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JMurphy at 20:08 PM on 2 July 2010IPCC were wrong about Amazon rainforests
Willis Eschenbach wrote : "Pachauri said repeatedly that the IPCC was based 100% on peer reviewed science. As a result, one is too many ... and the Amazon claim is certainly one." Well, since you love to demand citations (especially in front of an adoring crowd at WUWT), perhaps you could do so here and give links to Pachauri's 'repeated' claims ? Then, give the stats which show the "far too often" IPCC reliance on "propaganda pieces", etc - as you have already been asked. Then, tell why you believe Pachauri and the IPCC are one and the same, so that what he says is what the IPCC says. Do you have links to official IPCC paperwork, etc. which has statements by him claiming things like the IPCC 100% assertion you are so obsessed with ? Anyway, you have already been shown where to look to see all the answers, by a Phil Clarke, on the WUWT thread you wrote recently. But you seem to have ignored it, preferring to have a handbag fight with Richard North over who said what and when. Some of the posters on there were very upset at that - two of their so-called skeptic heroes not getting on ! Egos are such a pain, aren't they ? Here is another version of the link that you were given over at WUWT but ignored. -
daniel at 18:21 PM on 2 July 2010Sea level rise is exaggerated
Peter Hogarth at 05:19 AM on 2 July, 2010 "An alternative fit involving high short term variation which still explains the limited data points would involve undersampling and aliasing. Is this likely? You do not suggest it is, but you propose it is possible. It is not possible to know if it is likely given the data presented. But it is certainly possible and given the data presented, it's just as likely. "Without exception they display the poor resolution which you would rightly criticize if any study was the single source of our evidence." The Gehrels paper (annoyingly $25 USD) cited in the article has decent resolution through most of the period examined. (Coincidentally it lacks resolution through most of the period examined by the Donnely paper discussed). Another article which I still haven't read yet by Gehrels et. al. Quaternary Science Reviews 24 (2005) 2083–2100. Appears to have high resolution over the period discussed. But I think that as long as error estimates are high, comparisons to short term recent trends will be undermined. "One of the best that is free (I honestly did not select by author!) is Donnelly 2006. It is possibly close enough geographically to the 2004 data set so that gaps in the record in each could be reduced," Admittedly I haven't read the article yet but having skimmed over it and focusing on figure 7 and taking into account the height uncertainties, I can't see how either paper helps to validate the other. Donnely 2004 only covers a small portion of the Donnely 2006 reconstruction between samples R5 and R6 and has ~20cm total height error at 95% confidence (you can read the actual +/- ~10cm intervals in the text). Donnely 2006 has ~30cm total height errors and so cannot serve to further refine Donnely 2004. Donnely 2004 cannot serve to refine 2006 beyond possibly reducing the error margins to ~20cm total. "Likewise, archaeological and historical evidence on sea level changes, from around the world, taken in isolation, means little - and could easily be written off using local crustal depression etc." Certainly the overall global picture is not represented even if all of the papers we've discussed thus far are put together, I agree. Is crustal depression such a factor in any of these papers? I thought that the more recent papers tried to address these issues, Gehrels 2006 seems to. But I may have my (depression mixed up with my subsidence, my ignorance shows - but I could read up on that Doug) "It is the integrated wider evidence based picture that emerges when researchers try to put all this stuff together that proves persuasive to many, and to me." But the wider picture in terms of SLR thus far seems to be an integration of poor data (in the correctly calculated error estimate sense) and or conclusions. "A further point is that researchers like Donnelly cannot help but acquire a great deal of background knowledge or expertise, and will be aware of large amounts of evidence that might not even be in publication, but nevertheless adds to the overall common sense probability based conclusion. Is this conclusion overwhelmingly robust? I couldn’t say without analysis, but it is consistent with the majority of recent and emerging published data." I hope you don't get annoyed when I say that i think this comment again boils down to an ad hominem type argument roughly equivalent to "They're experts, just trust em, they know what they're doing." I wonder about the quality of all of that published data both on SLR and other climate factors. -
adelady at 18:13 PM on 2 July 2010An account of the Watts event in Perth
45 minutes! A slide show. What fun! -
Arkadiusz Semczyszak at 18:12 PM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
@Marcus I. At the rainfall (restricting the use of CO2) - IV Report says: there is strict correspondance in warming, but the number of dry areas increases. For example, particularly South Africa today has to suffer drought. But ... Drought, climate change and vegetation response in the succulent karoo, South Africa, Hoffman, 2009: “Because drought has significant ecological and socio-economic impacts, investigations into its causes, consequences and mitigation have been regularly undertaken in South Africa over the last 100 years. Recent climate change scenarios suggest that there will be an increase in the frequency of extreme events, including drought, particularly in the winter-rainfall region of southern Africa as a result of the predicted pole-ward retreat of rain-bearing frontal systems.” “Our analysis finds no evidence for a decreasing trend in annual rainfall from 1900–2000 for the six rainfall stations investigated, and except for Springbok, there was no increase in the incidence of drought over the 20th century. Our analysis is in agreement with Warburton and Schulze8 who also report no decrease in annual rainfall for the winter-rainfall region in the latter part of 20th century. In fact, they suggest that relative to the period 1950–1969, the winter-rainfall region experienced an increase [?!] in rainfall from 1980–1999. [...]” Thus, the Fourth Report - even describing the twentieth century - is untrue. The forecasts contained therein are very uncertain - precipitation - variability is here non-linear. II. “The second question which arises from the climate change scenarios is concerned with the response of vegetation to drought. [...]” III. Pests. In my country, farmers are afraid that a new thermophilic pests attack maize. It is the object of my work (response to climate change). Note. Even professionals often forget that in countries where these pests are already, the yields and profitability of maize production are higher than ours ... It is also worth knowing that severe pest outbreaks occur in 1-3 years after severe winters. Why? - First frosts kill overwintering individuals dominated by diseases and parasites ... IV. Protein - nitrogen - the latest research on this issue are so short (time, replication), full of “artefacts”, that these affirmative: CO2 “harms” - never and should never be published. At most, as preliminary - without further, generalizing conclusions. -
Willis Eschenbach at 18:03 PM on 2 July 2010IPCC were wrong about Amazon rainforests
doug_bostrom at 07:36 AM on 28 June, 2010 >>When the IPCC relies, as it has done far too often, on WWF and Greenpeace propaganda pieces, and newspaper articles, and the like... Willis if you quantify that assertion you'll be moving closer to joining the realist school of critique, moving away from applying your brush to impressionist strokes like that one. What are the statistics?>> Glad to. Pachauri said repeatedly that the IPCC was based 100% on peer reviewed science. As a result, one is too many ... and the Amazon claim is certainly one. >>Finally, in addition to the IPCC question, the science is at issue as well. I have yet to see anyone link to a peer-reviewed article showing any evidence that 40% of the Amazon is at risk due to reduced rainfall due to warming ... Thank you for affording me the opportunity once again to quote the authority on the subject, Nepstad, whose work this vapid brouhaha was all about: In sum, the IPCC statement on the Amazon was correct. The report that is cited in support of the IPCC statement (Rowell and Moore 2000) omitted some citations in support of the 40% value statement. >> I begin to despair. You do understand what "peer-reviewed" means, don't you? It is not simply the opinion of Nepstad or anyone else. Where is the peer-reviewed source document for the IPCC claims? That's what I keep asking for, and what you have not provided no matter how much handwaving you have done. -
John Chapman at 15:51 PM on 2 July 2010An account of the Watts event in Perth
One of the speakers was David Archibald. At a previous event he was promoting the benefits of CO2, and finished with the conclusion that he felt 1000 ppm of the gas was the optimum level! At least he didn't conclude with that statement this time, probably because Watts said they (- the skeptic team) were all "as green as the next bloke". Nova indeed lectured on how the AWG is just a gag for scientists to attract funding and for governments to reap taxes while the big financial institutions take their cut in the middle. -
Habilus at 13:53 PM on 2 July 2010How Jo Nova doesn't get past climate change
When science is settled, it's no longer science.Response: I'm not sure where that come from but we have a page specially devoted to the argument "The science isn't settled" - feel free to discuss the matter there. -
Joe Blog at 13:36 PM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
"As greenhouse gases stop heat from reaching the upper atmosphere, a distinct greenhouse signature is a warming lower atmosphere and cooling upper atmosphere." I might be being pedantic.... But i do find that this first point really grates with me, and it dosnt seem to be clarifies at all in the document... Obviously most of the LW that leaves the troposphere escapes directly to space.. and although the stratosphere indirectly effects pressure systems etc, for the most part the stratosphere and troposphere are independently effected by co2(although more H2O vapor in stratosphere will also contribute to cooling, and there will still be back radiation from stratosphere, but not overly significant) I know you are just keeping it simple, but i think this may be over simplifying... Maybe something more detailed as to the why of the stratospheric cooling in the document, to clarify the point. Because as it stands, it misleads on the mechanisms. -
Marcus at 12:29 PM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Another point, John D-here are the words of Dr. John Fitzgerald himself: "Results from the first three years of the experiment include increases in biomass, which in agriculture, translates into increases in yield and we’re seeing about a 20% increase in yield because of the elevated CO2. Now, the caveat there is that you can see increases in yield, but you also have to have sufficient water and nitrogen still to grow the crop and considering changes in climate, if this area of Australia, for example, has decreases in rainfall then we may not see the responses to be quite that dramatic in the future" & this: "Now, other results that are important to the agricultural industry is that we see a decrease in the plant nitrogen content. Now, nitrogen is a fertiliser, it’s what causes the green part of the plants to be green and that’s important…what happens is that translates into less nitrogen in the grain, which is less protein. So that interacts directly with quality issues and the wheat industry would be quite interested in understanding that. So, the nitrogen content, the protein content goes down and we’re seeing that very consistently. However, what’s interesting is that the total nitrogen extracted from the soil increases and that’s because there’s more biomass. So it’s just pulling a lot more nitrogen and that has potential impacts to future farming in terms of fertiliser requirements." When you also add in others factors which may well accompany a warmer world-such as increased incidence of plant pathogens & weeds-& we see the story behind the "CO2 is plant food" meme is not as simple, or as positive, as people like yourself would have us believe. Like I said elsewhere, other FACE studies are showing yield increases of little more than 8% in wheat (and only 6% in rice), & a consistent decline in the nutritional value of the rice & wheat-even without other impacts of global warming being considered. So, in fact, I'd suggest that all of my previous questions remain unanswered or-if they are answered-confirm my initial suspicions-which is that the claim that "CO2 is a plant food" is grossly over-simplistic when you consider the real world. Having contact with farmers in THE REAL WORLD also helps to confirm these suspicions. -
Marcus at 12:20 PM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
John D, I don't really feel that a change in Sowing Time is an accurate modeling of warmer temperatures in a 3-year trial. Indeed, I'm not entirely satisfied that the rainfed system accurately represents the drier conditions we have to look forward to. Perhaps over a 10-15 year period, but over 3 years, the inter-annual variability is just too high. For example, in Southern Australia, October, November & December of 2008 was exceptionally cold & wet by normal standards, yet November of 2009 was exceptionally *hot*! That said, the outcome of the trial was that only 2 out of the 8 varieties showed a significant increase in yield, under the optimum conditions. Protein levels were reduced in spite of an almost 25% increase in nitrogen uptake. The investigators also highlight a decline in mineral uptake & evidence of acclimation-hardly great news for the "CO2 is plant food" crowd. Unless you're suggesting the investigators themselves don't understand the results of their trial? -
Doug Bostrom at 11:59 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
For really fanatical enthusiasts, Roger Pielke Sr., Gavin Schmidt and Eric Steig explore Pielke's invitation on a thread at RealClimate, beginning here. -
billkerr at 11:11 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
hi John, Have you considered the choice b/w Pielke snrs invitation and hypotheses 2a and 2b? (Invitation On Assessing Three Climate Hypotheses) You seem to support 2b judging by your handbook's CO2 emphasis but 2a may be a better fit for the evidenceHypothesis 2a: Although the natural causes of climate variations and changes are undoubtedly important, the human influences are significant and involve a diverse range of first order climate forcings, including, but not limited to, the human input of carbon dioxide (CO2). Most, if not all, of these human influences on regional and global climate will continue to be of concern during the coming decades. Hypothesis 2b: Although the natural causes of climate variations and changes are undoubtedly important, the human influences are significant and are dominated by the emissions into the atmosphere of greenhouse gases, the most important of which is CO2. The adverse impact of these gases on regional and global climate constitutes the primary climate issue for the coming decades.
Response: I hadn't seen Pielke's hypotheses. It seems to me 2a and 2b aren't mutually exclusive - any climate scientist would agree that CO2 is not the only driver of climate and that we need to take into account all forcings. The reason for the emphasis on CO2 is because it is the most dominant and fastest rising forcing. The emphasis on CO2 in the Scientific Guide is also necessary as the 'Skeptics Handbook' fails to recognise the many lines of evidence that more CO2 forces up temperature - this is a somewhat more extreme stance than the more nuanced views of Roger Pielke Snr. -
villabolo at 10:18 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Bob Armstrong at 08:23 AM on 2 July, 2010 It's amusing to see to see Monckton named as source of this "meme" . I myself essentially learned it in grade school in the 1950s . ****************************************************************************************** It seems that I need to make a partial retraction of something that I've stated as well as an admission to a minor blunder. Concerning Lord Monckton being the first person to come up with the CO2="Plant Food" meme I specifically stated, "Lord Monckton is, as far as I know, . . ." It was a conditional statement since I knew better than to assume with absolute certainty, that my assumption was 100% correct. I appreciate the corrections pointed out to me. This is not a major point though since he is the one who testified to Representative John Shimkus, as Marian Ashley brought up in the third sentence of her post. Hence Lord Monckton, in essence, has popularized, in the recent past, this statement for his own purposes. As far as my blunder is concerned, I originally assumed, due to tiredness, that this was the same thread as the one immediately preceding it "What is Global Warming and the Greenhouse Effect?" That particular thread was, due to it's simplicity, geared towards explaining the basics to the Public in general. So were my statements on this thread which emphasized simple communication with the Public. Communication with the Public on basic issues is something we must stress or else we're preaching to the choir. -
Joe Blog at 10:11 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
"As greenhouse gases stop heat from reaching the upper atmosphere, a distinct greenhouse signature is a warming lower atmosphere and cooling upper atmosphere." Ive gotta ask... i understood the mechanism to be considerably different than the one stated here for the predicted stratospheric cooling.... basically arising from the fact that in the stratosphere CO2 works more as a coolant... with the heating o the stratosphere arising from UV breakdown o O2 and the subsequent formation o O3, and the absorption by O3 of UV being the heating mechanism in the stratosphere, but with the thinness of the atmosphere at those altitudes, CO2 works as a net emitter of LW, radiating more LW to space, after being excited by the aforementioned heating mechanism in the stratosphere. Thus more co2= more heat radiated away. -
A Scientific Guide to the 'Skeptics Handbook'
factfinder, That post argues against a complete misrepresentation of how the greenhouse effect works. GHG warming does not come from the absorption of incoming radiation, it comes from the fact that incoming radiation from the sun is mostly in or near the visible light wavelength, to which our atmosphere is largely transparent (which that post did not dispute). When that energy is radiated back out from the surface, it is at IR wavelengths, which GHG's absorb and reradiate, some of which goes back down to the surface. So the rate of energy leaving the surface is slowed down relative to the rate of energy coming in, causing an accumulation of heat energy. The closest this post comes to addressing the true cause of the GHG effect is here: According to Alan Siddons, less than 1% of the cooling of the Earth's surface is due to IR emission of the surface or the gases near the surface. More than 99% is due to direct contact and convection. Most heat loss directly from the surface is indeed via conduction or convection. In reality the greenhouse effect applies mostly to a "surface" at the low-to-mid-troposphere, with radiation becoming more dominant as an energy transfer source the higher you go. -
Rob Honeycutt at 09:52 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
FactFinder... You say that Alan Siddons is a "PhD physicist" but I'm having a hard time confirming this. I'm find that he is a "former radiochemist" but that's about it. In the interest of accuracy do you have better information than I'm currently finding on his credentials? -
Johnny Vector at 09:23 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Factfinder, you're missing a very important point. In fact, 100% of energy leaving the Earth leaves by radiation. There's no other way for it to leave. So your 1% number is way off. Even if it's correct for heating of the boundary layer of air at the ground (that's the first few mm, depending on wind), it's completely wrong for the net energy balance. Siddons may have a Ph.D., but he's kind of forgotten how to do physics. -
John Russell at 08:48 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
I note that Alan Siddons' paper was published on a site ('Climate Realists') that declares (in its 'About' link), "Climate Realists will actively promote the proposition that there is no such thing as Man Made Climate Change...". Does not that sound wholly political and as far away from the aims of science as it is possible to be? In consequence should not the paper lose all credibility for anyone in search of true scientific understanding? -
Doug Bostrom at 08:31 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
"Also notable is that the temperature of Venus, commonly cited as what "runaway" warming could do to us, is twice as hot as the sun can possibly heat any object in its orbit. That is, Venus must have some internal source of heat because it is radiating much more energy than it is receiving from the sun." --Bob Armstrong -
Bob Armstrong at 08:23 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
I dislike the term "plant food" to describe CO2's role as the anabolic half of the respiratory cycle of life . It implies something that is required in traces like phosphorus or potassium rather than , along with H2O , the actual substance of plants , and therefore all life . Each of us , like every bite of food in the world , is over 90% CO2 combined with H2O by sunlight . That's why we animals on the catabolic , destructive , side of the cycle inhale O2 and exhale CO2 and H2O and defecate the rest . It's amusing to see to see Monckton named as source of this "meme" . I myself essentially learned it in grade school in the 1950s . Here's a great graphic :
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Doug Bostrom at 08:15 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Was it Siddons who wrote this? Compared to the overall natural effects, these man-made effects are small, yet they are probably large compared to the effect of his adding CO2 and methane to the atmosphere. "Probably large?" Not exactly authoritative. Something was lost in translation there, perhaps, or regurgitated incorrectly. Anyway, Alan Siddons has a record of conveying drastically wrong impressions. Readers should take his work with a grain of salt. -
VoxRat at 08:14 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
factfinder: learn to link. That whole essay is here: http://climaterealists.com/index.php?id=5926 If and when that diatribe is accepted for publication in a peer-reviewed science journal, it will be worth discussing. At that point, I will give more credence to the proposition that the fact it doesn't make much sense to me is my fault, rather than the author's. -
KR at 08:10 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Factfinder - I read the article on the web. His hypothesis runs into some troubles with actual measurements, which show ~24W/m^2 heating of the atmosphere by conduction/convection, ~78W/m^2 by evaporation (latent heat), and ~396W/m^2 by IR. That's just under 80% by IR. Alan claims 1% by IR, 99% by conduction? I've said this before, I'll say it again - if your hypothesis is directly contradicted by the evidence, you need a new hypothesis. As to "all gases when warm radiate IR energy" - well, actually, no, certainly not with the same efficiency. N2 and O2 are basically transparent to IR, and very hard to heat/cool with it. It's like trying to heat glass with a heat lamp. CO2, water vapor, methane, etc. are very efficient IR absorbers/radiators, like heating a matte black surface. I don't think Alan has the science background to realize that; he's certainly not demonstrating it with that article. -
jenikhollan at 08:01 AM on 2 July 2010What is Global Warming and the Greenhouse Effect?
re #10: clouds reflect light and some very shortwave infrared, but the droplets/crystals are almost black (absorbing some 90 %, like soot for light) for longwave infrared. Clouds don't reflect LWIR, they just absorb it. (Well, they may reflect a per cent or two.) A simple graphics for SW (solar) and LW (terrestrial] radiation is in a NASA fact sheet. And re the main Kevin's article: water vapour does indeed let some wavelengths go through rather easily and is supplemented by other trace gases to make the full existing greenhouse effect. But condensed water (liquid or solid) absorbs all wavelenghts over two micrometers completely, within a layer of several millimetres. Any such radiation can penetrate a cloud only in case it misses all its particles (it is possible for clouds through which we see the Sun sharply). -
Joe Blog at 07:58 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
VoxRat at 07:24 AM on 2 July, 2010 This exert is taken from your link. Critical matter for livestock and native prairie animals The scientists observed that doubling CO2 levels caused strong and consistent increases in grass growth which was due to improved water-use efficiency. Under the elevated CO2 levels, it was also found that plant nitrogen content was declining in native grasslands. This is a critical matter for livestock and for native animals that have grazed these prairies for thousands of years. Increased CO2 dilutes nitrogen concentration in grazing vegetation. Animals require sufficient forage protein nitrogen to sustain normal weight gains. N uptake is always a bit o a limiting factor in pastoral farming, generally with rye grass(perennial or annual) legumes are mixed in the sew. White clover normally, well because grasses dont fixate nitrogen. The majority o N is brought into the system via N fixation by legumes, with lightning storms pulling in 1-2%, and farmers top up with urea. There isnt enough info available to tell exactly what they were testing in that link, but it reads as though they are talking wild grasses. It would kinda be essential to know what the legume response is. What plant species are present? Clover will dump most of its N into the system during the Autumn die off. And it will be recycled through cattle waste and breakdown of organic matter... So short term studies have the potential for a bias, -
kdkd at 07:56 AM on 2 July 2010Tracking the energy from global warming
KL #104Do a least squares for the last 7 years Chris and you get closer to 2mm than 3mm, which is where we started this discussion.
Except that if you did this, you'd almost certainly find that the error term for the 7 year fit overlapped the error term for the 17 year fit indicating no statistically significant difference between the two slopes. Your continual use of this kind of invalid argument which ignores the statistical reality of the situation strongly suggests that your aim is to confirm your preconceptions, not actually come to a proper understanding of the field. -
factfinder at 07:52 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Well John here is a report from a Ph.D. physicist that does not agree with you or your readers that still believe that the "greenhouse gas effect "exists. Lets see how John butchers some real physics. 30 June 2010 On Some Flaws in Greenhouse Gas Global Warming I have just finished reading an excellent article by Alan Siddons called The Hidden Flaw in Greenhouse Theory on American Thinker from way back on 25 February 2010. The article is a little slow in developing, but finishes with a death blow to the usual theory put forth by catastrophic anthropogenic global warming advocates. I intend to explain more concisely what Siddons explained and to add comments of my own in this post which make the deathblow much more gory. First of all, I am going to enlarge the context of the discussion. The primary source of heat for the surface of the Earth is the radiant energy of the sun. The solar wind of the sun, materials dumped into the atmosphere from space, heat from the deep interior of the earth, and the interplay of changes in the Earth's magnetic field and the sun's magnetic field are also contributors of heat, though the sum of these is much less than that from the sun's radiant energy spectrum of ultraviolet (UV), visible, and infra-red (IR) light. The entire catastrophic greenhouse gas hypothesis ignores effects upon the incident IR portion of this spectrum of light from the sun. This is foolish. UV light is 11% of the radiant energy from the sun. The UV light variance of 0.5 to 0.8% with the solar cycle is much larger than is the visible light variance of 0.22%. UV light is absorbed throughout the atmosphere, but much still reaches the ground and is absorbed there. The amount of UV radiation absorbed in the upper atmosphere is highly dependent upon the amount of ozone there. The amount of ozone is highly dependent upon the solar wind, CFCs, and volcanic activity. When UV light is more absorbed in the stratosphere than the ground, its surface warming effect is diminished. The absorbed energy is re-emitted as IR radiation and much of that energy is quickly lost to space. The entire atmosphere is transparent to visible light which is the form of 44% of the radiant energy from the sun, so aside from reflection from clouds and aerosol particles, the visible light reaches the ground or oceans and warms them near their surfaces. Finally, the IR radiation is not absorbed by nitrogen, oxygen, and argon gases which make up 99% of the atmosphere, so a large fraction of it directly warms the Earth's surface. Some, is absorbed by the dominant greenhouse gas, water vapor, and small amounts are absorbed by carbon dioxide and other greenhouse gases. The incoming IR radiation absorbed in the atmosphere is less effective in warming the Earth's surface than is that which is absorbed by the Earth's surface directly. This is because some this energy absorbed in the atmosphere then is radiated again in the form of IR radiation, but now half or more of that is directed out to space. In other words, more water vapor and CO2 in the atmosphere results in a less effective warming of the surface than does less of these gases with respect to the incoming IR energy from the sun. The greenhouse gases have a cooling effect on the original solar radiance spectrum for the 45% of the solar energy in the form of IR. In each case, whether UV, visible light, or IR, not all of the radiation of that form striking the Earth's surface is absorbed. Some fraction is reflected and the fraction is very dependent on whether the ground is covered with snow, plowed earth, grasses, forests, crops, black top, or water. There are two real ways that man does have some effect on the Earth's temperature. He changes the surface of the earth over a fraction of the 30% of its surface which is land. He also converts fossil and biomass fuels into heat. Compared to the overall natural effects, these man-made effects are small, yet they are probably large compared to the effect of his adding CO2 and methane to the atmosphere. Wherever the atmosphere is heated, there is transfer of heat. In the outer, very low density atmosphere, the primary means of heat transfer is radiant transfer by IR emission from an energetic molecule or atom, since collisions of molecules and atoms for direct energy transfer are rare. In the denser atmosphere, most energy transfer is due to collisions and the convective flow of masses of warmed air. Near the Earth's surface, almost all of the energy lost by the warmed surface is due to gas molecules striking the surface and picking up heat and then colliding with other molecules to transfer heat from one to another. Once a body of air is so heated, then masses of warmed molecules are transported upward into the cooler atmosphere at higher altitudes or laterally toward cooler surface areas by convection. Any warmed molecule, most of which are nitrogen, oxygen, and argon will radiate IR radiation. However, no molecule or atom at a low temperature such as that near the Earth's surface is a very effective energy radiator, since the Stephan-Boltzmann equation depends upon the fourth power of the absolute temperature, which commonly near the Earth's surface is about 290K. Thus, gas molecule collisions and convection are the very dominant means of heat transfer. These processes on balance cool the surface of the Earth and redistribute some of the heat back into the upper atmosphere and cooler places such as those shaded from the sun or the arctic regions. The favorite claim of the catastrophic greenhouse gas global warming people is that an increase of carbon dioxide and methane gas in the atmosphere will cause energy radiated into the atmosphere from the ground to be absorbed by these molecules and they will radiate half of it back toward the ground, where that energy will warm the surface again and reduce the cooling due to the ground originally radiating that heat into the atmosphere. According to Alan Siddons, less than 1% of the cooling of the Earth's surface is due to IR emission of the surface or the gases near the surface. More than 99% is due to direct contact and convection. Since the dominant source of energy warming the surface of the Earth is the sun, let us do a simple calculation based upon the facts presented above. Let us say that greenhouse gases absorb a fraction f of the incoming IR radiation from the sun, which is 45% of the sun's incoming energy. Thus the energy absorbed by greenhouse gases from the incoming spectrum of solar energy is 0.45f and a fraction of this, say k is radiated back into space without coming near the surface. NASA says k is 0.5, but it is actually slightly larger than that given that much of this absorption occurs at appreciable altitudes. The total cooling due to greenhouse gases, somewhere in the atmosphere, is now 0.45fk. Of this energy, had it become incident upon the surface as IR radiation, a part would have been reflected rather than absorbed. The fraction that would have been absorbed is q. The net energy then lost to the warming of the surface is then 0.45fkq. Now, let us suppose that a fraction g of the total energy from the sun is absorbed in the Earth's surface or in the very lower part of the atmosphere. We know that g is a larger fraction of 1 than is f, since most of the solar radiation does reach the ground, including that part in the IR part of the spectrum. Of the energy g absorbed in the surface, only 0.01 times it is emitted as IR radiation according to Siddons. Since the greenhouse gas content of the atmosphere is unchanged the amount of outgoing radiation, serving to cool the surface, is now 0.01gf. A fraction j of this energy will be emitted by the IR warmed greenhouse gas molecules back toward the ground. NASA has said this fraction is 0.5. Let us then say j is about 0.5. The greenhouse gas warming of the surface due to absorbing IR radiation from the ground would then be about 0.005gfq, where q is the fraction of back-reflected IR radiation that was incident upon the surface and absorbed. Remember that some radiation is reflected. Now we will compare the greenhouse gas cooling effect upon the incoming solar radiation of 0.45fkq to the re-warming of the surface due to 0.005gfq times the total solar radiant energy. Breaking down the parts: 0.005 is much less than 0.45, in fact it is 0.011 times as large. f appears in both factors, so the comparative effect is cancellation. The factor q appears in both the cooling and the warming quantities, so it cancels. k is somewhat more than 0.5, while g is the surface absorptivity for the entire solar spectrum and is likely to be near 0.7, or quite comparable. So let us say g and k are an approximate trade-off. Thus the net cooling effect of greenhouse gases is very greatly dominant because the re-heating effect is approximately 0.01 times the cooling effect. In sum, using a simple calculation we can approximate the effect of greenhouse gases on the surface temperature of the Earth. It turns out that the cooling effect due to keeping incoming solar IR radiation away from the surface is about 100 times the re-heating effect proclaimed by greenhouse gas alarmists. Now, if the effect were very large in either case, this might be cause for concern. We would likely be better off heating our planet than cooling it. But, then we are heating with land use changes and the release of energy from fossil fuels, so the generation of cooling CO2 may simply be compensating for these other small effects. Much more important to this issue than CO2 and methane is water vapor in any case. So, most of this cooling effect is due to water vapor and only a small part is due to CO2 and methane. Now, of course so much is going on here that this calculation is but an indicator of the likely net effect of greenhouse gases. A more careful calculation would consider the different weight of IR frequencies in the original spectrum of the sun and in the Earth surface emission spectrum. But, any changes due to these secondary issues are likely to be small compared to a factor of 100. In any case, this calculation makes mincemeat of the usual simple rationale for greenhouse gas warming alarmism. It is insane to focus only on the outgoing IR radiation from the Earth's surface while ignoring the large part of the sun's total incident radiation which is IR from the get-go. It is also insane to ignore gas collisions and convection currents as mechanisms for heat transfer. I used the greenhouse gas term in the presently conventional way, but in reality, all gases when warm radiate IR energy and as pointed out by Alan Siddons, they are all really greenhouse gases. But, here I used the term only for those gases that absorb IR energy. Posted by Charles R. Anderson, Ph.D. at Wednesday, June 30, 2010 Labels: Alan Siddons, CO2 emissions, greenhouse gases, solar radiationResponse: The evidence for the greenhouse effect comes from multiple lines of direct measurements. Airplanes measuring the infrared radiation escaping out to space find a big bite taken out of the spectrum at CO2 wavelengths. This is confirmed by surface measurements that find that big bite of heat returning to the Earth's surface:
We cover this topic at Has the greenhouse effect been falsified?. Please continue any discussion there. -
Berényi Péter at 07:38 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Here is Fig. 2. from Long 2006. He goes for a hyperbolic fit, but it looks more like logarithmic (at least for realistic values of [CO2]), C4 plant response under normal (not drought) circumstances being a scaled down version of C3 plants'. In open air (FACE) the results are a bit more controversial.
Fig. 2. Effects of elevated [CO2] on crop yield. Data are yields at elevated [CO2] relative to those at ambient [CO2] (arrow) for (A) soybeans in chambers (solid blue circles) and FACE (blue square, hidden behind red square) and wheat in chambers (red circles) and FACE (red square); and (B) C4 crops (maize and sorghum combined) in chambers (green circles) and FACE studies (green square). Error bars indicate mean ±90% confidence intervals around the means for the FACE studies. The chamber studies included 115 independent measures of soybeans (21), 211 of wheat (36), and 14 of maize and sorghum (table S3). These measures were divided into 10 classes of growth [CO2] in 100-ppm increments. Plotted values are the class means of growth [CO2] and yield. Solid lines are the least-squares fits for the nonrectangular hyperbolic response of yield to growth [CO2] from these enclosure studies of soybeans (blue line, r2 = 0.98), wheat (red line, r2 = 0.88), and C4 crops (green line, r2 = 0.99). The yield response of soybeans in chambers to growth [CO2] of 900 to 999 ppm [open blue circle in (A)] was an outlier and was excluded from the curve fitting. Full details of the meta-analysis methods and results from FACE are presented in the SOM and table S2.
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Doug Bostrom at 07:26 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
JohnD, you've made an assertion about how fruits and vegetables are cultivated and brought to table, namely that we may expect to see a plethora of mainstream foods in our markets that have been grown using C02 enrichment. So far you have done nothing to support that assertion with facts other than to cite a single opinion piece positing essentially the identical argument you're making and with no numerical information on how often consumers actually encounter products cultivated with C02 enrichment. Here's what you said: Perhaps the next time anyone visits a supermarket and salivates over the well grown fresh produce, and admires the beautiful flowers, just check out how much of what has been admired, or has been put onto your dinner plate in recent decades has been grown in an enriched CO2 environment. You're attempting to convey an impression in support of your thesis that C02 enrichment is a great thing even when it's not being engineered and instead is out of control. In support of that you'd like us to believe that we're already benefiting in a significant way from C02 enriched cultivation. So far you have produced no data to support your assertion. At the end of the day folks have to be able to form an estimation of what is more or less useful information, or has any useful information content at all. You are casting an impression about what we might expect to find in our markets but so far you've not conveyed any actual information. Repair your problem by posting some numbers on market penetration of fruits and vegetables cultivated with C02 enrichment techniques. -
VoxRat at 07:24 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Ah - you mean that Wittwer article. I didn't find it terribly useful, in that it lacked any references. But I gather that greenhouse nurseries, have in fact, used CO2 enrichment to boost the production of certain plants. Which would make sense. However, extrapolating those results from the highly controlled artificial environment of a greenhouse nursery, where soil nutrients are not limiting and where competing plants (i.e. weeds) are not an issue, to farm and prairie land would be pretty naive. these guys for instance, found that though grass grew faster in increased CO2, the nutritional content (specifically nitrogen, i.e. protein) was degraded. And these guys (among others) say that increasing [CO2] may already be responsible for shrubland encroachment into pasture lands. -
Ned at 07:16 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
caerbannog, all of Tamino's posts from before March of this year seem to have disappeared. I'm not sure what happened over there. -
johnd at 06:39 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
VoxRat at 06:25 AM , the article linked to in a previous post in my discussion with doug. -
johnd at 06:37 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
doug_bostrom at 05:51 AM, I wasn't asking you about CO2 enrichment, I was asking you if you know where the food you eat comes from. Most consumers are quite ignorant on the matter. In Australia labelling laws are being gradually tightened to keep consumers better informed, I don't know what the situation is in America. It may not be politically correct there to knowingly eat anything produced under enhanced CO2 conditions. It reminds me of the mad cow scare, how many USA consumers continued to eat meat rejected from export markets? Did they know it wasn't meeting export standards? -
VoxRat at 06:25 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
johnd at 5:45 ""... CO2 enrichment has been used commercially for decades and is as widespread as indicated in the article" What article? -
johnd at 06:23 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Albatross at 02:33 AM, understanding the role CO2 plays in plant growth for food production is essential in order to obtain optimum growth. Optimum growth means greater efficiency in terms of nutrient usage, water usage and land usage. That has been proved by those commercial green house operators that adopted the practice long ago. As has always been the case, there are many different varieties of most plant species, and they all respond in different ways under different conditions. The trials being done under enriched CO2 levels are identifying ahead of time which varieties respond best allowing scientists to concentrate on further development on the desirable genetic makeups. What seems to be overlooked is that all plants are not going to be exposed to higher CO2 levels starting tomorrow, levels began rising over 100 years ago. Any negative aspects of higher levels of CO2 should be detectable now, but I don't see that being discussed. It seems that current ambient levels are considered optimum by some and that it will be all downhill from here on. Of course greater growth means increased inputs, it seems that it is only some posters here think otherwise. A backyard carrot grower might be able to continually grow carrots year after year without putting any nutrients back into the system and think he is getting something for nothing, but that is not the case with commercial growers. -
johnd at 05:56 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Marcus at 00:18 AM, if you read and understand the results so well, then perhaps you can explain what was the difference between the TOS1 and TOS2 trials, and what the results of each indicated. Only then will I be confident that you have read and understood the report. Can you also confirm whether the protein produced per unit area increased or not under the higher CO2. -
Doug Bostrom at 05:51 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Why are you asking me about C02 enrichment, JohnD? You suggested I'd find my grocery store shelves richly supplied with fruits and vegetables grown using C02 enrichment but you cannot supply any data to support that claim. Don't ask me about enrichment, it's your impression you're trying to convey. -
caerbannog at 05:46 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
#18 Tamino (tamino.wordpress.com) had a very nice explanation -- unfortunately, it doesn't appear to be on-line now. For the time-being a copy can be fished out of the Google cache here: http://webcache.googleusercontent.com/search?q=cache:jbljNoHoUZIJ:tamino.wordpress.com/2007/07/16/lapse-rate/+lapse+rate+global+warming&cd=1&hl=en&ct=clnk&gl=us&client=firefox-a Excerpt: As we add more CO2 to the atmosphere, it becomes optically thicker for those wavelengths of infrared. This means that to escape the atmosphere, it must be radiated from ever-higher altitudes. The temperature at the altitude at which the infrared actually escapes to space is determined by the incoming energy from the sun, and so does not change as we add more CO2 to the atmosphere. But the temperature at the surface will be higher than the temperature of this high-altitude air, by an amount which is governed by the lapse rate (which doesn’t change much) and by the height of that radiating layer. So, even if the atmosphere has so much CO2 that it is saturated in those infrared wavelengths, adding more CO2 raises the altitude at which those wavelengths of infrared escape to space, increasing the distance to the ground, and therefore increasing temperature difference between the radiation layer and the ground (which is the product “lapse rate” x “distance”). That’s one of the reasons that arguments that CO2 absorption of infrared is saturated, and hence adding more CO2 won’t increase global warming, are mistaken. Because of the lapse rate, raising the altitude of CO2 radiation escaping to space will still warm the surface. -
johnd at 05:45 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
doug_bostrom at 19:18 PM, you are starting to sound as if you think there is a conspiracy involved. However, do you accept that the practice of CO2 enrichment has been used commercially for decades and is as widespread as indicated in the article? -
villabolo at 05:31 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Argus at 18:25 PM on 1 July, 2010 A comment to #6 villabolo and #7 Bern: "Animals and humans use oxygen primarily to get energy to keep us going through the day. Plants use CO2 to keep building biomass. They get energy from sunlight. Therefore it is more correct to call CO2 "food" for plants than "air" for plants. CO2 does not give them energy" **************************************************************************************** I was not referring to the metabolism of the organism but to an appropriate description of what it consumes in terms of whether it's in a gaseous state or solid state. Since this post was written in reference to simplistic phrases used as propaganda for the masses, my idea was to find a simple counter phrase that could be used in rebuttal to members of the general public who say that "CO2 is plant food". The best one I can think of is the old phrase "Too much of a good thing is a bad thing". Examples: Too much food, for humans that is; too much oxygen in the atmosphere (double the % of Oxygen and you'll burn even the wettest jungle down). This response should come before the basic explanation as to what too much CO2 would do. The issue I'm trying to stress is not semantics, as was brought up by carrot eater #14, but the best response to people who simply do not understand the issue. Since they are being instructed (brainwashed) in what are essentially "memes", I am suggesting counter memes such as the previously mentioned one, "Too much of a good thing is a bad thing". As far as I'm concerned, the main issue is that of communicating with the Public and doing so at THEIR LEVEL. We cannot expect them to absorb even the simplest of explanations. To the extent that they may be able to, it would be necessary to use a label (the counter meme I suggested above) to make a simple rebuttal of ours more easily accessible to the overloaded "filing cabinets" of their minds. Our statements to the general public have to ALWAYS be understood in the context of the Denier propaganda they are susceptible to. The issue of communication to the Public is not merely about the LOGICAL but the PSYCHOLOGICAL. My apologies if I seem to be quibbling over an issue separate than those being discussed at the moment but I believe that communication with the manipulated Public, on their level, is of utmost importance. -
Peter Hogarth at 05:19 AM on 2 July 2010Sea level rise is exaggerated
daniel at 17:15 PM on 1 July, 2010 I accept the data points on the chart are sparse, and have temporal uncertainty and height uncertainty. The time series trend developed from these samples is a simple low order curve fitted through them, which is common practice when trying to extract trends. This assumes low long term variation of the variable in question. An alternative fit involving high short term variation which still explains the limited data points would involve undersampling and aliasing. Is this likely? You do not suggest it is, but you propose it is possible. I have spent some hard earned cash looking at over a dozen recent site specific salt marsh studies related to sea level. Without exception they display the poor resolution which you would rightly criticize if any study was the single source of our evidence. One of the best that is free (I honestly did not select by author!) is Donnelly 2006. It is possibly close enough geographically to the 2004 data set so that gaps in the record in each could be reduced, which makes short term variations far less probable. Likewise, archaeological and historical evidence on sea level changes, from around the world, taken in isolation, means little - and could easily be written off using local crustal depression etc. It is the integrated wider evidence based picture that emerges when researchers try to put all this stuff together that proves persuasive to many, and to me. A further point is that researchers like Donnelly cannot help but acquire a great deal of background knowledge or expertise, and will be aware of large amounts of evidence that might not even be in publication, but nevertheless adds to the overall common sense probability based conclusion. Is this conclusion overwhelmingly robust? I couldn’t say without analysis, but it is consistent with the majority of recent and emerging published data. daniel at 17:15 PM on 1 July, 2010 I accept the data points on the chart are sparse, and have temporal uncertainty and height uncertainty. The time series trend developed from these samples is a simple low order curve fitted through them, which is common practice when trying to extract trends. This assumes low long term variation of the variable in question. An alternative fit involving high short term variation which still explains the limited data points would involve undersampling and aliasing. Is this likely? You do not suggest it is, but you propose it is possible. I have spent some hard earned cash looking at over a dozen recent site specific salt marsh studies related to sea level. Without exception they display the poor resolution which you would rightly criticize if any study was the single source of our evidence. One of the best that is free (I honestly did not select by author!) is Donnelly 2006. It is possibly close enough geographically to the 2004 data set so that gaps in the record in each could be reduced, which makes short term variations far less probable. Likewise, archaeological and historical evidence on sea level changes, from around the world, taken in isolation, means little - and could easily be written off using local crustal depression etc. It is the integrated wider evidence based picture that emerges when researchers try to put all this stuff together that proves persuasive to many, and to me. A further point is that researchers like Donnelly cannot help but acquire a great deal of background knowledge or expertise, and will be aware of large amounts of evidence that might not even be in publication, but nevertheless adds to the overall common sense probability based conclusion. Is this conclusion overwhelmingly robust? I couldn’t say without analysis, but it is consistent with the majority of recent and emerging published data. -
DarkSkywise at 05:17 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Ned #14 - I originally wanted to say "Thank you Ned, nice stuff!" but in that case I'll make it "Thank you, Nick! (And Ned.)" And yes, the Guide booklet is nice-looking stuff too! *ponders what it would look like in Dutch* *ponder ponder ponder* -
hengistmcstone at 05:17 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Hi John, I'm still a bit new to this so forgive me if this is a point made before. Why do skeptics need a handbook ? Seems to me it's more "the habitual contrarian's handbook" Salutations Hengist -
citizenschallenge at 04:43 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
caerbannog #16 can you offer some links to this information? thanks -
citizenschallenge at 04:39 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Regarding the Handbook, in light of my visit at jonova and her commentators, there is much ridicule about scientists now using wind speed voodoo, to get the results "we expect." from the handbook: “Confirmation of the hot spot comes from measurements of wind trends. As there’s a direct relationship between temperature and wind shear, this gives us an independent way to calculate temperature trends. This method finds peak warming above the tropics, just as we expect.” Is there someway to give an explanation of how this works, perhaps a link. In fact, all the way around a little more meat, or citations would have been good. Although with handbook like this we almost need three different grade levels: simple: high school; college. Nice job though, with a great look too.Response: The general plan will be the Handbook is the shorter, broader version - the website will contain the longer, more detailed, more technical explanations. This is probably preferable to having multiple versions of the Scientific Guide, particularly if I want to get any sleep at all :-) -
caerbannog at 04:34 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
It should be pointed out that even if the CO2-effect were "saturated", additional CO2 would still warm the Earth. As CO2 concentrations increase, the altitude of the "top of the atmosphere" (TOA) increases. (The TOA is defined as roughly where most of the outgoing IR can escape directly into space instead of being absorbed/reradiated by CO2 above it). As the TOA altitude increases, its temperature decreases (thanks to the lapse-rate that deniers have been flogging recently). Since the amount of IR escaping into space from the TOA is a function of its temperature, the new, "higher altitude" TOA will have to warm up so that the energy leaving in the form of IR balances the incoming solar radiation (first low of thermo). Since we now have a greater distance from the TOA to the surface, the lapse rate means that the Earth's surface must warm as the TOA warms in order to restore the incoming/outgoing energy balance. This will happen whether or not the CO2-effect is "saturated" at lower altitudes. Deniers keep forgetting that "CO2-saturation" at the surface does not mean "CO2-saturation" at high altitudes. They also keep forgetting that CO2 doesn't just absorb IR; it reradiates it. -
citizenschallenge at 04:30 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
I looked at your Handbook this morning I liked it for the first production draft. I agreed with much of the constructive critique in the above posts so didn’t add anything. Being the kind of guy who's always trying to get inside the thinking of others, I found myself at the jonova website and have spent the last couple hours being frustrated and I will admit getting a bit overwhelmed. Especially, after down loading and looking over that masterpiece poster "Climategate: 30 years in the making" Quite the profession production... but with one thing in mind - to win their point of view. The spooky part is when "winning" becomes everything, where does that leave learning and adapting. When so much of the story must be ignored to prop up ones own point of view, where is the value in that? -
What causes the tropospheric hot spot?
Baa Humbug > The charts presented by numerous organizations do not show warming across all latitudes for ghg forcing. They distinctly show warming at 30N to 30S at 8-10km aloft (yes along with stratospheric cooling) The models show enhanced warming at tropical latitudes (the hot spot), but there is also a clear overall warming of the lower atmosphere, which is also clearly visible in the satellite data. I think what you are really looking for is a chart showing what modeled results would like if a non-GHG forcing was causing the warming and comparing it to the actual model predictions and the empirical data. This isn't what the IPCC charts - or the other charts you cited - are doing, though that's the way they are often misinterpreted. I don't know if such a chart exists, but the key difference would be a cooling stratosphere, which should be visible with GHG warming but not solar or other warming. Both GHG and non-GHG charts would show a hotspot, which is why the hotspot is not a signature of GHG warming. The observed cooling in the stratosphere is therefore very strong evidence for the current warming being GHG driven, and a strong falsification of other attributions. If this cooling didn't exist, it would be a very strong falsification of GHG warming. In contrast, if the hot spot really didn't exist, it would shift our understanding of the process of global warming, but not the cause (since the hotspot is predicted for all causes of warming.) -
Ned at 04:03 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
I should note that I learned about that from Nick Stokes at his blog. -
Ned at 04:02 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
John, you probably already know about this ... but if not, check out the booklet Climate sceptic arguments and their scientific background. It's similar to what you do here, and what the US EPA did earlier this year. What makes this one interesting, however, is that it's put together by a large corporation that sees climate change as a serious threat to its financial future.
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