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Comments 94551 to 94600:
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damorbel at 21:26 PM on 24 February 20112nd law of thermodynamics contradicts greenhouse theory
Re 348 & 349 Thank you for your contributions, they enable me to appreciate how you calculate your results. But all that you write makes it increasingly clear that the idea that the upper atmosphere (UA) can raise the surface temperature simply doesn't work. Let us imagine for a moment that the surface and the upper atmosphere are at the same temperature. In this situation both surface and the UA are emitting photons with the same energy, that is a consequence of your formula SQRT(SQRT(B5/(Surface_E*5.6704*10^-8)))-273.15-4. The temperatures are the same because the energies of the photons from both sources are the same; there would be thermal equilibrium i.e. no energy transfer and no temperature change. In reality the UA is colder than the surface and your formula shows that the energy of its photons is lower than those of the surface, so the consequence is that energy is transferred to the UA (accordind to the 2nd Law of thermodynamics) where it is further radiated into deep space. Perhaps you find this difficult to accept but if the UA contained no GHGs at all it would not have a different temperature (apart from the stratosphere - which is warmed by O2 absorbing ultraviolet from the Sun) because heat is transferred in the atmosphere mainly by fluid flow e.g. convection. Below the stratosphere the temperature profile is largely determined by two factors, the temperature of the surface and the compression of the air due to gravity. -
kdkd at 21:17 PM on 24 February 2011Meet The Denominator
Poptech #729 Thanks for the fascinating insight into the psychology of climate change denial; where group think (assertion that poor quality evidence is good quality evidence) is not group think, and logical exposition of quality empirical evidence of climate change is group think. Welcome back to 1984! My work here is done :) -
Dikran Marsupial at 20:45 PM on 24 February 2011Models are unreliable
Chemist1 It would help if you actually read posts before responding to them. Here I explained that a model is only unreliable if the observations lie outside the stated uncertainty of the prediction, and you have ignored this point and are back here again saying the models are unreliable because the error bars are broad. If a projection has broad error bars, so broad that they swamp the variation in the ensemble mean, it means the models are telling you they don't know what is going to happen. If you ask someone if the planet is going to warm and they say "I think it may warm, but I don't really know, it could warm by 4 degrees, but it could cool by 1 degree, but the most likely result is that it will warm by 2 degrees", then if the planet cools by 0.5 degrees, their prediction wasn't unreliable, it wasn't even wrong, because they told you what happened was within the stated confidence of the projection. Large uncertainty does not imply unreliability. In fact it means that models are more likely to be reliable as the model projections cover a wider range of possibilities. If you ignore the stated uncertainty of the projections, that is your error, not a shortcoming of the models. As it happens, the error bars on projections for large time and spatial scales are not broad compared to the variation in the ensemble mean. See e.g. IPCC report chapter on attribution. If you don't take on board points that are made, or at least counter them, don't be surprised if contributors stop responding to your posts. -
HumanityRules at 20:24 PM on 24 February 2011Hockey Stick Own Goal
58 Tom Curtis "In fact, Hegerl produces the most coherent results, ie, with climate sensitivity of solar and GHG forcings being the same, if solar forcings are half that of the estimates which he used. With solar forcings only 1/4 of that which he used, the sensitivity of GHG and solar forcings will still be very close, within limits of error." Sorry Tom but I can't see in Hegerl were he says you need to 1/2 the forcing to get a good match. Are you sure you have this the right way around, not multiply by 2 (to 4)? The Foukal Nature Review that I referenced in #54 says "We also considered the case where the forcing by the dark and bright magnetic components was modified by adding a lowfrequency component69, amplifying the solar forcing range by 3 to 4 over this time period. In this case (red curve), the model cooling trend is closer to the reconstructed palaeotemperature trend." Foukal et al 2006 Nature Review And that is what I've been reading in the rest of the literature as well. "Although the most straightforward mechanism of the sun– climate connection is the direct heating of the earth by solar radiation [total solar irradiance (TSI)], it is unlikely that the entire solar influence on climate can be attributed simply to variations in the TSI (2–4)." Yamaguchi et al 2010 PNAS And from another review on the solar irradiance changes from MM to present based on multiple sources "These estimates for century-scale TSI changes of ~1.3-1.6 Wm-2 correspond to a change in mean global radiative forcing of only 0.16-0.28 Wm-2" Gray and many other 2010 The concensus seems to be changes in luminosity/TSI while often synchronous with temperature change are too small to suggest the direct energy changes are driving climate change. I don't know how Hegerl found that the magnitude of TSI changes were too high as you suggest. Anyway to bring this back to climate sensitivity. All these papers seem to agree there is no known mechanism by which solar can affect climate change on the scale we are looking at here. It does beg the question how you would calculate climate sensitivity on that basis. -
Albatross at 18:26 PM on 24 February 2011Hockey Stick Own Goal
Robert @106, "I haven't seen any comprehensive reconstruction of net forcing over the past millennia, so it would seem to be a non-sequitur to state that the Idso's are necessarily arguing for a high climate sensitivity in arguing for a warm MWP." Actually Hegerl (2006) looked into this. Estimates of the forcing data (solar, aerosol, GHGs etc.) are shown going back to 1000 AD, see Fig. 2. Mann et al. (2009) looked into the possible role of internal climate variability over the last 1500 years. -
Riduna at 18:14 PM on 24 February 2011Carbon Cycle Feedbacks
Andy S draws attention to the fact that as temperatures rise greenhouse gas emissions from sinks where they are now trapped will also rise. He notes that these include CO2 emissions from warming soil and tree destruction, now occurring, to which might be added the oceans as surface temperature rises in the future. More damaging are CH4 emissions, now becoming increasingly evident, caused by the thawing of clathrates and permafrost allowing embedded organic material to resume decaying. Hansen has warned that these emissions could result in runaway global warming and for good reason when one considers that I litre of solid clathrate yields ~165 litres of CH4. Millions of tones of methane clathrates are thought to lie beneath Arctic offshore sediments. They have started melting. Given the threat of these emissions, one is forced to ask why the need to limit average global temperature to no more than 2C above preindustrial temperature by 2100 is measured in terms of CO2 concentration in the atmosphere and not in terms of CO2-e? It is all very well to assert that the cooling effect of aerosols off-sets the effect of other warming greenhouse gas emissions but how can that be true when emissions of the kind described above are increasing? By ignoring their effect are we not underestimating the magnitude and rate of future global warming? -
RobertS at 17:44 PM on 24 February 2011Hockey Stick Own Goal
"The NIPCC report is claiming that the IPCC sensitivity range is too high by a factor of 10, but the Idso Prudent Path document, by claiming that the MWP was as hot or hotter than today, is arguing that the IPCC sensitivity range is too low. " I don't quite understand this argument; I haven't seen any comprehensive reconstruction of net forcing over the past millennia, so it would seem to be a non-sequitur to state that the Idso's are necessarily arguing for a high climate sensitivity in arguing for a warm MWP. A MWP comparable in temperature to today is virtually impossible given the slew of millennial temperature reconstructions showing otherwise, and there is little indication of any dramatic changes in TSI or volcanic activity that could lead to such a warm MWP, but I'm not sure the latter proposition contradicts Idso's concurrent argument that CS is low. -
dana1981 at 17:10 PM on 24 February 2011Hockey Stick Own Goal
Marcus don't you know? Whichever data set shows the least warming at any given time is the good one! -
dana1981 at 17:09 PM on 24 February 2011Hockey Stick Own Goal
Tom, thanks. Not tired, just doing too many things at once! Yes, I meant that if the original hickey stick were correct and the MWP weren't particularly hot, that would be good news. -
muoncounter at 16:07 PM on 24 February 2011Climate sensitivity is low
scaddenp - Yeah, I thought that was a peculiar phrase, which seems to add an unnecessary layer of complication. All I did was point to the link, as it seemed (in #105) that he couldn't find it. How he chooses to interpret this particular 3.7 W/m^2 is up to him, although both KR and you have made it very clear. -
kdkd at 16:00 PM on 24 February 2011Meet The Denominator
Poptech #727 The only people who take your inconsequential list seriously are you and your group think enthralled friends. The rest of us can see that it's seriously lacking on many many levels. End of story, and hopefully the end of this thread :) -
TOP at 15:22 PM on 24 February 2011Dispelling two myths about the tropospheric hot spot
Glad to see a discussion of SST effect on GW. -
iskepticaluser at 15:13 PM on 24 February 2011Carbon Cycle Feedbacks
Your comments re the photo of Yoho National Park (that the dead trees on the mountain slopes illustrate bark-beetle damage) contradict the wikipedia info for the photo. Poor choice of photos, however doesn't negate the point about warmer winters and the exploding range of this insect: see this RealClimate post for example. -
scaddenp at 15:09 PM on 24 February 2011Climate sensitivity is low
muon - the issue is does "reduction in the atmospheric window" mean the same thing to RW1 as I think it means. You can say yes, but I suspect that RW1 then has corollary from that shows a very different understanding. -
Daniel Bailey at 14:38 PM on 24 February 2011Carbon Cycle Feedbacks
The actual GHG values from gases released from melting permafrost are almost a lock to be worse than projected. Schaefer et al 2011 presumes (for purposes of ready calculation, I believe) 100% of emissions to be in the form of CO2, while in actuality much will be in the form of CH4 (methane). Should this stand up to further scrutiny & be confirmed by subsequent studies, this means an effective CO2 doubling from permafrost melt alone by 2200. In addition, Schaefer et al 2011 do not consider methane hydrate releases, which are currently underway in the East Siberian Arctic Sea. Needless to say, no current model begins to take this all into consideration. The edge nears. The Yooper -
muoncounter at 14:25 PM on 24 February 2011Climate sensitivity is low
Rahmstorf 2008, linked in the Advanced version of this post, gives 3.7 W/m^2 as an undisputed figure for CO2 forcing. Without any feedbacks, a doubling of CO2 (which amounts to a forcing of 3.7 W/m2) would result in 1°C global warming, which is easy to calculate and is undisputed. ... consensus holds that a doubling of CO2 causes a radiative forcing of 3.7 W/m2, which in equilibrium would cause 3°C±1.5°C of global warming. -
RW1 at 14:06 PM on 24 February 2011Climate sensitivity is low
My goodness, the answer is yes or no. You are claiming the 3.7 W/m^2 does NOT represent the reduction in the atmospheric window, right? (This is what I'm assuming you're saying). I do not find this information in the stuff you've referenced, and I've continued to search online to no avail. What we are talking about here represents a fairly simple thing. I sent an email to one of the links from the source you referenced to inquire: SpectralCalc.com Hopefully they will respond. -
scaddenp at 13:57 PM on 24 February 2011Climate sensitivity is low
Sigh. The Science of Doom takes you through text book. Is that documentation enough? The problem seems to be that you are looking for a statement that doesnt exist because it would make no sense. The way real physics is done is bears little relationship to way you are trying to approach it. We are trying desperately to show why that is. As far as I can see you either: a/ study the physics b/ see that since model matches measurement so model must be right. I am guess that are ignoring the textbook, SoD, papers, because they dont relate to George White's "logic" and you search in vain for an analogous treatment. However, this is the right way to do it. I'm beyond my power to help you further. -
muoncounter at 13:23 PM on 24 February 2011Models are unreliable
Chemist1, Your second linked abstract "Computer models are powerful tools ... " provides no actual scientific criticism of models. Their interplay helps to weed out model errors, identify robust features, understand the climate system, and build confidence in the models, but is no guard against flaws in the underlying physics. This is merely a caveat; the author suggests that models could have 'flawed' physics. Do you automatically assume that because an author says something could happen, it necessarily does? A far more robust criticism would be 'here is a model study with flawed physics.' I assume you did not use this because you have no such example at hand? -
SRNE2 at 12:37 PM on 24 February 2011Meet The Denominator
This is the 2nd time I write this. I scrapped my 1st post since I didn't want to partake in this insanity. I changed my mind. This needs to end. You are arguing with a professional troll that has spellbound you for years. And by pro I mean he is definitely hired by vested interests to do this. He has A+ skills. I don't want to rain on your parade, but this shill is wasting everyone's time. So, can we please just ignore him? No matter how "fun" these threads may appear, there are more pressing issues to address. Let's face it, we have been pwned.Moderator Response: (Daniel Bailey) While I deeply sympathize with your frustrations, please realize that you are not alone in enduring the train wreck this thread has become. All reading this would be well advised to not add fuel to the fire. -
Ron Crouch at 12:32 PM on 24 February 2011Carbon Cycle Feedbacks
Speaking of permafrost. NOAA Hot on Methane’s Trail A new study led by Kevin Schaefer, Ph.D., and a team of scientists from NOAA-funded Cooperative Institute for Research in Environmental Sciences and the NOAA Earth System Research Lab now predicts a 29 to 59 percent decrease in permafrost by 2200. Published in the journal Tellus B, the study estimates a large release of carbon – in the form of carbon dioxide and methane – from thawing permafrost over the next century, though much is still unknown about how these emissions will accelerate climate warming. Scientific climate projections do not currently account for carbon emissions from permafrost, but the study concludes that the effect is “strong enough to warrant inclusion in all projections of future climate.” It will certainly be interesting to see how much the inclusion of methane in future projections will change the range of outcomes. -
Ron Crouch at 12:14 PM on 24 February 2011Carbon Cycle Feedbacks
An ounce of prevention is worth a pound of cure. It held true in the past and it holds even truer today. -
Bibliovermis at 12:08 PM on 24 February 2011Meet The Denominator
Poptech (#710), The 97% figure comes from the Doran 2009 study as discussed on the argument #3 thread There is no consensus.97.5% of climatologists who actively publish research on climate change responded yes to "Do you think human activity is a significant contributing factor in changing mean global temperatures?"
Please respond to this point on that thread. -
Philippe Chantreau at 11:55 AM on 24 February 2011Meet The Denominator
PT post # 720. I don't doubt that this is the perception you get from reading E&E on a regular basis. In any case it is a sweeping accusation against all scientists, formulated with words that you have declared yourself as leading only to subjective statements. Your accusation must be substantiated with objective criteria, otherwise, even by your own stanadrds, it is null and void. You're demonstrating again and again that you're arguing for the sake of argument and that reality has no bearing whatsoever on said argument. It has come to a point that's beyond grotesque. -
Bern at 11:51 AM on 24 February 2011Carbon Cycle Feedbacks
David Horton @ #1 - paradoxically, I've heard that some areas are substantially increasing their logging rates because they know the pine beetle is going to kill most of the trees in the next few decades, and they want to harvest the timber before it gets ruined. Yet again, though, as this article points out, it seems wherever there is uncertainty, the deniers assume without question that the error is on the high side, and the actual value is at the bottom end of the uncertainty range. We're gonna be in one heck of a pickle if the actual values turn out to be at the top end of the range. Well, if nothing else, at least the unrest across the arab world may help promote alternatives to fossil oil. It's going to be a painful process to get through, though (and has already been painful for the folks in those countries, with more pain to come as their oil-dependent economies start to falter - I saw a report [free reg req'd, I think] this morning that an analyst has given a 25% chance for revolution in Saudi Arabia, which holds 20% of world reserves) -
RW1 at 11:49 AM on 24 February 2011Climate sensitivity is low
scaddenp, I'm not finding the information and/or documentation I'm looking for to verify the claims made by you and KR. You are saying the 3.7 W/m^2 increase is not the reduction in the atmospheric window? -
Philippe Chantreau at 11:48 AM on 24 February 2011Meet The Denominator
"My argument continues and has always been that only a small fraction of these explicitly endorse "anthropogenic global warming". But you have failed to demonstrate that by the standards you define yourself. By your own standards, it's entirely subjective. You can't even begin to prove it. "Credentialed scientist"? That is exactly the kind of thing you were arguing against, earlier, at some point. You've been doing this all along this thread, strongly defending against a semantic issue only to use it when it suited your argument. Just like you tried to argue that quality is subjective and then turned around to say that one could not objectively claim to be qualified as a reviewer from having a track record of numerous "mediocre papers". That is obviously a concept that you failed to objectively define. Nonsense on top of more nonsense. This is by far the most accurate assessment of your ramblings: "he's invested in the process of argumentation itself." You have nothing of substance to say other than "I have a list." That is so laughably limited as to be irrelevant to anyone who can think. -
Marcus at 11:27 AM on 24 February 2011Hockey Stick Own Goal
Robert Way. The thing I love was how the Hadley Climate Research Unit was the focus of the ludicrous "Climate-gate" beat-up, yet now all the "skeptics" are pointing to HadCRU temperature data as better than anyone else's-apparently because it shows a shallower warming trend than GISS or RSS. Boy the own goals from the Denialists are coming in thick & fast! -
Tom Curtis at 11:05 AM on 24 February 2011Hockey Stick Own Goal
Invicta @65, Dana @ 67, from the article: "When you combine the temperature record over the past millennium with climate forcings, you get a most likely climate sensitivity value close to 3°C, consistent with the IPCC climate sensitivity range of 2°C to 4.5°C. So if the temperature swings were actually larger than in the reconstructions used by Hegerl and other studies on millennial climate sensitivity, it means the climate sensitivity is actually higher than the IPCC has concluded." So, Invicta, the thread is saying that if the MWP were warmer than the reconstructions (and hence 1990's temperatures), that is a bad sign for the future because it indicates a high climate sensitivity. A hotter MWP, and a colder LIA would both indicate forecasts for future temperatures are underestimates. It does not argue that current temperatures being actually higher than the MWP is a bad thing for our future. That is in fact bad, but only because current forecasts with the current best estimate of climate sensitivity are grim enough. I have to assume that Dana was very tired when he responded to you, for his response contradicts the article. -
David Horton at 10:42 AM on 24 February 2011Carbon Cycle Feedbacks
Oh, and before any arrive, some interesting material coming to light eg http://climateprogress.org/2011/02/20/denier-bots-live-why-are-online-comments-sections-over-run-by-the-anti-science-pro-pollution-crowd/ and http://georgewashington2.blogspot.com/2011/02/government-and-big-business-gaming.html about the existence of highly sophisticated "denier bot" operations, able to swamp any climate change threads with denier diversions, while appearing to be genuine individuals with unique IPs, backgrounds, internet histories. I'm sure all of us have had our suspicions from time to time! -
scaddenp at 10:21 AM on 24 February 2011Models are unreliable
"Dikran the range of uncertainty is so wide that it makes long term projections or predictions unreliable." That would be unsupported opinion, at odds with models reliability to date. What's your idea of "short term"? At decadal level, models are hopeless. At longer scales they do exceedingly well. Cutting to the chase - how much accurate prediction by models can you take before you change your mind? -
Paul D at 09:53 AM on 24 February 2011Smoking, cancer and global warming
rhjames: "If someone says that doubling CO@ might result in a 1 degC increase, then I'll accept that as consistent with known science. Anything beyond that is just guess work at this stage." Logically your comment is in error. Your own logic would imply that the 1 degree increase is guess work, because you know that there are feedbacks that would alter the forcings. You are defying your own logic by accepting what you call known science. -
Paul D at 09:46 AM on 24 February 2011Smoking, cancer and global warming
rhjames: "only computer models and theory which are still based on very limited understanding of many contributing factors." I suspect very much that the details of all the processes, down to the quantum level are not well understood when it comes to understanding why smoking kills. Your assumptions are bull. -
Paul D at 09:41 AM on 24 February 2011Smoking, cancer and global warming
rhjames: "What I found is that over the past century, there has been increased precipitation in some areas, and decreases in others." erm, both imply change, compared to the past! One wouldn't expect the same patterns in every location, that would be silly. -
Albatross at 09:38 AM on 24 February 2011Hockey Stick Own Goal
HR @100, As shown by muoncounter in their post @40, MBH98 is not shown in Fig. 6-10b in AR4, MBH99 is. We have been over this, MBH98 is discussed in AR4 but only because of the controversy surrounding it. Really, you guys have nothing and it is showing. -
2nd law of thermodynamics contradicts greenhouse theory
damorbel - For temperatures in the second model, add a second "named range" of "Surface_E", value of ~0.97 (a better surface estimate, once I looked it up), and another column starting at E5 containing: =SQRT(SQRT(B5/(Surface_E*5.6704*10^-8)))-273.15-4 Copy this cell and paste down the column. This reverses the Stefan-Boltzmann equation to get degrees Centigrade, with a "4" fudge factor (sets the ~18C final result back to ~14C, accounting at least in part for the surface variations and T^4 increase in radiated power). Not perfect, but a reasonable back of the envelope correction. Given this model and that a doubling of CO2 should result in an imbalance of 3.7 W/m^2, the effective decrease in emissivity of 0.606 * 236.3/240 =.597, which fed into the model results in a temperature rise of ~1.1C, just about what everyone expects from a CO2 doubling with no feedbacks. -
David Horton at 09:22 AM on 24 February 2011Carbon Cycle Feedbacks
We know that carbon uptake by plants could't happen fast enough in the past to prevent severe climate change, why on earth would you think it could happen now with the greatly reduced, fragmented, damaged forest remnants we have; with the further damage to those forests being caused by the changing climate; and with the continuing short-sighted effects of logging, clearing, wood-chipping, recreational use, prescribed burning. It is also worth noting that it takes hundreds of years for a forest to mature, ie to have taken up the maximum that can be absorbed by vegetation in that area given the parameters of topography, soil, moisture, nutrients and so on. We don't have hundreds of years. -
HumanityRules at 09:19 AM on 24 February 2011Hockey Stick Own Goal
99 dhogaza OK I look forward to seeing the Mann 98 bring dropped by the IPCC. -
dhogaza at 09:07 AM on 24 February 2011Hockey Stick Own Goal
HR:if I talk about early Mann reconstructions I'm stuck in the past, If IPCC 2007 refers to early Mann reconstructions it's......
Because it was written in 2007, therefore didn't have Mann '08 and other recent papers available for inclusion.Ah yes I see your logic now.
Apparently yours is that IPCC 2007 should've trotted out their secret time machine and fast forwarded until after those more recent papers were published, and included them? What do you think AR5 will include? Here's my guess ... those papers that came out 2007-2010. You're stuck in the past because you're posting in 2011, not 2007, when AR4 was published. -
scaddenp at 08:58 AM on 24 February 2011Hockey Stick Own Goal
Sorry Fig 6.13 of AR4, WG1. -
2nd law of thermodynamics contradicts greenhouse theory
damorbel - When I worked up the two spreadsheets, I transcribed the content as individual cells with values surrounded by quotes. I've had little (read that, 'no') success in copy/pasting entire spreadsheets as text - hence the approximate formatting. Sorry about the difficulties; if it doesn't work blame my typing! For the first spreadsheet the initial setup is a set of 4 columns, 3 rows, with the items in quotes in each cell in order (don't type in the quotes!). Then copy the last line (4 columns) and paste it into the next 20-30 to converge. Here radiation to space is what's left over when the atmosphere returns some to the surface, and it converges when outgoing=incoming. For the second spreadsheet, the emissivity driven model, there's a single line with a "named range" of "Emissivity" (getting a bit tricker), initial value 0.6. Two rows down there's a section 4 columns across, 3 rows high, with items in quotes in individual cells (don't put in the quotes!). Copy those last 4 cells and paste into the next 20-30 lines for convergence. Try different planetary emissivities to see how the surface energy changes. Here "Emitted" is what's sent to space, and it again converges when outgoing=incoming. These are radiation only models, lacking (in the first example) any convection/evaporation, in order to make the point. In the first, I'm just looking at radiative energies - 240 W/m^2 from the sun, and in convergence 240 W/m^2 to space as IR. Since it's such a simple model temps are not going to be accurate, but it clearly shows that in the presence of an absorbing/spherically emitting atmosphere the surface will be radiating more than the input energy in order to put the total input energy out to space. The primary take-home from the first model is that surface radiated energy goes up in the presence of a GHG containing atmosphere, and that only happens if the temperature goes up. In the second model we can look at temperatures related to those energies; it's a simpler yet more accurate model looking at only the radiative elements. 240 W/m^2 is indeed the incoming solar power. 0.6 is close to the Earth emissivity (zero dimensional model). 396 W/m^2 is the energy radiated from the Earth's surface (surface temp of 14°C which should radiate ~390 given an emissivity of .91-.95, but surface variations and the T^4 relationship raise that to 396). This really simple model quite accurately captures surface emissions and hence surface temperature. I was actually quite surprised at how closely this agrees with the data. In either case - re-emission back to Earth, which shows as reduced emissivity of the planet to space, results in driving the surface to emit more energy to get the incoming 240W/m^2 back out to space, and hence conserving energy. -
scaddenp at 08:58 AM on 24 February 2011Hockey Stick Own Goal
"Besides, no computer model can replicate MWP". I've seen this claim a lot. Seems at complete variance with Fig 6.13 which has output from 12 models. Or is this problems replicating an imaginary MWP? -
John Hartz at 08:55 AM on 24 February 2011Greenland is gaining ice
There's a new peer-reviewed paper on this topic: "The role of albedo and accumulation in the 2010 melting record in Greenland" by M Tedesco, et al, Environmetal Research Letters #6 (January-March 2011) This paper can be accessed for free at: http://iopscience.iop.org/1748-9326/6/1/014005/fulltextModerator Response: [muoncounter] See also the discussion on the Flanner thread. -
RickG at 08:55 AM on 24 February 2011Models are unreliable
Chemist1, Concerning your first link please note that it is a news article in Nature, not a peer reviewed study. Secondly, the error about the Himalayan glaciers in the IPCC report has long since corrected "by the IPCC". However, the Himalayan glaciers are receding, just not as fast as initially reported. There are many discussions concerning the Himalayan glaciers on this site. Please review Return to the Himalayas. -
Chemist1 at 08:32 AM on 24 February 2011Models are unreliable
Dikran the range of uncertainty is so wide that it makes long term projections or predictions unreliable. Short term projections are so-so, but not great, and some models are almost completely unreliable, which I will get into at a later date. -
Chemist1 at 08:29 AM on 24 February 2011Models are unreliable
Okay so here is my edited, kick off on why the models are unreliable, and the IPCC report's over reliance upon them, from peer reviewed papers is a very poor decision. First link:http://www.nature.com/climate/2010/1003/full/climate.2010.19.html First Quote: Initial studies of how the rivers will respond to ice loss show modest changes in stream flow — far from the IPCC report's dire scenario of rivers running dry. Even if the glaciers were lost completely, flows down the Indus would drop about 15 per cent overall, with little or no change in the dry-season flow, one recent study found9. Lall cautions, however, that climate models are poor at simulating rain and snowfall, especially for the Asian monsoons. “I wouldn't hold these models to be very accurate,” he says. In the absence of clear predictions of what's to come, close monitoring of changes in the mountains is all the more important, as rising temperatures will probably affect the whole water cycle, says Eriksson of ICIMOD. “There has been too much focus on the glaciers as such,” he says. “It's urgent to understand the whole [impact] of climate change on snow, ice and rainfall, and that is not happening.” Second Quote back a few sentences prior to the above quote: Cogley. Upmanu Lall, director of the Columbia Water Center at Columbia University in New York, agrees. Lall says the idea that the rivers could run dry because of shrinking glaciers seems to stem from a confusion about how much glaciers contribute to river flows, compared with the contribution from melting of the seasonal snowpack." Link 2, I am introducing because it because you can download it and and place it into GOOGLE Earth and look at data and so called trends yourselves as individuals. It also illustrates how short any decent temperature record keeping has been around and how few stations there have been. The download is free. http://www.climateapplications.com/kmlfiles.asp The above link can assist everyone in analysisModerator Response: [Daniel Bailey] Please note: You are responsible for the content of your copy/pasting from other sites when you then post it here. Your comment previously appearing as number 297 contained multiple allegations of impropriety. Repeated violations of the Comments Policy will also be deleted and could subject you to further, more rigorous moderation. Be aware. -
Follow-Up Case Study in Skepticism
thepoodlebites - You're quite welcome, glad to add my tiny bit of pocket change to a reasonable discussion. To be honest, I don't have enough information about ACRIM vs. PMOD vs. Frohlich to definitively say which measure is most appropriate; just that all of them seem to indicate low levels of solar variation that don't line up with temperature changes. And yes, Steig vs. O'Donnell looks to be quite the mess. I think it points out that the reviewed should not be able to identify and yell directly at the reviewers, and that researchers disagreeing with each other should likely not be reviewing each others work. Most unfortunate. -
Dikran Marsupial at 08:23 AM on 24 February 2011Models are unreliable
Chemist1@300 Uncertainty is not the same thing as unreliability. Unreliability implies that the models have errors that lie outside the stated uncertainty of the projections. GEP Box said "all models are wrong, but some are useful". You have not established that the models are unreliable, nor have you demonstrated that the stated uncertainty of the projections is so high that they are not useful. It is well known that GCMs don't work well at smaller spatial scales, but that doesn't mean they are not accurate in projections of global climate variables.Moderator Response: (Daniel Bailey) FYI: Chemist1's long link-fest originally at 297 contained an extensive copy-paste with multiple allegations of impropriety; it and 3 subsequent responses were then deleted. That is why the numbering sequence on comments is off right now. -
Albatross at 08:23 AM on 24 February 2011Hockey Stick Own Goal
muoncounter @94, "'unforced free oscillations' idea -- call it UFOs" Thanks for making me laugh...that is hilarious. -
Chemist1 at 08:17 AM on 24 February 2011Models are unreliable
Here are a few more links straight from peer review regarding strenghts, weaknesses and areas where serious need of improvement, exist: http://iopscience.iop.org/1748-9326/6/1/014008: " Abstract This study assesses the accuracy of state-of-the-art regional climate models for agriculture applications in West Africa. A set of nine regional configurations with eight regional models from the ENSEMBLES project is evaluated. Although they are all based on similar large-scale conditions, the performances of regional models in reproducing the most crucial variables for crop production are extremely variable. This therefore leads to a large dispersion in crop yield prediction when using regional models in a climate/crop modelling system. This dispersion comes from the different physics in each regional model and also the choice of parametrizations for a single regional model. Indeed, two configurations of the same regional model are sometimes more distinct than two different regional models. Promising results are obtained when applying a bias correction technique to climate model outputs. Simulated yields with bias corrected climate variables show much more realistic means and standard deviations. However, such a bias correction technique is not able to improve the reproduction of the year-to-year variations of simulated yields. This study confirms the importance of the multi-model approach for quantifying uncertainties for impact studies and also stresses the benefits of combining both regional and statistical downscaling techniques. Finally, it indicates the urgent need to address the main uncertainties in atmospheric processes controlling the monsoon system and to contribute to the evaluation and improvement of climate and weather forecasting models in that respect." http://onlinelibrary.wiley.com/doi/10.1002/wcc.60/full: "Abstract Computer models are powerful tools that allow us to analyze problems in unprecedented detail and to conduct experiments impossible with the real system. Reliance on computer models in science and policy decisions has been challenged by philosophers of science on methodological and epistemological grounds. This challenge is examined for the case of climate models by reviewing what they are and what climate scientists do with them, followed by an analysis of how they can be used to construct new trustworthy knowledge. A climate model is an executable computer code that solves a set of mathematical equations assumed to represent the climate system. Climate modelers use these models to simulate present and past climates and forecast likely and plausible future evolutions. Model uncertainties and model calibration are identified as the two major concerns. Climate models of different complexity address different question. Their interplay helps to weed out model errors, identify robust features, understand the climate system, and build confidence in the models, but is no guard against flaws in the underlying physics. Copyright © 2010 John Wiley & Sons, Ltd." These two last links with Abstracts included are not skeptical arguments against using GCM's or climate change. Yet they highlight regional issues, weather events, patterns,microclimate, and making projections based upon these and finding trends in climate. Not that these papers conclude nothing can be understood better or analyzed but that models still contain lots of unreliability, which is the topic of this thread.
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