some more CO2 is added to the atmosphere, making it more opaque in a restricted thermal IR band. The real climate system has an astronomical number of degrees of freedom (vastly more than any computational climate model can possibly have), so it can adjust itself in any number of ways if a single parameter (like IR opacity in the 14-16 μm band) is changing.
If CO2 addition has decreased entropy production rate initially (that is, if the system was close to a MEP state), it will readjust itself to increase its entropy production rate if possible, but under no circumstances would readjustment decrease entropy production rate further. That is, there is a strong tendency to counteract climatic effects of CO2, but MEPP would not allow any change which would amplify it.
And indeed, that's what is observed. In the 7 years considered atmospheric carbon dioxide content went up from 376 ppmv to 390 ppmv, which is 5.3% of the radiative effect of a CO2 doubling. Yet, it has induced neither "radiative imbalance" nor "heat accumulation" in the system, as it is indicated by actual measurements (as opposed to computational models).
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CBDunkerson at 00:05 AM on 2 December 2010Stratospheric Cooling and Tropospheric Warming
Bob, one thing which this doesn't explain (and I'm not entirely clear on) is why the extra energy in the atmospheric window doesn't result in the stratosphere maintaining the same temperature. That is, even though CO2 is blocking the passage of a band of IR energy the total energy in and out must be equal. So the same amount of energy is passing through the stratosphere (in each direction) with or without the CO2 there. So why is the stratosphere cooler? Because the bandwidth distribution has changed? -
Peter Lang at 23:59 PM on 1 December 2010Renewable Baseload Energy
Talk about ideological - what is more ideological than anti-N and pro-renewables at any cost? I can't take much of the pro-renewables at any cost, anti- N ideological stuff when the advocacy is devoid of costs. I've pointed you to a number of links where you can compare costs on a comparable basis. If you are not prepared to try to get your head around this material then there is no point in continuing the discussion. You keep pulling out bits and pieces all of which are not on any sort of comparable basis. Come back with sensible, justifiable costings for a system that can produce the power demanded by modern society, and once you do you will understand why non-hydro renewables cannot do the job. And just before someone jumps in and says we are not concerned about cost I'll just add that renewables cannot do the job at any cost and are unlikely to ever be able to. But don't believe me, read the links I and Quokka hjave proivided today on the previous and this page. Over to you. -
oamoe at 23:57 PM on 1 December 2010Stratospheric Cooling and Tropospheric Warming
Regarding the change in spectra from 100 to 1000 ppm, the center bands in the CO2 spectrum appear to be saturated, with all of the change coming in the peripheral bands. If the central bands are saturated, what is going on with the scale on the y axis - shouldn't it drop to zero in the center of the spectrum? -
CBDunkerson at 23:46 PM on 1 December 20102nd law of thermodynamics contradicts greenhouse theory
damorbel #224: "Sunlight travels from a cold region of the atmosphere to a warmer one... indisputable fact."? Just what it says. The stratosphere is between the Sun and the troposphere. The stratosphere is colder than the troposphere. Ergo, for sunlight to reach the troposphere (and us to be able to see it) it passes from a colder area to a warmer one. Also: "The sunlight that passes through the atmosphere is not affected by it." Nonsense. In the same post you went off on an inexplicable tangent about sunlight causing ozone formation. That alone proves that sunlight is affected by the atmosphere. Also: "Oh, and the temperature at the stratopause is not that low, just about freezing, 0C." First, the stratopause is the boundary between the stratosphere and the mesosphere. Second, it is the warmest point throughout the mesosphere and stratosphere. Third, 0C is still significantly colder than the ~15C average surface temperature. Also in #237: "Whatever the configuration of the hot and cold bodies, the cold body will always absorb more photon energy (no. x E) from the hot body than the other way round." True... but here you finally admit that the 'hotter' body is absorbing photon energy from the colder one. Ergo, the hotter body must have more photon energy with the colder body than without it. Take the colder body away and the hotter is emitting the same amount of energy but not receiving any... ergo, it has less energy and is colder than it would have been with the colder body there. In other words, yes more energy flows from the warm surface of the Earth to the cooler sky than vice versa, but the IR photon energy flowing from the greenhouse gases in the atmosphere down to the surface means the surface is warmer than it would be without those gases. -
Ogemaniac at 23:07 PM on 1 December 2010Renewable Baseload Energy
Peter: You say: "Try putting properly comparable figures on your assertions (per $/MWh; even better, take it a step further and provide $/MWh of energy that meets our demand for power quality)." You then send me to a link that shows that coal and oil (not natural gas) have externalities of around $.08 or so per kwh, which is much higher than the subsidies renewables receive. And that's not counting the $312 billion in *direct* subsidies they receive every year. http://www.economist.com/blogs/newsbook/2010/11/fossil-fuel_subsidies I am sorry, but $312 billion/year + $.08 kwh is both a ying and a yang. -
JMurphy at 23:04 PM on 1 December 2010Renewable Baseload Energy
Peter Lang wrote : "When I see this sort of argument, I believe the people pushing it, and pushing CAGW, are not serious about CAGW. They are more interested in pushing their beliefs." Strange comment which needs some clarification. What do you believe CAGW means ? Who do you believe is "pushing CAGW" ? What "beliefs" do you believe those people are pushing ? Why is your belief better than what you believe other people believe, and why do you think the belief you are pushing is better than what you believe other people are pushing ? -
kdkd at 22:37 PM on 1 December 2010Renewable Baseload Energy
I'm unable to take anything Peter Lang says seriously I'm afraid, as the last time he turned up on this site, and was asked perfectly reasonable questions, he asserted that "this discussion is pointless" and disappeared. So I get the strong impression that there's an ideologically driven agenda here which when challenged results in logically flawed asserstions which are not proper arguments. As always I'm happy to be corrected, but am still awaiting an answer to the question that I posed prior to the post at the link above. -
Louise at 22:34 PM on 1 December 2010Naomi Oreskes' Merchants of Doubt Australian tour
cgp - You're question 'Are you worried that the current consensus cannot be falsified when we have the logic temperature rising it's global warming, temp cooling its weather' is answered elsewhere on this site - http://www.skepticalscience.com/global-cooling.htm Bottom line is, it's not cooling and there are at least ten different ways that this can be shown. Away from this site, http://www.realclimate.org/index.php/archives/2010/11/so-how-did-that-global-cooling-bet-work-out/ has a pretty good article on global cooling too. -
MarkR at 21:56 PM on 1 December 2010Stratospheric Cooling and Tropospheric Warming
(4) reluctant skeptic: it depends on a number of things. Very long term changes can be understood pretty well in terms of things like the carbonate silicate cycle. In summary, 'short term' feedbacks seem to be net positive - if you warm Earth you get some melting ice and more water vapour and more heating etc, although it is diminishing returns so you don't get a runaway effect. But longer term changes can swing us back the other way: more CO2 in the air means it dissolves more quickly in the oceans and silicate rocks weather more quickly at higher temperatures too, so they suck down CO2 as well. As CO2 drops away, the positive feedbacks amplify this cooling: cooler air holds less water vapour and cooling lets ice expand again. It's a very complex picture and it's different at different timescales, but the carbonate-silicate cycle is a great explanation for lots of geological observations so it's a good place to start! (even if it's not particularly relevant on 'short' timescales like the past few hundred thousand years)
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