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Comments 111651 to 111700:
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muoncounter at 06:05 AM on 26 August 2010Hansen etal hit a Climate Home Run -- in 1981
#18:"GISS-data are so much higher" #19:"GISSTEMP is virtually identical to that from HADCRUT, NCDC, and the RSS" See Ned's excellent summary of these virtually identical temperatures. -
Greenhouse effect has been falsified
Just an overall note on topics, Berényi - your half/double N2 comment really represents a red herring with respect to a conversation on the greenhouse effect. It's not helpful, and doesn't advance the discussion in any way. -
Greenhouse effect has been falsified
Berényi - So, you are just talking about the lapse rate here? Your comments seemed to involve nitrogen as a greenhouse gas, which I found quite confusing. Certainly, if you remove half the atmosphere, the dynamics and equilibrium of the Earth would be different - much as it would be if you removed all of it. I was under the impression, however, that we were discussing greenhouse gasses and the greenhouse effect, with only a few % of the atmosphere in question. Not wholesale planetary engineering or hypothetical worlds... -
Ned at 05:25 AM on 26 August 2010Greenhouse effect has been falsified
Will writes: As for Photosynthetic efficiency which is just one part of the effect I'm referring to, 2% is a stab in the dark. While it is claimed that crops such as wheat may achieve low efficiency of between 1-4%, sugar cain can achieve 7%, but photosynthesis is just one process plants use energy for. Oxygen production is another. Photosynthesis is how plants produce oxygen. It's the same process! A moment ago you were claiming that "40-50% of the incoming sunlight hitting the leaves is locked in by photosynthesis and the rest is reflected as short-wave". Healthy green plants absorb 90% or more of visible wavelengths of light, quite a bit less in the near-infrared. Only a small part of that, less than 10%, is converted by photosynthesis. The remainder warms the plant, and indirectly warms its environment. This is all irrelevant, though, since the analogy to a glass greenhouse is not intended as (nor appropriate as) a description of the physical mechanism by which CO2 warms the earth system.Moderator Response: Indeed. Will, in the post at the top of this page, see the section titled "The Term 'Greenhouse.'" -
Ned at 05:16 AM on 26 August 2010Greenhouse effect has been falsified
Will, glass is transparent to near-infrared wavelengths. It's opaque to thermal infrared wavelengths. See figure 2-3 here for an example. Lots of people get confused about this distinction, but if you're going to write about the earth's radiation budget you absolutely have to understand it. -
Tom Dayton at 05:13 AM on 26 August 2010Greenhouse effect has been falsified
You're right, Will, I should not have pointed you to Wikipedia for the definition of thermosphere. So let's use NASA. Or you could just search the internet for "thermosphere" and look at hundreds of definitions of it as a layer of the atmosphere. -
Berényi Péter at 05:12 AM on 26 August 2010Greenhouse effect has been falsified
#22 KR at 04:18 AM on 26 August, 2010 If's just the lapse rate you could swap nitrogen for argon or krypton (distinctly NOT greenhouse gases) with no effect No, you could not. These are monatomic gases (unlike nitrogen), therefore their adiabatic index is not the same (5/3 vs. 7/5). Dry adiabatic lapse rate would be higher. -
Ned at 05:12 AM on 26 August 2010Hansen etal hit a Climate Home Run -- in 1981
fydijkstra, what are you talking about? Over the past 30 years, the global (land/ocean) surface temperature increase in GISSTEMP is virtually identical to that from HADCRUT, NCDC, and the RSS satellite record -- they're all +0.16C/decade. The only major global temperature index that's noticeably lower is UAH, at +0.14. -
Will at 05:11 AM on 26 August 2010Greenhouse effect has been falsified
KR Glass is not opaque to IR either. See here: "The Diurnal Bulge and the Fallacies of the Greenhouse Effect."Moderator Response: To save us the trouble of editing your links, be sure not to include an extra space and line-break inside the quotation marks with the link URL. For example, use
<img width="450" src="http://image_url/">
rather than
<img width="450" src="http://image_url/
"> -
Will at 05:08 AM on 26 August 2010Greenhouse effect has been falsified
Ned I think I said EXPERIMENTAL verification! Please don't "Science of Doom" me. As for Photosynthetic efficiency which is just one part of the effect I'm referring to, 2% is a stab in the dark. While it is claimed that crops such as wheat may achieve low efficiency of between 1-4%, sugar cain can achieve 7%, but photosynthesis is just one process plants use energy for. Oxygen production is another. The point is that very little of the energy is converted to IR compared to say concrete slabs or Earth. At my site you find direct reproducible experimental evidence that pure CO2 causes less warming than ordinary air. Tom Dayton Wikipedia, please ? ! Go to the two links I have given above. The DIurnal Bulge has been deliberately hidden in plain view by renaming it as the Thermosphere. On the dark side of the Earth there is no Thermosphere. Therefore the Thermosphere is not a layer, it is a giant bulge on the sunny side. -
fydijkstra at 05:07 AM on 26 August 2010Hansen etal hit a Climate Home Run -- in 1981
Interesting! But is it a good idea to check Hansen's predictions with his own GISS-data? The fact that GISS-data are so much higher than the other datasets makes me suspicious. What if you do the same analysis with HadCRUT or satellite data? -
Greenhouse effect has been falsified
Berényi - "...if you removed half the nitrogen from the atmosphere, the Earth would freeze over completely...". Really? Are you talking about the lapse rate? If's just the lapse rate you could swap nitrogen for argon or krypton (distinctly NOT greenhouse gases) with no effect. I would love to see your reasoning (and math) for this non-GHG effect, as I don't see how that would occur. -
Greenhouse effect has been falsified
Will - An important point in the atmospheric greenhouse effect (which as Ned notes is not the same thing as a glass greenhouse in operation) is that GHG's aren't opaque to IR. They absorb thermal IR from the ground as per Berényi's post, and emit it again spherically distributed. This causes half of what they absorb to go back to the ground, which shows up clearly in the notches of the first chart of Figure 1. -
Berényi Péter at 04:08 AM on 26 August 2010Greenhouse effect has been falsified
#15 KR at 01:40 AM on 26 August, 2010 Nitrogen doesn't absorb/emit in the IR, and in fact most of it's absorption is in the UV True. It has no "greenhouse effect" whatsoever. Still, if you removed half the nitrogen from the atmosphere, the Earth would freeze over completely down to the very bottom of oceans. And if you raised its quantity twofold, global temperatures would go up by 40°C, cooking all of us for good. That much about the alleged 33°C warming from GHGs. -
Tom Dayton at 03:59 AM on 26 August 2010Greenhouse effect has been falsified
Will, please look up the definition of thermosphere. It is a layer of the atmosphere. The atmosphere is a poor conductor only relative to other substances (e.g., solid metal). That is irrelevant to this topic. What is relevant is the atmosphere's absolute conductivity. In a greenhouse or anywhere else, sunlight hitting leaves heats the leaves. Go find a plant that is exposed to sun. Put your hand on a leaf that is exposed to sun and compare its temperature to that of a leaf that is in the shade. You are correct that some of the sunlight hitting the leaf is consumed by photosynthesis, and that some is reflected, but some is absorbed as heat. -
Ned at 03:55 AM on 26 August 2010Greenhouse effect has been falsified
And, of course, Figure 1 in the very post at the top of this thread is direct evidence of the CO2 greenhouse effect. -
Ned at 03:50 AM on 26 August 2010Greenhouse effect has been falsified
Will, the troposphere is mostly heated from below, not from above, as KR notes above. The use of a glass greenhouse to illustrate the greenhouse effect is only appropriate at a coarse "end result" level, not as an actual model of how the CO2-induced GHE actually works. But in any case, the sunlight entering a (glass) greenhouse warms all dark surfaces within the space (floor, plant leaves, whatever). It doesn't significantly provide any direct warming of the air molecules inside the greenhouse. The air is warmed by contact with the various surfaces that are absorbing sunlight. Photosynthetic efficiency for most plants is less than 2%, and less than 10% in virtually all cases. Most of the sunlight absorbed by plant leaves just raises their temperature (directly) and that of the air around them (indirectly). Finally, there's experimental verification of the CO2 greenhouse effect -- see here or here (and continue on to parts two and three as well). -
Will at 03:30 AM on 26 August 2010Greenhouse effect has been falsified
Ned: The Thermosphere is not a sphere it is a bulge. The Diurnal Atmospheric Bulge and the Thermosphere are one and the same. The Diurnal Atmospheric Bulge (Thermosphere) is caused entirely by incoming EMR. I never said there was a connection between the "greenhouse effect" and the Thermosphere. I said there is no "greenhouse effect". I have proven this with experimental verification on my website at the following link: "The Diurnal Atmospheric Bulge, giant 1200º bulge of rapidly heated and expanding gases circling the Globe 24/7." KR: The atmosphere (air) is a excellent insulator and therefore a poor conductor. It exhibits various temperature gradient inversions. Partly because it is such a good insulator and partly because it is heated from the top-down by incoming EMR. All mysteries explained. Which way up is the temperature gradient in a greenhouse? Like I said before, a greenhouse still functions perfectly well with a full canopy of leaves shielding the ground completely from direct sunlight. 40-50% of the incoming sunlight hitting the leaves is locked in by photosynthesis and the rest is reflected as short-wave. No direct sunlight reaches the ground yet the greenhouse still warms that same as an empty one would. Where is the "greenhouse effect" bottom-up warming in this scenario? When your theory generates more questions than it answers, this is a clue that you are traveling away from the truth. When your theory is still awaiting experimental verification after 200 years . . . . . ? -
CBDunkerson at 03:12 AM on 26 August 2010Pakistan flood: many more will die unless more aid is delivered quickly
The high human population of the planet does play in to CO2 emissions, but population GROWTH specifically does not... precisely because that growth occurs in the areas which do NOT have high CO2 emissions. Environmental problems in general are different (and off topic) than CO2 emissions specifically. Getting back down to 350 ppm does not require a return to pre-industrial technology. If it did it would never happen. Instead, the obvious path to lower CO2 emissions is power generation from sources other than fossil fuels. -
muoncounter at 03:00 AM on 26 August 2010Warming causes CO2 rise
#2:"seasonal variations of these magnitudes must make it extremely difficult to be sure that the annual global increase of perhaps 2ppm is being accurately isolated. " I disagree. Seasonal amplitude is not the same as year-to-year rate of increase. Look from year to year at successive peaks and troughs and you find consistency in the annual growth rate.
I've done this with several arctic stations where the seasonal amplitude is as high as 15ppm; what was 1-1.5 ppm in the '70s is now 2-2.25 ppm. And that rise matches the growth in CO2 emissions from fossil fuel use quite well.
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Kernos at 02:42 AM on 26 August 2010Pakistan flood: many more will die unless more aid is delivered quickly
CBDunkerson #15: "China and India have long had huge populations... but their CO2 emissions were virtually non-existent until they began to industrialize." Which they are doing now and will be doing more of in the future. And, is it not largely farmers that clear land to grow crops? I think saying human population, global or regional, has nothing to do with global warming and other human environmental impacts is simply specious. "So again... no significant 'negative feedback' on CO2 emissions from natural disasters. At least not any time in the near future. " Is not one of the causes of environmental problems, short term thinking/ Should we not be thinking in the long term, say a millennium from now? "...how well technology has kept up with allowing us to adapt to the climate." I think the goal to not to adapt, but to turn back to pre-industrial levels, or say to 350 ppm, as some suggest. I certainly don't want coastal city dwellers inundating my grandkids as they all run for higher ground. Besides, these human disasters may be the only thing to get the politicians thinking beyond the next election. Or is that just wishful thinking? I do not think the environmental problems can be solved without taking human population(s) into account. -
Greenhouse effect has been falsified
Will - on your note that 79% of the atmosphere is completely missing: I assume you mean N2? Nitrogen doesn't absorb/emit in the IR, and in fact most of it's absorption is in the UV. Hence it's usually not shown on most charts of greenhouse gases - it's irrelevant to the IR spectra. -
Greenhouse effect has been falsified
Will - There's definitely heating from the sun involved in atmospheric expansion. Looking at the energy balances from Trenberth 2009 roughly 78 W/m^2 of sunlight are directly absorbed by the atmosphere. Another 161 get absorbed by the ground/water. However, what's emitted by the top of the atmosphere (as LW radiation) is ~169 W/m^2 - partly re-emission of atmospheric energy, mostly emission from ground/water thermal energy that has percolated up through multiple absorption/emission events. And the temperature profile of the atmosphere shows warming of the troposphere and cooling of the stratosphere - if this was all top-down warming you would see a hot stratosphere and colder troposphere, relatively speaking. The observed temp profile is one of the fingerprints of the greenhouse gas effect. So yes, some top-down heating does occur. But it's mostly bottom-up, as most of the solar irradiation goes through the atmosphere to the ground, only returning as IR. I would say that the diurnal bulging of the atmosphere is due to the atmosphere warming - because days are warmer than nights. But the temp profile clearly shows that it's warming from the bottom (IR), not the top (solar). -
Ned at 01:24 AM on 26 August 2010Greenhouse effect has been falsified
Of course the thermosphere and to a lesser extent the mesosphere are heated by the sun, mostly via UV absorption. But they're not that far from vacuum -- less than 1% of the mass of the atmosphere. And this is completely irrelevant to the greenhouse effect. There's simply no connection whatsoever. The situation in the troposphere -- the layer of the atmosphere closest to the surface, including most of the mass of the atmosphere -- is entirely different. Longwave radiation from the surface is absorbed by molecules of CO2 and other greenhouse gases, which in turn heat the more numerous N2 and O2 molecules kinetically, via intermolecular collisions. Thus, the entire mass of a given "parcel" of the atmosphere shares a single temperature -- you don't have different temperatures for CO2, O2, N2, etc. CO2 and the other greenhouse gases then radiate in all directions. Thus, the presence of GHG molecules warms the troposphere, and increasing the concentration of those molecules increases the efficiency of this warming. Keep in mind that the vast majority of solar irradiance is at relatively short wavelengths (visible and near-infrared) where atmospheric transmittance is relatively high. The solar flux at thermal IR wavelengths (over 3 micrometers) is minuscule in comparison to the terrestrial outgoing thermal IR flux. If you would like a good overview of the physics of the greenhouse effect, I would highly recommend the series of posts on "CO2: An Insignificant Trace Gas?" over at Science of Doom. Hope this helps. -
Byron Smith at 01:22 AM on 26 August 2010Arctic Sea Ice: Why Do Skeptics Think in Only Two Dimensions?
Ah, thanks for the clarification. That makes much more sense! -
dorlomin at 00:44 AM on 26 August 2010Arctic sea ice... take 2
HumanityRules at 00:35 AM on 26 August, 2010 Again the PIOMAS isn't measured data but modelled data, an important distinction. That's why it can be, and sometimes is, wrong. = = = = = = = = = = = = = = = = = = It is a model derived from measurements like almost every other metric used on a similar scale (100-1000 square kms). Even the isobars on an MSLP chart are effectively models. -
HumanityRules at 00:35 AM on 26 August 2010Arctic sea ice... take 2
Again the PIOMAS isn't measured data but modelled data, an important distinction. That's why it can be, and sometimes is, wrong. -
Will at 00:33 AM on 26 August 2010Greenhouse effect has been falsified
adelady: You are correct, it is of course radiation. Which is why I asked Ned to clarify if he was describing conduction or radiation. Assuming he even knows of course. Ned has opted to go on the attack instead of answering the question. I repeat to Ned, please follow the links and read my article. Then explain how an area with a circumference of 25% of the entire surface of the atmosphere can bulge up to an altitude of more than 600 km altitude under the solar point at around 2 pm in the sky, yet at 4 am on the dark side of the Earth this bulge completely collapses bellow the Mesosphere at under 90 km, if the atmosphere is so transparent to incoming full spectrum electro-magnetic energy. -
Jeff T at 00:29 AM on 26 August 2010Hansen etal hit a Climate Home Run -- in 1981
A triumphant title ("Home Run") may be warranted, but it may repel visitors who are undecided. Try this instead: "Global temperature has increased, as predicted by Hansen etal in 1981." Or: "... etal 29 years ago." -
Ned at 00:08 AM on 26 August 2010Warming causes CO2 rise
johnd: I guess I'm not clear about what you're suggesting. Are you saying that the observed rise in CO2 might not be anthropogenic? Or that we don't have to worry about it because perhaps natural sinks will suddenly change their behavior and start soaking up a lot more CO2? -
adelady at 00:02 AM on 26 August 2010Greenhouse effect has been falsified
Will, if air is such a poor conductor of energy, how can the atmosphere maintain its cool temperature in the face of (warming) radiation from any direction, sun or earth. Given that it is a poor conductor, the only way for the atmosphere to cool must be by, you guessed it, radiation at the top of the atmosphere. If it's radiating out at the top of the atmosphere, surely the molecules comprising the atmosphere would also be radiating all the way through the atmosphere. Unless there are GPS guided molecules that can work out where they are to start radiating in only one place? -
Ned at 00:02 AM on 26 August 2010Greenhouse effect has been falsified
These comments are a nice example of the problems I have raised many times on this site, most recently here. That is, we often get comments on this site from the more serious "skeptics" accusing us of wasting time on straw-man arguments and of rebutting claims that no one really believes. So ... here we have another commenter claiming that the atmosphere is directly heated by solar irradiance "top-down" and that the greenhouse effect does not exist. I could, of course, do what so many of us supporters of mainstream science have done over and over again, and patiently work on responding to these claims, explaining to Will why he misunderstands the physics of radiation in the atmosphere. It would be nice, though, if some of those supposedly serious, reasonable skeptics would join in and help answer Will's claims. If that were to happen, it might help me believe that there really are "skeptics" who are serious about science. So far, the only resident "skeptic" commenter to speak up has been Berényi Péter ... who quibbles over my use of the word "transparent" but is apparently unable or unwilling (or perhaps too busy) to contribute anything more directly relevant to addressing Will's questions. Is there anyone on the "skeptic" side here who understands what's wrong with Will's claims and is actually willing to say so? Or, once again, will the job of explaining Will's errors be left up to the rest of us? Of course, this isn't the most recent or active thread, so I suppose it's possible that many people might not notice these comments immediately. -
Peter Hogarth at 23:35 PM on 25 August 2010Warming causes CO2 rise
johnd at 19:04 PM on 25 August, 2010 Are you suggesting the CO2 trends, as independently monitored by multiple stations world wide, are in doubt? See Global CO2 data, and SCHIAMACHY independent satellite derived CO2 trends and seasonal variations (which corroborate the Mauna Loa data), and the NOAA ESRL trends website. The derivative method Hocker uses does reveal de-trended changes in atmospheric CO2 with seasonal variations removed, and these are interesting in terms of primarily land based sources and sinks (I will comment further or post in detail at some point) but these variations are a few ppm and swamped by both natural seasonal variations and the very well defined significant trend from long term anthropogenic emissions. -
Will at 23:22 PM on 25 August 2010Greenhouse effect has been falsified
Berényi Péter This diagram of absorption bands is interesting for what it doesn't show. 79% of the atmosphere is completely missing. -
Will at 23:18 PM on 25 August 2010Greenhouse effect has been falsified
Sorry but these statements are nothing but semantics. The Diurnal Atmospheric Bulge is incontrovertible proof of massive violent top-down atmospheric heating. Please follow the link and read the paper. A greenhouse with a full canopy of leaves completely shielding the ground from direct Sunlight still functions normally. More proof that air is heated by incoming full spectrum electro-magnetic radiation and NOT by OLR. Therefore the "greenhouse effect" hypothesis is false. Ned, Air is rated as one of the top insulators of all substances. That means that air is a very poor conductor of energy compared to most substance. In fact it is one of the poorest conductors of energy there is. What are you trying to describe in your last statement? Conduction or Radiation? -
tobyjoyce at 23:11 PM on 25 August 2010Medieval Warm Period: rhetoric vs science
The Norse Greenland colony, which was started in the 11th century and was abandoned in the 15th century, often comes up in connection with the Medieval Warm Anomaly. There is a very good account of it in Jared Diamond's Collapse. Diamond refers to several book-length accounts, but a shorter older account I have is Magnus Magnusson's Vikings (1980). Magnusson was an Icelander, a scholar and archaeologist woh made it quite big on television in Britain in the 1970s and 1980s. Magnusson's book is an apologia for the Vikings, who (he claims) were misunderstood traders. Hence he emphasises peaceful relations with the Inuit, whereas Diamond suspects the Vikings and the Inuit had primarily an antagonistic relationship. Certainly, the Norsemen never adapted any Inuit technology, which was better suited to the environment than theirs. However, the colony was marginal from the start. It quickly ran short of wood and iron for tools, and used Labrador as a source for each. Farm animals overgrazed the pastures and the short summers made life harsh. Its main export(walrus ivory) was a long distance from the market (Norway) and a difficult journey away. In modern terms, the colony was tiny: about 4,000 people in an "Eastern Settlement", just near the southern tip of Greenland, and 1,000 more in a "Western Settlement" (really North-Western). Diamond suspects the Western Settlement was wiped out by Inuit. Then as now, most of Greenland was ice capped. The colonists and the Inuit eked out an existence from the sea and the coastal strip. As I said above, the Inuit (who were also recent arrivals) had the superior technology and survival skills for the tough environment. There is no need, therefore, to appeal to climate ALONE as the source of the difficulties experienced by the Norse settlements, after their early successes. Diamond makes that clear. Magnusson refers to climate as a suspect in the final collapse but, writing when he did, he calls it the "Little Climate Optimum". So "climate determinism" falls down when the Medieval Greenland colony is discussed - climate may have contributed to its short flourishing period and its demise, but there are multiple other factors which also affected that outcome. -
Berényi Péter at 23:09 PM on 25 August 2010Greenhouse effect has been falsified
#5 Ned at 21:26 PM on 25 August, 2010 A large percentage of the total downwelling solar irradiance is in the near-infrared range, but the atmosphere is mostly transparent in this part of the spectrum That's how transparent it is.
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batsvensson at 23:05 PM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
JMurphy at 03:24 AM on 25 August, 2010 Did you understand what I wrote? -
ecotox at 22:42 PM on 25 August 2010Arctic sea ice... take 2
pikaia is right. The curve would not be linear, as the albedo effect of more dark ocean each year would act as a catalyst. Hence, curving the relationship between ice volume and time. (However, adding another difficult variable to an otherwise simple concept could prove troublesome for politician simpletons and John Q public.) -
Peter Hogarth at 22:26 PM on 25 August 2010The Past and Future of the Greenland Ice Sheet
Berényi Péter at 20:28 PM on 22 August, 2010 As promised, some thoughts on BC (Black Carbon) which I hope are of interest: Globally, over the past century, BC trends have risen, mainly due to low latitude contributions, with a possible tailing off after 1980. In line with previous work Kopp 2010 suggests our best current estimate of global effective Radiative Forcing due to BC is about 0.22 Wm−2. I do not want to downplay the role of BC in regions like the Himalayas, but this thread is about Greenland. Let us look at what the authors and co-workers of the paper you cite have actually said recently on the NH and Arctic regions: Flanner 2009: “Equilibrium climate experiments suggest that fossil fuel and biofuel emissions of BC+OM induce 95% as much springtime snow cover loss over Eurasia as anthropogenic carbon dioxide”; Hadley 2009: “Black carbon (BC) has been measured in snow and ice cores at levels that climate models predict are high enough to be the second leading cause in arctic ice melt and glacial retreat after greenhouse gas warming”; Zender 2009: “our GCM (General Circulation Model) simulations show that dirty snow can explain about 30% of the observed 20th century Arctic warming” Note so far we are talking in the main about simulations. Comparing modeled deposition results from measured observations Gilardoni 2010 we see good agreement in general, but not in the three Arctic sites selected (one of which is Alert, just off Northern Greenland), where measured equivalent BC levels are much lower than global averages. These sites show strong (5 to 10 times higher than background) annual BC peaks (to around 120ng/m3) through January, February and March, when insolation is relatively low. Lamarque 2010 - in support of more accurate simulations (some results shown for Greenland) has introduced a new 150 year global gridded dataset of anthropogenic and biomass burning aerosol emissions, and Hegg 2010 has reported detailed results from much higher spatial resolution measurements of light absorbing aerosols (including BC) in the Arctic. One surprising finding is that the main current source of Arctic BC is biomass burning, and not fossil fuels (as is the case in Eurasia). In the Canadian High Arctic in recent decades we see overall reductions in BC levels from the mid 1980s, with a shift in proportional contributions from Eurasia (due to emission controls) and the US Gong 2010. So what of Greenland? In the early 20th Century BC concentrations (from high resolution ice core evidence) were much higher, and may have changed the summertime surface energy budget by around 3Wm−2 McConnell 2007, however current levels are now significantly lower, and are also lower than global averages. At the same site Sulphate levels continued to rise until the 1980s in Greenland Lamarque 2010. Considering the early 20th century Greenland warming, these results are interesting and it is likely that anthropogenic aerosol effects contributed as has been noted previously by Wild 2009 and others, (see review of more than 20 recent papers introduced by Wild 2010)
(a) Monthly (black) and annual (red) measured BC levels at ice core site D4 in Greenland (71.4 N, 44 W) and (b) relative Winter/Summer levels from site D5, which is approximately 350km further south, from McConnell 2007
Given this evidence it is unlikely that BC contributes to the most recent increases in Arctic surface air temperature and Greenland ice margin melt rates, and is even more unlikely to contribute to warmer waters and warmer Ocean currents causing basal glacier outlet melt and overall accelerated mass loss in Greenland.
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Berényi Péter at 22:21 PM on 25 August 2010What were climate scientists predicting in the 1970s?
#46 gp2 at 23:25 PM on 24 August, 2010 the results clarify that the seemingly mysterious rise in global-mean stratospheric temperatures since 1993 is consistent with increasing stratospheric ozone juxtaposed on global-mean cooling of 0.1 K/decade I still don't get it. After the recovery from the Pinatubo event lower stratosphere temperatures go with no trend whatsoever.
At the same time there is no clear trend in ozone either. Some recovery is seen indeed after Pinatubo, but then it started to decrease again (after 1998, even more so after 2003).
For the same period GISS Surface Temperature Analysis shows at least 0.32°C warming for Global Annual Mean Surface Air Temperature.
According to the Manabe model, we should have five times as much cooling (that is, -1.6°C) in the upper stratosphere. Even if sensitivity characteristics of TLS are taken into account, one would expect at least twice as much cooling in lower stratosphere than the warming rate of the surface. It would mean 0.64°C in the one and a half decades considered (-0.43°/decade).
If Thompson 2009 is followed in that current lack of temperature decrease in lower stratosphere is due to an increase of ozone (in fact it is not), the -0.1°C/decade they find as a residual still seems to be far too small.
It would imply a 0.08°C warming of the surface in 15 years, that is, 75% of the observed warming should come from something else than GHGs (UHI? soot?).
The problem with this solution is climate sensitivity would be less than 1°C/doubling of CO2, that is, water vapor/cloud feedback is strong negative, which contradicts computational climate models.
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Ned at 22:07 PM on 25 August 2010Greenhouse effect has been falsified
Will, the "heat capacity" issue is irrelevant, too. CO2, methane, CFCs, etc. absorb longwave IR radiation, but they then transfer that heat to the rest of the atmosphere via collisions with other atmospheric molecules (roughly a billion collisions per second per molecule). -
JMurphy at 21:42 PM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
scaddenp wrote : "Guys, I think we have given PT enough rope. Moderator Response: Yes, there is no progress in that discussion, so let's just agree to disagree. Enough rope, as well as the hook, line and sinker. In the end, though, those of us with normal lives and outlooks on life, have to know when to call it a day and move on to something more interesting. I get very dizzy going round and round in circles. Any observer should be able to see how warped that list is by now but it will be interesting to see which so-called skeptic tries to link to it next ! (Cue Poptech posting : "I have not been given enough rope. My list is interesting. You have not...etc., etc., ad nauseum) -
Ned at 21:37 PM on 25 August 2010Arctic sea ice... take 2
Mikemcc, yes, you're right -- "albedo" is the average reflectance across either the visible spectrum or the visible & near-infrared range (say, 0.4 to 0.7 or 1.0 or 1.3 micrometers) depending how one wants do define it. The albedo of a surface determines what fraction of the incident light from the sun is reflected. The portion that isn't reflected is, of course, absorbed, raising the temperature of the surface. -
Ned at 21:26 PM on 25 August 2010Greenhouse effect has been falsified
Will writes: Ultimately the fallacious assertions in support of the bogus "greenhouse effect" depend entirely on the ridiculous notion that the atmosphere is heated bottom-up by OLR (outgoing Long-wave radiation). This in-turn requires that the atmosphere is completely transparent to incoming full spectrum electro-magnetic radiation, a large percentage of which is IR. Either you're forgetting the inverse-square law, or you're confused about the distinction between "near infrared" and "thermal infrared" wavelengths. A large percentage of the total downwelling solar irradiance is in the near-infrared range, but the atmosphere is mostly transparent in this part of the spectrum. Only a very small fraction of solar irradiance is in the thermal infrared region. If we look just at thermal infrared radiation, how much of the radiant flux in the atmosphere is from the sun and how much is from the earth? Obviously, the sun is much hotter ... but it's also much further away. Thus, virtually all the IR radiation in the atmosphere is coming from the earth, not the sun:
From Science of Doom
The yellow curve at the left is the blackbody radiation curve for the sun at a temperature of 5780K and a distance of 150 million km. The variously colored curves on the right are blackbody radiation curves for the earth at various normal earth temperatures.
Note, first, that the Y axis is log-scaled. Note, second, that in the thermal part of the spectrum (greater than 3 micrometers) the area under the "earth" curves is much, much larger than the area under the "sun" curve.
Bottom line, the sun heats the earth via visible and near-infrared radiation. The earth emits long-wave (thermal infrared) radiation. Increasing the concentration of greenhouse gases in the atmosphere traps more of that long-wave radiation and raises the temperature of the earth system.
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Mikemcc at 21:19 PM on 25 August 2010Arctic sea ice... take 2
I thought albedeo was primarily a measure of reflection of visible light, since that is where most of the energy is from sunlight. Dark water absorbs more of this energy than white ice. The energy absorbed by the water leads to heating, and some of the absorbed energy is then re-radiated as heat radiation (IR). -
dontcry at 21:02 PM on 25 August 2010Skeptical Science housekeeping: iPhone app, comments and translations
This is really a bit inconvenient to have no information about the user, no link to their profile page. Is it also possible that the email address or website could be displayed like a signature? Like this. Steve Zuc. from Pdfok -
Rob Painting at 20:50 PM on 25 August 2010Greenhouse effect has been falsified
Another question Will - if there's no Greenhouse Effect, why was it warmer in Earth's distant past at a time of reduced solar luminosity?. -
Rob Painting at 20:16 PM on 25 August 2010Greenhouse effect has been falsified
Will, if there's no Greenhouse Effect, why doesn't the Earth freeze over at night?. -
skywatcher at 19:46 PM on 25 August 2010Arctic sea ice... take 2
In that context, fitting a quadratic trend to either the sea ice extent or sea ice volume since 1979 produces a much better fit - ie the losses are accelerating through time, rather than simply declining linearly. Those trends reach zero (in September) for extent around 2030, and volume before 2020.
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