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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 106801 to 106850:

  1. It's the sun
    Ken Lambert - my apologies, I was thinking about the UV issue (several orders of magnitude insignificance), which apparently wasn't being brought up. Too many threads... The greenhouse gas forcing is only 4-5 times the TSI forcing, and the TSI change is currently going in the opposition direction from the temperatures. Not an order of magnitude - I was off by a factor of two. But it's still 4-5x the TSI forcings! It's really, really not the sun. TSI changes have not correlated with temperature changes over the last 40 years, GHG forcing changes have. Unless you somehow disagree with this basic and quite provable point?
  2. The sun upside down
    cloa513 - what about the "99%" (you can make that any number by choosing your criteria) do you think is relevent to this discussion? There a physical limitations to how much of an unknown (say an unknown volcano) can be affecting an estimate (eg global heat flow). Perhaps you could comment further on a more relevant thread than one about the sun? How much certainty do you need by the way for your decision-making? We constantly make decisions in face of imperfect knowledge.
    Moderator Response: I deleted cloa513's comment because it was off topic for this thread. cloa513, please peruse the "Arguments" page to find a more relevant thread.
  3. Skeptical Science housekeeping: Comments Gluttony
    I'd be interested in seeing such a post too but he had best be prepared for the full vigorous shakedown of his analysis haha
    Response: I think that's what put him off doing the post. Talk about a tough crowd! :-)
  4. The CO2/Temperature correlation over the 20th Century
    Arkadiusz Semczyszak, Whether it is the opposite? It can be the opposite and it can be the way it is now. CO2 can act as a feedback and a forcing. This is pretty straightforward science.
  5. New temperature reconstruction vindicates ...
    Sorry Ned, off post a bit, I'll get back on track shortly. protestant at 00:30 AM on 15 October, 2010 In the above case (156) the simple "Excel" moving average function plots a mean for the previous 10 years. You are correct that a 10 year average centred on 2010 is currently impossible but this is not the point. You have rather conveniently ignored the mathematically valid statement on ENSO periods with regard to linear regression and then confused this with averaging in terms of appropriate period. On a time series like this, a trend will significantly change with end point choice, a running average will not. You simply cannot arbitrarily choose peaks or troughs for linear trend start/end points to support your argument, and you really do need to calculate a linear trend over something like 20 years to avoid severe bias from ENSO (or try to subtract ENSO index as commented above). You continue with the misconception about warming halting in 1998. How can you validate this? Look at the ten year running average in red (now +/- 5yrs), and the most recent 20 year trend in dark blue below. Both sailing straight through the 1998 peak, on an underlying upwards trend. Do you really claim flattening or halting? I will come back to you in ten years on your final point, but if the 20 year trend was flat we could at least have some confidence that the underlying cause was not ENSO related.
  6. Do the IPCC use alarmist language?
    Ned, my understanding of the usage here is that 'panel' refers to the institute as a whole, rather than a group of individuals. To expand the sentence with the current verb usage, it reads "Do the members of the IPCC use alarmist language?" Some of them may at times, but the what they produce as a collective (ie, AR4) does not. (Last post on grammar, I promise. :-)
  7. Do the IPCC use alarmist language?
    Byron Smith... Exactly. The IPCC are sounding the alarm bell but they've wrapped the clapper with rags so as to not hurt anyone's ears.
  8. New temperature reconstruction vindicates ...
    #159: "Even if 2000 decaedal averge is higher than 1990avg it does not mean the temperatures couldn have halted in the end of 90's. If they just stay on the same level they rose to, the decaedal avg will be simply higher." I assume you meant to say that 'even if the 2000 decadal avg is higher than the 1990 decadal avg, it doesn't mean temperature [increase?] [warming?] couldn't have halted in the end of the 90s.' This is still not making any sense. Consider the examples below: 
    90s   |  00s   | 20 yr avg  |  Conclusion
+.5   |  +.3   |   +.4      |  warming on halt
+.5   |  +.4   |   +.45     |  maybe on halt
+.5   |  +.5   |   +.5      |  no change
+.5   |  +.6   |   +.55     |  maybe still warming
+.5   |  +.7   |   +.6      |  still warming
    The 90s average doesn't bias the result any more than the 2000s average. But I have to admire the dedication to message: Only a true denier would say that even if temperatures are higher, it doesn't mean warming didn't halt.
  9. Carbon Dioxide - Everyone's Favorite Pollutant
    KdKd at 190 times 2. It is too bad. BP used to make insightful comments.
  10. Do the IPCC use alarmist language?
    The IPCC are not alarmist in their conclusions, and they are no more alarmist in the way they report their conclusions. Yet their conclusions are alarming and quite possibly understated.
  11. New temperature reconstruction vindicates ...
    @Ned: I stand corrected. Your response to protestant was spot on, BTW.
  12. Do the IPCC use alarmist language?
    Many scientists find the IPCC too timid in its conclusions. One of them is Andy Lacis. Human-induced warming of the climate system is established fact. “My earlier criticism had been that the IPCC AR4 report was equivocating in not stating clearly and forcefully enough that human-induced warming of the climate system is established fact, and not something to be labeled as “very likely” at the 90 percent probability level.” http://dotearth.blogs.nytimes.com/2010/02/17/lacis-at-nasa-on-role-of-co2-in-warming/
  13. Do the IPCC use alarmist language?
    A recent set of articles comment about how you can now circumnavigate the Artic in one season (without sailing in an ice breaker.) For example - http://www.physorg.com/news/2010-10-crew-circles-north-pole-summer.html . A quote from this article " Less than 10 years ago the first steel-hulled sailboat managed to get through just one of the passages, and 100 years ago, a circumnavigation would have taken six years," the "Northern Passage" crew said in a statement. " How did the IPPC reports define the probability of this being possible in 2010 ?
  14. Climate Cherry Pickers: Falling sea levels in 2010
    BP @109, You keep on digging yourself deeper into a hole. 1) Let me remind you again that this thread is about Goddard cherry-picking, and make no mistake he is cherry picking. He clearly chose those data (failing to apply the inverse barometer correction) to support his claim that "Sea level falling in 2010". 2) You say that his analysis (if one could venture to call it that) "does not make" sense. Please, don't insult our intelligence BP, you know very well the game that Goddard is playing. The fact that you are not willing to call him on it is inexcusable, and flies in the face of you assuring me a while ago that you are interested in the pursuit of truth. 3) Let me remind you that nowhere in his post did John refer to accelerating increase in SL rise over the satellite record. And you are misrepresenting what Doug said in his post @ 42. He said "TTTM, look at this graph. Notice, sea level sort of bounces along, upward". Nothing about acceleration of the rate of SL rise over the satellite record. You and Ken are arguing a strawman. 4) Now that you have introduced the strawman about rate of SL rise not "accelerating", you give a wonderful piece of curve fitting at #49. First, 2010 is not over yet (in fact the UofC data only go back to June or so), so I am not sure what you mean when you claim that the rate of increase in global SL in 2010 is 1.9 mm/hr. Additionally, you do not support any statistics to support choosing the quadratic model versus a linear model. I have processed the UofC data in MINITAB-- for the linear model over the satellite record the R-sqd =0.934 (p-value <0.001; S=4.02); for the quadratic model the R-sqd is 0.938 (p-value <0.001; S= 3.84). I also plotted the residuals, there is not much at all to choose between the two models used to fit the data. Therefore, I can see no statistical justification of why one would feel compelled to choose a quadratic model versus a linear model. Moreover, there is no reason to expect that the quadratic model will be valid beyond the training period, but I am willing to bet that the linear model does have some skill beyond 2010. How about we revisit in 2015? That all said, I agree that over the duration of the satellite record there is no evidence of an acceleration in global SL. 5) The CSIRO data up until August 2010 just came in, they show that the mean rate of increase in global SL over the satellite record is 3.2 mm/yr. Now let us place this in context. Historic data show that the rate of increase in global SL early in the 20th century was about 1.7 mm/hr (Church et al. 2008), with "with an increase in the rate of rise over this period". Church et al. (2008) note that Jevrejeva et al.(2006)used a different technique but obtained a similar global curve. Also, look at Fig. 6 in Jevrejeva et al. (2006) and Fig. 3b in Church et al. (2008)-- the rate of increase in SL has been increasing, although it seems with a distinct cyclical component. And I think it is obvious that a linear model would not fit the data presented in Fig. 3a in Church et al. (2008), and indeed they fit the data with a quadratic model. In fact, look at Fig. 1 in Jevrejeva et al. (2008) which shows the global SL from 1700 until 2000-- another quadratic model. So the data and publications show that John Cook is completely justified in saying that "So a broader view of the historical record reveals that sea level is not just rising. The rate of sea level rise has been increasing since the late 19th century" As for you choosing this statement "Sea-level rise is accelerating faster than the IPCC predicted". That is not even worth addressig becasue a) It is true (see The Copenhagen Diagnosis) and b) It is another strawman argumenat by you. Regarding point a), from the Copenhagen Diagnosis: "Sea level has risen faster than expected (Rahmstorf et al. 2007), see Figure 16. The average rate of rise for 1993-2008 as measured from satellite is 3.4 millimeters per year (Cazenave et al. 2008), while the IPCC Third Assessment Report (TAR) projected a best estimate of 1.9 millimeters per year for the same period. Actual rise has thus been 80% faster than projected by models." You also claim that "They are usually connected to alarming projections of even more acceleration in the future (yes, projections, whatever that's supposed to mean, never predictions), based on the alleged accelerating ice loss over Greenland" Are you serious or engaging in some odd form humour here? The contribution from dynamic ice loss is one of the unknowns that does not work in our favour. What about the loss from terrestrial glaciers, the WAIS and possibly even the EAIS? And what information do you have to support your insinuation that the ice loss from Greenland is not accelerating or to refute the findings of Jiang et al. (2010)? Also, feel free to argue with the findings presented by mspelto which indicate ice loss from the Greenland ice sheet has increased from about 60 km^3/yr in 1993/1999 to 80 km^3/yr in 1997-2003, to >100 km^3 in 2003-2007. Re GRACE, it is not cherry picking when it is the only data you have-- and the GRACE data have been placed in context. Are you going to accuse people of using the JASON data record or the RSS MSU data record of cherry-picking next? Thanks BP for making me waste my morning chasing down your misinformation and straw mean arguments.
  15. Explaining Arctic sea ice loss
    RSVP, I think your semantic climate sensitivity is too high. Perhaps you'd feel better if I added a calming word such as "substantially" in order to make more obvious the qualifier "...although natural factors have always influenced the state of Arctic sea ice..." How about this: In sum, although natural factors have always influenced the state of Arctic sea ice, research strongly suggests that today's decline is substantially driven by the novel influence of anthropogenic C02 we've added to the atmosphere and thus is unique in Earth's history. Come to think of it, that actually reflects research findings better, though it hardens the language in favor of anthropogenic factors. How about "significantly?" Oops, same deal. Word-smithing won't really change the fundamental meaning of the sentence, unless we're so highly tuned that we consider "is driven by" to imply "excludes all other possible factors."
  16. Explaining Arctic sea ice loss
    Chris G #36 "I don't believe you'll find any claim that the variability of sea ice is only due to CO2." Please scroll upward and read the last paragraph of the original article. As for your comment about ice in a glass: since I am on the blue pill, the drink does seem cooler to me. ...and as for the rest... "When ice melts or water evaporates, energy must be taken from the environment in order for the ice or liquid to move to a less ordered state" http://www.theweatherprediction.com/habyhints/19/
  17. It's Urban Heat Island effect
    If you thought our cities are getting warmer, you're right. "Bureau of Meteorology researchers have found that daytime temperatures in our cities are warming more rapidly than those of the surrounding countryside and that this is due to the cities themselves."
  18. Do the IPCC use alarmist language?
    It's important to point out that the IPCC is tasked with the job of assessing the risks and likelihoods. So, really Roger A. Wehage's complaints that it's too complex to assess a rather moot point. The issue at hand (the point of the main blog post) is whether the IPCC use alarmist language. I have to agree that they do the best job they can to address all sides of the issue in a way that... well, ultimately is not going to please anyone. In my mind that probably means they're doing a good job (i.e, the best job possible given the circumstances). If you think about it, the IPCC's assessment of climate sensitivity is probably the very best overall indicator for the entire issue of climate change. 1) Climate sensitivity of 2C to 4.5C with 3C as best fit. 2) Sensitivity below 2C is very unlikely. 3) Sensitivity higher than 4.5C is also unlikely but can not yet be ruled out. (Hope I have that right.) Is this alarmist? Some alarm bells should be going off in everyone's head for sure. But they mitigate that alarm by saying we have a pretty strong inclination of about where things stand.
  19. New temperature reconstruction vindicates ...
    archiesteel writes: Uh, no, you don't. See Tamino's convincing argument to the contrary. I don't think Tamino gets that right, personally. He apparently just uses the numbers in Loehle's reconstruction as they are. But Loehle's reconstruction is just centered on its own long-term mean. In order to compare Loehle to anything else, you need to recenter it using some base period. In Fig 2, the "base period" is the entire period of overlap among all the reconstructions. In Fig. 3, it's the period of overlap with the instrumental record. Both of these are defensible, though I think the latter is better. Tamino's figure (comparing two reconstructions that have different base periods without recentering them) is simply wrong, IMHO.
  20. Explaining Arctic sea ice loss
    RSVP "I didnt see anything here about warmer waters causing ice in the north to melt. If anything the water would be cooling as a result." What waters would be cooling? The waters from the Pacific do flow into the Arctic and they can be very warm from an el Nino a year or so earlier. And the strength of an el Nino is related to CO2 heating the atmosphere and the oceans at large. The more warm water there is, and the higher its temperature, the more melting of sea ice from below.
  21. Explaining Arctic sea ice loss
    RSVP: "I didnt see anything here about warmer waters causing ice in the north to melt. If anything the water would be cooling as a result." Read post 22 again. If you have no understanding of the most basic science concerning what you are talking about you do not make a good impression. Warm ocean waters coming from both the Atlantic and the Pacific are part of the problem with melting Arctic ice. The warm ocean is the primary concern with Greenland. If you do not know what the issues are you cannot make informed comments about those issues. The meridional overturning circulation in the North Atlantic moves enormous amounts of energy and changes in it cause concern for the future. By contrast, references to waste heat just remind us that you do not understand energy transfer either.
  22. Do the IPCC use alarmist language?
    barry writes: Checking with the grammar police - 'panel' is singular, so shouldn't the title be "Does the IPCC use alarmist language?" "Panel" is a group noun or collective noun, and different English-speaking countries have different usage. In the US, collective nouns are generally treated as singular, whereas in the UK they're often treated as plural.
  23. New temperature reconstruction vindicates ...
    protestant writes: Your post maybde had an intention of also vindicating the original hockey stick shape and that the current temperature trend would be unprecedented. The original study doesnt support that. I'm not sure what you mean by "vindicating the original hockey stick shape". My post compares this new reconstruction (Ljungqvist 2010) to several others (see Fig. 2 and Fig. 3). The current decadal mean temperature (2000-2009) is in fact higher than any decade in the reconstruction. This is true whether you use the instrumental record "as is", or whether you just take the 2000s-1990s difference and add it to the end of the reconstruction (the method you specifically recommend in your previous comment). protestant continues: If you want to be credible also in the eyes of us sceptics', next time, when someone publishes a new proxy-reconstrucion, please cite the graphs used in the papers ant not making your own with your own undocumented un-peer-rewieved methodologies. I cited and linked to the Ljungqvist paper in the first two sentences of the post, and provided links to all other data sources. There is no peer-reviewed paper that shows the comparison I was making in this post (comparing Ljungqvist 2010 to previous reconstructions by Loehle, Mann, and Moberg). If there were a paper with figures showing that comparison, I would have used it. protestant writes: And if you add temperature data to Loehle, you get basically same results as Ljundgqvist. She shapes on both are remarkably similar. [...] It does NOT vindicate Mann, except with the apples-to-oranges comparison you just did and which was justifiedly strongly critisized on my last posts. The shapes of the original studies simply DO NOT agree. There is no way to "add temperature data to Loehle" other than the kinds of methods I used in Fig. 2 or Fig. 3 -- recentering it to match some other temperature record during some overlap period. The raw data in Loehle 2008 are just centered on their own mean. More to the point, Loehle 2008 is supposed to be a global reconstruction. Ljungqvist 2010 is a mid- to high-latitude Northern Hemisphere reconstruction. If you want to claim that "the shapes match" then that is a sign of problems with Loehle because a global reconstruction should not show a larger MWP-LIA amplitude than a mid- to high-latitude Northern Hemisphere reconstruction. In contrast, the Mann and Moberg reconstructions shown in Fig 3 are both Northern Hemisphere only. Thus, comparing them to Ljungqvist is much less of an "apples to oranges" comparison than the comparison of Loehle to Ljungqvist.
  24. Do the IPCC use alarmist language?
    Roger Wipage said "I know enough to know that I have neither the prerequisite background nor the tools to predict the probabilistic distribution of anything more than simple statistical examples." and then goes on to tell us that the IPCC cannot calculate probabilistic distributions. Why do these deniers always tell us about stuff they admit they do not understand? Alan Marshall: Many of the IPCC final conclusions were LOWERED by the government reviews before the report was approved. Remember that the Bush administration, Saudi Arabia and Australia all had to accept the conclusions. The lawers from countries who cause the most warming changed many of the risk levels.
  25. Do the IPCC use alarmist language?
    There are other threads here to discuss particular weather events, but SME's comment caught my eye: While events such as the Pakistan flooding are complex and cannot be simplistically categorised, a major point is that this disaster was NOT driven by an especially extreme weather event. The overall rainfall is reported to have been in the 20 year flood to 30 year flood range. Really? How about a reality check from the World Meteorological Organization? We don't have to guess at these things, there are people on the planet who know what they're talking about. For more circular discussion on the topic of weather extremes and their relationship to climate change, I'll tout this thread: NASA-GISS: July 2010-- What global warming looks like
  26. Do the IPCC use alarmist language?
    Roger A. Wehage wrote : "JMurphy @22: I believe that one should not use the severity or lack thereof in individual events as arguments for or against global warming or climate change. The same goes for floods and heat waves. Their frequency and severity certainly appear to be increasing. At the same time their impacts on the human population are becoming more severe because of artificial changes we've made to the environment and because of increased population density." All true enough but the problem is that the so-called skeptics try to pretend that things are not really that bad because such things have happened a few times in the past, while failing to realise that such things are happening more regularly now and are affecting more and more people, now and in the future. It's similar to suggesting that people, animals and plants, etc. will be able to cope by migrating, as they have done in the past when necessary - forgetting about those big populations, behind their political and national boundaries, who won't be so keen on helping others to mitigate global warming in their backyards.
  27. Do the IPCC use alarmist language?
    Key term in Chris' post: ...The 1936 North American heat wave... Here on SkS the topic is planetary-scale, secular change.
  28. New temperature reconstruction vindicates ...
    @protestant: I guess my original post was too "hot" and got deleted. I agree with the terms of use on this blog, and so will not complain about it. I'll simply repeat that you totally miss the point by accusing me of cherry-picking. The goal was *precisely* to show that short terms - including the one from 1998 - are not statistically significant when trying to analyze trends. "And if you add temperature data to Loehle, you get basically same results as Ljundgqvist." Uh, no, you don't. See Tamino's convincing argument to the contrary. "Seconly, the warming happened until 1998 until it halted to the "high" level." ...except it didn't. You know, unless you're cherry-picking, i.e. using an unusually warm year as a starting point. "What if the halt lasts also next 10 year, will you be then using 20yr avg to prove "warmest 20 years in the recorded history!"?" The "halt" has already stopped, as temperatures are once again appearing to go up. Of course, we'll have to wait a couple of years to make sure there's a clear trend, but so far there's *no* statistically-valid reason to claim the warming has stopped.
  29. Do the IPCC use alarmist language?
    Checking with the grammar police - 'panel' is singular, so shouldn't the title be "Does the IPCC use alarmist language?"
  30. Explaining Arctic sea ice loss
    ach, from* the surroundings
  31. Explaining Arctic sea ice loss
    Regarding, "I didnt see anything here about warmer waters causing ice in the north to melt. If anything the water would be cooling as a result. " Does the ice melting in a glass of water cause the water to get cooler? No, it only prevents it from getting warmer. It does not stop the glass from absorbing energy from its surroundings; it just stops the temperature of the glass from rising until the latent energy required to melt the ice is matched by the energy absorbed by the surroundings.
  32. Do the IPCC use alarmist language?
    Let me point out the obvious, RSVP and Robert. We act in life and death situations every day with a pitifully tiny amount of information. We walk, run, drive, and ride, for example, with only guesswork and little hard data. We constantly use the well-it-worked-before logic, even though the conditions have changed. In short, we bet our lives--and the lives of others--on what are often totally unscientific leaps of cheap reasoning. A great many of us, in fact, bet our time, money, and happiness (and the time, money, and happiness of others) on the idea that there is a supernatural being that has ordered the universe in some detailed way, according to a book written some thousand or thousands of years ago or according to someone who clearly has a vested interest in having us believe such a thing. And yet that's ok. Then we have the IPCC, which has collected the research and input of thousands of scientists, carefully weighed the significance of the data, modeled it in several different ways, checked and re-checked and re-checked the results, and published the information complete with error bars, recognition of weaknesses, and a host of caveats. If the IPCC had simply collected the data and published it all together without providing any models, people would be beating down the doors demanding models--with all their weaknesses. Do we have to stick our hand in the fire to know that doing so will hurt? Not as adults, we don't. We could stick our hand closer and closer to the fire, but we never know that the feeling of heat will not plateau at a certain point. We have theories, and we use the proxy of a stick, noting that the stick is destroyed (as a stick, not as matter) and that the same will likely happen to us. Children have a hard time understanding proxies, and so they stick their hands in the fire, get burned, cry, and get angry (and then end up projecting that anger on the people who warned them not to do it).
  33. Explaining Arctic sea ice loss
    RSVP, Regarding, "If the problem were only due to CO2 the effects would be symetrical, and they are not. " I don't believe you'll find any claim that the variability of sea ice is only due to CO2. Weather patterns, changes in salinity, oscillations of current and upwelling flow, albedo feedbacks, etc. all interweave to produce the variability. Wind patterns are driven by differences in energy content, which is also effected by the radiative properties of the atmosphere (CO2 influenced). It's like a multi-body problem in Newtonian physics. If you move one body, the forces acting on the other bodies change; so, they move, which changes the forces acting on the original body, and so on. There is some evidence that the increase in sea ice around Antarctica is driven by some combination of increased snowfall (If you warm the ocean, it gives off more moisture. If it is still below freezing, that moisture will precipitate as snow, which changes the albedo of the surface water, etc.), lowered salinity, and increased outflow of the land ice.
  34. Do the IPCC use alarmist language?
    Roger A. Wehage, Your exemple about the rectangle is the typical calculation we do when we calculate error tree and Monte-Carlo methos can catch it very easily. By the way, you confuse risk management with quality control, which are quite different beast. When doing risk management, you put your brain in the paranoid mode. Your exemple from NASA are typical case of how exactely NOT doing risk management. For both Challenger and Columbia, the risk was identified but dismiss because it was annoying to adress it. Hum, looks like climate change debate for me. Also, NASA estimate for risks were too low. In the beguining of the program the estimate was 1/300 failure, while observe rate is more like 1/66. But administrators, put it at 1/10000 but it has to be that way.
  35. Do the IPCC use alarmist language?
    #30, #31 There are no risk-free alternatives.
  36. New temperature reconstruction vindicates ...
    #154: "I understand Ljungqvist's comment that you cite ("a very cautious interpretation of the level of warmth since AD 1990 compared to that of the peak warming during the Roman Warm Period and the Medieval Warm Period is strongly suggested") and have no problem with that." But your reconstructions DO have a problem with that. Your post maybde had an intention of also vindicating the original hockey stick shape and that the current temperature trend would be unprecedented. The original study doesnt support that. If you want to be credible also in the eyes of us sceptics', next time, when someone publishes a new proxy-reconstrucion, please cite the graphs used in the papers ant not making your own with your own undocumented un-peer-rewieved methodologies. "However, the key point of my post is to assess the degree to which Ljungqvist "vindicates" Loehle (2008) vs "vindicating" other reconstructions. Loehle's reconstruction is supposed to be a global reconstruction, yet it shows a greater amplitude for NH-centric episodes than actual NH reconstructions (Ljungqvist, Mann, Moberg). To me, that suggests that insofar as Ljungqvist 2010 "vindicates" anyone, it's a much better match to Mann or Moberg than Loehle." And if you add temperature data to Loehle, you get basically same results as Ljundgqvist. She shapes on both are remarkably similar. Some differences occur - like Loehle fails to show RWP and also shows LIA a bit colder. It does NOT vindicate Mann, except with the apples-to-oranges comparison you just did and which was justifiedly strongly critisized on my last posts. The shapes of the original studies simply DO NOT agree. #155: "I don't understand that strategy. Crests are, by definition, noise from short term phenomena. Connecting the dots from 1998's crest to 2009's crest is just as arbitrary as connecting the dots from 1993's trough to 2007's trough. The conclusion that 'there's no statistically significant warming 1998-2010' is to use two and only two data points. How is that not cherrypicking?" Since 1998-2010 ENSO has no significant trend (well it HAS a slightly POSITIVE one). Any other short-term trend will get biased by ENSO (La-Nina to El-Nino trendis 4 example). #156: A running decadal average (red below) would be better at extracting underlying trends with minimised ENSO influence, but as this clearly shows the underlying rising trend few deniers would recommend this methodology." Ok, first of all, you cant calculate running 10 year average to 2010. The graph must end on 2005 since you dont know the avg of 2011 yet (needed for calculating 2006 etc.) Seconly, the warming happened until 1998 until it halted to the "high" level. You are trying to debunk a 12 year trend with a 10year average which is almost as long as the whole trendline which was in question. That doesn't really address my argument, really. Even if 2000 decaedal averge is higher than 1990avg it does not mean the temperatures couldn have halted in the end of 90's. If they just stay on the same level they rose to, the decaedal avg will be simply higher. What if the halt lasts also next 10 year, will you be then using 20yr avg to prove "warmest 20 years in the recorded history!"?
  37. Do the IPCC use alarmist language?
    This is getting off-topic, but since comment #7 is still there... Roger Wehage says NASA spent billions of USD on reliability analysis for the shuttle and still couldn't get an answer that was in the ballpark. First of all, as for the claim of billions spent on risk assessment, [citation needed]. A billion dollars will buy you 4000 years of full-time work from senior engineers; that's a lot of Probabilistic Risk Assessment. But more to the point, he provides a link which destroys his own argument. Follow the link he gives in comment #7 to see that the median reliability of the STS, across numerous studies, ranges from about 1/80 to 1/130. Huh, pretty much exactly the observed reliability. So whence the claim that PRA is impossible, Roger? Yes that's right, the risk assessment by the experts was correct. Remember, in the case of Challenger, all the engineers said "don't launch" until they were overruled by management. Seems to me this whole story does nothing but support the notion that the experts are quite capable of risk analysis of even complex systems, and are to be ignored at your own peril.
  38. Berényi Péter at 23:49 PM on 14 October 2010
    Climate Cherry Pickers: Falling sea levels in 2010
    #107 kdkd at 12:02 PM on 11 October, 2010 there don't seem to be claims about accelerating sea level rise Of course there is one in this very thread. It is based on a post from the same author. "In point of fact, observed sea level rise is already above IPCC projections and strongly hints at acceleration" Or here is another one, this time from Peter Hogarth. "there is a significant weight of evidence of a recent acceleration in rate of sea level rise [...] The weight of peer-reviewed evidence for this acceleration in sea level rise is robust" The meme at this site must have been started by John Cook himself, with an even stronger claim. "So a broader view of the historical record reveals that sea level is not just rising. The rate of sea level rise has been increasing since the late 19th century" Here is a fairly recent one. "Sea-level rise is accelerating faster than the IPCC predicted" These claims are not supported by evidence, still, they keep popping up, undebunked. They are usually connected to alarming projections of even more acceleration in the future (yes, projections, whatever that's supposed to mean, never predictions), based on the alleged accelerating ice loss over Greenland. That acceleration is computed using eight years of GRACE data. Now that's cherry picking. But I can't see it'd meet much opposition here. As for the "scientific approach", University of Colorado at Boulder sea level data are next to useless. They lack error bars completely and the sampling interval is 9.9156 days (several samples missing). It is about one third of a synodic month, but not quite. The difference is 6230 sec (1 h 43' 50''). As the signal itself must contain strong components at multiples of lunar cycle frequency, it looks like an odd choice. The gradual phase shift makes up a full lunar cycle in about 11 years, so on timescales significantly shorter than that it can introduce false trends. This is why Steve Goddard's four month sea level trend does not make sense, not because it is "cherry picking" (it is not, it's just some recent data). It is actually a bit worse than that. He shows data with no inverted barometer correction. If correction is applied, there is no trend whatsoever. Of course in the long run barometric correction should not change the trend at all, because mass of atmosphere is given and there are limits to how uneven its distribution can get before strong winds restore uniformity. But this time span is not sufficiently long. Otherwise there is nothing wrong with the idea that the ocean itself can be used as a global thermometer to check ocean temperature and heat content measurements. This is what Trenberth is trying to do, with not much success so far. The main problems with this ocean thermometer idea is that as we have seen it is not reliable in the short term (neither its long term precision is good enough) and volumetric thermal expansion coefficient of seawater is highly dependent on both temperature and pressure while ocean mass also keeps changing.
  39. Anne van der Bom at 23:28 PM on 14 October 2010
    Do the IPCC use alarmist language?
    Roger A. Wehage, RSVP, in the words of my father, "Your guess is as good as mine." Then I'll take an educated guess over yours or RSVP's. I prefer to use the best available information instead of willfully keeping myself in the dark and pretending the world is just a big blob of unknowable uncertainties.
  40. Do the IPCC use alarmist language?
    Roger @22: Indeed, if the population of the planet was only 7 million, instead of billion, and was projected to rise to 9 million then the imperative to act on the projected change in climate would be less. There would be plenty of space and resources to deal with, at best, a 2C change in temperature. But our population is so great, our use of resources so profligate that to continue on the present path is reckless.
  41. Tai Chi Temperature Reconstructions
    Peter Hogarth, I have a question for your original post. The approach you describe for averaging the proxies seems in my view to be very close to the Composite-Plus-Scale (CPS) method. Especially as it is applied in Ljungqvist, 2010. What are your thoughts on this?
  42. Roger A. Wehage at 21:36 PM on 14 October 2010
    Do the IPCC use alarmist language?
    JMurphy @22: I believe that one should not use the severity or lack thereof in individual events as arguments for or against global warming or climate change. For example, about two hundred years ago the mid Mississippi valley had a powerful earthquake that changed the course of the river. Only a few people died then because only a few people lived in the area. If that same quake were to occur today, hundreds of thousands could die. The same goes for floods and heat waves. Their frequency and severity certainly appear to be increasing. At the same time their impacts on the human population are becoming more severe because of artificial changes we've made to the environment and because of increased population density. For example, heat waves are most severe in paved-over cities that consume hugh amounts of energy to run millions of air conditioners. The unlucky ones are the poor and elderly who cannot afford air conditioners. Many flood disasters are similar. Man has destroyed most of the world's hummus and forest cover and built giant levees to hold back the surging water, only to worsen the situation. Over many decades the U.S. has naively spent many billions of dollars through the Corps Of Engineers to mess with nature; now it is spending many more billions to fix their first mistakes.
  43. Roger A. Wehage at 20:53 PM on 14 October 2010
    Do the IPCC use alarmist language?
    RSVP, in the words of my father, "Your guess is as good as mine."
  44. Do the IPCC use alarmist language?
    Come off it, chriscanaris. You start off on natural disasters and then move on to some early heatwave records, posting some material from WIKIPEDIA but ignoring everything that followed on from the bits you liked - 10 to 15 times more information from the 1970s onwards with lots more records.
  45. Do the IPCC use alarmist language?
    It is redundant to say something is very possible. A thing can either be or not be,... it is either possible or impossible. If it is possible, you can then move on to consider its likelihood (i.e., probability). We know that global warming, for instance is 100% possible, however the probability is indeterminant as the sample space is one.
  46. Do the IPCC use alarmist language?
    chriscanaris yes, there has been heat waves, cold spells, floods, forest fire, etc., in the past. Then what? You're completely missing the meaning of probability, which is what James Wight is talking about. Your pedantic list of extreme events is useless as far as the probability of these events is concerned.
  47. The sun upside down
    Joe Blog you're right, it was poorly worded. What I wanted to say is that the effect of UV by itself is not new, as clearly stated before when I cited the two papers; though, it may be larger than previously thought. On the contrary, the anti-phase change in the VIS is new.
  48. Do the IPCC use alarmist language?
    Heatwaves go back well before the 1980s but this may be purely coincidental: ‘The record for the longest heat wave in the world is generally accepted to have been set in Marble Bar in Australia, where from October 31, 1923 to April 7, 1924 the temperature broke the 37.8 °C (100.0 °F) benchmark, setting the heat wave record at 160 days... The 1936 North American heat wave during the Dust Bowl, followed the one of the coldest winters on record—the 1936 North American cold wave. Massive Heat waves across North America were persistent in the 1930s, many mid-Atlantic/Ohio valley states recorded their highest temperatures during July 1934. The longest continuous string of 100 °F (38 °C) or higher temperatures was reached for 101 days in Yuma, Arizona during 1937 and the highest temperatures ever reached in Canada were recorded in two locations in Saskatchewan in July 1937.’
  49. Explaining Arctic sea ice loss
    adelady #34 "You're not distinguishing between sea ice and land ice." If you compare the geographies, the poles are almost perfectly inverted. As per links (below), the area contained within the northern 70 degree parallel is ocean, coinciding with the Antartic continent which is also roughly contained with the southern 70 degree parallel. In the one case the pole is at sea level (and encapsulated by land), and in the other, the region is mountainous, surrounded by water. I didnt see anything here about warmer waters causing ice in the north to melt. If anything the water would be cooling as a result. http://geology.com/world/arctic-ocean-map.shtml http://www.lib.utexas.edu/maps/islands_oceans_poles/antarctic_region_pol_2005.pdf
  50. Do the IPCC use alarmist language?
    SME wrote : "Lack of planning and foresight by authorities thus seems to be a major factor. A fine example of Murphy at work." It wasn't me, honest ! Anyway, looking at lists of natural disasters, it's curious how most of those involving heatwaves are since 1980. Or is it ?

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