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Comments 70951 to 71000:

  1. Sober up: world running out of time to keep planet from over-heating
    "When will we be able to take really effective action?" 30+ years ago. What we're now faced with is selecting from the least worst processes and outcomes, rather than the good, the best, the economical, the gradual or the preferable. The best analogy I can think of at the moment is the River Murray. We knew we were in deep doo-doo the day in 1981 the mouth of the river closed 'despite' all the management of flows and levels. SA irrigators started modernising and restricting their take from the river while those further upstream increased their take and kept on with their lax (or lack of) technology. (It's a good idea to shield your face from the flying spittle when you talk to SA farmers recounting their horror stories of visiting eastern state orchards with their primitive open channels blithely evaporating tonnes of water.) 30 years later? Still arguing. Still proposing that upstream irrigators should be able to take more than scientists say is the absolute maximum they should be allowed if the river is to survive. And they'll still be arguing if they get their way. The next drought reducing the river to a filthy trickle will be described, again, as the fickleness of nature. A bit of a parallel, within a single country, to the North-South divide we see unfolding with climate impacts largely caused by northern hemisphere countries being felt first and worst by those nearer the equator.
  2. Sober up: world running out of time to keep planet from over-heating
    Le Monde have run the Down Escalator graphic & the indicators of warming graphis. Cool!
  3. Sober up: world running out of time to keep planet from over-heating
    When will we be able to take really effective action? I fear not for about twenty years. I think after continued warming and some nasty effects denialists will have become a spent force. But even after the denialists are marginalized (We won't completly get rid of them.) there will be problems about what should be done. The danger then will be panic measures and measures made more to make a staement of concern. These can unnecessarily push up the cost of mittigation. We will need to make careful and realistic calculations of the cost and benefit of mittigation measures. The denialist concern that mittigation measures could provide a means for special interests to rip off the populace is reasonable. I think we just need to be on guard against them. I think self righteousness on the part of climate change activists can make them vulnerable to exploitation by such interests.
  4. Sober up: world running out of time to keep planet from over-heating
    Link to LeMonde. It's a blog post, actually, and the skeptical science graphic (and link to skeptical science) is on page two ... nice!
  5. Sober up: world running out of time to keep planet from over-heating
    The excellent graphic here ended up in Le Monde's coverage (credited) of the Nature paper discussed above.
  6. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Returning to Camburn's original point @3, I would like to note that the trends for the TLS channel are: From 1978 to Dec 2009: -0.327 degrees per decade (from the graph above) From Jan 1999 to Dec 2009: -0.165 degrees per decade. I would like to note that: a) While the trend has approximately halved (reasons for which are off topic) it has certainly not "stopped" as claimed by Camburn; b) The period of the 1999-2009 trend is probably too short to be statistically significant; and c) The trend is still of the same approximate magnitude as tropospheric trends, though opposite in sign. Therefore any supposition that decreases in stratospheric temperatures have ceased to cause the TMT channel to underestimate increases in tropospheric temperatures is entirely unwarranted. TLS data is available here, under the MSU_AMSU_v.2 folder, and the monthly folder: ftp://ftp.orbit.nesdis.noaa.gov/pub/smcd/emb/mscat/data/
  7. SkS Weekly Digest #23
    I find the 2nd panel of that cartoon particularly funny, and accurate! Cheers Muon.
  8. SkS Weekly Digest #23
    Speaking of cartoons, I hope everyone enjoys this from the Sunday New York Times: -- full size source
  9. Watts, Surface Stations and BEST
    Bob, I suppose the IR reading is an approximation. I pointed the IR sensor at the furthest point from where I stood. The measured spot spreads out with distance; the temperature reading did not vary with what I pointed at. And I checked it with a local weather observation; they reported an air temp of 104F. Equilibrium temperature? A spot on the ground in the sun receives solar energy faster than the ground can conduct heat to adjacent spots in the shade. In such a case the ground temperature reading at one spot is much higher than its surroundings. That's not equilibrium.
  10. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Trying to ignore the off-topic parts of Camburn's points, I'll concentrate on this statement from #18: "We can observe that in the past 20 years the [stratospheric] temperature has been stable, within error bars." With the same data, the strong long-term decline in mind, and the closeness of the data to the fitted declining trends, this sentence can equally be restated as: "We can observe that in the past 20 years the [stratospheric] temperature has been declining, within error bars." Camburn is going up the down escalator here.
  11. Global Surface Temperature: Going Down the Up Escalator, Part 1
    I think I've realized what bothers me about the "skeptics" version of "the warming has stopped". I think it is a variation of the Fallacy of the Undistributed Middle. The question I ask is "what warming?" a) the warming due to human-induced increases in CO2? b) the warming due to a) plus all other factors that affect global temperatures? The temperature records shows b). Attribution studies attempt to tease out a) from b). Theory tells us that b) will not rise continuously at a steady rate: it will have fluctuations imposed on the long-term trend that is caused by a). Now here's the rub: the "skeptics" look at variations in b) and make statements like "the warming has stopped", but what they are trying to imply (whether they believe it or not, or whether they are just employing FUD), is that noting a change in b) means that a) has stopped. The word "warming" does not mean the same thing in a) and b) - that's the undistributed middle in the logical fallacy. To make an analogy, let's say we have a bathtub full of water. At one end, we have a small heater. At the other end, we measure temperature. Periodically, someone stirs up the tub. Over time, we see the temperature rise slowly, but it doesn't rise evenly because the mixing isn't uniform. Let's say someone periodically adds some ice at the thermometer end - that causes periodic drops in observed temperature. We know that the heater at the far end is still adding energy slowly warming the bath, but the "skeptics" want us to believe that the occasional drop in temperature (or decrease in the heating rate) at one end means that the heater at the other end has stopped - or even never existed at all. There is also (yet another) inconsistency in the skeptic position here: they often argue the strawman that climatologists ignore other factors when attributing the global temperature rise to CO2. Yet that is exactly what the "skeptics" are doing when they pretend that short-term fluctuations are evidence against the current scientific understanding of global temperature and the effects of CO2.
  12. Watts, Surface Stations and BEST
    Muon: 138 F for surface temperature with an air temperature of 108 F is not at all a surprise to me. Yes, the gradients in that 2m height can be that large, and they can be sustained. Two questions: - what exactly do you mean by "equilibrium temperature"? - how did you measure air temperature with the IR thermometer? It's easy to envisage taking the temperature of the dead grass with one: point and shoot. But what exactly did you point the IR thermometer at to get air temperature?
  13. Watts, Surface Stations and BEST
    I was a "weatherman" in army some 20 years ago. And these measurements were what we did. Our post was part of national network (civilian bureau), so we delivered SYNOPses every three hours. In my later life I've not been involved in climate science, but I'm proud those few measurements I (and my fellows) did long ago, are still part of the global dataset. We were trained not to make basic mistakes, and the issues about station locations were discussed. I feel always insulted when these accusations of "bias" or solid stupidity arise. I'm sorry for real professionals, who must take this kind of crap nowadays.
  14. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    GHG induced stratospheric cooling is most prevalent at about 50 km, roughly corresponding to the top line (TTS) on the STAR graph. Unfortunately, the SSU instruments failed in 2005 so there is no data since then. As others have said, the cooling was reduced after CFCs were phased out in the mid '90s. Also, the higher altitudes have larger solar components, so the solar cycle tends to interfere with any eyeball-based analysis.
  15. Eschenbach and McIntyre's BEST Shot at the Surface Temperature Record
    Have RSS or UAH discussed the discrepancies between the satellite products and the other reconstructions? Perhaps through replies to the Fu, V&G and Zou papers? Are there proxy temperature reconstructions covering the last four decades? Would be nice, perhaps, to have these in the mix as well...
  16. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Some interesting comments here. My main concern is the same as muon @53 - that Curry has repeatedly used the phrasing "warming has stopped," which implies a termination. "Paused'", while not a good descriptor, at least implies that it will soon resume. Pielke used the same phrasing. When dealing with global warming, about which a large group of people are trying to convince the public that global warming really has stopped, or at least is nothing to worry about, such inaccurate and cavalier language is unwise and damaging. DNFTD.
  17. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Tom#57: "you need to go back 14 years and pick one of two out of 240 possible ten year trends." I think that is an excellent and very compelling point. If this (2 out of 240!) was the strength of the warming argument, the skeptics and pseudo-skeptics would be jumping up and down crying 'Foul!' for good reason. But this is the strength of the pseudo-skeptic argument, so it must be ok.
  18. Dikran Marsupial at 02:02 AM on 7 November 2011
    Global Surface Temperature: Going Down the Up Escalator, Part 1
    Tom@57 Your method is way better than Curry's approach, a single time period which is so short that the test for the trend doesn't have useful statistical power and has a cherry picked startpoint tells you precisely nothing about the trends. It says quite a lot about Prof. Curry's grasp of statistics, as an experienced scientist she should be able to formulate her hypotheses uambiguously and rigorously test them before promulgating them.
  19. Global Surface Temperature: Going Down the Up Escalator, Part 1
    muoncounter @53, I am in wholehearted agreement with everything you say. IMO Curry has behaved despicably throughout. Her new wording, which certainly lacks clarity, is not what she was originally maintaining. It is, however, important to know she is not saying the same thing, and to criticize he as though she where saying the same thing. Regardless, however, even for what she is now saying, she is not justified in cherry picking start dates. At a minimum she should have been doing what I just did in 55. Even that, Dikran now advises me, is not a proper test. But it would certainly be better than cherry picking a single year, and as can be seen the results do not encourage her pretense. This whole storm started because Curry insisted that a single cherry picked data set of less than 10 years using dodgy end data showed us something significant. Well, to find a 10 year interval in the BEST data with a negative 10 year trend, you need to go back 14 years and pick one of two out of 240 possible ten year trends. That's quite some cherry pick she indulged in.
  20. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Here is another way to look at long vs. short: -- source The red is BEST with a 12 month mean; green is the linear trend. Then use the detrend operator to remove that, yielding the blue curve. Sure looks like the blue oscillates around 0; but if you wanted to play the 'eyecrometer pick-a-trend' game, are the peaks at the tail end of the blue curve trending up? Or does 'warming stop' every 4 years or so?
  21. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Out of interest, and using the last 30years of BEST data, the results of my test are: 30 Year trend: 0.275 degrees C per decade Number of 10 year trends less than zero: 2 Number of 10 year trends greater than twice the thirty year trend: 17 Total percentage of 10 year trends < 0 or > twice the thirty year trend: 7.9% So if my test has any value, the long term trend does not completely dominate short term variations yet, but it's very close. Out of interest, the two negative ten year trends where June 1987 to May 1997, and Dec 1987 to Nov 1997. The most recent ten year trend at double the long term trend was from March 1993 February 2003.
  22. Dikran Marsupial at 01:38 AM on 7 November 2011
    Global Surface Temperature: Going Down the Up Escalator, Part 1
    Tom, the problem with that approach is that the intervals are not independent (due to the overlap) which would invalidate the comparison (although picking a startpoint ater looking at the data, as Prof. Curry suggests, invalidates the test as well, especially if it coincides with a peak in ENSO!). How much of an effect that would have I couldn't say, but it seems a better approach to use GCM or synthetic data, where you know this isn't going to be an issue (although if you have the synthetic data you could test to see how much difference it makes).
  23. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Tom C#49: Curry's phrasing is confusing at best and quite possibly an attempt to mislead.
    "What is of interest on this timescale is whether natural variability (forced and unforced) can dominate the AGW signal on decadal timescales and produce a ‘pause’ or a ‘stop’."

    With that, she plays a very delicate game of semantics. The words 'pause' and 'stop' confuse the question. Anyone who hears the superficial 'warming stopped' does not hear the following 'because of a relatively large short term variation' and takes away only the carefully crafted message. If she agrees that "identifying an AGW signal on this short timescale isn’t useful," then she must agree that saying 'warming stopped' due to a short-term variation is a misrepresentation. All she can claim is that the short term variation is indeed large enough to mask the ongoing rise and make it appear to cool for a few years - something we see clearly demonstrated in the animation in Figure 1 in this post. But to imply this short variation is a 'pause' or 'stop' in the long term trend is an overreach. It is akin to Pielke's 'the trend has changed' based on a few years. What of all the past 'pauses' or 'stops'? Did warming stop each time? Suppose that your route up a mountain includes a detour down a small valley where you camp for the night. The next morning you continue climbing. Curry and Pielke would describe the overnight as 'climbing has stopped'. That would give the casual observer the incorrect message that you might be on your way down. Such an ambiguous (and false) report could delay a rescue team from reaching your correct position. But perhaps that's the reason for these semantic debates; look how much effort has to be spent attempting to set it right. Bravo to tamino for calling her out in front of her own denizens. When she’s asked point-blank for the scientific basis of her claims she changes the subject. When she’s shown the error of her ways she refuses to admit it. Science by pronouncement: As tamino says "It’s not a crime. It’s a sin."

  24. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Dikran @50 & 51, I don't have your statistical fire power, but I assumed you could answer Curry's purported question by determining the long term (30 year trend), and then generating all trends of a shorter length (say 10 years) over the interval of the thirty year trend. For 10 year trends, there will be 240 overlapping 10 year trends using monthly data over the 30 year interval. Clearly the average of all the shorter trends will approximate closely to the long term trend. With this data, Curries question reduces to, will at least 5% of 10 year trends have a trend at least twice the long term trend, or of opposite sign to the long term trend. If the answer is yes, then short term factors can still swamp the long term trend. If no, then they cannot. Now, probably in about 50 years, the answer will be unequivocally "no". At the moment, the answer is very close to "no", but perhaps not. Certainly, however, you will not answer this question by looking at a single cherry picked trend, and especially if you allow yourself the use of dodgy data (April and May of 2010 in the BEST data) to fudge the answer. Have I got that right, or have I sawed my way through the branch.
  25. Dikran Marsupial at 01:02 AM on 7 November 2011
    Global Surface Temperature: Going Down the Up Escalator, Part 1
    Just to add, the statistcal power calculation I tried to discuss with Prof. Pielke Sr is exactly the way in which you would go about assessing the likelihood of the expected trend being swamped by noise. The recipe is basically as follows: (i) generate lots of synthetic time-series with the expected trend (say 0.2 deg per decade) and ARMA(1,1) noise similar to the observed data. (ii) for each sesies calculate the statistical signiicance of trends over various timescales (iii) for each time-scale, calculate the proportion of trends that reach statistical significance (iv) plot these proportions as a function of the length of trend and label the y axis "statistical power". Statistical power is the probability of rejecting the null hypothesis when it actually is false, so in this case it is the probability that the noise can dominate the AGW signal. So that the test is symmetrical, I would suggest that the power should be 95%, so you just need to use a window lengh long enough to have a statistical power of 95% or greater. I expect this is around the 17 year mark. I hope to have a go at this mysel at some point.
  26. Dikran Marsupial at 00:53 AM on 7 November 2011
    Global Surface Temperature: Going Down the Up Escalator, Part 1
    Tom Curtis wrote: "I am going to go out on a limb here, and disagree with both Dikran Marsupial and [some other bloke hardly worth mentioning]." HERETIC!!!!! ;o) The problem is that Curry's second statement isn't meaning full for analysis of the observed trend "What is of interest on this timescale is whether natural variability (forced and unforced) can dominate the AGW signal on decadal timescales and produce a ‘pause’ or a ‘stop’." because how can you tell whether natural valiability is dominating the AGW signal or if the AGW signal isn't there anymore? You can't answer the question posed by looking at observations as you don't know which hypothesis is correct. You could however use synthetic data (as Tamino has) or the output of GCMs (as Easterling an Wehner did), where in both cases the AGW signal is there by contruction. In summary, you can't answer Curry's question by looking at the observed post-1998 trend, but the question has already been answered in other ways (includng by Santer et al, whom she cites!). The thing that worries me is that we now have a climate scientists on record as having said 1998 is a reasonable startpoint for assesseing a trend.
  27. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Camburn @18, your post continues the off topic discussion you seem intent on pursuing. If you wish to take the discussion to where it is on topic, I'll happily participate. As it stands I will merely observe that you draw your conclusion on the sole basis that you do not accept other theories. You have in no way shown the evidence supports it. If you want to give your reasons why the gradual recovery of ozone from the destruction due to sulfuric aerosols from a volcano (the only long term effect of volcanoes on the stratosphere) is a significant warming factor, while the gradual recovery of ozone from destruction by anthropogenic chlorofluorocarbons is not in an appropriate thread, I'll be all ears. In the mean time, could you keep on topic in this thread.
  28. Global Surface Temperature: Going Down the Up Escalator, Part 1
    JMurphy @48, I am going to go out on a limb here, and disagree with both Dikran Marsupial and Tamino. (That may be more akin to going out on a limb and then sawing of the branch on the trunk side;). IMO, Judith Curry is (almost) making sense in that post. The key point is that you can ask many different questions of a given data set. They may not be sensible questions, but you can still ask them. Given that, it is important that (apart from measurement error) what constitutes noise depends on the question you ask. If you ask the most obvious question, "What is the long term trend?", then small variations introduced by temporary or short term cyclical events like volcanic eruptions, ENSO and the sunspot cycle are noise. In that case, the short term data is dominated by noise, and short term trends in the data tell us very little, if anything, about the future long term change in temperature. That is the question Tamino, and Dikran are asking. Unsurprisingly (in one respect) Judith Curry agrees with them. She writes:
    "If one is seeking to identify an anthropogenic signal, one should choose years at each end point that are neutral in terms of ENSO and also the 9.1 year AMO signal discussed by Muller et al. For a short temperature record (i.e. of relevance to assessing whether there has been a pause over the past decade), this isn’t feasible. In any event, identifying an AGW signal on this short timescale isn’t useful."
    That is basically correct. You cannot identify the anthropogenic signal (ie, the long term trend) over short time scales. I think you can correctly quibble about her reasons given. Lack of statistical significance (Tamino and Dikran) is more important than finding corresponding conditions (Curry) both because finding corresponding conditions across multiple variables is rare even over the long term, and because we cannot be certain of which factors determine temperature and over the short term correspondence in the limited number of variables on which we are fairly certain does not necessarily mean correspondence on all conditions. Further, saying "identifying an AGW signal on this short timescale isn’t useful" is an odd turn of phrase. Of course identifying the AGW signal would be useful. What it is not, in the short term, is practicable. However, Curry then goes on to ask a very different question:
    "What is of interest on this timescale is whether natural variability (forced and unforced) can dominate the AGW signal on decadal timescales and produce a ‘pause’ or a ‘stop’."
    In my own terms, the question is, are the short term variations of temperature due to temporary or short term cyclical events of similar slope to the long term trend introduced by anthropogenic forcings? I am not saying this is a useful question, but it is certainly one you can ask. And because it asks a question about the relation between short term effects on temperature and the long term effect, neither are noise. For this question, the only things that would count as noise are measurement error, and a change in the long term trend. Such a change would prevent us from knowing whether any "pause" or "stop" was due to short term variations or to a change in the long term trend, and thus prevent a comparison of the two. Therefore Curry's question only makes sense on the assumption that the long term trend is continuing unabated. Now, fairly obviously, if the slope of the long term trend was similar in value to the slopes that would induced in the temperature by short term variations in a stationary climate, then when those short term slopes are negative, the data will show little or no positive slope, whereas when the stationary short term trends alone are positive, the data will show positive slopes nearly twice the value of the long term trend. This is where Curry comes unstuck. Because short term effects can effect the slope of the data in both directions, both positive and negative slopes are relevant to this question. Further, because not all short term effects have the same absolute magnitude, the correct way to answer this question is by a statistical analysis of all short term trends of a given length over the period in question. If you were to analyze the data correctly for this question, you would be interested in the fact that the trend in the data from January 1998 to March 2010 is 0.22 degrees C per decade, 0.5 degrees C per decade then the 30 year trend to the same period. But you would also be interested in the fact that the trend from Sept 1995 to Dec 2007 (ie, the same duration as the 1998-2010 trend) was 0.46 degrees C per decade. Curiously Curry shows no interest in this fact. I think the reason is straightforward. She wants to give cover to (or keep on side; or maintain an open dialogue with) the people who are trying to ask the wholly illegitimate question of, "Has the long term trend stopped?" Illegitimate, of course (and solely because) the short term trends do not give enough information to answer the question. That is because, for this question short term temperature effects (such as ENSO) are noise. Indeed, earlier in the week it seemed like Curry was asking this question too. She seems now to have changed he tune to give herself a cloak of intellectual integrity, but does not pursue the question she is purporting to ask in any sort of legitimate way.
  29. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Camburn: "why a layer of Earth's upper atmosphere went through its biggest contraction in 43 years." Or it could be based on this observation from 2009: Careful measurements by several NASA spacecraft show that the sun's brightness has dropped by 0.02% at visible wavelengths and 6% at extreme UV wavelengths since the solar minimum of 1996. The changes so far are not enough to reverse the course of global warming, but there are some other significant side-effects: Earth's upper atmosphere is heated less by the sun and it is therefore less "puffed up."
  30. Watts, Surface Stations and BEST
    Bob L#51: "On a hot, summer day, the overlying air will be cooler." Back in August, I measured the mid afternoon air temperature in my backyard with in IR thermometer - 108 F. At the same time, the temp of the dead grass in the full sun was 138 F. Clearly the ground temp is not an equilibrium temperature and is therefore not a relevant measurement to this question (it does help explain the dead grass, though).
  31. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Thank you Glenn @ 16&17. I have read both your explanations as reasons as well as others. It is clearly evident that a large erruption has a long term influence on the stratosphere. The question becomes how long does this influence last. We can observe that in the past 20 years the temperature has been stable, within error bars.
  32. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Another odd thing from Curry, from her website, which Dikran (as well as one or two others) have queried over there, is this assertion :

    A key issue in identifying and interpreting the pause is the start date chosen to evaluate a pause. If one is seeking to identify an anthropogenic signal, one should choose years at each end point that are neutral in terms of ENSO and also the 9.1 year AMO signal discussed by Muller et al. For a short temperature record (i.e. of relevance to assessing whether there has been a pause over the past decade), this isn’t feasible. In any event, identifying an AGW signal on this short timescale isn’t useful. What is of interest on this timescale is whether natural variability (forced and unforced) can dominate the AGW signal on decadal timescales and produce a ‘pause’ or a ‘stop’. This is the issue addressed by Santer et al., searching for the AGW signal amidst the natural variability noise. Santer et al. argue that “Our results show that temperature records of at least 17 years in length are required for identifying human effects on global-mean tropospheric temperature.” So in this context, starting the analysis in 1998 is not unreasonable.

    Can anyone understand how all that allows her to start her analysis "in 1998" ? Or is just another case of her own words being misinterpreted (again) - whatever she really means ?
  33. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Camburn @8. Looking at the TTS, TUS & TMS cuarves after the peak one tends to see the volcanic peak, then a dip below the trend line that recovers after several years. Suggesting that the impact of the eruptions on the stratosphere takes longer to fade away than in the Troposphere. This isn't too surprising at one level. If a major event can inject some sort of change into the Stratosphere the significant mixing timne delay between Troposphere and Stratosphere could easily mean that 'clearing' the effect could take a number of years. As to what might be 'injected' into the stratosphere, I can speculate about 2 possibilities: Water vapour is injected into the stratosphere where it might have a disproportionate impact. Or, as a result of some unknown process, the eruption might have an impact on the availability of OH Radicals in the Stratosphere and thus the conversion of Methane to H2O. Both seem at least possible, but beyond that these are just conjectures on my part.
  34. Global Surface Temperature: Going Down the Up Escalator, Part 1
    Hey! I was just updating some climate graphs (as I do) when a whole new aspect of skeptic cherry-picking showed itself. We know that any meaningful regression or smoothing exercise demonstrates a continual rise in global temperatures. And we know this is why skeptics have to cherry-pick the data to get any chance of it supporting their delusions. One feature of the temperature record they regularly home in on is the prominence of the 1998 ENSO-induced temperature maximum and that is all that matters – the peak global temperature 13 years ago. And with such a ripe cherry, it is logical to say that the world has been cooling ever since 1998. But this is also cherry-picking in the sense that it is only half the story. These skeptics concentrate their so-call analysis solely on the maxima within the global temperature record. The rest of it they do not even notice – I can't think why. We all call what we're doing to the climate “global warming” but it is the nature of GHGs not to warm us but to prevent us from cooling down. It should be called “global not-cooling-down” and with not-cooling-down the issue, perhaps those clever skeptics should turn their enormous analytical power on minima rather than just maxima. So is there any evidence that we are getting less cool? The answer looks a pretty convincing 'No'. Year minima value 1976 -0.29 1978 -0.07 1982 0.00 El Chich'on 1985 -0.06 1988 +0.09 Mt Pinatuba 1992 +0.05 1996 +0.13 2000 +0.26 2008 +0.29 This data (which is HadCRUT3 rolling annual average) is probably best seen graphically. The link here should allow that. HadCRUT3 & ENSO graph The only times the minima pause in their upward march is after a big volcano. Without a volcano blowing there is zero evidence of any pause in the warming, let alone the cooling so often alleged by those skeptic folk.
    Response:

    [DB] For convenience, here's the graph linked to above:

    Click for larger image

  35. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Camburn Note the series from TTS, TUS & TMS at the top of the Star graphic - my apologies for the poor quality, the colour scheme used by Star & shrinking it to fit the SkS format has reduced its clarity. You could look at the Star original for more detail. What it shows is that cooling over much of the stratosphere is more clear-cut than in the lower stratosphere with Volcanic eruptions having less of an impact. But that is a secondary point. The key issue is that in considering what the temperature anomaly for the Upper Troposphere is at any point in time, we need to take the corresponding anomaly in the lower Stratosphere into account. How the stratosphere came to have that value isn't relevent to interpreting what is happening in the Upper Troposphere.
  36. Extreme Melting on Greenland Ice Sheet, Reports CCNY Team
    DB - my thanks for your response and my apology for straying too far off topic - I hadn't realised how rigorous are the thread parameters here on SkS. My thanks too for your invitation to write up these ideas for consideration as a guest post - which I'd be glad to make time for. Regards, Lewis
  37. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    Friends of Science volunteers. Dr. Tim Patterson - Not included in WoS. Dr. Chris de Freitas - One peer-reviewed paper. Dr. Madhav Khandekar - No peer-reviewed papers. Not the international status Director Ken Gregory has been advertising.
  38. Watts, Surface Stations and BEST
    In #50, I talked about what it takes to get a good measurement of air temperature. But what does air temperature tell us? That depends on where we measure it. Anyone that has walked around in bare feet on a sunny summer day knows that actual ground surface temperature varies greatly. Bare concrete? Hot. Wet grass? Cool. Dry grass? Somewhere in between. But what about the overlying air? On a hot, summer day, the overlying air will be cooler. In fact, with at least a gentle breeze so that we have some mechanical turbulence, the temperature will decrease logarithmically with height - the change from 25cm to 50cm, will be about the same as the change from 50cm to 1m, or 1m to 2m. This decrease in temperature will be related to the rate at which thermal energy is being transported away from the surface into the air. Another characteristic is that as you move away from the surface, the air temperature becomes dependent on the surface temperature over a wider and wider area. With a wind, it is basically dependent on the surface that is upwind of the location. A rough rule of thumb is that at 1m height the air temperature is dependent on the upwind surface of 100-200m distance. What climatologists call "surface temperature" is really an abbreviation for "surface air temperature", and is typically measured at a height of 1.5m (IIRC). So, this "air temperature" represents a fairly large area. It is desirable to keep this area uniform, so that things like wind direction don't cause shifts in what the air temperature is responding to (or representing). This is how siting can affect temperature readings, as a station with different surface conditions will experience a different air temperature. ...but again, the use of anomalies in global temperature trends means that any bias at a particular station won't affect the trend unless the bias is changing.
  39. Global Surface Temperature: Going Down the Up Escalator, Part 1
    (cross posted with excisions from Tamino's blog) I’m reading Kahneman’s new book “Thinking, Fast and Slow”. (Nobel prize in economics 2002.) I think part of the cognitive problem is that we have teh ol’ eyecrometer….we’re can’t turn it off and it says “10 year pause”. Kahenman points out that it’s experimentally demonstrated that humans are terrible intuitive statisticians, especially for small samples. Those of us trained to ignore the eyecrometer don’t “see” a 10 year pause….those without the training don’t get why we don’t trust our eyes or theirs.
  40. Watts, Surface Stations and BEST
    Coming into the fray a bit late.... Let's start with part of the first paragraph of the post:
    "It has been known since its invention that when using a thermometer to record weather, siting is of vital importance. It was also known that a thermometer could not measure air temperature accurately unless it was shielded from precipitation and direct sunlight. One device used to shield thermometers is the Stevenson Screen.
    The physics of this is also well understood. To start, the only thing you can measure accurately with a thermometer is the temperature of the thermometer. To do anything useful, you have to find a way to get the thermometer temperature close to the temperature of the thing you're interested in. In our case, we are interested in air temperature. A thermometer has an energy balance. There are three primary forms of energy transfer we are concerned with: - radiation - thermal transfer - evaporation We can express this energy balance as follows:
    C*dT/dt = Q* + QH + QE
    where C is the heat capacity of the thermometer, dT/dt is the rate of temperature change of the thermometer with time (i.e., how fast is it warming or cooling?), Q* is the net radiation (sum of received visible and IR, minus losses of visible and IR), QH is the rate of thermal energy transfer between the air and the thermometer, and QE is the loss of energy due to evaporation from the thermometer. QH depends on the temperature difference between the air and the thermometer. Obviously, if we want to measure air temperature, we want this term to equal zero. We also want the thermometer temperature to be stable (at least, as stable as air temperature is), so we want dT/dt to equal zero. How do we accomplish this? Well, we want to block radiation, so that Q* = 0, and we want to keep the thermometer dry, so that QE = 0, So then we have C*dT/dt = Q* = QE = 0, and thus QH = 0 and our thermometer gives a good measurement of air temperature. If we have a radiation error (Q* > 0), then our thermometer reads high. If our thermometer gets wet (QE > 0), then our thermometer cools until QH = -QE. Keep it good and wet, and compare it to a dry bulb thermometer, and you can measure the humidity of the air (see Wikipedia Wet bulb temperature discussion). So, what is needed for good air temperature measurements is some form of radiation shield, a way of keeping the thermometer dry, and a way of making sure air flows over the thermometer. The Stevenson Screen is the classic (although many other devices exist). In olden days, Stevenson Screens were often left to use natural ventilation, but now days all the ones I've seen use forced ventilation (a fan and air intake). Forced ventilation is a requirement for wet bulb/dry bulb humidity measurements, and it helps bring a thermometer to rapid equilibrium and reduces radiation errors for a normal temperature system. If a sensor has errors (e.g. radiation), then a long-term trend in temperature requires that the error change over time. This is why anomalies are used instead of actual temperatures. I'm going to give away my age, but my bookshelf includes the second edition (1990) of Principles of Environmental Physics. I see there is a third edition available. The first edition was published in 1973. Many, many useful discussions of such basic micrometeorology. I'll make my next point in another comment.
  41. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Camburn, you posted a source just as I commented above, thanks for the source but it does not support your statement.
  42. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Camburn, you're still not providing a source that supports your statement. From your link: "An increase in CO2 could be one reason why a layer of Earth's upper atmosphere went through its biggest contraction in 43 years." I'd also be intrigued as to how the mysterious Dr Svelsgaard could attribute a 30-year declining trend (or any 'plateau' since Pinatubo) to a solar cycle which began in 2008?
  43. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Thanks skywatcher. Glad that I could be valuable to you as I posted the link, but really did think this was common knowledge.
  44. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Unsupported assertions like Camburn's in #7 really need to be highlighted to show that they are as valuable as me suggesting that there are fairies at the bottom of my garden.
  45. Watts, Surface Stations and BEST
    Like Watts, no qualification in climate or meteo. But I clearly don’t understand the point. My problem is not the IR photo in particular, but what is measured by the thermometer. I imagine a sensor, in the middle of a field. First case, nothing happen around the field from 1970 to 2010. Second case, the field is progressively surrounded by houses, roads, factories, etc. There are no other change except these local ones. Because the sensor is shielded in a box, it will be absolutely indifferent to change in sensible and latent heat fluxes in the environment, or radiative changes from albedo ou local GHG concentrations ? And the sensor will not register any temperature difference in the two cases, after 40 years of differential land-use?? But... what is measured by the sensor??? Totally weird for me.
  46. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    dana1981@9: Do you have an open source for the paper presented in this link? It is behind a paywall but there may be a copy that you have read?
    Response:

    [DB] Try here.

  47. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Per DB request at 7: I thought everyone who reads would know about this: Eathers shrinking atomosphere
    Response:

    [DB] Perhaps you should look into what the thermosphere is...and isn't.  Like it's not the stratosphere, for one.  You are being off-topic.  Cease.

  48. Watts, Surface Stations and BEST
    logicman, the link to Fall et al 2011 in your article is broken. Replace it with this one. http://pielkeclimatesci.files.wordpress.com/2011/07/r-367.pdf
    Response:

    [DB] Updated link, thanks!

  49. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Camburn, please actually read the link I posted @5. Ozone is only one of many factors impacting stratospheric temperatures. Part 2 of 'going down the up the escalator' will also address "skeptic" misconceptions about "step changes" in temperature.
  50. Eschenbach and McIntyre - Seeing the BEST part of the Satellite Temperature Record?
    Tom: TUS, TMS and TLS were on a very substantial cooling path till Mr. Pinatubo. Since the time of erruption, for whatever the reason, the cooling virtually stopped. I don't know why, I have not been able to find out why. I have read numerous reasons as to why, but upon close examintation they didn't make sense, to me at least. If you know the reason I am all ears to learn.
    Response:

    [DB] "If you know the reason I am all ears to learn."

    Read the links you were given; questions, if any, may be placed there.

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