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Comments 71201 to 71250:

  1. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    Monkey--Let me take a look at that. Good idea.
  2. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    Correction, the the two sunspot images are my screen snapshots, taken from the J Kirkby talk on CERN CLOUD, about midway. http://www.youtube.com/watch?v=63AbaX1dE7I
  3. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    Sphaerica: It is my chart, originally done for my personal interest when I first became interested in the subject some time back. The base graph is from Wikipedia here The Solar Activity graph is traced off this Wikipedia graph here . It was reversed, to run the timescale L-R, compressed horizontally but uniformly in Powerpoint then overlaid, with as good a timing match to the start and end timeline points as possible by eye. The vertical scale is distorted simply to show the correlation of shape, and hence an implied causal correlation. No more than that. The Solar irradiance line is traced off the IPPC AR4, Ch 9, fig 9.4 Matching to the timeline as above. Again the vertical scale is stretched simply to check for correlation of shape. Apologies for any inaccuracies, reasonable effort was made to make an accurate trace and time fit within the limitations of Powerpoint. The purpose was simply to check for any broad historic correlation between global temperature, solar activity, and solar irradiance. The broad correlation does seem apparent. Nothing more than that is intended by the chart. No values are associated with the vertical scales of the traces. If it is considered misleading, please feel free to have it deleted. As for the other 3 images, they are all from NASA.
  4. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    It would be useful if you could show the journal for each paper listed - it would give a clearer picture (i.e. are these papers in appropriate journals, or have they been slipped into low-impact journals on topics barely related to climate science? Excellent work though.
  5. Pielke Sr. and SkS Dialogue Final Summary
    Victull @ 62 - my bad. As far as ENSO is concerned we need to differentiate what we are talking about here. You (and Tristan) are quite right that ENSO is an internal redistribution of heat, and therefore cannot cause long-term warming (we happen to obey the laws of thermodynamics on this blog! - to paraphrase Homer Simpson). On shorter timescales, ENSO profoundly affects the global weather. La Nina causes cooling of surface temperatures, and El Nino warming. The bulk of this is due to the exchange of heat in the top 500 metres of ocean, and this is essentially the tilting of the thermocline in the equatorial Pacific. The effect is so large it is global in scale. But the key point is this: over 90% of global warming is going into the oceans, and La Nina is a time of strong ocean warming, even though the surface layer is cool. It's this surface layer that globally affects surface temperature, misleading the average punter into thinking that this "slowdown" in surface temps mean a slowdown in global warming. It isn't - global warming is still "Full steam ahead, both engines!" This will be covered in upcoming posts, because it's an area that's not really well understood by the public at large. But no. you can't treat ENSO as an external forcing because it isn't. The "cool" phases are eventually balanced by the "warm" phases, as heat within the system sloshes back and forth.
  6. Mythic Reasoning about Climate Uncertainty
    This myth lives on without end. Here is JCurry giving the Uncertainty Monster talk in Santa Fe, complete with graphics poking fun at various scientists and the very idea of consensus: Don't listen to what one scientist says. Listen to the consensus reached by over a thousand scientists. As if it is inherently bad when more than one researcher finds the same thing. Isn't that the way it's supposed to work? These folks continue to drag science down the drain. Then she makes her pitch for 'scientific integrity.' This was a dinner talk - hope nobody had to make a run for the exit!
  7. Climate's changed before
    265, lancelot, Sorry, I just realized that you used TSI incorrectly, and I responded to my instant interpretation of the acronym, not what you meant by it. TSI stands for Total Solar Irradiance, and has to do with the amount of solar radiation (all frequencies) hitting the earth at TOA (top of atmosphere). It does not refer to the amount of radiation actually reaching the ground.
  8. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    E&E might best be handled by another sort of 'footnote' like I had suggested for withdrawn arguments. That is, list the papers, but then note that there are reasons to consider the 'peer review' of E&E suspect. Err on the side of inclusion, but note factors which could reasonably have been used to exclude some things.
  9. Climate's changed before
    FYI, there is evidence on TSI... evidence that there has been no corresponding increase coincident with the warming of the last 30 years. That's why they started reaching for GCRs and other special effects. Except that there are proxies for that, too, and they don't appear to have had that sort of climate effect in the past, so why would we think they suddenly have a large effect now? And, lastly, if such an effect is large, then it implies a high climate sensitivity -- and a big part of the skeptic argument today has turned to a begrudging admission that it is warming (unless some new evidence says it's not or it's stopped), a begrudging admission that CO2 is the cause (unless some new idea says maybe it's not), but an adamant belief that any such warming will not be too great because climate sensitivity is low and the planet has a natural negative feedback to constrain temperatures to a narrow range (this despite the evidence of great swings between glacial and interglacial periods, and other proxy evidence of past extreme if much slower changes in climate, observational evidence of positive feedbacks in today's warming world, and well conceived and modeled mechanisms that would point to the currently estimated sensitivity of 2˚C to 4.5˚C).
  10. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    33, lancelot, Please answer my question here, but continue any discussion of the sun itself on another thread. I'm curious. What is the source of your solar activity and irradiance graph in comment 33? I mean, any number of sources will show you a very, very different record of solar irradiance and solar activity. The author of that graph is clearly guilty of extreme misrepresentation of the data. FYI, here is the actual solar activity reconstruction that was almost certainly the source of the data (based not only on 14C, as stated, but also two sources of 10Be and Group Sunspot Number), from Solanki et al Nature 2004. Note the down-tick in solar activity at the very end, too, from actual sunspot counts. Pay attention to the years... 14C dating ended 1895. 10Be ended around 1950. The graph ends 11 years ago at 2000. The rise in solar activity is from roughly 1900 to 1950, and does not correspond to the recent, accelerated warming. Here is that graph overlaid and scaled to fit with the graph you supplied. Clearly, the creator of the graph took great liberties in choosing the 14C proxy when it suited him, or the 10Be proxies or GSN proxy when they looked better, and even then he shifted things left, right, up and down to better match the temperature record. And then he left off the down-ticks at the end. Doesn't this annoy you just a little? Solanki et al 2004 is available here. An intelligent discussion at Real Climate can be found here.
  11. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    The trouble is, if you say E&E does not belong, then you are saying you are not going to rely solely on the WoS but are somehow going to decide journal by journal which belong and which do not. I presume there is a range of peer-reviewed practices among journals that make some better at it than others, but how to go back to say 1995 and decide that?
  12. Climate's changed before
    Sphaerica, no problems. You are right to curtail, but I am not running out of ideas. I had a specific list of questions, I have now gone through it. The topic question was: What does past climate change tell us about warming? Part of the answer would be: Identify all natural causes which may have caused warming, and which may still be causing warming. Once they have been carefully and rigorously eliminated, it leaves only AGW. The list of the 'possible others' was: 1 Solar irradiance - yes of course, but variations are not powerful enough to account for recent variations. 2 Does Solar activity/GCR influence cloud formation? Answer - perhaps, but no firm evidence for that theory yet. 3 Is cloud formation influenced by the biosphere? Answer - perhaps,some interesting studies in hand, but no firm evidence of a significant effect yet. 4 Earth heat, release of mantle heat underwater? Answer - no evidence. 5 Increase in surface irradiation (TSI) due to any other unknown cause, as yet undetected. Answer - the subject has been discussed in another thread. TSI data is incomplete and there seem to be no historic proxies. So, no evidence either way on that. 6 Fairies (joking) That was my entire list of 'suspects'. I have had clarification on all, for which many thanks to all. In summary, on the basis of current evidence: Past climate change and assessment of all conceivable natural causes tells me that AGW looks a 95% certainty. My point about bankers? Well, all professionals carry responsibility for their advice and decisions. I am one. I have to make decisions too, some of them determined by an assessment of the AGW case. If AGW predictions are correct, the world will be grateful for your advice. It not, the world will be quite unhappy about wasted resources. No judgment there, just the way life is. Good luck.
    Response:

    [DB] Here we are, a flurry of responsive comments later (all subsequent to your comment with unsourced graphics).  I remind you again of the need to provide sources for these asserted graphics as others having to point out the issues with these is dragging this whole thread off-topic.

    Or else I will have to clean up this thread a bit.

  13. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    Jim... If you haven't seen this list you should check it out. I think the great information you're compiling here makes the most impact when placed in context to how much science is actually out there on climate change.
  14. Philippe Chantreau at 02:53 AM on 4 November 2011
    CO2 measurements are suspect
    Fitz, you can take a look at this. Concentrations in multiple bubbles are averaged, known events used for indexing, there is a variety of ways to ensure the reliability of measurements and extract the best data. It's another one of the things that real scientists have already worked on quite a bit. This paper from the Vostok team has a methodology discussion and a bunch of references, many on methodology: http://cdiac.ornl.gov/trends/co2/vostok.html
  15. Mercury Scientist at 02:34 AM on 4 November 2011
    Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    15, Mark: I agree. VERY generous. I would not call E&E a scientific journal. But we could get sued for saying that. :)
  16. Baked Curry: The BEST Way to Hide the Incline
    green: BEST's data ends in the spring of 2010. As the full year was tied with 2005 for the 2nd warmest on record and 2011 to date hasn't exactly been cool, when those data are appended, you may well be right. Let's see them spin that into 'no evidence that warming hasn't stopped.'
  17. Visual depictions of CO2 levels and CO2 emissions
    Excellent, cheers mate
  18. Pielke Sr. and SkS Dialogue Final Summary
    I was under the impression that ENSO can't be a 'forcing' because it's effectively zero sum. All it can do is create noise.
  19. Baked Curry: The BEST Way to Hide the Incline
    Being a bit pedantic. Due to very warm years 2000 to 2010 global warming is accelerating.
  20. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    This is a useful post and a great reference. But I think Jim is being VERY generous to include anything from E&E. In my opinion ANy paper in E&E is totally discredited. This link Why E&E is flawed articulates quite well the problems with E&E. It's a politically driven journal (self-admitted by it's editor), published more "skeptic" papers than any other journal by a very long margin, has peer review processes which have been seriously questioned, and has a citation impact factor around 0.42 - less than one citation every four years. Nature, one of the most central scientific journals in this field, has an impact factor of around 30. The Journal of Climate, a mainstream but smaller climate journal, has an impact factor of 3.57.
  21. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    Lancelot @33 and 34, the source of your first graph is trying to sell you falsehoods. Below is the IPCC graph from which the "irradiance" graph is derived (click on image for larger version): The caption reads:
    "Figure 9.4. Contribution of external forcing to several high-variance reconstructions of NH temperature anomalies, (Esper et al., 2002; Briffa et al., 2001; Hegerl et al., 2007, termed CH-blend and CH-blend long; and Moberg et al., 2005). The top panel compares reconstructions to an EBM simulation (equilibrium climate sensitivity of 2.5°C) of NH 30°N to 90°N average temperature, forced with volcanic, solar and anthropogenic forcing. All timeseries are centered on the 1500-1925 average. Instrumental temperature data are shown by a green line (centered to agree with CH-blend average over the period 1880-1960). The displayed data are low-pass filtered (20-year cutoff) for clarity. The bottom panel shows the estimated contribution of the response to volcanic (blue lines with blue uncertainty shade), solar (green) and greenhouse gas (GHG) and aerosol forcing (red line with yellow shades, aerosol only in 20th century) to each reconstruction (all timeseries are centered over the analysis period). The estimates are based on multiple regression of the reconstructions on fingerprints for individual forcings. The contributions to different reconstructions are indicated by different line styles (Briffa et al.: solid, fat; Esper et al.: dotted; Moberg: dashed; CH-blend: solid, thin; with shaded 90% confidence limits around best estimates for each detectable signal). All reconstructions show a highly significant volcanic signal, and all but Moberg et al. (which ends in 1925) show a detectable greenhouse gas signal at the 5% significance level. The latter shows a detectable greenhouse gas signal with less significance. Only Moberg et al. contains a detectable solar signal (only shown for these data and CH-blend, where it is not detectable). All data are decadally averaged. The reconstructions represent slightly different regions and seasons: Esper et al. (2002) is calibrated to 30°N to 90°N land temperature, CH-blend and CH-blend long (Hegerl et al., 2007) to 30°N to 90°N mean temperature and Moberg et al. (2005) to 0° to 90°N temperature. From Hegerl et al. (2007)."
    Assuming the creator of the graph has scaled one of the two reconstructed solar forcings (the green line and the dashed green line), then the uptick at the end of the graph as presented by you is incorrectly scaled. Indeed, for the dashed green line (the best fit on general shape), in the IPCC reconstruction the final values are lower than the initial value. Alternatively, the graph is based on the reconstructed temperature using all forcings (silver line, upper graph) which does indeed have the appropriate uptick, but is not a reconstructed solar irradiance. I will note that it is inappropriate to rescale one forcing as in the graph you presented without rescaling all forcings by an equal amount. Failing to show the other forcings cherry picks the data.
  22. Fred Singer Denies Global Warming
    I believe Roger Helmer is also the European reprepresentative of the Competitive Enterprise Institute and has spoken against AGW in a number of UK/EU right wing situations. Say no more
  23. Pielke Sr. and SkS Dialogue Final Summary
    Bob & Rob @59 &60 Sorry if my 'I guess' seemed cute. It is a result of Amero-Irish language exposure. I figure that you two are more expert than I am on these climate change topics, however I do have some background in heat transfer and thermodynamics. " Perhaps you took victull's statement as one indicating long-term averages" - right on Bob - that is the point I was making. Is not global warming all about long term averages rather than short term variations? If you would indulge maybe a slightly off topic area; I do have one more question for you which has been troubling me. Dr Pielke and others have made much of the slowing in warming over recent years and Dr Trenberth also refers to a stasis in warming. Aerosols, reduced Solar and ENSO - La Nina cycles are suggested as reasons. ENSO - La Nina cycles are usually considered as internal redistributions of heat which is already in the system. In that case they should not contribute to global heating or cooling. If that is not the case then why should ENSO - La Nina not be treated as external forcings just like Solar and Aerosols?
  24. Climate's changed before
    261, lancelot, 2 things. First, I'm getting the impressions from your posts that you're currently in a "yeah, but what if" mode. You are looking as hard as you can for alternative explanations, but you're starting to run out of ideas (as have the deniers/skeptics). This is fine, and the path you have to take to some degree. But you should be leery of resting a position on ignorance (i.e. it might be those impossible to define natural forcings, or just plain something we haven't thought of yet). That's not science, it's magical thinking. There is also a whole lot to learn. Molecular physics, atmospheric physics, how the myriad proxies work, past climate change events, ocean mechanics, how ENSO works, how models are constructed etc., etc. Your time would be much better spent studying what we do know rather than trying to pin down what we don't know in order to give a wave of the hand attribution of climate change to something other than CO2. The science is fascinating, in and of itself, and you will understand the gaps in our knowledge (where they are, and how deep) much better by learning what we do know than what we don't know. Second... apologies for having parts of your post snipped, but unlike WUWT and many other denial sites, we like to stick exclusively to the science. Occasional this rule must be bent because of current events or the topic of a post (such as public policy), but as a rule, physics doesn't belong to a political party or have a socio-economic reason for warming the planet, so those factors aren't worth discussing.
  25. Visual depictions of CO2 levels and CO2 emissions
    Tristan, further information on the GOSAT Observations (and the disinformation from Mr O'Sullivan) at The Blackboard.
  26. CO2 measurements are suspect
    I see a lot of comments that suggest that CO2 in the ice cores are not accurate because of the fixing of CO2 in the bubbles in the first place happens over decades so that flucuations of less than ~80 aren't recorded and then the interaction of the trapped air with the ice surrounding the bubble. I couldn't find an article that refutes this argument so I thought I'd ask it here. Would anyone care to comment on the accuracy of the ice core data?
  27. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    33, lancelot, Yes. That's why I said "and other relevant factors (such as magnetic field strength)." But it has to be something that affects earth's climate. If you can't come up with a mechanism, then the fact that it's happening is of no immediate relevance to climate science. The sun is a marvelously complex environment-system-thing, well worth studying, but of relevance here only where a real connection can be drawn. Note, too, that even minor changes in TSI which are relatively constant over the course of hundreds of years can result in climate change such as the 200 year descent into the "Little Ice Age." That descent amounted to a roughly 0.5 degree decrease in 200 years. The recovery appears to have been a roughly 0.5 degree increase in 100 years. Modern warming represents a minimum of a 0.6 degree increase in 30 years, and the climate has still not stabilized at its equilibrium level. Also note (I find this fascinating) that CO2 is implicated (not proven) as a possible factor (not sole cause) in the descent into the Little Ice Age. Basically, the Black Death killed 100 million people, so a lot of cleared fields turned back into forest. Not long after, small pox and other European diseases decimated 20 million or more Indians, and even more cleared land turned back into forest. This sucked CO2 from the atmosphere to grow the trees, and the drop in CO2 is measured in the ice cores. Just food for thought. Note that as DB (the moderator) pointed out, this has wandered far off topic. If you wish to continue on this, we can move the conversation to a more appropriate thread. But you have to pick a topic... rate of warming? natural causes? solar insolation? clouds? Just post your next comment some place appropriate. I'll see it.
  28. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    I have looked through the list for papers in E&E. In addition to the ones by Kininmonth and Labohm, there are single papers by Ball, Easterbrook, and Rorsch. Five in total. Again, these are the ones that come up in the WoS that meet the criteria I used.
  29. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    Just to clarify 33: The Reconstructed Temperature image is not from the IPCC, only the superimposed Solar Irradiance graph (bright yellow line).
  30. CO2 – Some facts, figures and outcomes
    DougCarbon#22: "point is quantified in the literature referred to in this summary" Sorry the anonymous webpage of a 'consulting geologist,' who refers to the discredited geocraft CO2 graph, is hardly 'the literature.' Apparently you missed the words 'forest degradation,' clearly referring to the reduced carbon uptake of stressed forests. "Take it or leave it. In my view" Yes, we may indeed take or leave your unsubstantiated opinion. That's about where we left off the last time we heard nonsense about the earth's core heat warming the surface - and that the sun does not.
  31. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    muoncounter 30: thanks for showing the pure BEST chart. Much clearer that way. I won't argue about the shapes of the lines. You can slice a salami any number of ways. I agree my 'gradual and uniform' was too thick a slice. Can we say longish rise of 0.9 deg 1800 - 1970, then steep rise of 0.9 deg 1970 - 2010, the latter very likely due to AGW? Sphaerica: I am perplexed! TSI varies only +/- 0.1%, agreed. But I have always considered the definition of solar activity (which includes many phenomena) to be distinct from simple irradiance (heat energy): IPCC uses the same distinction:= eg: Image and video hosting by TinyPic You write: "But sunspots themselves are nothing more than visible blemishes on the sun which signal changes in solar activity. Sunspots themselves are nothing from that point of view." Image and video hosting by TinyPic Image and video hosting by TinyPic Image and video hosting by TinyPic Perhaps getting into GCR territory..! But surely solar activity is much more general, complex and variable than simple irradiance.
    Response:

    [DB] When posting graphics it is considered good form to also link to the paternity of the graphic.  Please provide such for your above graphics.  Else I will delete this comment as this is going too far off-topic.

  32. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    Very interesting work. I look forward to seeing the future developments. One thing you might want to indicate somehow is papers advancing arguments which have subsequently been withdrawn. For instance, Lindzen has conceded that various iterations of his 'cloud iris' hypothesis have been disproven. I didn't see any papers from Spencer or Christy on their early satellite temperature record, but if any do eventually get added it would be worthwhile to indicate that they later agreed they had gotten it wrong. Et cetera. Barry's idea about cross-checking your results against lists of 'skeptic papers' is also a good idea. SkS has a database of peer reviewed skeptic arguments here. However, it is user maintained and thus not always accurate - and certainly not all inclusive.
  33. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    Now I recall the problem. E&E is not one of the electronic journals made available by the University of Southern California, the only one to which I have access. From E&E's website, it appears the only way to get to back issues of E&E is to buy a personal subscription, which I am unwilling to do. Thus the only way I can provide the text or abstract of an article in E&E is to find it somewhere else, as with the papers by Kininmonth and Labohm. E&E has this statement on its website: "E&E is now included in ISI's Social Sciences Citation Index and current contents."
  34. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    Mikah--the paper by Kininmonth was in E&E and evidently Heartland picked it up and printed it. I need to reference the original. Heijdensejan--that paper by Labohm was also in E&E but the link does not lead there. Will fix.
  35. It's waste heat
    Donthc, others have commented on some of the fundamental errors in your analysis, but there was a particularly odd one which hasn't been remarked on yet; "The heating effect of the sun is a constant..." Right. Constant. Other than... variable levels of clouds blocking it, different surface albedo conditions reflecting it, changes in the intensity of the greenhouse effect, that whole 'day and night' thing, progression of the seasons, orbital variations (c.f. 'Milankovitch cycles'), the ~11 year solar cycle, other variations in solar output such as the Maunder minimum, the fact that the Sun is now about 30% 'hotter' than it was in the Earth's early history, et cetera. You could accurately say, 'the average annual heating effect of the Sun is currently showing only small variations on a multi-decadal scale'... but no, it is nothing like 'constant'.
  36. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    Mikeh--I will check that. Macoles--Excellent point. Heijdensejan--will check. Barry--will check. Thanks to all. Please keep the comments and suggestions coming.
  37. 10 Indicators of a Human Fingerprint on Climate Change
    NBotB, for info on 'ice ages' I'd suggest reading the article on Milankovitch cycles. As the other responses indicate, our understanding of the glaciation cycle is just one of many independent lines of evidence which confirm that fossil fuel CO2 emissions are the primary cause of recent warming. The list of 'skeptic' arguments and the 'search' box at the upper left of the page are good places to find answers to various questions.
  38. Visual depictions of CO2 levels and CO2 emissions
    Lots of crowing that the theory of AGW has again been put to death due to patently poor reporting. Plenty of allusions that John was 'fired' from the site he posts on for revealing such earth shattering information.
  39. Climate's changed before
    lancelot @261, our understanding of what will happen in the near future does not just depend on projections from known physics. We also have the record from the past. The advantage of the record from the past is that we do not need to know all the factors involved to read that record. We do not need to know what the cloud feedback is, for example, for that feedback has been integrated into the results by the best model available to us, ie, the real world. Given that, it is worthwhile examining two particular events, the Paleocene-Eocene Thermal Maximum (PETM), and the Last Glacial Maximum. The PETM was a warming event at the boundary between the Paleocene and the Eocene. Boundaries between geological eras are marked by significant changes in fossil assemblages, ie, by extinction events followed by repopulation with new species. In this case the extinction event was probably brought on by the release of a large amount of methane, which was oxidized to form CO2 and H2O, with the CO2 showing up clearly in the geological record. The effects are summarized in the abstract of one review article as follows:
    "During the Paleocene-Eocene Thermal Maximum (PETM), 56 Mya, thousands of petagrams of carbon were released into the ocean-atmosphere system with attendant changes in the carbon cycle, climate, ocean chemistry, and marine and continental ecosystems. The period of carbon release is thought to have lasted <20 ka, the duration of the whole event was 200 ka, and the global temperature increase was 5–8°C. Terrestrial and marine organisms experienced large shifts in geographic ranges, rapid evolution, and changes in trophic ecology, but few groups suffered major extinctions with the exception of benthic foraminifera. The PETM provides valuable insights into the carbon cycle, climate system, and biotic responses to environmental change that are relevant to long-term future global changes."
    The interesting thing here is that best estimates show that the climate response to a doubling of CO2 evidenced by the PETM is 3.6 degrees C per doubling. That is a climate sensitivity of 0.973 degrees C per Watt/m^2 of forcing. In contrast to the PETM when temperatures where substantially hotter than today, at the LGM they where substantially colder. Again the climate sensitivity can be calculated from known forcings at the LGM and the known temperature difference. Most estimates in doing so come close to that by Hansen and Sato, with a value of 0.75 +/-0.25 degrees C per Watt/m^2. That represents an estimate of 2.775 (1.85-3.7) degrees C per doubling of CO2 (compared to the IPCC estimate of 2.8). Again, I emphasize, no assumptions about feedback values from water vapour, clouds or anything else go into these calculations. The Earth just does what it does, and the comparison between known forcing and known temperature response yields the climate sensitivity. But despite the significantly different continental arrangements, and the very different temperatures, the climate sensitivity estimates from these two periods are in the same ball park, and indeed, in the same zone as the IPCC estimates. When it comes to the basic feedbacks, it is certainly possible that scientists have missed something. Evidence is strong, for example, that they have been underestimating ice and snow albedo feedbacks (positive). They may well also be overestimating the cloud feedback (possibly positive or negative). For that to create a significant problem for their predictions, these errors need to mostly line up in the same direction. What is troubling about the assumption that these errors will fortuitously come out in our favour is that it is also an assumption that the Earth's climate sensitivity is, fortuitously, approximately half or less of what it is when the Earth is hotter (PETM) or colder (LGM) than it currently is. That somehow, and with no physical basis for assuming so, we just happen to be in a goldilocks zone of low climate sensitivity even though hotter and colder conditions are known to have high climate sensitivities. What makes the heroism of this assumption even greater is that it is known that throughout the entire existence of vertebrates on Earth, from the late pre-Cambrian to the present, climate sensitivity has never been far from 2.8 degrees per doubling of CO2. Over 540 million years of high climate sensitivity, but it just happens when we start emitting CO2 at industrial scales, we happen to be in a goldilocks zone of low climate sensitivity? That, at least, is what the so-called climate "skeptics" would have you believe.
  40. Climate's changed before
    261 - lancelot "So if it turns out in a few years that something has been 'totally overlooked', climatologists will be about as popular as bankers!!" It's worth noting - taking the long view - that CO2 as the key to global warming was, in the '70-'80s, the "other factor". You might also want to ask; if it had been overlooked and, indeed, the anthropogenic origins of the observed warming had been overlooked... just how popular would the climatologists been? If you're going to do counterfactuals; Imagen a future generation suffering from land-loss, a crippled bio-sphere, extreme weather etc. Just how popular will our generation be if we had overlooked the anthropogenic side of the equation and possible mitigation policies and if we don't act on them?
  41. Climate's changed before
    May I just say that I really appreciate the well-considered (and well-mannered) comments to my questions on this site. Sphaerica: When I wrote before I was 'half serious' I was referring to my somewhat flippant suggestion of breeding microbes to seed clouds. That idea, even if feasible, wouldn't go very far of course. I do have a purely scientific interest as you say, but there are larger interests too. (-Snip-). Report of an Ad Hoc Study Group on Carbon Dioxide and Climate, Woods Hole, Massachusetts July 23.–27, 1979 to the Climate Research Board , Assembly of Mathematical and Physical Sciences, National Research Council: “We conclude that the predictions of CO2-induced climate changes made with the various models examined are basically consistent and mutually supporting. ... Of course, we can never be sure that some badly estimated or totally overlooked effect may not vitiate our conclusions. We can only say that we have not been able to find such effects.” (-Snip-) CO2 is a GHG. 100% certain. Natural forcings exist. 100% certain. All possible natural forcings or long term effects on climate have been identified and accurately quantified. __% certain. (Fill in the gap?) muoncounter: Dimming is an urban island phenomenon, ok. Not sure how that relates to the question of net irradiance at surface level globally. From Bob Loblaw's posts I suspect the situation is: we use satellites because they are there. But gee whizz, if we could use actual surface monitoring, we would be so much more certain that our estimates are correct. GCOS looks really interesting. Re sphaerica's comment that oceans cover 70% of surface, I don't see why BSRN type monitoring couldn't be done from ship decks. Use some of that £18bn perhaps?
    Response:

    [DB] Ideology snipped.  Stick to the science, please.

    Your Woods Hole report is badly dated.  Various scientific organizations, including the National Academies last year, have greatly linked the certainty of climate change/global warming (as fact) to its human attribution (greater than 90% likelihood).

  42. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    I think this is a worthwhile project. It will only enhance the site to have someone familiar with all the skeptic papers and able to provide an overview. If nothing emerges to challenge the scientific consensus, visitors to the site can be assured we have done our homework.
  43. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    The irony is that Anthony Watts is a co-author of the Fall et al paper mentioned above. "Analysis of the impacts of station exposure on the U.S. Historical Climatology Network temperatures and temperature trends" http://pielkeclimatesci.files.wordpress.com/2011/07/r-367.pdf So one of the great deniers has 0 publications throwing doubt on global warming, but one paper debunking the very issue on which he made his name! :)) Delicious!
  44. Philippe Chantreau at 18:27 PM on 3 November 2011
    It's waste heat
    Donthc, the papers cited in this thread quantify waste heat and find it 100 times too small. If you want to argue that this quantity is in error you have to provide some evidence, not just an opinion. What calculations are you relying on? Nitrogen a GH gas? That's a good one. What else do you have in store? This makes no sense whatsoever: "If CO2 is responsible for warming, why does nuclear plants, which does not produce CO2, still emits waste heat that serves to heat up the surrounding air?" How could the radiative warming from GH gases prevent the waste heat from cooling towers to be dissipated? Why would these 2 processes be mutually exclusive? There is absolutely no reason, unless you have some new funky laws of physics up your sleeve.
  45. Philippe Chantreau at 18:01 PM on 3 November 2011
    CO2 – Some facts, figures and outcomes
    It is unfortunate that SkS has to entertain even the most egregious nonsense for the sake of "balance" or to avoid accusations of censorship and what not. As a result, even the most severe cases of D-K must be tolerated. Perhaps some of the most extreme in this stuff should be dropped altogeher. I mean, really, there are things that are not matters of opinion, and questions to which there is one right answer. Sheesh...
  46. Pielke Sr. and SkS Dialogue Final Summary
    Bob Loblaw - it was this bit: "but heat gets into the oceans by I guess". It is a very common misconception. Perhaps I've misinterpreted his comment, but the "guess" word set off my "spidey sense".
  47. It's waste heat
    Donthc@96 To engage constructively here one is required to provide evidence for one's claims. Amongst many other things in your "thesis" that are without foundation the most obvious is: Nitrogen is not a greenhouse gas...try wikipedia for "greenhouse gas". (this site has a lot of work to do... it's like sweeping grains of supposition off a beach of ignorance)
  48. 10 Indicators of a Human Fingerprint on Climate Change
    #68 and #69, can I add ... Three: we observe the increase in downward longwave radiation and decrease in outgoing longwave radiation at CO2-specific wavelengths. Not only is CO2 the only explanation for warming, we actually see it happening directly. That's the "less heat escaping to space" in the graphic above.
  49. It's waste heat
    Fuel + Oxygen --> Heat + Water + carbon dioxide. more combustion will bring about more production of heat and CO2. Decrease the rate of combustion, and you will decrease the amount of heat released, and reduce the rate of warming of air. The heating effect of the sun is a constant, and will always be there no matter what you do, whereas the burning of fuel is a variable. It is clearly heat which warms up the surrounding air, not CO2. Does reducing CO2 concentration decreases the amount of energy generated from bond breaking of the fuel? An analogy will be that of taking the elevator. When a single person takes a ride in the elevator, he is producing CO2 and radiating body heat via IR. This excess heat introduced to the atmosphere within the elevator is removed easily by the ventilation fan, which draws out heat at a constant rate. (Similar to heat dissipating heat out to space. Ever been in a crowded elevator? When you increase the number of occupants inside the elevator, more people equates to more radiation of body heat, and more emission of CO2,(analogous to increased combustion of fossil fuel), and the ventilation are unable to ventilate the elevator as efficiency. You can place a vat of CaOH to remove all the CO2 in the air, but the elevator will still remain hot and stuffy. Since CO2 is a byproduct of heat liberation, it should be perceived as an indicator of warming, rather than a causative agent of warming. I agree that CO2 is a GHG, but its effects are overrated. If you think that an increase in a slight percentage of atmospheric concentration of CO2 can bring about climate change (despite the doubling, it is still at around 0.3% atmospheric concentration, remaining more or less constant), then why not the idea that the small amount of AWH generated can actually be a more important factor in causing warming than CO2? And if you want to argue about greenhouse gases being responsible for drastic warming, why is everyone ignoring the presence of the 80% atmospheric concentration of nitrogen, which is also a greenhouse gas? Should 80% of a greenhouse gas be more significant than 0.3% of greenhouse gas? Compared to nitrogen, the decimal percentage increase of CO2 can be regarded as negligible. In the previous thread, people have been likening AWH to a cracker and GHG as icecreams, and their effect on weight gain. It is important to realise that what actually brings about a change is the presence of a non-constant factor. If your staple food consist of eating 2200 calories of icecream daily, without any gain in weight, and put on weight only after eating a 50calorie cracker, it is actually the cracker which causes the weight gain, as it is a deviation from the existing equilibrium. The output of the sun has been more or less constant, while man's energy consumption has been increasing steadily, and shouldn't the warming be attributed to this rise in energy consumption? Referring to another analogy on this thread, while a candle may not hit up the room fast enough, a furnace may. Man's energy consumption has grown from a "candle" into a "furnace", and it is this massive increase in energy liberation that accounts for the drastic rise in temperature of the room, which remains as a constant, not changing in its dimensions. And lastly, the example of a nuclear plant is a highly relevant and interesting one. If CO2 is responsible for warming, why does nuclear plants, which does not produce CO2, still emits waste heat that serves to heat up the surrounding air? The only way to reduce warming, is to increase energy efficiency, so that less energy is wasted for the unintentional heating of air.
  50. Is there a case against human caused global warming in the peer-reviewed literature? Part 1
    A bunch of anti-AGW papers are linked here, if you're not already aware of the page.

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