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Comments 126501 to 126550:

  1. Record high temperatures versus record lows
    SeveL, thanks. You described what I was picturing, although has the tail for the max. temps not also become longer? Maybe someone who has the raw data could generate the PDF for the temperature data. I could try to do so, but don't know where to source the data.
  2. The albedo effect
    Henry Pool, given that you think that absorption is a confusing word and that the missing intensity at some wavelgths at the earth surface are an indication of higher reflectivity, belive me, i can't anticipate what your conclusions might be.
  3. The albedo effect
    Riccardo, you have fallen in my trap. If you know the answers coming from my experiment, and if you say that the earth is a greenhouse then......what is my conclusion????
  4. Record high temperatures versus record lows
    I think I can picture the probability function changes described by the study (based on 24 hour periods, each standardized to the mean for that day of the year) -- the tail toward lower temperatures has shortened while the tail toward higher temperatures has stayed the same [affecting the kurtosis] and the bulk of the data have shifted slightly toward higher temperatures [affecting the skew of the distribution]. I don't know if this is what you (@19) mean. You write "rather than each day being +2C warmer" suggests that you might be talking about variance among days of the year rather than changes on a given day of the year. That would be quite a different way of looking at the data.
  5. The albedo effect
    Tyndall in 1859 did this kind of eeperiment for the first time. Since then it has been reproduced by many other. If each time we have to repeate two centuries of science, we'd be stuck at Galielo and Newton or maybe even Archimedes.
  6. The albedo effect
    Really, we are going around in circles. Why not first answer me on 127? If I look at those graphs then there is really only a very small corner of earth radiation cut off by the CO2 at 14 um. It is not the surface area of the absorptions that is important, it is the width in um of the waveband lengths where absorption takes place (even the slightest absorption). This is where reflection (or scattering) takes place. Anyway; I have thought of the following simple experiment to settle this matter. Do you think it would work? If not, why not? Experiment 1 We have a glass vessel, about 1000 liters, flushed and filled with 80% nitrogen and 20% oxygen, representing the earth and its atmosphere at the beginning. We have a probe on the side, in the middle, connected to a thermocouple and a temperature recorder. We have a large heating element in the middle of the vessel. The vessel is closed from the outside. The outside temperature and humidity is kept constant, at all times. A measured amount of energy is released into the vessel. The resulting increase of the temperature in the vessel is recorded until it falls back to the base line. The area below the curve is measured. The measurements are repeated until a constant result can be reported. (A) We now double the amount of energy released into the vessel, this increase representing the doubling of energy released by human activity on earth from 3.5 billion people in 1960 to 7 billion people in 2009. The area below the curve is measured. The measurements are repeated until a constant result can be reported. (B) In the case of this first experiment, the result is predictable i.e. if you double the amount of energy released in a vessel you should find close to a doubling of the area under your graph. This already proves that Henry’s theory rather than a 25% increase in carbon dioxide may have some bearing on global warming. (For the time being Henry’s theory is still that global warming is caused by people releasing energy when flying, moving, cooking or just wanting to stay warm or cold) Experiment 2 Experiment 2 is exactly the same as experiment 1, but now the vessel is filled with air, which includes all 350 ppm or so carbon dioxide currently available in 2009 air. The results are C en D. What would be interesting for me to know is the difference between A and C and between B and D – in other words: if we release similar amounts of energy into the vessel, what effects, if any, does the carbon dioxide and the other gases present in air have on temperature retention inside the vessel?
  7. Record high temperatures versus record lows
    Interesting study, got Anthony Watts all steamed up. I have not looked into the specifics, but I was wondering if anyone has determined whether or not there has been a statistically significant shift in the probablility distribution function/s (PDF)for the min. and max. temperatures? It is my recollection that AGW is going to manifest itself (or rather already has) in the shift of the PDF of temperatures, especially the tails, rather than each day being +2C warmer, for example, as many people tend to think. Anyhow, a PDF analysis might be more robust and insightful than the data contained the figures here.
  8. Why is Greenland's ice loss accelerating?
    @RSVP: The mixing of a fresh water pulse is described in a paper written by Detlef Stammer last year in JGR. To summarize, it takes a while before it is mixed and it mixes globally, not locally at suggested here. We are talking about time scales of 100 years or so.
  9. Increasing CO2 has little to no effect
    re comment 1 (HumanityRules), referring to apparent increases in radiation in the 800-1000 part of the spectrum in the Harries paper (the full version of which you can find through Google Scholar): on page two, 2nd column, that paper does indeed offer a potential explanation, viz. incompletely-cleared artifacts in the data (due to ice-cloud absorption). Considering the study is the first of its kind, its finding of reduced radiation precisely in the wavelengths associated with increased GHG concentrations remains remains highly suggestive, no?
  10. Record high temperatures versus record lows
    One detail I noticed on the UCAR page: there´s a special box for journalists. This is great. Communication of scientists with the press shoul be smoothed as much as possible.
  11. The albedo effect
    Henry Pool, it's not me that's eventually wrong, it's two hundreds years of physics of radiation. Instead, for you it's correct that the radiation missing at the earth surface does not show up in the reflected spectrum and it's not absorbed (absorption, for you, is the word that confuses people). Then not even energy is conserved in the process ...
  12. The albedo effect
    Henry, you wrote "I did try to look at that paper but it is something to do with testing in high pressures and high CO2 concentrations which cannot be related to what we are talking about here." Henry, you need to actually read the posts, not just skim them. I pointed you to not just that article, but I went to the trouble to tell you specifically which figure to look at in that article, and I explained specifically how it relates to "what we are talking about here." CO2's Raleigh scattering is inconsequentially small at its partial pressure in Earth's atmosphere, and more importantly any increases in its partial pressure (concentration) in the range of even the most horribly tremendous human-or-natural-caused releases would leave its Raleigh scattering still inconsequential. Look at that figure in that article.
  13. Record high temperatures versus record lows
    RSVP: 1, actually there are probably fewer blue dots in the summer too (the news release attributes the pattern to warmer nighttime temperatures). 3, agreed, but I think self-interest is only one of several factors involved (religiosity, propensity to listen to talk radio, generally being set in one's ways, etc). Nobody has either agreed or disagreed with me regarding whether ratios or percentages are a better way to summarize the information. I'm surprised because I thought that might be the most substantive thing I've written in a while.
  14. Record high temperatures versus record lows
    John @15, to stay sidetracked (sorry John C.), my father is in the "extractive industries" field--a professor of petroleum accounting at a Texas university, but having a physics background--and is constantly bombarded with the usual Fred Singer quotes from his colleagues. The SkepticalScience site has really been great at supplying him with ready responses to these sorts of comments. He's learned a lot and has a much deeper understanding of the issues. So great thanks to John Cook for taking all the time and energy to sort through the science and distill complex findings into clear and succinct summaries that the general public can understand. And for maintaining a site that is free of political ranting! I've not found a better site for this, and I've looked quite a bit.
  15. What does past climate change tell us?
    Chris# I think you may have typo'd here... "and the Greenland ice cap is likely committed to melt at atmospheric CO2 equivalents above around 280 ppm" or are you really letting us off the hook?
  16. The albedo effect
    @Tom on 44, I did try to look at that paper but it is something to do with testing in high pressures and high CO2 concentrations which cannot be related to what we are talking about here. I think Riccardo is wrong, he does not understand what the gases are doing in the atmosphere when you see the sun's radiation on top of earth (before the atmosphere) and at sea level (below the atmosphere). This has been measured many times. Look at your own doc. Surely that difference (the radiation reflected), is what makes the bulk of earth's albedo? If you look at the sun's solar radiation spectrum then you can see that a bulk of UV is cut off, especially where the sun's curve is the biggest.
  17. The albedo effect
    Henry, when water snow falls it traps air in between the snowflakes. Accumulating weight of the snow on top compresses the flakes but does not squeeze out all the air. So the ice cores contain lots of trapped air, including CO2.
  18. The albedo effect
    Henry, many people have told you repeatedly that testing has been done. Just one example is a scientific paper I pointed you to, that you can read for yourself and so not have to take my word for it. I even told you where in that paper to look, so you don't have to read the whole thing. Yet you continue to write as if no one has pointed you to any sources.
  19. The albedo effect
    Terrestrial albedo is not determined by the atmosphere but mainly by the planet surface (oceans, lands, ice, forest, etc.) and clouds. As for the atmosphere, reflectivity in the true meaning is zero because the index of refraction is 1, apart from the forth or fifth decimal place. What matters, instead, is Rayleigh scattering by molecules. It depends, among other things, on concentration (hence mainly N2 and O2 give some, although small, contribution) and on the inverse of the fourth power of the wavelength (hence contributing in the blue-UV part of the spectrum). Any supposed effect on earth albedo must consider this good old (and yet undisproved) 19th century physics.
  20. Record high temperatures versus record lows
    Just to show how easy it is to get side tracked I will throw in a data point that my father also doesn't seem to buy into global warming. We just don't discuss it anymore. While I won't give away his age, he remembers WWII quite well. My father-in-law doesn't believe in much these days RIP! Regards, John
  21. Record high temperatures versus record lows
    1) From the graph, it is apparent that as you move to the right, the red dots are hugging the black line as they should. At the same time, extreme cold becomes rarer and rarer over time. Most people (out there) think of Global Warming as a general rise in temperatures. What it really means is Milder Winters. This fact was apparent in an earlier post that pointed to a link containing historical data from Greenland. It showed milder winters, with summer temperatures generally unchanged. 2) While you cannot know by the red or blue dots what extreme temperatures are behind them, this may not be important. The graph is useful and portrays what is really going on (given sound interpretation). 3) As far as father in laws, maybe it would be interesting to see a plot of belief in global warming (on a scale of 1 to 10) vs age. My sense is that younger people would tend to be more concerned, since they are more likely to be affected in their lifetimes.
  22. An overview of Greenland ice trends
    I guess what I'm saying is that Chris has the fantastic ability to outline a scenario as though it is set-in-stone when in reality there is still serious debate about even the fundamentals. Hot off the press. Take temperatures. You would think its a simple case of looking at a thermometer and writing it down in a book. But maybe we haven't even got that right yet. Klotzbach, P. J., R. A. Pielke Sr., R. A. Pielke Jr., J. R. Christy, and R. T. McNider (2009), An alternative explanation for differential temperature trends at the surface and in the lower troposphere, J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841. Or the models we use are they accurately predicting reality Knorr, W. (2009), Is the airborne fraction of anthropogenic CO2 emissions increasing?, Geophys. Res. Lett., 36, L21710, doi:10.1029/2009GL040613.
  23. The albedo effect
    Henry@Tom at #40 thanks very much for that explanation, that has always puzzled me a bit. If you are correct then there is no CO2 freezing up at the poles either? How could they have done core ice analysis and find CO2?
  24. The albedo effect
    Henry@Tom 37/38 e.g. I have shown in my quote used in #28 (this is the one Steve is complaining about) that oxygen/ozone, water vapor and carbon dioxide are the ones that seem to cause the bulk of earth's albedo. If earth's albedo has increased (as has been shown by Palle et al 2008: see in the conclusion) then it is is logical to assume that this must be due to increases in carbon dioxide and ozone and water vapor. I have proven to you that these gas concentrations have indeed increased. The good news is: they will keep increasing. Now Tom admits: "To be clear, CO2 does reflect radiation at some wavelengths, but (this?) reflection is inconsequential for the Earth's current situation of global warming." At least we are making some progress here. The question now is: how do you know that the reflection of carbon dioxide is inconsequential unless you have done some testing?
  25. Record high temperatures versus record lows
    Pico This maybe unrelated but there is certainly a link between El Nino and Eastern Australian weather. I've got a question on El Nino. Have they been more frequent since 1980? Does this graph from Santer suggest two El Nino in the 1980's and 4 in the 1990s? https://www.llnl.gov/str/JulAug02/gifs/Santer5.jpg
    Response: There certainly is a link between ENSO and eastern Australia - I plan whether we go on a snow holiday based partly on whether we're in La Nina conditions (which leads to colder, wetter conditions at Perisher).
  26. Record high temperatures versus record lows
    I think the point is that changes in local, extreme weather have different consequences than changes in regional, average weather, so looking at how extreme weather changes in response to climate change is valuable. It's important to compare models expressing what we think extreme weather will do to how extreme weather actually reacts. This might be one of the first papers to do this with a realistic null model (I don't know). In future, hopefully better alternative models can also be presented. Borrowing from your idea of looking at shorter periods, a model comparing rates of new records to rates anticipated for adaptation might be valuable.
  27. An overview of Greenland ice trends
    Re 34: I don't believe in a lag, either. I believe that glaciers begin to respond to climatic changes very quickly but, as Chris points out, they don't necessarily come to equilibrium quickly or even approach equilibrium at similar rates. Re 33: I haven't read any of the papers listed in this thread and I'm unlikely to do so. It's completely unclear to me what you're trying to say by citing the ones you do. I assume there are also papers that suggest there will be greater rises in sea level. The question is, downgrade from what and upgrade from what? Generally accepted estimates of climate sensitivity to 2xCO2 have changed little over time, but there are papers suggesting more sensitivity and there are papers suggesting less. Maybe a good research topic would be to review predictions of expected sea level rise, too, and see how these have changed. You think uncertainty is underemphasized, but IPCC AR4 found sea level rise prediction to be so uncertain that it ignored dynamic changes. I think your opinion on uncertainty is unfounded.
  28. Record high temperatures versus record lows
    It's interesting and to some extent fun but exactly whats the point? Given that temperature isn't a random system is there anything to be gained from looking for randomness. As can be seen from the graph highs and low do diverge after the 1980s to suggest warming but they also diverge in the 1960-1970 but in the opposite direction suggesting cooling for that period, statisical significance for both period would be interesting. To add to that I wonder what happens when, following a cold snap (1970s), you look for randomness in the distribution of highs and lows? Common sense would suggest you'd see more highs. An alternative analysis might be to analyse the data from the begining of each period (warming and cooling) to look for trends within that period although this would have the disadvantage of shorter time course.
  29. An overview of Greenland ice trends
    Steve One more point on lag. This is from the Rignot paper's conclusion "We reconstructed the Greenland ice sheet total annual mass budget from 1958–2007. The ice sheet was losing mass during the warm period before the 1970s, was close to balance during the relatively cold 1970s and 1980s, and lost mass rapidly as climate got warmer in the 1990s and 2000s with no indication of a slow down. Hence, the temporal variability in mass balance is significant and closely follows climate fluctuations. " Clearly he doesn't believe in lag.
  30. An overview of glacier trends
    David You may want to watch what you write on this website I got my wrists slapped for writing "outlandish comment" Chris It's funny I accuse you of confounding local and global and you accuse me of the same. Points i) and iii) did attempt to highlight specific local conditions something that should be irrelevant over an averaged global scenario. I have no problem with the general principle of warming air = melting ice. I have a problem with the degree to which the historical process is minimised by yourself in order to over emphasis what is occuring today. Take the use of the term accelerating retreat, used to describe the retreat from 1970s to the present. Technically accurate, suggestive of an extra ordinary process occuring over the past 2 decades but go further back in time and you realise what is happening is a return to a previous rate of retreat in the 1940-50 before the pause around the 1970's.
  31. Record high temperatures versus record lows
    Steve L @9, yes, that's what I meant. To me, comparing record high minima (night-time minimum temps) against record low minima - and, separately, record high vs record low maxima - would be much more significant than just high maxima vs low minima. Wonder if I can dig up the raw data and do that myself...
  32. An overview of Greenland ice trends
    Chris i) I see you're reviews in post #2. I don't have time to read everything but essential these papers are using the same sort of data (archaeological, salt marshes etc etc) which Grinsted uses when looking beyond the sea gauge data. These have all the same problem that you have pointed out previously- local, sporadic etc etc. ii) Accepted. It works both ways. Grinsted graph shows higher peak temp in the MWP than in the year 2000. It there on the graph. iii) I'm not sure that the temp rise was very slow and prelonged. Sure the rise started in 600Ad and end around 1200AD but according to the Grinsted graph most of the rise occured over a much shorter time period. I have a real problem with the attempt to compared the rate say over the past 20years with an average rate over a period of 600years, it seems inherently flawed to me. Better would be to compare similar time periods. Obviously the scale on the Grinsted graph makes the following a little dodgy but still i think it gives good ball park figures. We agree sea levels have risen 18cmm in the 20th century. Lets pick a 100 year period around the MWP. let go for 1000-1100AD as this is the time of steepest rise on Grinsteds graph. Print the graph to fit A4 paper and you can probably measure about 10cm of sea level rise for that century. That puts the rate about half the average rate in the 20th century if you accept the 18cm figure. Are you now suggesting a 200-300year lag in sea level rise? So we are seeing sea level rise due to climate conditions from 1710-1810? Does that mean the 14cm rise in 20th century sea level rise which is anthroporgenic is due to mans activity in the 17th century? There seems a logic in consistency in this process #Steve It's an interesting point you make about Chris point iii). Another thing that had occured to me is that if the 1960-1970 represented and static and in some cases reversal of glacier melt than that offers the possibility that come the resumption of retreat post 1970s there is the possibility of an exaggerated bounce ice is cleared fro I aplologise for the poor posts they are usually rushed in the time between experiments and tend to try to cover too many point (like this one). But part of the problem is that I think this science is far from complete, often publications contain contradictory statements, expressing that uncertainty is a problem for me. I think there is much more uncertainty in this process something that is often expressed by many of the better authors themselves. But many other are more cavelier. Take one of Chris' reviews from #2 Church JA et al. (2008) Understanding global sea levels: past, present and future Sustainability Sci. 3, 9-22. Reviews have time and space to look at all aspects of a subject but this review doesn't mention uncertainty in relation to historical data, a very important aspect. How about this paper GEOPHYSICAL RESEARCH LETTERS, VOL. 34, 2007 Meteorologically driven trends in sea level rise Alexander S. Kolker Which claims to identify important meteorological factors that affect apparent sea level rises independant of global mean temperatures. This paper also "downgrade rates of warming induced sea-level change along Atlantic shorelines" Or how's about this publication GEOPHYSICAL RESEARCH LETTERS, VOL. 31, 2004 Ocean freshening, sea level rising, sea ice melting Peter Wadhams et al which also downgrades 20th century eustatic rises.
  33. The albedo effect
    Henry Pool wrote "Apart from the radiation trapped and reflected by CO2 we also sit with the problem that cooling may occur higher up the atmosphere (CO2 freezes at -40 degrees C I think?). Obviously where it freezes it must reflect a lot more sunshine. (compare water vapor with water droplets - I am sure the droplet reflect more sunshine." No, CO2 does not freeze in the Earth's atmosphere. It does not even form liquid droplets. The partial pressure of CO2 in the Earth's atmosphere is far too low. "Partial pressure" is the pressure of CO2 if it were the only gas in the atmosphere. Since the total pressure of the Earth's atmosphere is (by definition) 1 atmosphere, and CO2 is on average 0.038% of the atmosphere, CO2's partial pressure in the Earth's atmosphere is on average 0.00038 atmospheres. At the higher levels of the atmosphere where the temperature gets low, the partial pressure is drastically lower even than that. You can see from CO2's phase diagram that it cannot possibly change from gas to liquid or solid at those pressures--not even at the Earth's surface, let alone high in the atmosphere.
  34. Record high temperatures versus record lows
    Proposed new website: "Father in-law Science". Matt @7, do you mean you'd like to see record high daily minima and record low daily maxima? I think I agree -- let's look at nighttime and daytime temperatures separately.
  35. Record high temperatures versus record lows
    It would be interested to see a similar analysis for Australia. The heatwave and other temperature records of Victoria and South Australia are being blown away year after year. Something really screwy is happening. Now we are seeing a heatwave in Spring that exceeds the record from a few years ago for summer heat waves.
    Response: It's funny you should mention that - Meehle 2009 refers to a similar study on record highs/lows being done for Australia. I scratched around for it but it appears to be not yet published - will add it to the It's Freaking Cold page when it comes out.
  36. Record high temperatures versus record lows
    Fascinating study, and well delivered - thanks. What would be especially interesting would be to see the data on record high maxima versus record low maxima, and particularly record high minima versus record low minima.
  37. The albedo effect
    Re 36, Henry: how can longwave radiation of the wavelength relevant to CO2 increase at the Earth's surface if CO2 is reflecting that out to space before it gets to Earth? I'm not going to go to much effort with you unless you're willing to think about this. In my opinion, you're not being taken entirely seriously here for the following reasons: 1. You make comments based on your own vague interpretations, 2. When asked for citations you make it hard for people to see what you mean and/or you cite things that don't make the point you pretend they do (both exemplified by the Astrophysical Journal abstract you quote in #28), 3. You seem to think that other people have to do things for you -- as SNRatio says, the burden is on you to be convincing, especially given all the evidence that there is an enhanced greenhouse effect (Venus is a good example of a high albedo but hot planet that you would have to explain). I think you can be more effective if you try to adjust your approach.
  38. Why is Greenland's ice loss accelerating?
    One more number to put the extra inflow into context. The 400 GTon/yr correspond to 1.3*10^4 m3/s which in turn translates into 0.013 Sv. Both the Labrador current and the east Greenland current are several Sv.
  39. An overview of Greenland ice trends
    Hi Chris, I think you've been quite clear that response time is about re-establishing equilibrium (ie the full response). I don't know how well HR distinguishes this from lag times, which I think for him are periods of nothing happening (no detectable beginning of a response). But I can't be sure, because I don't find HR's writing to be very clear. One thing I thought I should ask about your point (iii) above, surely as the amount of available ice left to melt decreases, the rate of sea level rise will decrease. We may be far from running out of ice, but it seems to me that ice retreating up mountains is harder to melt, and even a linear response in sea level could be expected from that. Or perhaps this is where the geography comes in, as land gets steeper as you go up? Maybe I should have limited my comment to: Can we say at what point in a steadily warming world sea level rise stops accelerating?
  40. The albedo effect
    To be clear, CO2 does reflect radiation at some wavelengths, but reflection is inconsequential for the Earth's current situation of global warming.
  41. The albedo effect
    Henry Pool, you wrote "as I have clearly shown you, over and over again I should say, CO2 also causes reflection of sunshine." That is incorrect, as several people repeatedly have told you," and even have referenced peer-reviewed scientific papers that you, yourself, can read. "Reflection" is a specific physical phenomenon that is qualitatively different from absorption-followed-by-emission.
  42. Record high temperatures versus record lows
    mea culpa - formatting errors: I wrote two posts too quickly, and have messed up a blockquote here: http://www.skepticalscience.com/An-overview-of-Greenland-ice-trends.html post #31 and a bold text closure here: http://www.skepticalscience.com/An-overview-of-glacier-trends.html post #24 my very bad! Is there any way of resetting the formatting to the default at the end of each post so that careless numpty's like me don't keep messing up the formatting?
    Response: Chris, I've manually fixed those two comments. There's probably some clever code I could write to automatically fix stuff like that but I'm too busy (and lazy) to dream that up at the moment so I'll just throw a bandaid on the problem for now :-)

    BTW, I've tried emailing you several times with no reply. Do you no longer use the o2.co.uk email address you signed up with or are you just ignoring me?
  43. The albedo effect
    Are these papers freely available to the public? Or are they hidden somewhere?? In any case why is it so difficult for anyone to show me the calculation as to how they came to that value of 1.7? You cannot do only measurements of downward longwave radiation because as I have clearly shown you, over and over again I should say, CO2 also causes reflection of sunshine. So you have to look at both.....and than you must report the net effect of the cooling and warming, if possible with measurements at various CO2 concentrations. Without the results of proper investigations into this, to say that we must reduce CO2 might be just as non-sensical as saying we must reduce water vapor or ozone (which are also greenhouse gases).
  44. Record high temperatures versus record lows
    There are three possibilities: 1) Global Climate stays the same. 2) Global Warming. 3) Ice Age. It was stated years ago that... "Nothing endures but change." http://en.wikiquote.org/wiki/Heraclitus If true, there are actually only two possibilities. And ironically, if we were heading for an ice age, the demand for burning wood and and fossil fuels would be on the increase.
    Response: That Heraclitus quote is apt - climate has and always will change, with or without human intervention. This is because when the planet is in energy imbalance - when it's accumulating or losing heat - temperature changes. Currently, CO2 is imposing an energy imbalance due to the enhanced greenhouse effect. So past climate change actually provides evidence for our climate's sensitivity to CO2.
  45. Record high temperatures versus record lows
    Well, I've now followed the link to the news release and found that fewer record lows (rather than more record highs) was general and expected (because nighttime temperatures are expected to increase faster than daytime temperatures). I have one more observation about the data, though: I think a better way to present such things would be to show the percentage of new records that are highs. 50% would be even, twice as many highs as lows would be 67% (rather than requiring a log scale in Figure 2). PS -- thanks cbrock, I just need to translate these pages. Any interest in translating your work, John? (Or maybe the common skeptic arguments are actually different ones in other languages.)
  46. An overview of Greenland ice trends
    (i) Not really HR. I was addressing your specific points re local, relative sea level. The data obtained fron the central latitudes re global eustatic sea level changes (see reviews/papers cited in my post #2) indicate that eustatic sea level variation has been small in the latter parts of the Holocene, once polar ice sheet decay reached near equilibrium with Holocene temperatures. (ii) You can't accept Grinsted's pre-industrial sea level variation without accepting their 21st century projection. They are intimately linked within the same model. (iii) Sea levels may well have been higher during the MWP compared to now. The temperature rise to the high point of the MWP was very slow and prolonged, and land ice melt was able to come close to equilibrium with the forcing (higher temperature). We're well above the MWP temperature now, but contemporary temperature rise has been so rapid that we've only surpassed MWP temperatures since the 1970's. It takes an awful long time for (especially) polar and glacier land ice melt to re-equilibrate with a change in forcing, and so the rise in sea level well above the MWP level will take some time. It's rather tedious that you don't read the papers you refer to but this is very obvious from Grinsted et al (2009): they state:
    The 12–21 cm higher sea level stand during the MWP is likely the highest sea level since the previous interglacial period 110,000 years ago, and was produced by an extended period of warming, allowing time for glaciers and thermal expansion to reach a climatic balance. Hence, the cooler than present temperatures in the MWP is consistent with higher than present sea level. Table 2 (T 0) shows that the sea level at 2090–2099 will be higher than MWP even with no rise in temperatures above the present.
    That's obvious isn't it HR? We've been discussing glacier response times on the other thread. These are generally of the order of 10-100 years (largely depending on glacier geometry). The sea level response time is larger than that since it's dominated by the slow component of polar ice sheet melt (there may be faster dynamic response components). e.g. going back to Grinsted et al:
    The inclusion of paleo-temperature reconstructions allows us to determine that present-day sea level rise is dominated by a fast 200–300 year response time to temperature
    (iii) Yes 18 cm sea level rise for the 20th century [14 cm, or nearly 80% of which was anthropogenic according to Jevrejeva et al (cited in post #28)]. Sea levels are currently rising at ~3.2 mm per year. So sea levels rose more slowly during the earlier periods of the 20th century than now. As temperatures rise the rate of sea level rise increases. That's obvious isn't it? As temperatures continue to rise, ice sheet responses will be driven towards ever increasing new equilibrium (denuded) positions, and the rate of sea level rise will continue to increase.
  47. Why is Greenland's ice loss accelerating?
    RSVP: In my opinion, no harm no foul. In regards to my calculations above, while it is probably moot, I will note that in fact, a portion of the melting would actually take place out of the water with the phase change being caused by above zero ambient temperatures (for the short while this actually happens) and what sunshine they get up there. I took a quick look to see if I could get a number for sunshine hours, but quickly realized it wouldn't give me what I needed anyway so I gave up. Regards John
  48. An overview of glacier trends
    re #22. As on the other thread you're playing fast and loose with the particular and the general and the local and global. One might think you were attempting to muddy what is a rather straightforward issue! If one samples over populations of glaciers, one finds that there is an overall glacier recession in a warming world (good examples in the USGS report you linked to) and advance in a cooling one. This is a sufficiently obvious and robust finding that one can use glacier recession as a crude "thermometer" of historical global temperature rise. One should incorporate what we know about glacier responses, as Oerlemans did (see paper cited in my post #21); he took account of the response time of the individuals glaciers studied, in other words the time it takes for glaciers progress towards the new equilibrium length/mass balance in response to temperature change (see [*] and papers by Oerlemans cited in my posts #15, and 21). Using glacier recession as a thermometer is bound to be a "crude" means of measuring global surface temperature (wouldn't you say?), but it's "obvious" that the straightforward relationship between glacier advance/recession and temperature (as in the USGS report you linked to) allows this to be done. Nothing wrong with including "crude" and "obvious" in a single sentence! Not sure what your insinuation re glacier response times is supposed to convey. This is a well characterized phenomenon, is specific to individual glaciers and can be assessed on an individual basis (see papers by Oerlemans cited in my posts #15 and #21 and [*]). If one wants to understand the relationship between temperature change and glacier response, we should assess response times and incorporate these into our understanding. You introduce a delicious false argument (with an interesting precedent) here: HumanityRules: "Your points i) and iii) seem to suggest that local, specific factors may dominate individual glaciers. If you accept that then really you can't make any general points about glaciers whether the data is to support one arguement or another." We could reframe your argument in the manner that it was used by antiscience propagandists of a recent generation, to highlight its deficiencies. If you assess cigarette smokers you'll find that their risk of contracting lung cancer relates to a number of factors outwith smoking that are both genetic and environmental (e.g. diet related). These latter factors are specific to the individual (highly "local"). One can then resurrect an analogous false argument by replacing a few appropriate words of your argument; e.g. "Your points (personal genetic/environmental factors) seem to suggest that local, specific factors may dominate individual lung cancer susceptibility. If you accept that then really you can't make any general points about smoking and lung cancer whether the data is to support one arguement or another". Do you see the deficiency in that argument HR? This relates to your focusing on the specific (individual glaciers or single specific local relative sea level as on the other thread) as if this negated the possibility of determining general trends by sampling over populations (and especially by taking into account what we know about the local factors). That’s obviously and crudely fallacious (apologies for using “obvious” and “crude” in a single sentence). You’ve made some odd misrepresentation of the text I pasted from the Solomina review: (i) 2003 in Europe was hot (we were in France that summer and it was definitely toasty). Solomina point out that those conditions would eventually cause most Alpine glaciers to disappear completely. Not very controversial. Your false précis of Solimina’s statement isn’t very interesting. (ii) Glaciers respond to changes in temperature. The response time is related to some rather well-characterised factors involving glacier geometry (e.g. the steepness of the glacial valley; its size). It’s silly to pretend that we don’t know about this. Try this paper [*] (or do some Googling), and work forward through the large number of papers that address this. (iii) If we want to understand natural phenomena we don’t dismiss what we know, and attempt to interpret observations in terms of caricatures denuded of meaningful detail. [*] David B. Bahr et al. (1998) Response time of glaciers as a function of size and mass balance: 1. Theory J. Geophys. Res. 103, 9777-9782
  49. Record high temperatures versus record lows
    Steve: Just point your father-in-law to this site--it worked for me with my father!
    Response: Skeptical Science helped convince your father-in-law? You've had better success than I. I've given up on my father-in-law as a lost cause. In fact, even my own father (also a skeptic) refuses to talk to me about global warming science (his argument is that he heard some guy on the radio say that the world was 5 degrees colder a few decades ago).
  50. Why is Greenland's ice loss accelerating?
    John Cross After re-reading what I wrote, I can see why you thought this, since I was not more specific... sorry about that. My mistake. I can assure you that that was not my intent. In any case, I did like your approach. I am also aware that my tone as pointed out by others went over the line and I will try hard not to let this happen again.

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