Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  1853  1854  1855  1856  1857  1858  1859  1860  1861  1862  1863  1864  1865  1866  1867  1868  Next

Comments 93001 to 93050:

  1. Examining Hansen's prediction about the West Side Highway
    Muoncounter @55, interesting, but Hansen still consistently predicts greater sea level rises than the consensus position. It is, therefore, certainly justified to examine his independent predictions, so long as you actually do so rigorously (see 54). Of course, the deniers are simply taking rhetorical short cuts rather than actually examining Hansen's predictions.
  2. Examining Hansen's prediction about the West Side Highway
    This is getting more and more absurd. In a normal scientific review process, the 1998 interview would be long forgotten, as it was superseded by this more recent research brief. The two models suggest that ocean waters in this area could rise another 18 cm to 60 cm by mid-century, as the planet warms. By the 2080s, sea level could climb by 24 cm to nearly 110 cm ... As sea level rises, flood levels produced by the 100-year storm could reach 3 to 3.8 meters by the 2050s, and between 3.2 to 4.2 meters by the 2080s. --emphasis added So its not sea level rise alone, its the combination of sea level rise and the 100 year storm that floods the West Side. -- Figure 2 ... the current 100-year flood return period would shorten dramatically. By the 2080s, the likelihood of a flood engulfing the area in blue (Figure 2) would be once in 50 years, given present rates of sea level rise, and as often as once every 4 years, in the worst-case scenario. Given the huge percentage of NYC's infrastructure that is underground, this should be a serious concern, because there is no 3 meter sea wall around lower Manhattan. Instead its become a denialist playground. Go figure.
  3. HumanityRules at 10:49 AM on 11 March 2011
    What would a CO2-free atmosphere look like?
    Chris Colose, I'd agree with you the Lindzen picked a number off the top of his head but the wider issue of CO2 as a GHG is not disputed by Lindzen (video 26-27mins).
  4. Examining Hansen's prediction about the West Side Highway
    HR @51, we absolutely believe the scientific community should be held up to scientific scrutiny. The first step in that process is to examine the predictions made in scientific articles or conference proceedings rather than equivalent predictions made of the cuff in interviews. It is very clear that the former will be more precise, and will more accurately reflect the considered views of the scientist. (If the of the cuff remarks widely differ from the considered views, that raises a separate issue, but no one has suggested that to be the case.) The second step is, where there is any ambiguity as to what was meant (which is certainly the case in this example) is to clarify with the author the actual intended meaning. Did Hansen mean 40 years regardless of CO2 levels? Did he mean 40 years, provided that CO2 levels had doubled? Or did he mean 40 years after CO2 levels had doubled? The exact interpretation makes a very large difference as to whether or not the prediction has been (or will be) falsified in 2018. Neither WUWT nor you have taken either of these steps. The notion that you are trying to hold Hansen up to scrutiny is therefore nonsense. In fact, what WUWT appears to be doing is to raise a straw man of Hansen's views in order to make him the subject of ridicule. Finally, if you want to subject Hansen's views to genuine scientific scrutiny, you need to remember that any prediction is based on multiple claims. Because the purpose of scientific scrutiny is to test those claims, where some of those claims are already modified, the prediction needs to be altered accordingly. Let's assume (contrary to what I believe is the most natural interpretation), that Hansen predicted that: "If CO2 levels double by 2028, the West Side Highway in New York will be under water." The theory underlying that prediction is based on Hansen's model work of that period. So it includes the sub-beliefs that: a) CO2 levels can plausibly to double by 2028; b) Climate sensitivity is 4.2 degrees C per doubling of CO2; and c) A 4.2 degree C rise of global temperatures above preindustrial levels will raise sea levels sufficiently to flood the West Side Highway. For scientific scrutiny, (b) is now irrelevant. The evidence, partly published by Hansen himself, shows the climate sensitivity is more probably 3 degrees C. Now, should we test Hansen's predictions without substituting for (b), (b') that climate sensitivity is 3 degrees C, and altering the prediction accordingly, then all we test in the prediction is the conjunction of (a), (b), and (c); which is boring because we already know (b) is probably false. In other words, if in fact the West Side Highway is not under water in 2028, all we learn is that either CO2 has not doubled, or climate sensitivity is lower than 4.2, or sea rise at 4.2 degrees C is not sufficient to flood the West Side Highway. As we are already fairly certain about the second of those possible conclusions, we learn virtually nothing. So, if you really want to examine Hansen's position: 1) Find, if possible, an equivalent prediction from the period in his primary literature; 2) Clarify any ambiguity if any; and 3) Adjust the prediction to allow for recent advances in knowledge. And if you are not prepared to do that, you are not holding Hansen up to scientific scrutiny - you are indulging a rather tawdry rhetorical ploy. Just don't expect us to be deluded by it.
  5. Dispelling two myths about the tropospheric hot spot
    Well the Douglass et al paper ignored radiosonde biases despite the authors apparently being aware them. See Santer et al to see why that paper disappeared. The other two I am unaware of. Got a link to them? Cant find either in easily in google scholar.
  6. What would a CO2-free atmosphere look like?
    Ranyl, I think the dashed lines are not "real" states. What really happens, if if you're on one of the lower solid lines and you increase CO2 so much that you run out of solid line, then the temperature rapidly increases until you reach the upper solid line at the same CO2 level. If CO2 now drops (because all that melted ice has exposed rock that can weather) you slide down the upper solid line. If it drops enough, you "fall" from the upper solid line to the lower solid line (for the right ice albedo).
  7. Ian Forrester at 10:18 AM on 11 March 2011
    Christy's Unconvincing Congressional Testimony
    Michael Tobis has some scathing comments from Ben Santer on Christy's testimony.
  8. Examining Hansen's prediction about the West Side Highway
    HR: It's 17 years until Hansens speculation, but more generally the satellite data is still failling to show anything but a linear rise. Come on HR, you have been shown time and time again that Hansen did not put a time frame on the sea level rise. The reference was a doubling of CO2. There's not a single scientist on the planet speculating that a CO2 will double by 2028. What does it take for you to understand that?
  9. What would a CO2-free atmosphere look like?
    Chris, I enjoyed the article, and hope it is to be the first of many on this site. Can you confirm that the sections of the bifurcation graph with dashed lines are transition states? That is, once the CO2 level reaches high enough a level to start melting ice in a snowball earth scenario, the temperature will continue warming until it reaches that of the equivalent for the equivalent CO2 level in the ice free state; and if CO2 levels drop below the minimum to maintain the upper solution, the earth would cool to a snowball state at the appropriate temperature for that CO2 level? Are they also unstable state? Ie, if the glaciation and CO2 levels where those at the white dot on the graph, could an equilibrium be maintained, or would it inevitably transition to one of the grey dots due to changes in albedo? Finally, I notice that in the non-snowball Earth case, at 666 ppm the model clearly indicates the Earth to be ice free. As the model was using less than current insolation, doesn't this mean the model is predicting an eventually ice free Earth for doubling of CO2 from current levels?
  10. Examining Hansen's prediction about the West Side Highway
    HR @49, "If your data is correct then New York should be one of the spots on the earth were accelerating SLR should be showing up earliest." First off, they are not "my" data. Second, that is your interpretation of the paper which is talking about future GSL. Nice try though. That said, this satellite-derived map of GSL, does show a hot-spot for GSL rise (> 5 mm/yr) off the northeast coast of Canada for the period 1993-2009. [Source here]
  11. HumanityRules at 09:50 AM on 11 March 2011
    Examining Hansen's prediction about the West Side Highway
    45 Phila There is nothing I can do if you feel the climate science establishment shouldn't be held to scutiny. There is nowhere for our discussion to go from here. Again your appeal is that you want the discussion to be limited to what you think is relevant, you don't seem to be able to see that. There is plenty I disagree with on this site but I never(I think!) try to limit the scope of the discussion. Finally the title of the article is "Examining Hansen's prediction about the West Side Highway". That's what I'm trying to do, you seem to think the title is "Bash WUWT". Look if John wants to post an article with that title I'd be happy to join the conversation there if I thought I was going to get something from it.
  12. Examining Hansen's prediction about the West Side Highway
    tomurray @43, I have read the original post at WUWT. I noticed, for example how they carefully showed the windows of the offices of not only Hansen, but also Schmidt (who was totally unconnected to the article), two men known to have received death threats. (I also read their very weak defense of that action in the comments.) I also noticed how they are taking an ambiguous prediction from a casual interview rather than the equivalent prediction from Hansen's scientific work (which would be precise, and not in need of interpretation) as the basis of their commentary. Finally, I also notice that you have set up a standard whereby if what Hansen has predicted for the 2090's is not fulfilled by the 2010, then his work (all of it, apparently) can be dismissed. Finding pretexts to dismiss evidence may be preferable (for some) to actually understanding the evidence. However, it does not impress.
  13. HumanityRules at 09:37 AM on 11 March 2011
    Examining Hansen's prediction about the West Side Highway
    25 Albatross Albatross all that modelling work is fine but did you look at the data presented by Charlie A in #20. If your data is correct then New York should be one of the spots on the earth were accelerating SLR should be showing up earliest. I don't see it in the on the ground data, it looks pretty much linear. When are we going to start to see this exponential growth? It's 17 years until Hansens speculation, but more generally the satellite data is still failling to show anything but a linear rise.
  14. Examining Hansen's prediction about the West Side Highway
    Tomurray, "He needs to be right all of the time." No, that is a fallacy. Applying your logic we should not be funding the National Weather Service in the USA to issue warnings for severe weather because they are not correct 100% of the time. Yet, there is immense value in their warnings. Same goes for medical doctors-- and they get payed much, much more than does Hansen. You are being unrealistic and are not grounded in reality. I hope you now realize the folly of your reasoning. I strongly suspect that you are placing unrealistic expectations to set someone up for a fall, just so it can reinforce your skewed perception of reality and dismiss their inconvenient findings. I do agree that Hansen should be held to a high standard, and he is, pretty much every word he says is scrutinized. What would be disappointing (and telling) is if you did not apply your critique or skepticism equally, that is what a true skeptic would do. So I find it odd that you do not concede that Watts is misrepresenting what Hansen actually intended to communicate. And let us not be naive, Watts is embarking on an orchestrated misinformation campaign and relishes in defaming climate scientists.
  15. Examining Hansen's prediction about the West Side Highway
    @46 tomurray In fact, he does defend all of his positions within the scientific community. There is no error in his statement. If CO2 doubles, whenever it doubles, sea levels will rise a meter. No one doubts that. You are grasping at straws, which only shows how weak your position is.
  16. What would a CO2-free atmosphere look like?
    Interesting post Chris. This graph is fascinating, if you raise CO2 in the partially ice covered state and follow the dashed lines a rising CO2 results in a global cooling which is none mechanistic. Therefore presuming a rising temperature with a rising CO2, could the increase go vertically so to speak? Could a rising temperature due to radiative forcing (like the changig alebdo effect)in the partially ice covered earth cause jumps in temperature? Can temerpatures of the top line be reached before the ice melts followed by the melt? Antarctica is going to take a long time to melt even if the world rose several degrees c. What does this sort of graph mean for climate sensitivity? Interesting graph, when is the Pierrehumbert et al., 2011, accepted paper being published?
    Moderator Response: [mc] Use width=500 or smaller within img tags.
  17. Interactive animation of the climate change impact on agriculture
    John D "I have no doubt that you associate and talk to others who share similar views as yourself. Whether or not they are representative or not is another matter. Are you also sure they are not concerned more about short term weather events such as droughts?" First of all, my work doesn't allow me to *choose* who I associate or talk to-any more than it does my colleagues-yet still the majority of the farmers we come in contact with express a deep level of concern about global warming-not short term weather effects, as you suggest, but explicit mention of global warming (though they do mention its impacts on things like droughts, which most of them have noticed getting worse over the last 30 years). Second of all, do you *honestly* think that an organization like the NFF genuinely represents the view of the majority of ordinary farmers? That's like saying the ACTU represents the view of the majority of blue-collar workers. Indeed, the view I get from the farmers themselves is that the NFF really only represents the views of the so-called "agri-businesses", or "factory farms", not the views of multi-generational family farms.
  18. A Scientific Guide to the 'Skeptics Handbook'
    KR, I second your props to John. Regular contributors to this site: See the Organizational Nominees at George Mason University's 2011 climate change communicator award. Vote early, vote often!
  19. A Scientific Guide to the 'Skeptics Handbook'
    Jo Nova recently reposted her handbook - apparently her site has received some attention in the news recently, and she wanted to call attention to her write-up. I commented there, and pointed people at some SKS threads, including The Scientific Guide to Global Warming Skepticism. I expect the number of thumbs-down on my post to soon reach the point of hiding my post, which paradoxically calls even more attention to it. John Cook - fantastic work on this site. I understand it's a labor of love, and what a labor it is. You are to be congratulated on your devotion to the future and to your children (and their children's children). I don't think that gets said often enough; Thank you.
  20. Examining Hansen's prediction about the West Side Highway
    Actually, Phila, Hansen should be held to a higher standard. He has the titles. He gives expert testimony before congress. He is cited by NOAA, IPCC, etc. as an expert. He needs to be right all of the time. It's not "unbalanced" to expect that he be able to defend all of his positions. He shouldn't be making them if he's not sure. Otherwise, why are we paying him? Or are you admitting the uncertainty of the whole subject?
  21. What would a CO2-free atmosphere look like?
    logicman - I believe the increased albedo would lower retained energy enough to keep the Earth in a stable ice-covered state, although I haven't run the numbers - it might be worth looking at a simple climate model or two to see. That would hold until either Milankovitch effects or volcanic activity (unbalanced by weathering, as most available rocks would be covered) increased CO2 enough to lead to a feedback cycle that would take the would warm things up, releasing CO2 from the oceans. Still - this is a Gedankenexperiment thread. It's sufficient to show that if a variable is changed the current world would not have the same state as it does now.
  22. What would a CO2-free atmosphere look like?
    "... if the Earth were magically ice-covered today, this would be a completely stable situation and there would be no tendency to escape that state unless the greenhouse effect was substantially enhanced or the sun got brighter." By definition, it would be a desert planet, just as much of Antarctica is, by definition, a desert. Now add what I like to call the Best effect - after the Elizabethan scientist George Best who first published a description of it: insolation at tropical levels at the poles in their respective summers. Following tropical-level melting at the equator and North polar seas, warm water would put some minimal GHG into the atmosphere. Over a long enough time, the 'compound interest' of GHG - at first from the oceans, later from land - would lead to a planet with much less ice everywhere except Antarctica. George Best
  23. Examining Hansen's prediction about the West Side Highway
    HR: Phila it's not being personnal to critically examine what a scientist says about the science whether that is speculation or predictions. IMO, it is indeed personal when that "critical examination" obsessively targets high-profile climate scientists, while giving far more error-prone "skeptics" a pass. The result of this approach is that someone like Hansen has to hit a bullseye 11 times out of 10, while "skeptics" aren't even required to aim at the target. (As an added bonus, they get to reject any claim about AGW that strikes them as "alarmist," which is a cute way of "winning" every debate before it properly begins.) If you can come up with some other credible explanation for this demonstrably unbalanced approach than a desire to discredit the science by attacking individuals -- and portraying any alarming scenarios as unscientific by definition -- I'm all ears. In fact if you and others say that this has nothing to do with science then I'll drop it. The balls in your court. I can understand why you'd want to reduce this debate to a false dilemma. Presumably, you can understand why I reject that approach. Per Tom Curtis @39, "That criticisms of such comments seems so important to deniers suggests they have nothing substantive to say about the actual science." Which was the point of my initial comment, as well.
  24. Christy's Unconvincing Congressional Testimony
    PS. Great to see hard data on the Brisbane flood, thanks Tom.
  25. Christy's Unconvincing Congressional Testimony
    Actually, there is plenty of recent science that suggests intensity is increasing. I believe it is, but it would be hard to proove yet. The two recent papers regarding precipitation go a long way to prove it. A 1:2000 event locally is quite feasible in probability terms - an analysis of the data would be needed in depth. It is clear though that we are in for more of these swings in the weather. Perhaps we will be back to drought in a year or two and be wishing we still had all that water. The problem is that we just don't know which way the climate system will head for Australia. The models are based on our current understanding only. The additional moisture in the atmosphere will drive more intense/energetic storms, but whether they are over Australia or not is still unknown in my opinion. We are pushing the climate hard towards the unknown and we have to do something about it. Not listen to those who want to delay action!
  26. Climate Emergency: Time to Slam on the Brakes
    Fred Staples - Your last post contains a huge list if misconceptions and disproven skeptic arguments; enough that it could qualify as a Gish Gallop. Taking it in the light of a well intentioned post, I would suggest you read: - Temp record is unreliable - It's Urban Heat Island effect - The first global warming skeptic (Angstrom) - 2nd law of thermodynamics contradicts greenhouse theory (Read it again - please!) - The Imaginary 2nd law of thermodynamics - The Real 2nd law of thermodynamics - What caused early 20th Century warming - Why did climate cool in the mid-20th Century - CO2 is not the only driver of climate - There's no tropospheric hot spot And finally, before posting other objections to the clearly established science, I suggest you take a look at the Most Used Skeptic Arguments and see if it's already been discussed. I'm not going to bother writing a point-by-point rebuttal of your post; that's already been done on those various pages.
    Moderator Response: Thanks. Now there have been sufficient pointers to relevant Argument threads, for both Fred and everybody else to comment there rather than here. I'll start deleting any further off topic comments that appear here.
  27. Climate Emergency: Time to Slam on the Brakes
    Fred, When you first mentioned that the "mid-troposhere was not warming" @70, you said nothing about the fact that you were looking only at equatorial temperatures. Now we hear that you cherry-picked temperatures in the tropics, when you know very well we are dealing with global warming (AGW), and that the greatest warming has been in the mid and high latitudes (as predicted by AGW theory). You also mistakenly claiming that the alleged missing 'anthro' equatorial hot spot refutes the theory of AGW, when in fact you should know that the equatorial hot spot is not a signal of anthro warming, one should see the same hot spot regardless of the source of warming. Also, you talk about mid-tropospheric temps and do not show data for 500 mb, which is considered to be the mid-troposphere in meteorological circles. If you want to debate the equatorial hot spot, please take that tot he appropriate thread. The NOAA and RATPAC data show that globally tropospheric temperatures are increasing. Additionally, the RAPAC data show that globally (since 1958) the 850-300 mb layer is warming faster than the instrument-based surface temperatures. To dismiss that fact is to be in denial. I'm with NOAA and the climate agencies on this one, but thanks for trying to obfuscate-- readers here will see right though that though. You will be guaranteed success at WUWT. And lastly, please stop wasting everyone's time and cluttering the threads by parroting long debunked "skeptic" myths. Thanks.
  28. Interactive animation of the climate change impact on agriculture
    And for those who claim that plants do better in CO2 "enriched" environments under water stressed conditions, the observations (from a global network of flux towers) show otherwise. From Jung et al. (2010, Nature): "Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science." More here. This research is corroborated by independent research (using satellite data) conducted by Zhao and Running (2010, Science) who found that: "The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production." NPP= Net Primary Production, a measure of "the amount of atmospheric carbon fixed by plants and accumulated as biomass". That is, photosynthetic activity.
  29. Climate Emergency: Time to Slam on the Brakes
    As promised, perhaps I can reply to some of the individual comments on my posts.. KR, 51, I agree that there is no significant difference between the trends in all the main records of global temperature anomalies. They all suggest that increasing CO2 did very little until 1979, when it had reached 350ppm. I know how much quality control is required to record accurate temperature measurements. You might like to try it in your own house (not forgetting the loft), and then try the garden. You car temperature gauge will demonstrate the urban heat island effect every time you drive through a town (the M4 into London is very flat, if you want a specific reference). Sea covers 75% of the globe. Do you know how sea temperatures were measured before the recent instrumented projects. Ships with buckets and thermometers. RickG, 52, The Physics of infra-red absorption by CO2 is well known, and calculable both by the wave and particle views of photons. (Radiation, page 252, by Grant W Petty, University of Wisconsin Madison if you do not accept the dual wave /particle theory) Angstrom demonstrated the saturation effect about 100 years ago, when he found that CO2 concentration made little difference to atmospheric warming. Woods demonstrated that back-radiation from an absorbing medium will not warm the interior of a greenhouse. Do you think that 100% CO2 will warm dramatically faster than air? Have a look at this high school experiment http://www.espere.net/Unitedkingdom/water/uk_overview.htm. The application of CO2 to AGW is where the problems begin -trapped heat, warming from back-radiation, little silver bullet photons, dependence on the lapse rate, etc. Many, perhaps most, of the explanations offered on the internet directly violate the second law of thermodynamics.. There were people predicting global warming in the seventies, BH, but they were not taken seriously. CO2 is certainly well mixed, but its absorption is swamped by water vapour in the humid lower atmosphere. It is the CO2 action (and re-action) that takes place in the dry mid and upper troposphere that is said to be responsible for surface warming. Hence the problem with the UAH temperatures. The observed trend difference between the upper and lower air temperatures is absolutely not to be expected. Exactly the opposite is to be expected. The temperature difference itself is due to the lapse rate, as you can see when you drive your car up a hill. Adelady, 54, there were no unnoticed signs (of CO2 impact) 60 or 80 years ago. The point is that there were no signs at all.. 55 Muoncounter. I will accept your views on past temperature movements (pre 1979) if y0u accept that they had nothing to do with increasing CO2 concentrations. 61 Villabolo If you are right, we are going to see some sharp temperature increases as the CO2 emmissions during the western industrial revolution take hold. We can expect to move up the Hansen A line, 66. If you are wrong, temperatures will continue to plod along the Hansen C line, while CO2 move close to the A line. As the CO2 and temperature lines diverge, support for AGW will wane. 76 Albatross, I analysed the HadAT Radio-sonde data myself, two years ago, from 1958 to 2009. The tropospheric lapse rate continues up to about 10 Kms, which corresponds to the HadAT 300/200hPa charts. I wanted to test the significance of the warming (and cooling) in the record, at the 5% level, by calculating the point when change becomes significant in years back from the (then) present. The results were interesting: 11 Kilometers ( 200 hpa) : 51 years (no significant warming) 9 Kilometers (300hpa) : 27 years 1.45 Kilometers (850hPa) : 13 years For significant cooling, (steps, flat periods, and volcanoes included), 29 years at 13.47 kilometers. So, low down, but still well above the surface layer, warming is clear. Higher up it falls away, and is not significant at the top of the troposphere. This is less conclusive than the UAH measurements, but it supports my argument. I will bring these results up to date. Propaganda, 80, is not necessarily false, but it is still propaganda. I seek to do no more than bring some balance to this blog. I will, if anyone is interested, reel off anecdotal evidence on the sceptical side of the argument, but that too, is propaganda. 83 I really dislike thought experiments. Thinking, of course, is welcome. 91 James Wright. I did not claim that (if I did it was a mistake). I do not know the temperature of the medieval warm period (although I have seen the same plots as everyone else). I do know that it was not caused by increasing CO2 levels. I also know that it was very cold in the Little Ice Age. Incidentally, when the Hockey stick was first published, George Monbiot in the Guardian abolished both. Propaganda again.
    Moderator Response: I told you to respond on the appropriate threads, not here. Please copy your individual replies to those relevant threads. Then I will delete this comment from this thread.
  30. Examining Hansen's prediction about the West Side Highway
    "Whether this is a prediction or speculation is irrelevant, it's helped shape the wider debate of climate science" This is a valuable insight into the denier's view of what constitutes the 'debate.' I suspect that if someone asked Dr. Hansen the time and his watch was 5 minutes slow, the deniersphere would still be trumpeting 'Hansen can't tell time!' 5 years later.
  31. Examining Hansen's prediction about the West Side Highway
    Has anybody on this site even read either the Watts post or the Salon article? It doesn't sound like it. After quoting the Salon article verbatim, and then posting some pictures of the GISS offices and the viewscapes available therefrom, he compares that to Hansen's admittedly vague prediction of sea level rise. Vague in the sense of how many years and how much of an increase in CO2. Fine. But a prediction, nonetheless, of flooding in New York. So, Watts concludes, "So much for local climate change predictions by the leading global authority on climate change." How ClimateHawk can conclude that, "In the meantime, we can stop using this conversation from 1988 as a reason to be skeptical about the human origins of global warming."? It is Hansen (via Reiss) himself that brings into question the validity (or at least the prognostic abilities) of Mr. Hansen and his predictions. And, Watts is talking about local changes that Hansen himself brought up. ClimateHawk seems to think that a skeptics comments about predictions of local change are the same as a pronouncement about "human origins of global warming". Simply amazing.
  32. What would a CO2-free atmosphere look like?
    Gilles, There is an upward surface LW of approximately ~390 W/m2, with the outward flux at the top of the atmosphere (TOA) about equal to the absorbed shortwave coming in, i.e. S(1-a)/4 (or ~240 W/m2). Therefore there is ~150 W/m2 of LW absorbed by the atmosphere, a number that goes to zero in the limit of no greenhouse effect and becomes large in very opaque atmospheres (Venus)
  33. The Earth's Sixth Mass Extinction May Be Underway
    I don't know why this story appears here, extinctions of the overwhelming majority of species in the last 400 years is nothing to do with climate change, it is simply about the ignorance of man not appreciating the impact our activities have. I do not deny man is responsible for a large number of extinctions, but I do think it is stretching to; 1) link extinctions to global climate change (man made or natural) at this time. 2) say that the extinction level is up to that of Mass extinctions.
  34. What would a CO2-free atmosphere look like?
    I have already a problem with the first equation GHE = sigma( Ts^4 -Te^4). Because the average flux emitted by a surface with a temperature gradient is by no means the flux emitted by the same surface at the average temperature ( average of (T^4) is not (average of T) ^4).
  35. Interactive animation of the climate change impact on agriculture
    Folks, how about we defer to the experts on this? Here is what Dr. Peter Reich had to say in response to Monckton's misinformation (similar to what is being perpetuated by "skeptics" on this thread) on this issue (from here): "The best evidence from state-of-the-art free-air carbon dioxide enrichment experiments is inconsistent with the notion of major sustained increases in crop yield in a world of doubled atmospheric CO2. Quantitative analyses and syntheses of those experiments indicate that the direct effects of elevated CO2 will increase crop yields by 13% (on average for those with the C3 photosynthetic pathway, such as wheat, soybeans, rice) or 0% (on average for those with the C4 photosynthetic pathway, such as corn, sugar cane, and sorghum); not the 40% Lord Monc[k]ton suggests. Moreover, these estimates ignore (1) indirect effects of CO2 as a greenhouse gas on future temperatures, precipitation, and their variability, and hence on future crop yields and (2) other consequences of fossil fuel burning such as rising ozone pollution that will reduce crop yields. The bottom line for crop yields: combined effects of fossil-fuel burning (rising CO2, rising O3, climate change) are uncertain but at least as likely to be negative as positive, and shifting increasingly towards the negative the higher that CO2 concentrations rise." Dr. Peter Reich: Regents Professor and Distinguished McKnight University Professor, University of Minnesota’s Department of Forest Resources. His teaching and research focus on ecology, global change, and the sustainability of managed and unmanaged terrestrial ecosystems. Regionally, his interests lie in the forests and grasslands of mid-North America and globally on terrestrial ecosystems in aggregate. I'm going with the science and Dr. Reich on this one.
  36. Dispelling two myths about the tropospheric hot spot
    The studies I see not being cited are, Christy et al 2010 (a review article of the science and the debate), McKitrick et al 2010, Douglass et al 2007. Why?
  37. Christy's Unconvincing Congressional Testimony
    Tom Curtis at 22:33 PM, you make it all seem that the AEP is changing such that an area prone to flooding is being created where a city has long stood, rather than a city being created where a flood prone area always stood.
  38. michael sweet at 03:10 AM on 11 March 2011
    Examining Hansen's prediction about the West Side Highway
    It is interesting to see the skeptics here say we can just raise the sea walls a meter and in other threads they say it is too expensive to do anything to lower CO2 emissions. How much will it cost to raise all those seawalls? Remember you have to raise the road bed also. Will you build Miami's sea walls on their beachfront? Once sea level rise really gets going after 2050 it will not be cost effective to raise the sea walls, the city will have to be moved. London is reported to be able to raise their sea walls 2 meters and then have major problems. Miami's water supply will be underwater long before then.
  39. Examining Hansen's prediction about the West Side Highway
    HR >"Hansen was assuming CO2 would double by 2028. Are you saying that assumption is wrong." Depends-- if he was talking about CO2 equivalent as they do in the IPCC, then he might be pretty darn close. And that is part of the problem, this was an off the-cuff comment, not a formal scientific projection. Anyhow, Tom's post @39 really makes some excellent points. Thanks Tom-- I enjoy your posts, I learn a lot from them.
  40. Climate Emergency: Time to Slam on the Brakes
    Moderator, 77, at the thread entitled "Greenhouse effect and the second law of thermodynamics" I contributed a simple demonstration, 337, (with an isothermal atmosphere) that radiative insulation (the blanket theory of AGW) was quite different from conductive insulation. I added some basic thermodynamics to explain the difference between heat and energy, a source of much confusion in the blog. Very Tall Guy, 329, agreed with my comments and responded with the "higher is colder" theory, complete with a chart. I then attempted to comment as follows (but the thread, sadly, had closed): "The explanation you offer, Very Tall Guy, is the only plausible explanation of the AGW effect. It is the preferred explanation of the founding fathers over at RC, and you can find it in the Rabbet rebuttal of the G and T paper, (immediately following their absurd multi-layer, back-radiation explanation). It begins with the lapse rate, a function of gravity and specific heat, which has nothing to do with radiative effects. Without this lapse rate there would be no possibility of AGW. The argument is that increasing CO2 in the cold, dry, upper atmosphere, impedes outgoing radiation, and moves the effective radiation point to higher (and therefore) colder temperatures. Outgoing radiation is reduced, incoming radiation remains the same, and the whole atmosphere and surface warms up to restore the balance. As your drawing demonstrates, the lapse rate moves to the right". This explanation is plausible, but is it true? Notice that this is a top-of-the atmosphere effect. It is absolutely incompatible with the UAH published results (Global Warming at a Glance) for the mid and lower troposphere. And if the stratosphere is not masking mid-troposphere warming, the AGW explanation of warming over the last 30 years cannot be sustained. Which brings us back to the "upper troposphere warming is masked by stratospheric cooling" argument. The data I quoted, 70, was from the Hadley centre radio-sonde data, not the satellites. I have seen no satellite stratospheric temperatures, but I would welcome a link. I followed the link in 85, and read this: " As the lower atmosphere warms due to an enhanced greenhouse effect, the upper atmosphere is expected to cool as a consequence. The simple way to think about this is that greenhouse gases are trapping heat in the lower atmosphere. Since less heat is released into the upper atmosphere (starting with the stratosphere), it cools" Simple indeed. Those words look sensible, but like "Friday is faster, far, than a fried egg", they are literally meaningless. Heat is not energy. It cannot be trapped or stored. It is, by definition and the second law of thermodynamics, the net transfer of energy between a higher and a lower temperature. Freeman Dyson refused to discuss the matter any further with the Independent's science editor when he made a similar comment. We can use the term "heat transfer" loosely, so long as we know what we mean. I am as ready as the next man to accept that if the facts don't agree with the theories (models), so much the worse for the facts, but there are limits to credibility. Returning to the subject of this thread, China has vast resources of accessible coal, and the US is wedded to transport and air conditioning. They will not be convinced by the story so far "to leave their remaining fossil fuels in the ground".
    Moderator Response: No, that thread (2nd law of thermodynamics contradicts greenhouse theory) is not closed. Maybe you were logged out for some reason, or there was a temporary glitch. Try commenting there again. Everybody else, do not reply here; reply over there. Thanks.
  41. Daniel Bailey at 01:44 AM on 11 March 2011
    Examining Hansen's prediction about the West Side Highway
    @ RickG and Jesús Rosino RickG has the right of it. The skeptics' favorite toy, the Bounoua et al 2010 paper, must be evaluated in context: it is intended to investigate a thought model of what happens to evapotranspiration, plant growth, planetary albedo and global surface temperatures under an already doubled CO2 scenario, under which all other variables/forcings are constrained (assumes low climate sensitivity of less than 2°C, air+ocean thermal response to doubled CO2 already achieved, etc). It is a modeling study narrowly designed to evaluate an investigative line of thought only (i.e., not a forecasting model per se). What it does not do is speak to the other multitude of other feedbacks known to exist affecting sea level rise and ice sheet response to a warming world, factors known to already be at play. As such it is of zero value with regard to the topic of this post (well, maybe when the moon is in the 7th house and Jupiter collides with Mars ☺ ...). Hope that helps, The Yooper
  42. A Real-World Example of Carbon Pricing Benefits Outweighing Costs
    When considering the impact of the requirements for cleaner transport, it's always worth considering how technology evolution really works - and, in this case, a good case study is Horse-Manure The point being, in the case of the car for example, that the technologies can be pretty rubbish and expensive till the market need reaches a sufficient level, after which the best are selected and can really take off. Looking around at what 'people' are doing in the here and now, with relatively niche technologies - like the current gen of electric cars - is meaningless.
  43. A Real-World Example of Carbon Pricing Benefits Outweighing Costs
    Marcus, sorry, I don't have any oil (or gas or nuclear or aeolian industry) shares (actually I don't have ANY share, even if it may be surprising for you- only old fashion spare account.) Some years ago, I had some money available from an expired life insurance contract. My banker advised me to invest in stock markets, but you know, at this time , I already read some things about impending crisis and peak oil. It was in 2007. So I preferred to buy gold- more as a game, to test my own confidence in these kinds of predictions, than to really make money. Actually stock markets plunged one year after and gold has gained twice its value. As a physicist, I like empirical tests of the predictive power of theories). Besides i have a little car burning 6l/100 km - 40 miles per gallon, I am heated by a combination of heat pump (very low carbon intensity in France thanks to nuclear energy) and wood in a close chimney ), I try to take public transportation and electric trains as much as possible : well I think there are worse ways of life. so back to the problem. I'm just stating that I don't see any solution in the evolution of car market, even including HEV that do NOT spare much fuel compared to small optimized vehicles , and the ridiculously small proportion of EV planned in the near future. But I'm ready to test this kind of predictions in the near future as well.
  44. Examining Hansen's prediction about the West Side Highway
    First, HR, Hansen's comments where clearly designed to illustrate a speculative scenario. They are not a scientific forecast. They are a spur of the moment speculation. That criticisms of such comments seems so important to deniers suggests they have nothing substantive to say about the actual science. Second, even if we allow Hansen's comments as being a substantive scientific contribution as the deniers seem to want us to do, they are clearly obsolete. This is worse than trying to dam AR4 because The First Assessment report contained a minor error. This does not mean it is inappropriate to compare Hansen's predictions with later events. However, to do so, you should take his published opinions (not of the cuff remarks), and you should allow the predictions to be adjusted in light of detailed knowledge in which there has been a clear advance since the prediction (such as the range of plausible values for climate sensitivity). This is not mystical prognostication, it is science. Third, it is very unclear what is actually predicted. The most straight forward interpretation (to me) of the prediction is what would New York look like 40 years after a doubling of CO2, ie, after the effects of such a doubling had time to impact the global climate system. So, this conversation is premature anytime before 40 years after such a doubling. On current estimates, that should be some time around 2090.
  45. Examining Hansen's prediction about the West Side Highway
    With regard to possible sea-levels at unspecified times in the future, it seems things are still not looking as hopeful as some so-called skeptics would like to believe : Polar ice loss quickens, raising seas
  46. Eric (skeptic) at 23:07 PM on 10 March 2011
    Climate Emergency: Time to Slam on the Brakes
    Moderator: the post #8 by alan_marshall contains extra html and body tags which affects some browsers such as lynx (although not Mozilla). The specific effect is that all the posts following are unnumbered (probably due to the /html in #8)
    Moderator Response: [DB] Fixed, thanks!
  47. Examining Hansen's prediction about the West Side Highway
    Jesús Rosino, Thanks for the links. The Bounoua et al 2010 paper is interesting but also rather confusing, at least to me. They state a base line of 350 ppm and talk about doubling to 700 ppm. What is confusing is that all three of their modeled scenarios only extend 30 years. That is not anywhere realistic for a doubling of CO2. I admit that I only gave it a fast read and maybe I'm missing something. Nevertheless, I still think the Hansen discussion is a pre industrial base line.
  48. Christy's Unconvincing Congressional Testimony
    From Christy's written testimony:
    "Secondly, regarding the recent Australian flooding as a physical event in the context climate history (with the estimated 2010 maximum river height added to the chart below) one sees a relative lull in flooding events after 1900. Only four events reached the moderate category in the past 110 years, while 14 such events were recorded in the 60 years before 1900. Indeed, the recent flood magnitude had been exceeded six times in the last 170 years, twice by almost double the level of flooding as observed in 2010."
    Christy supports these claims with a chart of flood heights of historical Brisbane River floods as measured at the Port Office, with the height of the 2011 flood marked in as a red bar. What he does not do is mention the effects of dams built on the Brisbane River and Stanley river (a tribuatary of the Brisbane) designed specifically to have a very large flood mitigation capacity. Is is very obvious why he does not. Modelling of the effects those dams would have had on historical floods has been carried out, and show that had those dams existed throughout the period of settlement, the 1893 flood would have peaked at 3.36 meters and the 1974 flood at 3.48 meters, compared to the 2011 flood's 4.46 meters. This is not evidence that helps make Christy's case, so unsurprisingly he makes no mention of it. But to not mention the potential impact of two major dams on the headwaters of the river when making such historical comparisons is at best negligence that calls Christy's ability as a scholar in to serious question, and at worst is a deliberate and transparent deception. Curiously, on the same day Christy made his testimony, SEQWater released its report on the 2011 flood. It shows modelling of the size of the 2011 flood as it would have been without dams. I have indicated the levels of the 1893 flood (no dams) and 1974 flood (Sommerset only) on the chart: (You will notice that although the 1893 flood would have been reduced below 2011 flood levels by the presence of both dams, it in fact had a greater volume of flow unimpeded. The difference is due to the different impacts of the dams based on differences in location, timing and patterns of rainfall. I did not have that information in my blog linked above, so some claims in it are in need of updating.) Christy goes on in his testimony to repeat slanders from The Australian, in particular that the flood was caused by negligence by the dam operators, and that 80% of the flood water came from a massive emergency release. On the chart above is modeled the flooding in Brisbane had there been no releases from the dam, and the flooding in Brisbane if only water released from the dam had been involved. At no point until well after the peak does the water from the dam exceed the levels of water from other tribuataries of the Brisbane. Clearly the Australian's claim, repeated uncritically by Christy is false. In fact the immediate cause of the flood was an Annual Exceedance Probablity 1 in 2000 year rainfall onto the immediate surrounds of Lake Wivenhoe, that rapidly drove the lake above safe levels. Of course, mentioning an AEP 1 in 2000 year event which was part of a larger AEP 1 in 100 to 1 in 200 year event, which followed just a fortnight after an (estimated) AEP 1 in 50 year event, which in turn followed by a mere 37 years an AEP 1 in 70 year event does not make a compelling case that wild weather is not on the increase. Far better to repeat glib falsehoods (apparently) then to actually analyze the data. (As a side note, Christy got his chart of Brisbane Flood levels from Roger Pielke Jr and hence had access to the information above about the effects of the dams before he made his report based on my comment 17.)
  49. Examining Hansen's prediction about the West Side Highway
    HR: Hansen was assuming CO2 would double by 2028. Are you saying that assumption is wrong? Aside from Hansen not giving a time-line, his comments were about a doubling of CO2. Any time-line is irrelevant.
  50. Christy's Unconvincing Congressional Testimony
    John Christy, from his written testimony:
    "In the first aspect of temperature change, we have shown that the pattern of change at the surface does indeed show warming over land. However, in very detailed analyses of localized areas in the US and Africa we found that this warming is dominated by increases in nighttime temperatures, with little change in daytime temperatures. This pattern of warming is a classic signature of surface development (land cover and land use change) by human activities. The facts that (a) the daytime temperatures do not show significant warming in these studies and (b) the daytime temperature is much more representative of the deep atmospheric temperature where the warming due to the enhanced greenhouse effect should be evident, lead us to conclude that much of the surface temperature warming is related to surface development around the thermometer Subcommittee Energy and Power 14 John R. Christy, 8 March 2011 sites. This type of surface development interacts with complexities of the nighttime boundary layer which leads to warming not related to greenhouse warming (Christy et al. 2006, 2009, see also Walters et al. 2007, Pielke, Sr. 2008.)"
    (My emphasis) First, Christy claims that increased night time temperatures relative to day time temperatures is a "classic signature of surface development", which is itself false. Replacing grassland with concrete or tarmac (as at an air field, for example) will increase day time temperatures and decrease night time temperatures because of the reduced water content and hence heat capacity of the surface. It will also increase the difference because vegetation takes some of the incoming energy and stores it as chemical energy, which is then released over the full diurnal cycle. What is worse than that nonsense, however, is the claim that warming due to the green house effect will have a maximum effect in day time relative to night time (b). That is a straight forward falsehood. I doubt Christy can produce a single GCM result that supports that claim. On the contrary, simple analysis (as first done by Arrhenius in 1896, and confirmed by GCMs since shows that the effect of greenhouse gases is to reduce the diurnal cycle. IMO, this is not a mistake that could be made by anyone familiar with the literature on the green house effect.

Prev  1853  1854  1855  1856  1857  1858  1859  1860  1861  1862  1863  1864  1865  1866  1867  1868  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us