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  1174  1175  1176  1177  1178  1179  1180  1181  1182  1183  1184  1185  1186  1187  1188  1189  Next

Comments 59051 to 59100:

  1. Lindzen's Clouded Vision, Part 1: Science
    shoyemore @12 - aerosols are sort of a "fudge factor" in models by necessity, simply because we don't have good measurements as to the strength of their cooling effect. We do have good measurements of the temperature change, and of most other forcings, so the aerosol focing is allowed to vary within certain constraints in order to best fit the observed temperatures. You can call that a 'fudge factor' if you like. However, as noted in the post above, they do not have zero temperature influence, as Lindzen assumes. Better to treat them as a 'fudge factor' than a neglected factor.
  2. Lindzen's Clouded Vision, Part 1: Science
    JoeT @10 - the timescale to equilibrium is something of an unresolved question, which I think we'll be addressing in a future blog post. Off the top of my head, I think that after 50-100 years, somewhere in the ballpark of two-thirds to three-fourths of the equilibrium warming is realized. It mainly depends on how efficiently heat mixing happens in the oceans, which is the somewhat unresolved question. So yes, if we were to suddenly stop emitting CO2, we'd see most of the consequent warming within a century, but not all of it.
  3. Lindzen's Clouded Vision, Part 1: Science
    CBDunderson: Thanks very much for your post. Actually the hundreds to thousands of years was in post #2 just above, which also says the response time is not decades. What I got from your post is that there is a fast and slow time response. Could you elaborate for me -- or point me in the right direction -- as to what constitutes the physical processes that account for the two time scales. Thanks again. I've learned a great deal in the short time I've been following this site.
  4. Lindzen's Clouded Vision, Part 1: Science
    Incidentally, Professors Lindzen and Happer, plus Roger Cohen (formerly of Exxon) have responded in the letters section of the May 9th New York Review of Books to Yale Professor William Nordhaus' critique of the op-ed "No Need to Panic About Global Warming" by the group known as the Wall Street Journal 16 Their response to Nordhaus is basically a scatter gun (or Gish gallop, if you prefer!) with not much science. The most scientific parts are general attacks on climate models for not including all sources of variability, and for including aerosols as a "fudge factor" only. Perhaps a future post could cover this? Professor Nordhaus' reply is shorter, clearer and more effective, IMHO. In the Climate Casino SkS covered Nordhaus' original article here: Nordhaus sets the Record Straight
  5. CBDunkerson at 04:01 AM on 8 May 2012
    Lindzen's Clouded Vision, Part 1: Science
    JoeT, I think the 'hundreds to thousands of years' you are referring to (which doesn't appear to be in the comments to this post) may be the 'long term' sensitivity. Most estimates put the eventual warming for doubled CO2 at around +6 C after all slow feedbacks have played out over hundreds to thousands of years. We're about half way to doubled CO2 forcing now, so ~3 C would be the eventual long term warming expected from current CO2 levels. However, the +3 C figure more frequently cited is the 'fast feedback' value... if we double atmospheric CO2 levels then we expect to see +3 C warming within decades. How many decades depends mostly on how fast we raise the CO2 level, but certainly less than a hundred years. The warming we've been seeing the past few decades has been the result of direct CO2 forcing (which is more or less immediate) and these 'fast feedbacks'. If we could stop CO2 at current levels then within about 50 years the FAST warming would stop at around +1.5 C (we're currently at ~ 0.8 C) and then only slowly go up to +3 C over the course of hundreds of years.
  6. Ocean Heat Content And The Importance Of The Deep Ocean
    BC @59, as you seem to have realized, 1000 Petagram = 1 trillion tonnes, and yes, to have a better than 50% chance of avoiding rises in Global Mean Surface Temperatures below 2 degrees C, we need to keep total CO2 equivalent emissions below 1 trillion tonnes. It is generally accepted that rises of GMST or more than 2 degrees C will have major, net harmful effects, and a considerable body of opinion thinks the relevant limit is 1.5 degree C, to avoid which we need to keep CO2 levels below 350 ppmv, or as we have already passed that, quickly bring CO2 levels back down. With regard to the ENSO effects, changes in ENSO state have been shown to significantly effect the accumulation of Ocean Heat Content from 0-750 meters, with the "missing" heat turning up in the 750-2000 meter range. That is certainly much deeper than the mixed layer, but whether you would call it the upper levels? I don't know. What is more, I known no more about it than that, so I cannot comment on the specific movements of heat involved.
  7. 2012 SkS Weekly Digest #18
    My "canary" is the biosphere's visible response to the warming planet. That is like the squawk of the canary as it struggles to breathe. The thump of the canary on the cage floor will be widespread food riots.
  8. Lindzen's Clouded Vision, Part 1: Science
    Sorry to even further low-brow the thread, but I'm trying to catch up on the topic. Great article, but when reading it my immediate question was in fact -- what is the time scale for equilibrium? I see in the comments that the answer is hundreds to thousands of years. Is it mistake to infer from this 1- That present warming is a result of emissions from a hundred years and more. 2- That if all CO2 emission were cut-off now, it would take hundreds of years to see the warming stop.
  9. Rob Honeycutt at 03:00 AM on 8 May 2012
    Lindzen's Clouded Vision, Part 1: Science
    What really got me when watching the video where Lindzen states that it "should have" warmed 3C by now was... If you look at any projections by any scientists, or the IPCC, there is no one anywhere who has ever put out a graph showing 3C of warming by now. Zero. None. It's a completely outrageous claim that Lindzen makes. It's the mother of all straw man arguments. I was literally slack-jawed in amazement that he made such a statement.
  10. Lindzen's Clouded Vision, Part 1: Science
    Dana @4, I agree with you that Alex is missing the point. I would also argue that he is not accurately reflecting the content of Dr. Held's recent blog post, but I won't let us get sidetracked by that red herring. "He's arguing for ~1°C sensitivity, for which there is almost no supporting evidence." It is worse than that Dana. Lindzen has, for a long time, been arguing for a climate sensitivity less than < 1 C for doubling CO2. In 1997 Lindzen published a colloqium paper in PNAS, he stated that: "Indirect estimates, based on response to volcanos, suggest sensitivity may be as small as 0.3–0.5°C for a doubling of CO2, which is well within the range of natural variability." In the much refuted Lindzen and Choi (2009) paper, Lindzen and his coauthor claim that: "...and ERBE data appear to demonstrate a climate sensitivity of about 0.5 C which is easily distinguished from sensitivities given by models." There is that 0.5 C again... In Lindzen and Choi (2011), they revised their estimate upwards slightly to 0.7 C for doubling of CO2: "As a result, the climate sensitivity for a doubling of CO2 is estimated to be 0.7K (with the confidence interval 0.5K - 1.3K at 99% levels)".
  11. Michael Whittemore at 01:31 AM on 8 May 2012
    2012 SkS Weekly Digest #18
    My "canary in the coal mine" is increased infrared radiation from CO2 hitting the Earths surface. It seemed so obvious to me when I found that out. It also seems very cunning how the "Words of the Week" explain this process so well just as the "canary" question is asked. But this increased radiation seems impossible to ignore. Even if there was a cloud feedback due to cosmic rays, there would really only be a cooling and warming from their fluctuations. The average global temperature would still increase with added CO2.
  12. Lindzen's Clouded Vision, Part 1: Science
    DC: Good question. The relationship is indeed non-linear - logarithmic in fact. Since we are now at 1.41 x preindustrial, and 1.41=√2, the forcing is almost exactly half way to that of a doubling of CO2. The 76% figure comes from adding the CO2-equivalent of all the other greenhouse gasses we've put into the atmosphere.
  13. Lindzen's Clouded Vision, Part 1: Science
    Sorry to low brow the thread but I was wondering how the figure of 76% (additional) of pre-industrial CO2 forcing is arrived at? my current thinking is along the lines of: CO2 in 1750 ~= 280 ppm CO2 in 2012 ~= 393 ppm So CO2 increase is about 114 ppm which is an increase of (114/280) 41% Where am I going wrong? Is this related to the non-linear relationship between forcing and increased CO2?
  14. Michael Whittemore at 00:59 AM on 8 May 2012
    Lindzen's Clouded Vision, Part 1: Science
    Great post, and good commenting, people are so quick to twist the truth. Even if this truth twisting is done advertently or inadvertently, climate science needs people to make sure the topic is on the right track. Keep up the good work.
  15. 2012 SkS Weekly Digest #18
    Issue of the week: for me, it's the obvious and known Arctic sea ice.
  16. Lindzen's Clouded Vision, Part 1: Science
    alexharv074 @1 - first of all, we at SkS always keep our posts free of ad hominem attacks, so there is nothing unusual about this. Second, you're not addressing the point of the post. The point of the post is not that no evidence exists for relatively low sensitivity. The point is that Lindzen's argument - that the fact that the planet hasn't warmed 3°C means climate sensitivity is low - is wrong. Third, Schmittner's best estimate equilibrium sensitivity was 2.3°C, and there are good reasons to believe the estimate is too low, as we discussed in our post on the paper (mainly their estimate of the interglacial temperature change is much lower than any previous estimate). Fourth, Lindzen isn't arguing for ~2°C sensitivity, which would be within the IPCC range. He's arguing for ~1°C sensitivity, for which there is almost no supporting evidence. I'm glad we do at least agree that Lindzen's claim is ludicrous.
  17. Ocean Heat Content And The Importance Of The Deep Ocean
    I've just looked it up. The limit was that emissions must be less than 1 trillion tonnes = 10**18. Sorry about the confusion.
  18. Ocean Heat Content And The Importance Of The Deep Ocean
    Actually maybe it was a trillion Kg = 10**15?
  19. Ocean Heat Content And The Importance Of The Deep Ocean
    Tom @58, thanks. That explains the CO2 side quite well. Is a 1000Pg pulse = a trillion gigatonnes (=10**(12+9+6)=10**27g)? I'm pretty sure that this was a target mentioned by Julia Guillard (Australian Prime Minister) last year that the world needs to stay below. The La Nina occurs when there is a flow across the Pacific from east to west with the ocean up-welling colder water near Peru (this is my understanding anyhow). So I'm guessing from your not mentioning it that this doesn't involve the deep ocean, just the upper levels?
  20. Bob Lacatena at 23:14 PM on 7 May 2012
    Lindzen's Clouded Vision, Part 1: Science
    Alex, I see no reference whatsoever to a sensitivity of 1.9˚C in the Schwartz paper. Are you sure that you are reading it properly? It's a very interesting exercise in estimating climate sensitivity, and yet it is constrained (as the paper itself points out) by the inherent errors of the observations used as inputs into the model as well as the method used. In particular, multiple sources of inputs are used, yielding a range of sensitivities that roughly cover the span presented by the IPCC AR4. And as always the issue is muddled by the difficulty in estimating the negative aerosol forcing over the past 100 years. You also seem to fail to distinguish between transient and equilibrium climate sensitivities, and the distinction is important. I suggest you read up on that. Lastly, I myself have to question any method that attempts to infer equilibrium climate sensitivity from short term observation. The reality is that I think one needs at least 100 years of clean data, maybe more, with a constant, measured forcing, in order to do so. Trying to estimate equilibrium climate sensitivity from 20th century observations is a little like trying to guess the top speed of a race car on a track by observing one minute of acceleration and braking in deep mud on a hazy day from a distance of 5 miles with an hour glass for a timer. The bottom line here is that (1) the discussion of climate sensitivity is complex and (2) Lindzen's claim is ludicrous.
  21. Lindzen's Clouded Vision, Part 1: Science
    Alex: I'm puzzled by your response. There is certainly a real discussion on the actual values of both the TCR and the EQS. You highlighted some low estimates, we could also find some high ones. But the IPCC itself suggests estimates in the range 2-4.5C for EQS, and 1.9C certainly isn't out of the question. However, Lindzen's claim is that according to the consensus position we should have seen 3C temperature rise by now, rather than 0.75C we have seen. But that's not what the consensus scientific position says. The 3C figure he quotes is a response to total change in forcing from pre-industrial, not GHG forcing alone. And the time required for that response to be reached is measured in centuries to millenia, not decades (e.g. Hansen and Sato 2011 Fig 7, or similar figures from Held, Padilla and Vallis 2011, or Rypdal 2012). So I don't understand how Lindzen's claim can be seen as anything other than a complete misrepresentation of the consensus position.
  22. 2012 SkS Weekly Digest #18
    Yes, I noticed that. Very gratifying. A nice recognition that the approach here is useful for others aiming to educate.
  23. 2012 SkS Weekly Digest #18
    I was pleased to see the number of SkS graphics appearing in the DCCEE's patient debunking of Plimer's book targetting schoolkids.
  24. Why Are We Sure We're Right? #2
    (-Snip-)
    Moderator Response:

    [DB] Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Moderating this site is a tiresome chore, particularly when commentators willfully submit offensive posts with direct accusations of dishonesty. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.

    Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues may be in the offing.

    Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

  25. Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
    I think it's worth adding to this discussion that the rectifying properties of a diode are due to a voltage barrier or gradient inside the material. Following this analogy (not a good one I think), it's the temperature gradient in the atmosphere that causes the its "rectifying" properties. Indeed, the greenhouse effect depends on the lapse rate (temperature gradient) and there would be none if the atmosphere was isothermal. The OLR would be the leakage current of the "atmospheric diode", luckly not a good one :)
  26. alexharv074 at 17:45 PM on 7 May 2012
    Lindzen's Clouded Vision, Part 1: Science
    Hi Dana, Thanks for the interesting post and for keeping it unusually free of ad hominem attacks. I would like to question your claim that,
    There simply is no question - Lindzen's claim that the Earth hasn't warmed as much as expected, which is the basis of his low climate sensitivity argument, which is the basis of all remaining relatively credible climate contrarianism, is entirely false based on three fundamental physical flaws in his argument, as demonstrated by simply comparing the models and observations.
    This is a very bold statement, and I think an exaggerated and false statement. I think you would be more skeptical if you were less selective in your appeals to the literature. We have seen Gillett et al. (2012), even discussed here, that suggests the transient climate response (TCR) is in fact less than expected, based on observations. And just the other day Isaac Held published a very interesting article here arguing that Gillett et al. are probably about right. Prof. Held also argues that the observations of TCR are consistent with fixed relative humidity models with no cloud feedback. Recently, Schwartz (2012) has also argued from observations of the 20th century that equilibrium climate sensitivity is about 1.9 K per doubling of CO2. Although Held apparently has reservations about extrapolating from TCR to ECS, I do note that the IPCC AR4 states that climate models, without the cloud feedback, predict a climate sensitivity of about 1.9 K, the same as what Schwartz has found. We have seen other arguments from paleodata - e.g. Kohler et al. (2010); Schmittner et al. (2011) showing, for completely different reasons, that ECS is likely to be about 2.3 K per doubling CO2. Finally, Prof. Lindzen has referred to a number of other papers in literature that support lower sensitivity and you appear to have ignored all of them.
  27. muoncounter at 13:03 PM on 7 May 2012
    ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
    Cole#40: "I'm not simply declaring Agees results as 'meaningless'." Sorry, what I must have misunderstood is your #30: "So the results of said paper are spurious at best." If you've read anything beyond the abstract of Agee's quite comprehensive review of the current literature, you wouldn't be throwing 'spurious' around: It is clearly evident that the positive trend in previous solar cycles and lower troposphere cloudiness has not continued for the cycle 23-24 QP, which adds to the controversy of the GCR-CCN hypothesis. Not only has the GCR count received a record high level during the cycle 23-24 QP, but the lower troposphere global cloudiness has dropped to a record low level, further challenging the validity of the hypothesis. I suggest you study the remaining references in this post that question the cosmic ray-climate connection. Then there's Love 2011, as noted here and Laken 2011: We find no evidence that widespread variations in cloud cover at any tropospheric level are significantly associated with changes in the TSI, GCR or UV flux, and further conclude that TSI or UV changes occurring during reductions in the GCR flux are not masking a solar-cloud response. "As for your Realclimate post, how would you like it if I started relying on blog-science?" That 'blog-science' was written by Dr. Jeff Pierce, who has published on cloud nucleation mechanisms. Refer also to Pierce and Adams 2009: In our simulations, changes in CCN from changes in cosmic rays during a solar cycle are two orders of magnitude too small to account for the observed changes in cloud properties; consequently, we conclude that the hypothesized effect is too small to play a significant role in current climate change. "the direct correlation between CRF and T over the Holocene that clearly doesn't exist with CO2" Talk about an 'own goal.' Please show us the cosmic ray flux data - not any of those suspicious 'proxies' - for the Holocene. Then refer to numerous articles here showing the excellent correlations between CO2 and temperature.
  28. Lessons from Past Predictions: Hansen 1981
    pauls: I've actually had a chance for a quick look at the IPCC section you linked to. Please refer to the section of text in Section 8.6.2, and note the part where is says:
    and is often simply termed the ‘climate sensitivity’. It has long been estimated from numerical experiments in which an AGCM is coupled to a simple non-dynamic model of the upper ocean with prescribed ocean heat transports (usually referred to as ‘mixed-layer’ or ‘slab’ ocean models) and the atmospheric CO2 concentration is doubled.
    You referred in your comment to the "slab ocean", and called it "little more than a surface with a low heat capacity". In contrast, the IPCC report talks about the mixed layer (roughly 60-100m thick) of the ocean, and specifically says that it has "prescribed ocean heat transports". That doesn't sound like "a surface with a low heat capacity" to me. It sounds like they are leaving out the deep ocean, not calculating ocean movements, but just specifying the heat storage and transfer within the mixed layer. Can you explain why you think this is "just a surface with a low heat capacity"? I will continue to look through the IPCC report, to see if there are more details. It may be necessary to look at some of the papers in its references, however. I'd like to know more about just what "ocean heat transports" are prescribed.
  29. Report Warns of Rapid Decline in U.S. Earth Observation Capabilities
    cutting off funding from the only people who are minding the storm. Talk about shooting yourself in the foot. Off topic, but... what are the longitudinal bands in the image above? Dust? Artifacts?
  30. ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
    I'm not simply declaring Agees results as 'meaningless' I'm saying you are misunderstanding them. Agee reported on a 'possible' disconect and even mentioned large uncertainty in the data they used to come to the conclusion. As I've stated many times now, we don't have the technology to detect a 2% change in GCC so your whole answer up untill the microphysics comment is ineffectual. Furthemore, just because we can not detect a two percent change does not mean it isn't happening. As for your Realclimate post, how would you like it if I started relying on blog-science? Maybe I should look up some denier sites and use their arguments? If you want to refute, please use a solid peer-reviewed science. "Your jump from Kirkby's " Kirkby is just a small example on this subject, I was only trying to show you the direct correlation between CRF and T over the Holocene that clearly doesn't exist with CO2. I was simply making a statement in the context of the Holocene, that is very much supported by the data.. If you would really like I could show you a plethera of papers, on this subject spanning the entirety of the geologic eras and show you exactly the same thing. Your statement of the Agee paper being a "swing and a miss" for Svensmark ended up being an own goal for yourself, given what the paper actually said. (-snip-).
    Moderator Response: [DB] Off-topic snipped. Again, please review the Comments Policy linked earlier before commenting further.
  31. ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
    skywatcher, Cole - And don't forget: (d) A bad paper is published, recognized as such by the majority in the field, and essentially ignored (not cited) by anyone who isn't following the same bad logic. For example: the Gerlich and Tscheuschner paper claiming the 2nd law of thermodynamics (truly silly, now disavowed even by folks such as Fred Singer) was well on its way to that fate when repeated trumpeting by 'skeptics' led to published rebuttals.
  32. ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
    You've got to love how arguments from authority operate in one direction in the skeptic universe. Suddely because a skeptic's paper is successfully published by the RAS, it is deemed to be flawless, having clearly undergone thorough and utterly rigorous peer-review by experts in the relevant field(s). Yet nearly every relevant climate expert on the planet, and certainly every relevant scientific organisation, agrees that anthropogenic CO2 is causing most of the current rapid warming. Many thousands of papers have been published with this view, all peer-reviewed. Why the disconnect for the 'skeptics'? Bad papers get published. Lets ignore for a moment that the RAS are probably not the greatest repository of scientific expertise on climate, and mention a few other papers. One (McLean et al 2009) was published in GRL even though the authors removed the long-term trend then argued that the short-term variation was causing the long-term trend. Another paper confused degrees with radians at a crucial point. Yet another paper (Spencer and Braswell IIRC) managed to examine a bunch of models and leave out the model runs that demonstrated their hypothesis was critically flawed. So Cole, quite apart from muoncounter's excellent points, which of the following statements do you agree with: (a) There is no such thing as a 'bad' paper and everything that is peer-reviewed is clearly good science. Peer-reviewers are always flawless in their work. (b) Some bad papers get published. These bad papers are either ignored, or subseqiuent responses are published that demonstrate the critical flaws in the reasoning of the author(s). Peer reviewers are human, and despite doing an excellent task in filtering out the very worst papers, occasionally give a pass to a poor paper. This most often happens when the journal's expertise is not ideally matched to the subject matter. [An example of a response is Foster et al 2010, the response to McLean et al 2009] (c) The RAS has never, ever, published a paper subsequently discovered to have been flawed in some way.
  33. Lessons from Past Predictions: Hansen 1981
    pauls: Thanks. I'll try to read through it. I'll also be off the net for the next week or so, so I won't be able to reply soon.
  34. muoncounter at 09:26 AM on 7 May 2012
    ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
    Cole#35: You can summarily declare Agee's results 'meaningless' if you like, despite publication in the Journal of the AMetSoc. Perhaps not as prestigious as the Monthly Notices of the RAS, but that really proves nothing. But look at the references in the post: Calgovic, Erlykin x3, Lockwood x2, Pierce... all with negative re-evaluations of the so-called 'looks pretty good' correlation between CR flux and temperatures. Lakin (more than paper) had similar results. Your objection to Agee ("we can't really detect changes in GCC") makes it clear how weak the whole GCR->cloud story really is. We just came through a 50 year high in GCR flux (2009): Where are the clouds? As for the supposedly 'glove-fitting microphysics,' Pierce took that apart at RealClimate. Perhaps you'd be better off with the 'does not fit' defense. Your jump from Kirkby's "... question of whether, and to what extent," to "Clearly, carbon dioxide is not the all-important dominating factor... " in one sentence is stunning. Kirkby's language is the same style as the 'possible disconnect' you found objectionable in Agee. We've gone from GCR->clouds to supernovae->GCR->cooling->mass extinctions. Of course, you've missed the fact that the peak SN frequency on Svensmark's graph is some 50 Myrs before the PTr extinction. You've also ignored what should be the primary objection to the supernova idea: they're not necessarily the source of GCRs. And then there's Montenegro et al 2011, showing that the PTr extinction coincided with increased ocean anoxia and that decreased ccean pH "brought about by the increase in atmospheric CO2 is biologically significant.". Supernovae doing that, too? "you guys deliberately misrepresent papers... " That kind of language usually gets your comments deleted. Please try to come up with more than 'that statement is ludicrous' -- and have a look at the Comments Policy.
  35. Lessons from Past Predictions: Hansen 1981
    Bob Loblaw, IPCC chapter 8. Check the caption for table 8.2.
  36. Why Are We Sure We're Right? #2
    Tarcisio José D @37, I have responded in detail on another, more appropriate thread, and suggest that you do likewise. I understand that you are using "Google translate" in order to overcome a language barrier. You are to be commended for your efforts to do so, but "Google translate" is not up to the task, and I recommend that you enlist the aid of a technically proficient, and bilingually fluent friend to aid you. In essence, my response points out that the atmosphere does in fact have the diode like property of emitting more radiation downward to the surface than it does upward to space (which my not be quite what Tarcisio meant by his use of the phrase), and that it has this property despite the fact that no individual component of the atmosphere has the property. I go on to point out that detailed modelling shows the property to exist, and that those models have been shown to be remarkably accurate by empirical observation, and that indeed that diode like quality of a higher downward IR radiation from the atmosphere than the upward IR radiation at the Top of the Atmosphere has been observed empirically.
  37. Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
    This is a response to Tarcisio José D from another thread. In response to my explanation, he asks:
    "My question is, which quality of your atmosphere makes it only absorbs IR radiation that rises in the atmosphere and free passes IR radiation that the atmosphere emits more toward the ground."
    In fact nothing I wrote suggests the gases within the atmosphere act as a diode. Each IR active gas will absorb IR radiation with equal facility from all directions, and emit it with equal probability in all directions. However, the atmosphere as a whole acts as a diode. That is, it emits more IR radiation upwards to space than it does towards the ground. It does this because the emission to space comes from higher, and cooler layers within the troposphere as explained in the article above, and also in my posts 36, 51, and 58 above. Importantly, Line By Line (LBL) models, which calculate the IR emission and absorption in the atmosphere at each wave number, and which require each layer of the atmosphere absorbs IR radiation with equal facility whether the radiation comes from below or above, or from the atmosphere or the surface, and which requires that each layer radiates equal amounts of IR radiation upwards and downwards, produce this diode like effect, provided that the atmosphere is cooler at higher altitudes. You can see this for yourself with Modtran. If you run the model on default settings, the outgoing IR radiation equals (Iout) 287.844 W/m^2. Altering the settings to sensor altitude = 0 km, and "looking up" shows the downward long wave radiation from the atmosphere (Iout) is 348.226 W/m^2. The accuracy of these LBL models is shown in the section "Settled science" in the main article, and in my post number 43. It should be noted that the observed upward IR radiation from the top of the atmosphere is 239 W/m^2, while the observed downward IR radiation at the bottom of the atmosphere is 333 W/m^2, amply illustrating this diode like quality of the atmosphere as a whole, even though no individual component (gas molecule) of the atmosphere acts like a diode. I understand that Tarcisio José D is facing a considerable language barrier in communicating in English, and is to be commended for his efforts to overcome that barrier. I recommend that he read carefully this post, the main article above, and the posts linked to in my response. If he is having difficulty in understanding the issue, I also recommend he enlist the aid of a technically proficient friend who is fluent in both English and his native language (which I assume is Spanish or Portuguese). Google translate is not up to translating technical discussions accurately, and will only lead to ongoing confusion. Finally, the issue he needs to address is, why should we prefer his hand waving explanation to the detailed results of LBL models which have proven remarkably accurate in predicting the observed radiation in the atmosphere, whether sampled from satellites, the ground, or aircraft at intermediate levels of the atmosphere?
  38. 2012 SkS Weekly Digest #18
    "canary in the coalmine"? I take that as something we'll look back on in 30-50 years time and say - someone should have put it all together right then and there. For me, that's the reduction in inflows to Perth's water storages in the 70s. Few cities are better placed to show the effects of expansion of Hadley cells ..... and that it's a bad thing.
  39. Why Are We Sure We're Right? #2
    victull @28 - you're comparing different energy imbalance estimates. As I said, take a look at the Levitus post. Model-based estimates of a 0.9 W/m2 imbalance were probably over-estimates. We'll have more on this in the future.
  40. ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
    Tom, "A higher sea level will result in flooding of low inland ar-eas, and increase the total length of coastline and the area of the continental shelves. This results in more heterogeneous habitats in which species can evolve, leading to an increase in diversity, and Miller et al. (2005) offer this as the reason for the development of the three eukaryotic phytoplankton clades (lineages) that dominate the modern ocean. >But the rough correspondence between marine invertebrate diversity and sea level seen in Fig. 19 is plainly not the whole story
    Moderator Response:

    [DB] Allegations of misrepresentation are seriously in violation of this site's Comments Policy, just as they are on the SkS FB page.

    Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive or off-topic posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.

    Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.

    Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

  41. Why Are We Sure We're Right? #2
    Tarcisio Jose D. What I find so interesting is the statement: "I am very sure that I am right in saying that all who believe in the warming of our planet is caused by CO2 are totally wrong," which then implies that you have chosen to believe a couple of video from dubious sources with laughable science over the bulk of known heavyweight physics. Now why would do such a strange thing? As you are finding out, things are more complicated than thought and the science is better, but why did you choose to trust such strange sources over known science. You claimed to be "very sure" which is also extraordinary. It would be really interesting if you could explain why you trust one source over another. As the "rectifier". DK, Bob, I dont think Jose is claiming the atmosphere works like a rectifer. He is trying to understand Tom and thinks that climate theory requires the atmosphere to behave like a rectifier because he hasnt understood the theory. This isnt that straightforward to follow. Eli Rabett did a good explanation I think but I cant find it. Any got a pointer? Jose, people are trying to make the greenhouse model explicable but ultimately the test is in doing the calculation. The real model with the equations can be found in Ramanathan and Coakley 1978. You need a computer to calculate the equations, but how do we know that is it right? Well because it predicts what we can observe of spectrum etc, with a very high degree of precision.
  42. ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
    Muon, Sure, he's the sole Author, big deal. It passed review and look where it's published. Agee's result is meaningless. We would only need a 2% change in global cloud cover (GCC) to account for the warming trend experienced. As I stated we can't really detect changes in GCC (let alone a mere 2%) as we don't have the proper technology. Agees' result is spurious at best, and the paper even makes it clear that it is only a "possible" disconnect. The CLOUD results didn't prove Svensmark correct as they couldn't make actual clouds. The thing it did prove is the microphysics are defiantly at work. According to Kirby they should have conclusive results within 5 years. The SKS "coffin nails" article is really counting chickens before they hatch. Sure the CLOUD experiment didn't prove Svensmark theory, but the microphysics fit like a glove. Furthermore, if you look at the correlation between CRF and T over the geological eras right up until present it's quite uncanny. Just looking at the last 10-12,000 years Kirkby (2008) rightly notes, “the question of whether, and to what extent, the climate is influenced by solar and cosmic ray variability remains central to our understanding of the anthropogenic contribution to present climate change.” Clearly, carbon dioxide is not the all-important dominating factor in earth’s climatic history. Within the context of the Holocene, the only time CO2 moved in concert with air temperature was over the period of earth’s recovery from the global chill of the Little Ice Age (the past century or so), and it does so then only quite imperfectly. The flux of galactic cosmic rays, on the other hand, appears to have influenced ups and downs in both temperature and precipitation over the entire 10-12 thousand years of the Holocene, making it the prime candidate for “prime determinant” of earth’s climatic state. http://arxiv.org/abs/0804.1938
  43. Why Are We Sure We're Right? #2
    Tarcisio José D: How can I say this politely? Models of radiation transfer in the atmosphere do consider both upward- and downward-directed radiation, and the absorption/transmission/scattering/emission in both directions. Where on earth did you get the idea that they don't? Your ignorance is shining through like the headlight on an oncoming train. You really need to find some better sources of information.
    Moderator Response: [Dikran Marsupial] Can I suggest that we ignore Tarcisio José D until he either posts a reference to a scientific paper that suggests the atmosphere does behave like a rectifier.
  44. kampmannpeine at 05:59 AM on 7 May 2012
    Report Warns of Rapid Decline in U.S. Earth Observation Capabilities
    when I observe this here from Europe I see larger problems arising. On the other hand I recently heard that China is enlarging their space programme by themselves. They obviously do not like cooperation with anybody else ... Sad, sad, sad
  45. Rob Painting at 05:44 AM on 7 May 2012
    Why Are We Sure We're Right? #2
    Victull - "How do conclude that the imbalance is growing when it was about 0.9W/M2 and over the last 5-6 years is about 0.6W/sq.m?" Dana is likely referring to the long-term trend. Greenhouse gases, such as carbon dioxide, have a very long lifetime in the atmosphere, so the warming effect will be persistent and will grow over time as more fossil fuels are burnt. By contrast, the recent cooling effect imposed by natural (volcanic) and human-made aerosols, are short-lived and may not grow to match them. Additionally, despite the short-term fluctuations (as shown in figure 11 of Hansen [2011]), the global energy imbalance has undergone a long-term increase. SkS will be covering this in the near-future, as it's a source of confusion for many.
  46. Tarcisio José D at 05:18 AM on 7 May 2012
    Why Are We Sure We're Right? #2
    Sphaerica @36 and Tom Curtis @ 32 Replay my post corrected..... Tom Curtis @ 32 Very interesting theory. But ..... My question is, which quality of your atmosphere makes it only absorbs IR radiation that rises in the atmosphere and free passes IR radiation that the atmosphere emits more toward the ground. I believe that there is'nt this "rectifier diode" in our atmosphere and the greenhouse effect works both in one direction as another.
    Moderator Response: [Dikran Marsupial] Please can you supply a reference to a peer-reviewed scientific paper that suggests that GHGs only absorb IR radiation that rises in the atmosphere, a page number in the IPCC WG1 report will do fine. Unless you supply evidence that mainstream science makes such an assumption, I will assume that it is merely an attempt to disrupt the discussion. If you are unable to provide a reference, then this suggests that the problem lies with your understanding of the greenhouse effect. If you don't understand the greenhouse effect, then simply ask someone to explain it to you.
  47. Bob Lacatena at 04:56 AM on 7 May 2012
    Why Are We Sure We're Right? #2
    34, Tarcisio José D,
    I believe that...
    Why do "skeptics" so often start sentences like this (usually followed by some perspective on the problem which is based on their own world experience, but completely unsupported by any true science)? Do you any evidence whatsoever to support your "rectifier diode" theory? Do you think there's some reason why perhaps no one else in the world has developed and supported your theory?
  48. Why Are We Sure We're Right? #2
    Tarcisio Jose D @31 Sorry it took a bit to get back to you, but I was cutting back my candytufts a week before Mother's Day...I used to love those old pictures of Mom in front of the white blooms on Mother's Day. Jose, you've got to help me out here, because this how I start to get worried when I have these conversations. OK. For a non-scientific view, if in the year 2017 (five years from now), global land and sea temperatures continue to rise, 3 of those years land in the top 10 of warmest years on record, New Orleans gets hit with a category 5 AND Mexico gets hit with a category 5, Richard Lindzen has changed his mind, and JimF now cuts back his candytufts 3 weeks before Mother's Day rather than the current one or two, do you begin to question your stance on this? Is there any point that you say, "I still don't think that man is the primary cause to GW, but we add to it, and we need to start to do something about it?"
  49. Tarcisio José D at 03:05 AM on 7 May 2012
    Why Are We Sure We're Right? #2
    Tom Curtis @ 32 Very interesting theory. But ..... I said, what the quality of its atmosphere makes it only absorbs IR radiation that rises in the atmosphere and free passes IR radiation that the atmosphere emits more toward the ground. I believe that there is this "rectifier diode" in our atmosphere and the greenhouse effect works both in one direction as another.
  50. Why Are We Sure We're Right? #2
    I'd like to add a few historical bits to what Tom wrote. First, I'm sure Tarciso didn't mean hydrogen as an absorbing gas. Indeed, Tyndall tried oxigen, nitrogen and hydrogen but reports a negative result, i.e. no absorption. Now we also know why. Tyndall would also have something to say on the saturation effect. In a Memoir published in 1872 he writes: "The acqueous vapour constitutes a local dam, by which the temperature at the earth's surface is deepened: the dam, however, finally overflows, and we give to space all that we receive from the sun" and Tyndall knew that water vapour is a stronger absorber than CO2. Following the same analogy, increasing absorption deepens the dam, i.e. increases temperature at the surface. This is in 1872 and it's not the full and correct explanation, but he was almost there.

Prev  1174  1175  1176  1177  1178  1179  1180  1181  1182  1183  1184  1185  1186  1187  1188  1189  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


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