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Comments 69501 to 69550:

  1. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    84/86 - Tom Curtis, Mango: Apologies, I think I read and reacted to quickly, not having read the original text in the Torygraph. IMHO using excel, in the casual point-and-click way alluded to in the email, is almost a 'sackable' offence for any serious, reproducible, work! It is not only bizarre to read that people think this a key skill; but indicative of how many people are clued out as to how science is actually done in real life. Anyway, sorry again for a poor post.
  2. Sea level is not rising
    This explanation is not up to the standards of excellence I would expect from this site. What would be helpful is more explanation in support of the statements that LMVoB (Monckton) has blatantly doctored graphs, notably a discussion of his key claim that "a global isostatic adjustment correction" is open to questioning. He says in the caption to the graph that appears before the second one you show: "The question is whether or not this “correction” is justifiable." Quite. Given this is his justification for tipping the graph like so, I would be grateful if someone with a better grasp of such things than I could furnish an answer.
  3. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Victull, Higher sensitivity implies that surface temperatures will rise faster due to greater climate feedbacks and a shorter time to reach an equilibrium Not necessarily. Greater feedbacks simply result in a greater radiative energy imbalance, which takes the system further away from equilibrium. That leads to faster initial warming, but also to more eventual warming so speed to achieve equilibrium will be largely unaffected. In the range of GCMs, there is a fairly robust 2:1 ratio for equilibrium to transient response regardless of sensitivity. Differences between the models on speed to reach equilibrium relate to thermal inertia and thermal capacity of the system, particularly the oceans, not to magnitude of sensitivity.
  4. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    victull : 'Higher sensitivity implies that surface temperatures will rise faster due to greater climate feedbacks and a shorter time to reach an equilibrium; and conversely with lower sensitivity. In energy gain terms there might not be much difference as a higher forcing imbalance over a shorter period might equal a lower imbalance over a longer period' This is not the way I interpret the difference between high and low sensitivities. You suggest that they differ in the rhythm of warming until a new equilibrium is reached. But more fundamentally, they diverge in the estimation of total radiative feedbacks (albedo, WV, lapse rate, cloud, carbon cycle) due to a 2xCO2 forcing, with moderate feedbacks in low sensitivity and pronounced feedbacks in high sensitivity. The pace of warming, whatever the sensivity is, is related to other factors : ice response, oceanic thermal mixing, etc. As far as I remember, there are no particular correlations in IPCC models between the levels of transient and equilibrium climate response, nor clear indications of total relaxation time's range among models.
  5. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    bartverheggen @16 the model is fitted to the locally reconstructed temperature, it is forced to give less cooling by lowering climate sensitivity. Looking at the behaviour of their model, it gives a sensitivity of 3 K when applied to current global warming. If not constrained by the MARGO dataset, like in this paper, the model gives a cooling of 3.6 K with prescribed ice sheets. In my (humble, really) opinion much of the low sensitivity they found is due to the dataset and to a regional bias. I'm confident that others will take a deeper look into these results.
  6. Pete Dunkelberg at 01:30 AM on 28 November 2011
    Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    You say "This is particularly true since the LGM only experienced fast feedbacks,...." I'm not sure why you say that.
  7. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    #16 boba10960 : I agree with this strange divergence about proxy interpretation, that I mentioned in another discussion (interested persons can read the full Shakun et Carlson 2010 paper). #17 bartverheggen : ‘It's a little strange at first sight that the UVIC model resulted in a larger temp trend than most other models due to colder pre-ind temperatures’ As I interpret it (to be confirmed), this is not exactly the point made by tamino, and I don’t think it is a good argument against CCCMA skill for paleoclimate simulations. Tamino showed that when simulating the 20th century in IPCC runs, CCCMA obtains a too low warming in the first half of the period, and a too high warming in the second half (albeit with a correct overall warming trend for 1900-2000). The most plausible explanation is that such models of intermediate complexity deals poorly with decadal variations due to AO circulation (short term natural variability) and, maybe, that aerosol forcing for industrial period is not correctly parametrized in the model. But I don’t see the poor realism on short period with relatively small variations (20th century, 0,8K) as a fatal flaw for simulating longer periods with more pronounced changes (LGM-Holocene, 3 or 5 K on 10 ka). #11 Andy : these technical questions remains quite obscure for me too... even with Tom Curtis' explanations on #13 or Annan's on his blog!
  8. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    dana1981 The Schmittner et al. (2011) paper has aready been seized upon by deniers to claim that the global warming story has been exaggerated. The Murdoch mouthpiece Weekend Australian has already quoted it in Editorial in an attempt to cast doubt. It is important that the issue of climate sensitivity not be given too great an emphasis so that the clear case for the cause of global warming is not sullied. Higher sensitivity implies that surface temperatures will rise faster due to greater climate feedbacks and a shorter time to reach an equilibrium; and conversely with lower sensitivity. In energy gain terms there might not be much difference as a higher forcing imbalance over a shorter period might equal a lower imbalance over a longer period.
  9. What's Happening To Tuvalu Sea Level?
    DrTsk @6 Well DrTsk, I don't see any of the respondents disagreeing with my point about the last 10 years. You are talking to a lukewarnmer here - not a skeptic. That does not mesn that any query about a confusing picture need be dismissed as 'pink elephantry'. Rob Painting - I noted the 'hide the incline' post, however La Ninas don't run for 10 years. The 2010 La Nina was a big one but would not account for a 10 year trend.
  10. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Anyone working in paleoclimatology is well aware of the fact that any proxy for temperature is influenced by other factors as well, and correcting for these other factors introduces substantial uncertainty in paleo temperature estimates. For example, for sea surface temperature (SST) estimates, it was recently shown that the Mg/Ca ratios of foraminefera shells, one of the most commonly used SST proxies, has a large salinity bias (J. Arbuszewski et al., Earth and Planetary Science Letters 300 (2010) 185–196), particularly in the subtropical Atlantic where Schmittner et al. note warmer SST values than expected. Also, I have seen unpublished data showing systematic offsets of about 4°C between SST values derived from alkenones in surface sediments (another commonly used SST proxy) and historical SST data. One must be cautious in interpreting paleotemperatures, both on land and from the ocean. A reflection of this is can be seen by comparing another recent synthesis of Last Glacial Maximum temperatures presented by J.D. Shakun and A.E. Carlson (Quaternary Science Reviews 29 (2010) 1801-1816), who reported a global average cooling of 4.9°C: "The magnitude of the glacial-interglacial temperature change increases with latitude, reflecting the polar amplification of climate change, with a likely minimum global mean cooling of (approximately minus) 4.9 °C during the LGM relative to the Altithermal." This is substantially greater than the estimate by Schmittner et al. Shakun is the third author of the Schmittner paper, so I am curious to know why Schmittner et al. do not cite Shakun's finding.
  11. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    @les #83 Like most people in the world, I'm a nobody. However, I strongly believe the use of a particular software package doesn't stop people from doing their job properly. I used to work at a university in the UK and I know of a professor, who held in high regard, but he didn't know the SI unit for something in his own speciality and, I heard, he had to be told by one of his students. Didn't stop him from doing his job and being bloody good at it.
    Moderator Response: [John Hartz] Correction: Every person in the world is a somebody.
  12. Hyperactive Hydrologist at 23:22 PM on 27 November 2011
    Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    My last house mate is a post doc Researcher and generally tries to avoid using any Microsoft software. Instead he mainly uses Linux based computers running R for stats analysis and for producing graphs. All his publications are written using LaTeX instead of Word. His background is Theoretical Physics, which may explain why, however his current research is in carbon capture and storage. My point is that scientists may not know how to do simple functions on excel because they use other packages to perform that same function. These other software maybe more suitable for there general needs. I think most people will agree excel isn't very useful for more than general applications such as simple personal accounting.
  13. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    les @83, MangoChutney said that inability to use Excel was not a sackable offence. While it may be that the Vice-Chancelor of the University of East Anglia disagrees, it seems very implausible, so I do not see your problem with his comment.
  14. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    81 - Mango - just who are you to dictate that? I was once speaking with a MS engineer who told me he had learned that people where using Excel in an operating theater (something to do with anesthetics or something) - he almost hit the roof as, in his opinion, it was dangerous to depend on Excel in that context. Excel does some things well but a lot of the add-ons (not least of all graphing) are decidedly dodgy and it's often not possible to know or control what it does. If you are producing assured results, you should use a tool which is built to do the job (R, matlab, etc.). Maybe, maybe not 'sackable'; but arguably - by those who know the domain - unprofessional. So, again, who are you to make decide how appropriate this is?
  15. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    Oh and BTW, I have in the past had my comments deleted by moderators here. Yes it is annoying, but life goes on and one finds ways of expressing ideas within the context of the rules.
  16. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    Karl an 'ad hominem' attack has to be directed at a person, not a loosely defined group of people. Regarding my observation of America. It was an observation and an expression of disappointment in the current situation. I am on record as being critical of all current political ideologies, whether left or right.
  17. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    #80,81 Mango - thanks for your honest assessment of this particular non-controversy.
  18. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    sorry, i was referring to the wrong email. Inability to use excel is still not a sackable offence
  19. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    @garythompson gary, I'm sceptical of the whole AGW thing, but I think the inability to use Excel isn't a sackable offence, even if Jones meant the comment seriously. When making this remark Jones was refering to Scott Rutherford's mistake when providing data to M&M - Rutherford transposed data wrongly because he didn't realise the limitations of Excel. Again a genuine error
  20. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    It's a little strange at first sight that the UVIC model resulted in a larger temp trend than most other models due to colder pre-ind temperatures, whereas in this Schmittner study that same model resulted in a warmer than usual LGM temp. It's a bit apples and oranges of course, but it seems to require some explanation or the other?
  21. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    With regard to Gary Thompson's efforts to start a fake controversy over whether Phil Jones uses Excel, Fortran, or Matlab for his statistical analyses; clearly that is no more grounds for controversy than whether he uses an IBM, HP or Acorn computer in his office. Frankly, who cares. But he is correct that email 1885 is evidence of a genuinely controversial act which reflects very poorly on the person involved. I refer, of course, to David Whitehouse's attempt to argue that global warming has stopped because over a six year period with a warming trend, that trend was not statistically significant. In Phil Jones' words, "Quickly re-reading this it sounds as though I'm getting at you. I'm not - just at the idiots who continue to spout this nonsense. ... I would have thought that this writer would have know better! I keep on seeing people saying this same stupid thing." Indeed, stupid nonsense is right. Arguing that evidence of continued warming is evidence of a cessation of warming because the evidence of warming is not statistically significant (Whitehouse's argument) is beyond absurd. You would think denier's would be more wary about drawing attention to such examples of ... stupidity(?), dishonesty(?) ... I'm not sure how to categorize it. Perhaps the deniers are to used to people staring fixedly at the Great and Powerful Oz, rather than looking at the small man behind the curtain.
  22. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    So we should judge the experties of a scientist from his ability to use a spreadsheet? I bet most would let a student do the dirty job. This email is telling for another reason. Jones is well aware of what trends and statistical significance are, unlike other skeptical scientists; Pielke Sr. and Curry come to mind.
  23. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    In references to Lars earlier comments about Nordic swimming exploits (Although Beowulf probably beat him) and water temperatures. Although Lamb's comments are anecdotal, they may well be right. Surely that is the whole gist of the map from Mann 2009. If the North Atlantic basin, particularly around Greenland was an area that showed so much warming, one would expect the water to be warmer. In fact our Nordic Hero/Shepherd couldn't have done what it is claimed he did if it wasn't. And it is most likely that an incursion of warm water into those regions was the likely cause of the hot spot on Mann's map. Nothing exceptional about any of this. But it has no relevance whatsoever to the question of whether the whole Earth was warmer at this point in time. Which is surely the point of why skeptics love to cite Greenland, grapevines in England etc ad infinitum but don't mention the North-East Pacific, Australia, etc during the same period. That is surely the point. It is what the global picture looks like that counts.
  24. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    Dan Bailey, I would suggest deleting the e-mails from Gary Thompson's comment. I personally don't think SkS should be a party to publishing private e-mail correspondence, no matter how prevalent such a transgression may be across the rest of the Internet.
    Response:

    [DB] Agreed and done.

  25. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    74, garythompson, I'd also suggest that he's probably more used to working with the actual numbers and a stats package and could care less himself about graphs. He deals with other (numerical) aspects of the data. He could well have other people create graphs for the people that need them. Graphs are for amateurs. He pretty much says this in his e-mail, when he says "This is a linear trend - least squares. This is how statisticians work out trends. They don't just look at the series. The simpler way is to just look at the data...".
  26. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    74, garythompson, I've known tons of very high paid CEOs that also could not even start Excel, let alone create a graph... yet they do presentations for multi million dollar deals all the time. How do they do it? Oh, that's right, they have other people to handle the trivial details like creating graphs. They do the hard part, the thinking. Similarly, scientists have legions of grad students. Can many scientists do this? Yes, probably. Does it mean he's incompetent? Not remotely. Get off of your high horse.
  27. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    I have 2 problems with email #1885. First, It shows Mr. Jones doesn't have a basic grasp of data analysis that should be routine for any scientist-let alone one that requires this type of analysis to prove his hypothesis. Forget about Excel, he says that he can't graph 2 columns of data and no one at the office knows how to do it either! Do they hire any scientists at CRU? According to the email he had someone do this for him in 2006. Again, he can't do it himself? Many people in the world can't do this type of work but they don't call themselves scientists. I can't hit top spin on a tennis ball but I am not a professional tennis player. A scientist who can't do this simple data analysis would be equivalent to a plumber who can't use a pipe wrench, an electrician who can't read wiring diagrams, an auto mechanic who can't change the oil in a car or an astronomer who can't understand the celestian coordinate system. Pretty simple stuff and Jones appears to lack it. Second, Jones makes claims about trends when he hasn't plotted the data and when he knows it is not statistically significant. He says the "trend is up" even though he also says the data isn't statistically significant and he hasn't plotted the data to verify this. So it is now ok to eyeball the data, come to conclusions based on prior bias and not worry about statistical significance? ok, got it. Think how the AGW team would feel if they realized these types of comments came from a prominent skeptic. How would you be reacting? (-Snip-)
    Response:

    [DB] First, as noted earlier, Dr. Jones expresses an unfamiliarity with Excel, laments that no one who is familiar with Excel is currently available there at that time, and then proceeds to walk his correspondent through the methodology on how to calculate significance.

    Scientists have email corespondences like this all of the time, many more caustic.  Those who hacked the servers to steal these emails who have then selectively released a cherry-picked, minute portion are counting on fake-skeptics to overlook that loss of context.

    It doesn't say what you imply that it does.  The skeptical thing to do would be to acknowledge that and get over it.

    Second, Jones makes claims about trends when he hasn't plotted the data because he knows it is not statistically significant because the time series length is too short for any trend to rise to the level of significance (so no need to plot the data and then test for significance).

    He says the "trend is up" even though he also says the data isn't statistically significant and he hasn't plotted the data to verify this, because he knows it is not statistically significant (as defined above). So in this case it is now ok to eyeball the data and say that the "trend is up" even though he also says the data isn't statistically significant.  Because the time series length in question is too short.

    And how does he know that a trend since 1998 is too short?  Because he has already tested for significance in temperature trend time series analysis often enough to know that such a length of trend is far too short for it to be significant.  Got it?

    Third, your focus on "teams" is misplaced.  Science is not performed by "teams" (or "tribes").  There is no "us versus them".  There are scientists doing science.  Period.  Anything else is ideology.

    Copy of stolen property snipped.  A link to it would have been sufficient.

  28. Karl_from_Wylie at 15:17 PM on 27 November 2011
    Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    bill @1 You say... I seriously doubt that concern for the poor is an actual motivation... The Comments Policy states.... "You may criticise a person's methods but not their motives."
    Response:

    [DB] Please cease with the Concern Trolling.  Thank you.

  29. Karl_from_Wylie at 15:11 PM on 27 November 2011
    Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    Paul D @2 "... politics in the US has taken a path for the worse, resulting in political trench warfare" Your comments are Political... "....I actually consider many AGW skeptics today to be modern luddites" AND ad hominem...... Both are against the Comments Policy Comments Policy
    Response:

    [DB]  The relevant portions of the Comments Policy you refer to are:

    • No politics. Rants about politics, ideology or one world governments will be deleted.

    Paul D was fairly even-handed in his discussion of politics, so it cannot be construed as a rant.

    • No ad hominem attacks. Attacking other users or anyone holding a different opinion to you is common in debates but gets us no closer to understanding the science. For example, comments containing the words 'religion' and 'conspiracy' tend to get deleted. Comments using labels like 'alarmist' and 'denier' are usually skating on thin ice.

    Since Paul D is not addressing anyone specifically, but is referring to "many AGW skeptics" he is, at worst, "skating on thin ice" with his use of the word luddite:

    1. One who fears technology (or new technology, as they seem pleased with how things currently are...why can't everything just be the same?)

    2. A group led by Mr. Luddite durring the industrial revolution who beleived machines would cause workers wages to be decreased and ended up burning a number of factories in protest
    A luddite generally claims things were "just fine" back in the day, and refuses to replace/update failing equipment/software/computers on the basis that they were just fine 10 years ago.
  30. SkS public talks in Canada and AGU, San Francisco
    Hi John, It's interesting that you will be joining Callan Bentley from NOVA. I taught a geology course at the Annandale campus there in 1980 or '81. I don't know Callan personally but have been following his blog. I'm especially interested in his geology photos. Best of luck on your talks and seminars. My wife and I had a great trip to Vancouver Island and Victoria a few years ago. Be sure and see the butterflies. Tom
  31. SkS public talks in Canada and AGU, San Francisco
    That's great, John. Let's hope you all get plenty of positive publicity. (If not, I guess you will know how to correct it - grin.)
  32. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    #72, it's also interesting that you demonstrate your own ignorance on the subject, taking interpretations from the self-confessed "Interpreter of Interpretations", Delingpole. If you follow the link back to the source, you'll see that Jones was explaining how to do a simple plot and least-squares regression in Excel, but cannot be faffed to do it at that monent (hence the keyword "now"). That he claims modesty on the speed of his computer skills is nothing new - many brilliant people do exactly the same thing, but only a fool would take that completely literally. He was complaining about a junk article by David Whitehouse, who clearly has no idea about how to determine if global warming has stopped, and provided a nice explanation for the guy who answered the question. If Jones couldn't work a spreadsheet, why is it that the second quoted paragraph is a perfectly reasonable explanation of how to plot and do a simple LS regression in Excel? Or do you just swallow whole every bit of misinformation from "the Interpreter of Interpretations"?
  33. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    Does anyone else find it odd that Phil Jones doesn't know how to plot data in Excel? Or more importantly, how he makes claimes about trends without doing the plotting and while knowingly stating that the data is statistically insignificant? Sounds odd. It's in email #1885 and here is a link. http://blogs.telegraph.co.uk/news/jamesdelingpole/100119495/climategate-2-0-the-not-nice-and-clueless-phil-jones/#disqus_thread
    Response:

    [DB] "Does anyone else find it odd that Phil Jones doesn't know how to plot data in Excel?"

    Many scientists do not, as Excel isn't the best platform for their work (R, or one of several other packages, are better suited for their work). 

    "while knowingly stating that the data is statistically insignificant?"

    PRATT.  Jones knows it's statistically insignificant because the time series length is too short for the trend to have risen to the typical level of significance.

    Please show the original email in its context, not Delingpole's odd-sounding, served-up-on-a-platter, version.

    That's what a real skeptic would do.

  34. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Tom Curtis In general, climate change occurs faster over land than at sea, but that is because of the large thermal inertia of the oceans. Over long time spans, the temperature change should equalize. Sutton et al. (2007) is a model study which finds that the land-ocean warming contrast is a robust feature of equilibrium warming as well as transient. To me this suggests equalisation wouldn't be expected. There's supposedly a more detailed follow-up paper on the land-ocean equilibrium response due this year - Dong, B.-W., R. T. Sutton, and J. M. Gregory, 2011: Understanding land-sea warming contrast in response to increasing greenhouse gases. Part II: Equilibrium response (in preparation)
  35. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    @Mikel #70: If someone reading this comment thread knows of such a site, he/she will likely post it. In the meantime, I suggest that you engage in some serious surfing of the web on your own.
  36. The Debunking Handbook Part 4: The Worldview Backfire Effect
    Steve, tactic or tactful? I wouldn't describe tact as dishonest though many tactics could be. The big thing to remember always is that approaches within tertiary education, not just the hard sciences, tend to be robust ... to put it politely. otoh, I work with students who have various learning problems - very few of them have any intellectual difficulty - just a bad history of inappropriate teaching added to a simple visual or aural processing problem, sometimes short-term memory issues. The big thing is that a 'robust' approach is exactly opposite to what they usually need. And it is not dishonest to tell such a student that the fraction calculation they've done is 'clever!', even though standard testing tells you that they're 4 years behind in maths. It is clever - they just never had the chance to show it previously. When such students change their 'behind' measure by 2 or 3 years within 6 to 12 months, it's glaringly obvious that cleverness is not a problem, the teaching is. We tell ourselves that we're the realist, clear thinkers on scientific issues. But we can be unrealistic, muzzy thinkers about those we see as uninformed, misled or poor thinkers. Many teaching moments are missed if we give a standard scornful, oh, come on! keep up! response to someone who's clearly out of their depth. SkS is actually one of the best blogs at finding a responder who will make the most of a teaching moment. It's not dishonest to always treat people who come across as aggressive or dishonest themselves as though they are looking for information or support. Parents among us can recognise the stroppiness of toddlers or teenagers as cover for confusion or distress. And those of us who've worked with the general public have often encountered adults who are in the same boat. And seen our ham-handed colleagues make bad situations worse by focusing on the attitude rather than the problem. And we must keep in mind what we're asking. To be a realist about what's happening with climate, you have to stare into the horrifying abyss. And then you must take a deep breath and get on with your work, family and social life. Finding ways to tell people that it really is as near to catastrophic as dammit is to swearing - that we can avoid the very worst of it - but a lot of people will die anyway ... not the rosiest of teaching moments.
  37. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Here are the figures from Schmittner et al showing both their data sources and model. Note the paucity of land data and the significant differences between data and model: None of the warmish areas in the northern hemisphere that appear in the data are in the model; the Med isn't cold enough; the equatorial and tropical Pacific isn't warm enough. If your model truncates the high and low extrema in your data volume, is it any wonder that sensitivity appears lower?
  38. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Andy S @11, if we had precise knowledge and could measure the climate sensitivity exactly under a variety of conditions (GMST, continential positions, etc) we would find it varies slightly depending on those conditions. If we plotted all those variation, we would be plotting the probability density function (PDF) of the sensitivity. If the PDF of the sensitivity showed a distinct peak with little variance, that would give us great confidence that the sensitivity measured from the LGM or the Paleocene-Eocene Thermal Maximum would be a good predictor of the climate sensitivity over the next century or so. If the PDF of the sensitivity showed multiple peaks and/or substantial variance, we would have less confidence. In contrast, the probabilistic estimate of the sensitivity is the probability that the sensitivity has a particular value given a range of measurements. In this case we know that the climate sensitivity at the LGM had a unique value. We do not know what that value is, but we know there is a high probability that it lies withing a particular range. Because the climate sensitivity at the LGM over land and over sea should be very close to each other (my point @1 and @12), we know that the climate sensitivity should lie somewhere in the overlap of the two land and ocean PDF functions as James Annan says. As it happens Schmittner et al gave the land PDF very little weight in their estimate which means their land plus ocean estimate, while lying within the overlap, is heavily biased towards the ocean estimate. My argument @1 is that there are good reasons to give the land PDF much more weight. The multiple peaks in the PDF is a consequence of Schmittner et al's method of comparing models with sensitivities to their reconstructed temperatures. It is not noise, but probably not very significant either given that they used only one basic model. If multiple models showed the same pattern, it probably would be significant.
  39. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    muoncounter @8 and skept.fr@7, when I said that "the temperature change should equalize" I did not mean that temperature changes in different latitude bands would be equal, or indeed that their should be the same temperature change within a given latitude band for all seas and land surfaces. Obviously there will be regional variations based on changes in circulation and in changes in land cover. Because these factors do change, we would only expect that " Land temperatures ... should fluctuate about a mean that is close to sea surface temperatures." Close, but not identical. Further, as a point of clarification, this should apply to zonal means rather than to the global mean. Indeed, it will not apply to the global means because of the different zonal distribution of ocean and land surfaces. That we should expect this effect, however, is seen by considering two hypothetical examples, a desert world (no oceans), and an oceanic world (no land). For the thought experiment, assume feedbacks are identical in both. IN that case, doubling CO2 in both will lead to approximately equal increases in GMST because the increase in GMST is determined by the value needed to establish equilibrium in the TOA energy equation. There will be slight differences in the final outcome depending on differences in heat transfer from equator to poles. The main difference will be that while the land only world will reach the equilibrium temperature in a few years, the ocean only world will take a few centuries. In the real world, as noted we will expect slight differences in zonal mean changes in temperature between land and sea. However, those differences will be less than the differences in regional changes in temperature due to changing currents, winds and land cover. With regard to Schmittner et al's figure 1 (the figure three in the caption is a typo), I would regard it as supporting my argument rather than rebutting it. The relevant points are: 1) There observational data shows an increase (!?!) in sea surface temperatures north of Iceland. As the area north of Iceland was almost certainly covered with perennial sea ice, the apparent increase in temperature would indicate that the proxy is measuring under ice temperatures rather than surface temperatures, as per my hypothesis; 2) In the model, in all areas not associated with significant sea ice during the LGM, land temperatures are withing 1 degree of SST temperatures; and in contrast 3) In the model, in areas associated with sea ice land temperatures are significantly colder (up to 4 degrees) than are sea surface temperatures. Please note that this is very much what my explanation predicts. For a true check using models, however, we would need to check out a hot example, where my explanation would predict land temperatures lying withing a degree of sea temperatures in the same zone over the entire globe.
  40. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    69 John Hartz SkS provided a very good series of articles about twelve months ago reviewing the furore over the CRU emails, including an article on FOI requests. I was hoping SkS or others viewing this site might know of some other site that looked at the legal issues arising from the release of the CRU emails. I am not expecting SkS to provide a forum but I was asked to set out what I consider to be some of the legal issues.
  41. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    @Mikel #68: Why whould SkS provide a forum to discuss the "legal" issues that you have raised?
  42. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    66, JMurphy 67, Philippe Chantreau OK, I'll keep it brief and, yes, I have read the Muir Russell investigation report, the UEA undertaking to the ICO and seen the guidance from the ICO on research information. 1) Offence committed: Yes, but likely to be an offence under the Computer Misuse Act 1990 not the Theft Act. Although unlikely, a leak could be an offence under Section 55 Data Protection Act. Ultimately, a decision for the CPS; 2) Privacy, in particular privacy at work and the difference between privacy and confidentiality. Privacy in the UK derives from the Human Rights Act. Confidentiality can derive from common law, contract law, commercial/trade secrets, need to protect free/frank exchange of views, to name but a few; 3) Status of the IPCC with regard to rights of access to information. IPCC Secretariat is based in Switzerland and subject to Swiss law?; 4) Records retention policy, in particular with respect to email; 5) Ownership of research information. The academic or the institution? 6) Definition of 'holding' information. Use of personal accounts on external systems; 7) Anonymising personal data to remove that data from being covered by the Data Protection Act. Tension between absolute anonymity and highly probable anonymity in the DPA.
  43. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    I'll confess from the beginning that I don't understand, in Figure 1, what Marginal posterior probability distributions for equilibrium climate sensitivity really are. James Annan says of this figure:
    remember, they are not estimates of "the pdf of sensitivity" but rather, probabilistic estimates of the sensitivity - but they do need to overlap in order to be taken seriously
    I'm not sure I grasp that distinction either. Nor do I understand why the land-ocean line has five peaks (penta-modal?) Is the lumpiness of this curve meaningful or is it just noise or artefact? Any help would be most welcome.
  44. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    This is figure 4 from Schmittner (2011): Their temperature reconstruction (which they attempt to match the model to) seems to show Arctic temperatures at the Last Glacial Maximum (LGM) warmer than today.
  45. The Debunking Handbook Part 4: The Worldview Backfire Effect
    Hi Adelady, thanks. I've been thinking about what you've written. Also re-thinking about what I wrote. I suspect that the proper approach depends on the target audience (surprise!). This debunking handbook is a tool for people who are trying to win recruits or at least trying to soften opposition. Myers' site and many internet fora may be primarily about reassuring and motivating those already on-side. So, combining this with what you've written about honesty, the lesson may be that brutal honesty is effective within ranks but gentle, careful dishonesty(?) is the right approach outside. Intuitively I want to think that both approaches are useful (and ethical!) so I don't like what I've written here about how to interact with opponents. But really, the goal is finding the right tactic to eradicate misinformation that is protected by someone's cognitive psychology. We have to trick them into lowering that guard. It's called effective communication, and I'm not sure it's entirely honest. To avoid the 'Worldview Backfire Effect' when speaking with someone whose worldview one finds odious, perhaps dishonesty is required. Note, on another thread someone pointed to a Naomi Klein article in The Nation in which she indicated the climate problem was perfect for the Left, because addressing it requires supporting things the Left wanted anyway. Almost immediately someone jumped in to say that Klein needed to be pushed back because this is ammunition for political opponents. In searching for the article a second ago I found a Guardian column called "Dear Naomi Klein: Please Stop Making My Work Difficult." Here Klein's use of the word "reparations" needed to stop. The last line in Part 4 above says that framing isn't "about manipulating people." But it is. All communication is! The question I'm asking is whether it helps to reject/censor communication from one's own side if it has a chance of backfiring. Or is exposure of the target to a diversity of approaches more effective?
  46. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    dana #3 : "we might expect similarly radical climate changes to result from similar radical temperature changes" Oh yes, for sure. For example with just a small change in temperature and chiefly westerlies humid fluxes from the Atlantic, we know that large parts of Southern Europe (and France's 'Midi' for my personal interest!) may become a semi-arid region, very different from now. We don't need a 3 or 4 K local warming for that, a more modest switch in temperature/humidity mean and forced circulation would be sufficient.
  47. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Tom C#1: "Over long time spans, the temperature change should equalize." Perhaps, but this MARGO graph and the accompanying paper suggest that the sea water temperature did not equalize: Our reconstruction reveals the presence of large longitudinal gradients in sea surface temperature in all of the ocean basins, in contrast to the simulations of the Last Glacial Maximum climate available at present. Per the Schmittner paper, the MARGO data are the source for their SSTs. Can we expect land-based temperatures to 'equalize' with SST if there is such a distinct variation in SST? (Note that the yellow-beige represents an anomaly of +1C, as computed from LGM - WOA985 values). The Schmittner model (their Fig. 3) neither matches the variation in this graphic nor shows 'equalized' temperatures from land to sea.
  48. SkS public talks in Canada and AGU, San Francisco
    Break a leg, John! You will do us proud.
  49. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Tom Curtis #1 : "I have been wondering about the very different climate sensitivities determined using sea surface temperature data, and land data, as shown in figure 1. In general, climate change occurs faster over land than at sea, but that is because of the large thermal inertia of the oceans. Over long time spans, the temperature change should equalize." Interesting. Layman question : why would we expect the same equilibrium ∆T on oceanic and land surfaces ? For example, don't SST depend mainly on underlying circulation changes (changes in salinity, pressure, thermohaline, etc.) and land surface temperatures on other factors (such as vegetation density, melting of permanent ice at mid and high latitudes, etc.)? (For those interested by LGM, here , another work, more precise, with another model and proxy data set, Roche et al 2007)
  50. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    skept.fr @2, Thanks for the link to the presentation on the preliminary CMIP5 results. Interesting.

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