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Comments 106401 to 106450:

106401. FLansner at 08:28 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Hi Peter Hogarth! Im very positively surpriced by your kind tone and welcome indeed. One could hope the climate debate was like this in general. I am answering questions on 3 blogs now on this issue, so i hope you can forgive im a little late, here. As I understand you, there are trouble for GISS projections in regions near pacific equator. Well... :-) Why do GISS then do this? But very important: What I showed in my original article was, that GISS projections for SST has problems all over the world. May i remind you this important graphic from the article: http://hidethedecline.eu/media/ArcticGISS/fig6big.jpg I have made many areas black so that only GISS projected SST are shown in the UPPER graphic. And then the corresponding HADLEY SST is shown in the lower graphis. The match in the whole world [SNIIIIP] aerm... is not good. Its not just the Arctis, its not just somewhere we see a terrible mismatch. Its everywhere. If such a match is good enough for a method to be used by NASA, its really incredible. K.R. Frank Lansner
106402. kdkd at 08:07 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        Chriscanaris #61 "What false premise?" The one where one creates policy based on assuming that the true value of an estimate is at the extreme negative value of a very wide error bar. "However, your suggestion that I should be more careful in how I express myself lest I be seen as trotting out sceptical talking points does test my patience." Sorry, I should be more clear here. Scientific language is generally very cautious and conservative. Much of the 8 year or longer training process for practicing scientist involves getting practitioners used to this aspect. It's not a personal attack, or a search for heresy, it's an observation about the conventions that allow us to use scientific data to draw conclusions.
106403. DSL at 07:55 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        RSVP, wth? You aren't even trying anymore. So it's not true that any object above 0K will radiate? You should win the Nobel for this one. Tell me something, though: how does the nugget know when it's surrounded by ground? Is there a God particle involved? Does the nugget somehow magically 'sense' that it's surrounded by ground and stop radiating?
106404. scaddenp at 07:48 AM on 21 October 2010
        Increasing southern sea ice: a basic rebuttal
        See the intermediate version of this article. The Zhang paper looks at SST 1979 to 2004 showing significant warming all around antarctica.
106405. Peter Hogarth at 07:37 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Berényi Péter at 01:53 AM on 21 October, 2010 If you go to the "advanced" post linked at the beginning of this article, you'll see some actual buoy data. You can assume most published work on Arctic surface temperatures in the ten years since 2000 (such as Polyakov 2002) will reference this. GISS are of course well aware of the satellite and buoy data, and DMI incorporate buoy data. I cover this briefly. michael sweet at 06:34 AM on 21 October, 2010 The "analysis" link is not connecting? Although the DMI data is from a model, the model is loaded with actual measurements, and quite a lot of them from satellites to get the high spatial resolution necessary for "weather forecasting".
106406. RSVP at 07:30 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        doug #92 Simpifying... the answer to your question... A hot nugget will radiate, but not when buried in a hole in the ground. As for the rest, take a break. See you tomorrow.
106407. michael sweet at 07:08 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Why is BP posting data that does not show the last 13 years of warming? Those years are when the Arctic warmed the most.
106408. dana1981 at 06:56 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        Oh that precious Steve Goddard. After ranting about how John's graph shows more recent warming than the Hadley land+ocean data, he adds an update. "Reader “robert” tells me that Cook is using land-only northern hemisphere data in his “northern hemisphere” graph." No freaking duh. Past temperature reconstructions are based on land proxies (mainly in the Northern Hemisphere), and thus represent land-only NH temps. So that is the appropriate instrumental data to use. As usual, Goddard spends an entire blog post criticizing somebody who's correct. What a joke. Goddard also claims that John "goes on and does climate sensitivity calculations based on bogus data from a cherry-picked hemisphere." Aside from the data neither being bogus nor from a cherrypicked hemisphere (anyone even slightly familiar with temperature reconstructions should know they're usually done for the NH, from which more proxy data is available), John doesn't do any climate sensitivity calculations at all in this post. It amazes me that somebody so completely ignorant about climate science could be so utterly oblivious as to write a climate science blog.
106409. Lazarus at 06:35 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        I see you have rattled a cage over with Steve Goddard who is claiming your Moberg graph is 'a new level of BS'; http://stevengoddard.wordpress.com/2010/10/20/cooks-hokey-stick/
106410. michael sweet at 06:34 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        BP, Adrian, Flansner, Where is the data from 30 years ago to compare the current bouys to? GISS has published an analysis of this data and have shown that their estimates are closer to reality than using the global average. HADCRU has published a paper stating that they underestimate the arctic temperature rise due to their use of the global average. Can you produce peer reviewed papers that support your claim that the GISS estimates are inferior to your proposals? Without data you are just suggesting you are smarter than GISS. The DMI data comes from a model, not actual measurements. Can you suggest why it is better than the GISS model? Provide data please, not just opinions. The data Peter shows here shows that the two analysis are similar. Perhaps the bias introduced by DMI changing models is the only problem.
106411. Doug Bostrom at 06:09 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        RSVP honestly your perceptions are so muddled or at least dysfunctional in the mechanical sense that it's very hard to understand what you're intending to convey. What your words rather clearly implied is that certain tangible things on Earth can emit IR while others may not. If you were referring to surface area as opposed to volume or more precisely specific heat times mass being a measure of ability to store energy, find a way of saying so that is articulate. Elsewhere on Skeptical Science you've demonstrated a clear inability to discern between orders of magnitude, or at least you're unable to admit how you do understand such a thing as 10 X 1 = 10. This is consistent with such confused remarks as "We experience delays in communication systems daily. These may last two seconds at the most. Are you trying to say that two more seconds of lingering heat after the Sun sets is causing global warming?" Our (or my) understanding of what you know is based on what you say; with your track record of misunderstanding I'm simply going to read what you say and not attempt to use x-ray vision to tease out whatever cogs are seized up and stripping on their axles in your brainbox. All this would ordinarily be fine and dandy; it's a fact that people here are usually amazingly kind and patient. Some of us (me, again) become irritated with you when you express your inner fog with assertions implying your perspective is more useful, such as the embarrassingly tangled "AGW folks are the real unprepared optimists, because they think this problem will go away when CO2 emissions are reduced, when in fact the level of stored energy has no reason to drop without a significant radiative forcing also dropping off."
106412. archiesteel at 06:07 AM on 21 October 2010
        It's the sun
        @KL: I don't dispute your capacity to make mathematical operations. I simply think you're not very apt at clearly presenting your arguments, hence the impression that you obfuscate issues by throwing around of math. Your inability earlier to understand such as simple matter as relative deltas instead of absolute values seems to confirm this hypothesis. If you truly understand an issue, you should be able to explain it to non-technical people like me. The fact you cannot seem to make a clear argument with all those equations is telling, and that's all I'll say on the matter before getting even more off-topic.
106413. e at 05:57 AM on 21 October 2010
        It's not bad
        hapivibe, There is a lot of discussion of AGW because the science is being actively debated (I would say more like attacked) by a large and influential group of skeptics. Breast cancer for example does not require this discussion, as nobody seriously doubts that it is real and thus there is no discussion to be had. If you find AGW so unworthy of discussion, then tell me, why are you here adding to it? If you would rather discuss overconsumption, then visit a blog about overconsumption, or better yet, start your own. If you can generate some interesting and compelling discussion then your pet issue will attract more attention, and more power to you if it does.
106414. KR at 05:52 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        An image illustrating the GHG notches from Has the greenhouse effect been falsified: Integrating under the curve of the top image gives you the total energy radiated to space. Without GHG's the spectra would be a smooth curve (lacking notches), and a lower temperature would give an equal amount of energy radiated to space.
106415. KR at 05:46 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        And, very importantly, a planet and an atmosphere with GHG's has a very different emission spectra than one without GHG's - it has notches where ~half the IR gets re-emitted back to the surface. In order for the integrated thermal spectra leaving the atmosphere to equal the energy coming in as sunlight (where the atmosphere is essentially transparent), a planet with GHG's (notched spectra) must have a higher temperature than one without (close to blackbody spectra), when both are at equilibrium.
106416. e at 05:23 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        RSVP, The travel time of emitted photons is not the only thing determining delay. There is also a delay between absorption and subsequent emission of said energy. The rate of this emission is bound by the Stefan-Boltzmann Law. Also consider that we aren't talking a single round trip transmission like in your communications example. The energy could be "bouncing around" many times.
106417. KR at 05:19 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        My apologies, I was incorrect in my last post. The figure as represented on the summary web site shows white from -1.0 to +0.5, but the originals from the paper show a light blue from -1.0 to -0.5, and white from -0.5 to +0.5. Looks like some color fidelity got lost when putting together the summary website.
106418. CBDunkerson at 05:19 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Huh, that's weird. In any case, a better copy of the image from the original source;
106419. KR at 05:14 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Examining the image (having copied it into an image processing program from the original site), the -1.0 to +0.5 region is entirely white. There's an apparent contrast over the -0.5, but that's an optical illusion. Poor choice of image colors, in my opinion.
106420. CBDunkerson at 05:08 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        If you go to the original site by clicking on the image it is possible to see that the -1.0 to -0.5 range is actually a very light grey rather than white.
106421. e at 05:05 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        TOP, >The ocean's albedo is extremely low which means whatever gets in very little gets out You've got that backwards. Kirchoff's law states that low albedo implies high emissivity. If something absorbs more energy then it also has to emit more. This is a consequence of the 2nd law of thermodynamics.
106422. archiesteel at 04:28 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        "all you need do is wish different physics into being and you'll be entirely impossible to ignite" doug_bostrom wins the Internet.
106423. Albatross at 04:27 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Adrian @35....no, it seems not. Weird. It is a poor quality image, so maybe the colours are not represented correctly.
106424. adrian smits at 04:25 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        I see -1.0 on the left side of the white -0.5 in the middle and +0.5 on the right side of the white part of fig. 9 are my eyes playing tricks on me?
106425. Albatross at 04:05 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        I encourage people to actually read the discussion section of the paper by van Hoof et al. that BP is citing @64. There are many caveats in there. BP also left out this part regarding what is meant by "A significant CO2 change during the 13th century AD" as inferred from their research: "The effect of the synthetic smoothing of CO2 [SI] leads to a 25% reduction of the amplitude from 34 ppmv in the raw data to a maximum of 25 ppmv according to the model output." Others found an increase of 12-15 ppmv in the 14th Century. So the changes are at most < 10% of pre-industrial levels of CO2; to place that in context we have already increased CO2 by 40% over pre-industrial levels and will go on to double the concentration of CO2. And we know form isotope analyses that the increase in CO2 levels are primarily from anthropogenic activities, not hypothetical random walks or hypothetical "century scale unforced changes" (more on that below). It should also be noted that that particular study found the increase in CO2 in the Antarctic ice core to occur around 1300 AD, whereas multiple paleo temperature reconstructions for the N. Hemisphere show the peak MWP to be around 1000 AD (e.g.,Ljungqvist, Mann, Moberg), with notable cooling starting shortly thereafter. So the MWP occurred some 300 years earlier than the small increase found by van Hoof et al. This is not surprising given that in the past CO2 changed primarily in response to feedbacks, and probably indicates that the small (<10%) increase observed in CO2 circa 1300 AD was in response to the warming in the N. Hemisphere (most likely arising from regional warming b/c of changes in internal climate modes) during the MWP some 300 years prior. So, to me, these papers that BP is citing demonstrate that in ambient CO2 levels can increase/decrease in part because of (lagged) positive feedbacks, and that these feedbacks can occur on account of internal climate variability or internal climate modes (such as the AMO and NAO, see Mann et al. 2009). Looking forward, the contribution of the feedbacks to global CO2 levels will probably be dwarfed by present and future anthro emissions. I am a little suspicious of the CO2 levels shown in Kouwenberg et al. Note the huge decadal variability/noise-- with shifts in CO2 levels of 50-100 ppm between subsequent data points (separated by as little as 50 years). We have over 50 years of high temporal resolution and reliable CO2 measurements from Mauna Loa, and there is no sign whatsoever of natural variability or random walks causing huge departures (on the dacadal time scale) from the long-term trend. So again, Kouwenberg seems to be way too noisy and it is quite conceivable that the century-scale variability in CO2 that BP is alluding to is an artifact of that noise. Regardless, the climate sensitivity has been derived from multiple, independent lines of evidence, including estimates of climate sensitivity following volcanic eruptions (e.g., Pinatubo). And they all point to a climate sensitivity of near +3 C for doubling CO2. At the end of the global SATS are currently warmer were observed during MWP (e.g., Mann et al. 2009), and Hansen et al. (2010) has showed that the long-term rate of warming has continued more or less unabated. What we are going to experience ion terms of warming will dwarf the MWP, so "skeptics" harping on the MWP is, IMHO, a simple diversionary tactic from this:
106426. CBDunkerson at 03:51 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Should have also mentioned; those maps BP put up are 13 years out of date.
106427. Phila at 03:40 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris: At the same time, I certainly want to know more whether it's in my professional life or in an area of interest. What may be confusing people is the apparent implication that this somehow makes you different from anyone else, or that this view is some sort of alternative or corrective to what the what of us think. Everyone here wants to know more. Climate scientists also want to know more, obviously, and are working hard to do so, even though it's a thankless task at the best of times. That said, we also know that we need to act, for the simple reason that the uncertainties here are unlikely to work in our favor. Things could be much worse than we expect, a little worse, about the same, a little better, or a lot better. The only one of these possibilities that doesn't require timely action is the last one, and it's also the least likely.
106428. TOP at 03:39 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        @Very Tall Guy "Looking at an old post by Eli... it appears that the atmosphere sans GHGs is almost transparent to IR: ... This implies to me that the atmosphere is far too thin to act as a blackbody and merely transmits surface emitted radiation." If you remove GHG (See Doug's Graph on page 1) not only will you emit IR to space but you will get far more energy at the surface because GHG also block a lot of the UV coming in. Anyway, Doug's graph shows how the black body temperature could shift to the right without any CO2. But looking at the bigger picture, if you could somehow remove water vapor and still keep the oceans you still would absorb a huge amount of solar radiation and not emit it back to space. The ocean's albedo is extremely low which means whatever gets in very little gets out. This includes IR. Water is a GHL (Green House Liquid).
106429. Philippe Chantreau at 03:39 AM on 21 October 2010
        Increasing southern sea ice: a basic rebuttal
        chriscanaris, this image says it is for 10/18/2010. Do you have SST temperature anomaly data for a longer period of time (like 30 years or so)? That would be necessary in order to assert that Antarctic waters are cooling.
106430. e at 03:39 AM on 21 October 2010
        It's not bad
        hapivibe > You have not provided evidence that proves that global warming is the biggest threat. The goal of this site is not to rank every threat faced by mankind. I'm not sure what the point of such a ranking would be anyways. Are you implying that humanity is only capable of dealing with a single issue at a time? Should we halt all cancer research until we solve overconsumption or whatever issue you feel tops the "worst threat" ranking? There are over 6 billion people on this earth, I think we can deal with more than one issue at a time.
106431. CBDunkerson at 03:38 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Adrian #32: "What am I missing when I look at those maps?" The 'white' range is actually -0.5 to 0.5, rather than just -0.5 as you stated. A white area on the map could thus represent anything from mild cooling to mild warming. Also, while there is alot of white, the Winter and Fall maps show areas of warming greater than 0.5 in the 80 degree area (innermost circle) and Spring shows alot. Only Summer is completely white and thus 'flat'. The other three seasons show warming. Thus the warming trend shown in the annual DMI data for that region and only the Summer data being flat... because of the ice cover. Looking at satellite images of the Arctic ocean it looks like the 80 N area has been almost completely ice covered even at the September minimum point every single year recorded. There simply haven't been any large / prolonged areas of open water in that zone to allow temperatures to start increasing. Yet. If ice volume continues to decline at the rate it has been that previously permanent ice cover in the 80 N circle is going to change in the next few years... and then we'll see increasing temperatures for that region just like most of the rest of the planet (i.e. pretty much everything except a similar small area around the opposite pole).
106432. Roger A. Wehage at 03:35 AM on 21 October 2010
        Record snowfall disproves global warming
        Re: Daniel Bailey @3: I didn't claim that lake effect was the only contributing factor to the large snowfalls in the Upper Peninsula. But it is likely the most significant factor. If it were not, then one might expect similar snowfalls over northern Minnesota, northern Wisconsin, the Upper Peninsula, and parts of Canada to the west and northwest of Houghton. For example, the most snow to fall in a season anywhere in Minnesota was 170 inches, far short of Houghton and Calumet. One could look at current and historical weather radar data to see the origin and extent of rain and snowfall in particular areas. Typically one often sees precipitation originating and falling over the water and moving inland. Another factor is that warm, moist air over lake waters likely moderates temperatures downwind and increases the amount of snow associated with Alberta Clippers. And I agree with your comment about heavy snows from the southwest, which shouldn't be affected by lake moisture. Minneapolis has experienced a number of heavier snowfalls over the past 40-50 years, and it is likely that more of the moisture comes up from the southwest.
106433. KR at 03:34 AM on 21 October 2010
        It's not bad
        hapivibe - I have to agree with Ned. This site is dedicated to discussing/dissecting the "skeptic" response to global warming, which involves a great deal of bad logic, cherry-picking, and some very odd approaches to science. Overfishing is a big problem. So is population growth, resource overutilization, and any number of other topics. But those topics are not what this website is devoted to, unless those are related to global warming. They are simply off-topic and inappropriate here; and it feels like you're nagging participants for putting energy into this discussion.
106434. hapivibe at 03:07 AM on 21 October 2010
        It's not bad
        Sorry I know I am curious and I couldn't find a section on the site. Let's say I'm sceptical about being sceptical about being sceptical but an answer would be good as I am interested in any psychological aspect. If you are in the gw 'bubble', it is indeed an open forum where I can enter and challenge this and I appreciate it. Sorry for any offence and I do honour web etiquette.
106435. Ned at 02:56 AM on 21 October 2010
        It's not bad
        We talk about climate change because this is a website about climate change. This is one of those basic rules of web etiquette. The web is a big place. If you want to talk about overfishing or poodle-grooming or sports or whatever, there are plenty of other sites elsewhere. But going to a discussion forum dedicated to Topic X and telling people that they really ought to be discussing Topic Y instead is generally not appreciated.
106436. hapivibe at 02:49 AM on 21 October 2010
        It's not bad
        No, i'm sorry. You have not provided evidence that proves that global warming is the biggest threat. And I still don't know why there is so much attention paid to it compared to the other issues. You have not shown me a link to a discussion site where people are this involved for any other topic. Why does this topic generate a disproportionate amount of interest? Can you just give straight answers if possible and not links this time as I don't need links? Thank you.
106437. Ned at 02:48 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris writes: I certainly don't believe we should quietly continue business as usual in the expectation of a series of volcanic eruptions conveniently saving our bacon. [...] Ultimately, I'm asking because I'm curious rather than contrary. Yes, I understand that and appreciate your reasonableness. However, I do think you're still stuck on the (mistaken) idea that cloud cover is somehow independent of climate sensitivity. The uncertainty in cloud albedo feedback is directly responsible for much of the uncertainty in climate sensitivity. So, if someone looks at the MWP/LIA (or at Pinatubo for that matter) and concludes that those events had a significant impact on climate, you're right that that implies a "high" (or at least non-"low") climate sensitivity. But the further implication is that there isn't a huge negative feedback from clouds. Remember that with no feedbacks at all, climate sensitivity is around 1C. The sensitivity range given in IPCC (2-4.5C, with a best estimate of 3C) specifically includes the effects of feedbacks. If feedbacks turn out to be more negative than the best estimate, then sensitivity must also be lower than the best estimate, and that would argue against the existence of a high-amplitude, globally consistent MWP or LIA. assuming we're on the same continent, we both seem to live by a most uncivilised timetable Actually, I am writing this from New England, USA, where it is just about noon on a gorgeous autumn day.
106438. adrian smits at 02:31 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        Has anyone really looked at Berenyi Peter's seasonal sat.trends figure 9? If you look at the scale white would seem to indicate some cooling above 80 degrees for summer fall and winter.I don't get it.What am I missing when I look at those maps? The middle of the white scale is -0.5. So I'm correct in assuming the arctic has been cooling for three seasons and not just the summer.....anyone?
106439. chris1204 at 02:29 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        skywatcher @ 62: I suspect that clouds (like the poor) will always be with us. AR4 pretty well declares that they comprise a substantial negative feedback albeit with what certainly looks like a 'scary to terrifying' margin of error. Some cloud cover changes under a warming scenario may comprise a positive feedback - hence presumably the size of the error margin though agreement between these data and model projections remains problematic. I've just noticed Ned's post @ 65 - assuming we're on the same continent, we both seem to live by a most uncivilised timetable :-). Thank you for putting in the time and effort to explain your argument. Climate sensitivity on a purely intuitive basis seems clearly 'high' - I think Mt Pinatubo serves as prima facie evidence. Mt Pinatubo significantly exerted its transient effect in the face of what was already a substantial CO2 forcing. So what forcing comes most strongly into play will depend very much on whether increased CO2 will be accompanied by concomitant rises in aerosols and the nature of changing cloud cover all of which as best as I can ascertain from my forays on the Internet remain very uncertain (though for the sake of coherence, I have highlighted work pointing towards a more pessimistic scenario). I certainly don't believe we should quietly continue business as usual in the expectation of a series of volcanic eruptions conveniently saving our bacon. I guess the question remains whether a low range (as opposed to a very low range) climate sensitivity renders a LIA or MWP impossible or highly implausible as opposed to merely unlikely. I don't feel remotely qualified to attempt an answer to that one but can't help but wonder in the light of the error margins involved. Moreover, while any atmospheric aerosol or cloud at a particular point in time represents a transient phenomenon (in contrast to anthropogenic CO2 which is very long lived), cloud cover and aerosols comprise a self-renewing and hence non-transient process. Ultimately, I'm asking because I'm curious rather than contrary.
106440. Ned at 02:28 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        adrian smits writes: No Ned they are guessing because they use temperature measurements from 1000 km away on land that is not covered with ice.That's why the GISS temperature anomaly is so far out of whack with the DMI measurements. Except they aren't "out of whack" at all. Did you even bother reading the article by Peter Hogarth at the top of this thread? The 50-year trend for DMI is +0.37C/decade and for GISS it's +0.35C/decade. Here's Figure 3 from Peter's post, in case you're having trouble finding it: Figure 3: Annual DMI and GISS Arctic temperature anomalies and trends So, if you like the DMI data, you ought to conclude that GISS does a good job of estimating Arctic surface temperature trends.
106441. Ned at 02:20 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        BP, that's basically non-responsive. If anything, the figure you paste in confirms my point nicely -- trends at or near the pole tend to be more similar to trends elsewhere in the high Arctic than to trends further south. Presumably, if your figures extended to the equator, there'd be no visible correlation at all there. Lansner specifically asked why GISS doesn't just leave the Arctic blank. I answered that question -- leaving any region "blank" when calculating a global mean temperature anomaly implicitly assumes that that region's anomaly is identical to the average of the rest of the globe.
106442. dana1981 at 02:19 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        HumanityRules - there are certainly gaps in our knowledge. However, a significantly higher climate sensitivity to solar effects than greenhouse gases is not consistent with what we know. Consider for example the early 20th century, during which there was a significant increase in solar activity to the "Modern Maximum". Yet during that period, when there were other positive radiative forcings at play, the planet only warmed about 0.4°C. The data just doesn't jibe with a higher climate sensitivity to other forcings.
106443. Albatross at 02:09 AM on 21 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        Reading the posts by "skeptics" (or critics of the HS (reconstructions) on this thread seems to perfectly illustrate that they indeed do not realise/know what they're arguing for....what I see are non-coherent and sometimes even contradictory arguments.
106444. JMurphy at 02:07 AM on 21 October 2010
        It's not bad
        hapivibe wrote : "This web site is unbelievably passionate and detailed to the tune that it comes across as believing that global warming is the biggest threat facing humanity. Where is the evidence for this? I know it's a threat but is it definitely, beyond doubt the biggest threat? I would hate all this effort to go to waste if we realised too late that overconsumption, for example is the biggest threat and the focus on global warming means we are taking our eye off the ball. Is the biggest threat not over consumption? Should we all be debating about how to consume less and do more to change things for the better?" Global warming is a threat alongside and above all the other causes you seem to be trying to emphasise as greater threats (without any evidence so far). I have already given you examples of how AGW is connected with the rainforest and fishing, and it is also linked to availability of drinking water, coastal habitation, agriculture, etc., etc. Each on its own is a serious problem but AGW has detrimental effects on all of them. Surely that warrants special attention, since it's mitigation will have consequent benefits for all the concerns you have ? As for over-consumption, that will continue for as long as there are goods to consume and there are goods that can be made to be consumed. Again, AGW will have an effect on that because our carbon-based economies make over-consumption easier and cheaper to carry out - while polluting the atmosphere. Anyway, many people have many different opinions as to which threats are most important, and there's even a WIKIPIDIA page which lists them all. There is also a UN organisation (UN DESA) which tries to join-up reaction and help to all of them, including AGW. In other words, don't worry about us here (on a site pertaining to AGW) not spending too much time on all those other matters - there are many others out there who are. Perhaps that is where you should be addressing your questions ?
106445. Berényi Péter at 01:53 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        #26 Ned at 00:31 AM on 21 October, 2010 Which seems like a more reasonable estimate for the temperature anomaly at the North Pole: a weighted average of temperature anomalies at other Arctic sites, or the average temperature anomaly for the whole rest of the world, the vast majority of which is outside the Arctic? Neither one, of course. The proper thing to do is to measure it directly. As you can see arctic temperature trends are quite different above land, sea ice and open sea. As there are all kinds of buoys drifting in the ice, air temperature above the Arctic ocean is actually measured. Why is it so hard to incorporate these data into the surface datasets? Or at least to use them as controls to validate eerie interpolation algorithms? Informatics anyone? There is even a buoy with a webcam deployed each year right at the pole, with its own temperature record.
106446. adrian smits at 01:44 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        No Ned they are guessing because they use temperature measurements from 1000 km away on land that is not covered with ice.That's why the GISS temperature anomaly is so far out of whack with the DMI measurements.Besides CBDunkerson claims the temperature hardly changes at all in the summertime in the high arctic so why should they be extrapolating from so far away where the land does get clear of snow and warm up.CBDunkerson has explained the mechanics of of how things work up there reasonably well.but those mechanics where the same 50 years ago and with more and more open water in that region supposedly getting warmer and warmer why does DMI show average cooling that is fairly pronounced in the summertime over the last 50 years....still waiting. thank you.
106447. VeryTallGuy at 01:37 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        The thought experiment on how an atmosphere without GHGs would affect (or otherwise) the Earth's temperature is interesting. Looking at an old post by Eli http://rabett.blogspot.com/2009/12/answer-to-puzzler-couple-of-days-ago.html it appears that the atmosphere sans GHGs is almost transparent to IR: "If there is no absorption at a particular frequency you are looking at emission from the surface." This implies to me that the atmosphere is far too thin to act as a blackbody and merely transmits surface emitted radiation. Ergo the surface temperature would average -15 or whatever the albedo corrected blackbody temperature would be. I'd guess that convection would smooth day/night differences to somehat less than would be the case for no atmosphere whatsoever. I look forward to those with more expertise than me critiquing this ! On a somewhat related point - the lapse rate is something I've never really understood properly. What would be the atmospheric temperature profile in this scenario?
106448. Peter Hogarth at 01:36 AM on 21 October 2010
        DMI and GISS Arctic Temperatures: Hide the Increase?
        FLansner at 23:58 PM on 20 October, 2010 Thank you for responding here. My sincere apologies for the typo on your name at the start of the article, I have corrected this. The "advanced" version does cover the question of the 1000km interpolation used by GISS in the high Arctic. This has been shown to be reasonable based on studies of the station data and NP and IABP drifting buoy data, temporary Ice Station/aircraft comparative studies, as well as the satellite data from AVHRR. The temperature anomalies are fairly homogenous over quite large distances in the ice covered Arctic. This is clearly not the case in the tropical regions where El Nino upwelling occurs, which is the example of land/ocean transition you use in your article to cast doubt on the use of interpolation. Obviously the tropical land/ocean and polar land ice/sea ice coastal regions are very different. DMI also suggest that transitions (bias) for example from ERA-40 to later higher resolution models could account for some of the Summer differences you have highlighted. These differences are clearly small compared with the average overall rising trend in the same DMI data. You may be interested in the more detailed comparison of GISS 12 month rolling average data gridded above 80N compared to DMI >80N rolling 365 day average data in the chart in the advanced version? The Arctic region presents challenges, and we should treat the data carefully, but as Ned says, we are far from wild guessing.
106449. Daniel Bailey at 01:22 AM on 21 October 2010
        Record snowfall disproves global warming
        Re: Roger A. Wehage (1,2) While I appreciate you using an example so near to my hometown (Marquette), I would be cautious in extrapolating local conditions from an area of complex weather patterns to the globe as a whole. Given the proximity of the Great Lakes to the Northern Jet Stream and the Arctic in general, weather here is highly variable. Even in conditions optimal for snow, if the wind direction is slightly out of alignment for any length of time, the big snow cannon in the lake doesn't hit full output. When winds are more stable, it is common to receive 4-8" of snow overnight...for many consecutive nights. The big dumps, however, come from system-generated snowfalls, not lake-effect. An "Alberta Clipper" dipping down out of the Canadian plains brings with it compressed isobars due to the deep low at the core. The high winds and energy sheer drives blizzards of 1-2 day duration, along with 18-24" snowfalls. The other source, more common now than when I was a boy in the '60s &'70s, is pressure systems moving up from the Gulf of Mexico. The enormous moisture levels they import, coupled with the colder air masses at surface levels and the tight rotation of the lows, results also in 18'24" snowfalls. The difference between them being the moisture contents of the snow they bring. Gulf-originating snowfalls tend to have moisture contents nearly double that of the Alberta Clippers. And as snowfall accumulations here are a function of moisture contents, total precipitation may be a better comparator for weather patterns here pre-1980 and post 1980. But thanks for the trip down memory lane. By the way, the record snowfalls up in the Copper Country (where Houghton is located) is 355" in the winter of 1978-1979. Marquette received over 320" the winter of 2001-2002. PS: Snow melts throughout the winter (through various warm spells), but spring onset happens well before May. This year, March had no snowfall recorded here and temps were in the 40s. Apart from a brief 2-day snowfall in early April, spring came in March this year, with April hitting 80s and May, 90s. Too hot. The Yooper
106450. RSVP at 01:19 AM on 21 October 2010
        Throwing Stones at the Greenhouse Effect
        hapivibe #80 Yes, but for the blow by blow you would have to go to the thread that argues for the contribution of industrial waste heat. If anything changed in my mind from that discussion, it was 1) an increase in CO2 simply redistributes energy vertically, such that it might be a tad warmer in lower altitudes at the cost of a cooler stratosphere, and 2) any additional energy that is accumulating has its source in industrial waste heat (this means the total amount of exothermic energy released since the beginning of the Industrial Revolution)... which is consistent with AGW's model that assumes forcings have only favored retention of radiative energy, so this extra energy (accounting wise) has had no outlet so that any extra energy has simply been accumulating, and 3) the effect is clearly observable in retreating glaciers, etc. I will admit that it may be hard to tell the difference as to what is going on given that heat is heat is heat, however the implications for CO2 are very different. AGW folks are the real unprepared optimists, because they think this problem will go away when CO2 emissions are reduced, when in fact the level of stored energy has no reason to drop without a significant radiative forcing also dropping off.
        Moderator Response: No more discussion of waste heat on this thread. In the Search field type "waste heat."

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