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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 71951 to 72000:

  1. The BEST Kind of Skepticism
    Dale, The leader of the BEST project, Richard Muller said this at a speech a few weeks ago: "Global warming in my evaluation is real and much of it, if not most of it, is caused by humans," --Richard Muller, Sept. 28, 2011 http://wsutoday.wsu.edu/pages/Publications.asp?Action=Detail&PublicationID=27853&PageID=21
  2. The BEST Kind of Skepticism
    Dale, please refocus on the science and spare us the tone. Your restatement of the BEST study was just that: a restatement. But in that restatement you changed the meaning significantly. When quoting please use "quotes" (and ideally italics to avoid any misunderstanding. And the Tamino post I linked in 37 above is well worth reading. Edit: Please also see Tamino's response to this comment over at Open Mind.
  3. The BEST Kind of Skepticism
    @40. I never said or implied any of that. I simply answered @29's question. You assumed the rest.
  4. The BEST Kind of Skepticism
    Dale, That's a pretty big if. Where's the evidence? Where is the logic? Where is there anything except for a desperate hope that it is true, simply because you don't want to believe otherwise, in the face of all evidence? What about this paper makes you personally believe that their inference is true? And why do you put so much weight into a single statement in a paper which as far as I knwo contains no data which would support such an assertion. A statement which is a mere "may," and if true only implies that AGW may be "overestimated" (they don't say by how much)? What sort of skeptic clings to a single, unsupported sentence in a single paper whose focus is not anything in the arena of that statement?
  5. Arctic Ice Volume is diminishing even more rapidly than Area
    Am I correct in saying that if the ice volume minimum trend continues its present course that sometime during the next decade the arctic will become ice free for some period of each summer? Are there any articles discussing the effect of SST change on lifeforms living in altered sea/ice environments. Thank You.
  6. The BEST Kind of Skepticism
    Gee, so sorry for not getting the exact wording correct. My point still stands though in response to @29 that BEST took a stab by pointing at AMO (whether it's GHG's or natural variability that influences it). And if it is natural variability then the human component may be over estimated.
  7. The BEST Kind of Skepticism
    It's interesting how the correlation (without causation) between the AMO and the global temperature signal has been highlighted. We have several issues: 1) identifying a cycle in a timeseries so short that few 'cycles' are present - add some aerosol cooling here, a little enhanced solar activity there, et voila we have the appearance of a 'cycle' within the warming trend. 2) the Atlantic (while large) represents a relatively small fraction of the Earth's surface. How does that drive global temperatures? 3) We have the issue of the direction of cause. The AMO correlates with global temperature. Without a mechanism, who is to say that global temperature drivers also drive AMO temperatures?
  8. Clouds provide negative feedback
    RW1, Net positive feedback does not lead to runaway warming (Venus result) anymore than net negative feedback leads to Snowball Earth. So, the answer to your question is no. If you do not understand why, you did not understand what you read.
  9. The BEST Kind of Skepticism
    Tamino has expressed the opinion that the warming apparent in the AMO is that of global warming itself. http://tamino.wordpress.com/2011/01/30/amo/ However, others share a different opinion and this matter is not yet considered consensus.
  10. The BEST Kind of Skepticism
    Further to Dale's misquote, ThingsBreak has a more detailed explanation. Seems that the 'misinterpretation' is coming from the GWPF via WUWT. What a surprise, eh ? (Not)
  11. The BEST Kind of Skepticism
    Dale, have you looked at a definition of the AMO lately? From Wiki: "The AMO signal is usually defined from the patterns of SST variability in the North Atlantic once any linear trend has been removed. This detrending is intended to remove the influence of greenhouse gas-induced global warming from the analysis." [my highlighting] Kinda tricky to see how the AMO will drive warming, when the warming trend has been removed from the AMO...
  12. The BEST Kind of Skepticism
    Dale wrote: "In the multidecadal oscillation paper they say the cycle fits AMO very well, and that human involvement is most probably over estimated." No, they don't. If you believe that paper says anything of the kind you have been misinformed or misunderstood something. What it says is that observed temperature fluctuations fit the AMO better than other commonly cited cycles (particularly ENSO). They also say that the ~0.55 C warming observed over the AMO cycle could be due to greenhouse gases or some unidentified other factor... and if it is some theoretical other factor then that could also play a part in the observed land temperature increase. They provide no evidence for another factor or against greenhouse gases. Basically, they identify a correlation in trends and then speculate on possible common causes without any analysis of those speculations or reference to other research on the matter.
  13. Clouds provide negative feedback
    DB, I already have Ray's book and have read a lot of it. I guess you're not interested in answering my questions?
    Response:

    [DB] If full understanding of the text was not achieved then perhaps you should place those questions over at RC where Ray has a presence.

  14. The BEST Kind of Skepticism
    Bern @29 BEST do take a stab at the cause of global warming. In the multidecadal oscillation paper they say the cycle fits AMO very well, and that human involvement is most probably over estimated.
    Response:

    [DB] "human involvement is most probably over estimated"

    I must have missed that part; my pardon.  My copy says:

    If the long-term AMO changes have been driven by greenhouse gases then the AMO region may serve as a positive feedback that amplifies the effect of greenhouse gas forcing over land.  On the other hand, some of the long-term change in the AMO could be driven by natural variability, e.g. fluctuations in thermohaline flow.  In that case the human component of global warming may be somewhat overestimated.

    And then in the conclusion:

    In conclusion, our analysis suggests that strong interannual and decadal variations observed in the average land surface temperature records represent a true climate phenomenon, not only during the years when fluctuations on the timescale of 2-15 years had been previously identified with El Nino events.  The variations are strongly correlated with the similar decadal fluctuations observed in the Atlantic Multidecadal Oscillation index, and less so with the El Nino Southern Oscillation index.  This correlation could indicate that the AMO plays an important intermediary role in the influence of the Pacific ENSO on world climate; alternatively, it might indicate that variability in the thermohaline flow plays a bigger role than had previously been recognized.

    [Emphasis added where bolded]

  15. Clouds provide negative feedback
    RW1, you seem rather desperate to demonstrate a net negative feedback for the whole climate system, not just clouds, yet how do you explain palaeoclimatic variations with a net negative feedback? Leprechauns? Positive feedback need not equal runaway feedback.
  16. Test your climate knowledge in free online course
    Thanks for giving us the link to the PICS site. A very nice communication tool! I liked it so much I put up my own article to highlight it at http://climatetruth.gather.com/ Keep up the great work, John (et al.)
  17. Clouds provide negative feedback
    DB, "Your question presumes that there is a current energy balance at the TOA; the best understanding of the science indicates otherwise." No, my question presumes the opposite - that there is virtually always an energy imbalance of some degree, especially over the more shorter time scales that the dynamic physical processes of water vapor and clouds operate. The imbalance is either energy in > energy out or energy in < energy out. You are aware that the system is almost never in perfect equilibrium at any given time or over any given time period, right? "You also do not define what physical process you refer to that is providing the "net negative feedback required for basic stability and maintenance". Energy balance is the sum of physical processes, not hypothetical ones." Yes, the planet's energy balance is the net result of all the physical processes (and feedbacks) in the system. Do you agree the net feedback that operates on all the physical processes in the system - whatever they actually are, is negative?
    Response:

    [DB] With all due respect, the last time we discussed this several threads ago, you first need to learn more about the physics of climate science before trying to bend them to your will.  To that end I also recommend Raymond Pierrehumbert's textbook "Principles of Planetary Climate".

    In any event, given the nature of your questions here, it is evident that you have not yet pursued that option.  That is your choice.  But that leaves you on your pre-existent orbit of asking the same questions repeatedly in the hopes that one day you might find an answer more to your liking.  All in all a non-effective path to greater understanding and a waste of other's time.  And indicative of your earlier statement that you were "not here to learn anything"

  18. Clouds provide negative feedback
    DB, Is net negative feedback required for basic stability and maintenance of the current energy balance or not?
    Response:

    [DB] Your question presumes that there is a current energy balance at the TOA; the best understanding of the science indicates otherwise. 

    Energy in ≠ energy out (energy in exceeds energy out).

    You also do not define what physical process you refer to that is providing the "net negative feedback required for basic stability and maintenance".  Energy balance is the sum of physical processes, not hypothetical ones.

  19. Clouds provide negative feedback
    CBDunkerson (RE: #192), "You argue that 'the notion' of positive feedback from water vapor cannot be reconciled with 'tightly constrained' temperature variations in various other cycles (e.g. ENSO, seasons, day/night, 11 years solar cycle, et cetera)." No, I'm arguing that positive water vapor feedback in conjunction with positive cloud feedback cannot be reconciled with how the planet's energy balance is so tightly - but dynamically, maintained.
    Response:

    [DB] "I'm arguing that positive water vapor feedback in conjunction with positive cloud feedback cannot be reconciled with how the planet's energy balance is so tightly - but dynamically, maintained."

    The casual reader will note that, in the absence of doing the physics and showing your work, your statement is devoid of substance and amounts to empty assertion without merit.

  20. Test your climate knowledge in free online course
    On further reflection, I think the question asked was: If the current rate of SLR stays the same, then how much would sea level rise by 2100 [over present]? At the current rate of 3.0 ± 0.4 mm/yr, I suppose the best answer would be 30 cm, of the possible answers offered. I’m very doubtful that 30 cm is realistic although it agrees with AR4 projections. The SkS page on this topic shows a range of 75 cm to 180 cm (depending on the scenario) based on findings reported in Vermeer 2009. The A1F scenario that we seem to be tracking looks to be headed for 140 cm by 2100, according to Figure 3, or 120 cm if the A2 scenario is preferred. [A very minor point: these numbers are referenced from 1990 so they should be reduced by 6 or 7 cm to put them into the present context.] SkS - How much will sea levels rise in the 21st Century? I won’t go into Dr. Hansen’s ten-year doubling time for ice sheet disintegration, somewhat of a thought experiment, but I remind you that he’s often ahead of his peers. He said the following in 2007:
    The nonlinearity of the ice sheet problem makes it impossible to accurately predict the sea level change on a specific date. However, as a physicist, I find it almost inconceivable that BAU climate change would not yield a sea level change of the order of meters on the century timescale.
    Hansen 2007 - Scientific reticence and sea level rise (pdf)
  21. Climate's changed before
    225, lancelot, 1. Yes. The term you want to search for is "hindcast" (e.g. "hindcast climate model"). But note that your specific parameters (+/- 0.5 deg C) may be too constrained. There are lots of parameters to be accurately modeled beyond global mean temperatures, and lots of ways in which a model may or may not be accurate, but in particular, models handle climate, not weather. It is nearly impossible to predict weather, and no model attempts to do so. In fact, models work using ensembles (multiple runs with the same starting conditions, which are averaged together). Also, we do not have accurate, precise measurements for starting conditions a thousand years ago. These must be inferred from proxies or just plain guesstimates. We also do not have accurate values for many inputs (solar irradiance, volcanism, etc.). These can only be guessed at. So getting things within any predetermined expectation ("a half a degree in June, 1980") is asking a whole lot, and in the end is not meaningful in evaluating the skill of the model. But yes, obviously one important way to evaluate the models is measure their ability "predict" what we already know has happened. Yes, scientists do this, and yes, models hindcast with enough accuracy to validate their ability to forecast as well. 2. Again, see the answer above. This isn't really a valid criterion. There is a lot more to climate than just temperature, and choosing a point in time is problematic (what if there's a real world ENSO event at that time, but not in the model run?). 3. I don't know that anyone has answered this question in exactly that way, because it's not really meaningful. Various events do affect climate to some degree (active volcanism, solar variations, etc.). There is no real "normal" temperature. Taking an average of the last 2000 years is of little value. Beyond this, proxies are difficult to calibrate and work with. While scientists have done a wonderful job filling in the blanks and trying to infer past temperatures, we just don't have enough global readings (proxies) with enough accuracy to compute anything like what you are asking.
  22. Clouds provide negative feedback
    lanC (RE: #189), "The earth radiates energy as E=epsilon*sigma*T^4, where epsilon is the emissivity (0.61) and sigma is the Stefan-Boltzman constant. If you increase the average earth surface temperature (287K) by one degrees you'll increase E by 3.3 W/m^2" Correct. Now, why specifically is the emissivity 0.61?
  23. Clouds provide negative feedback
    RW1 wrote: "Have you noticed that even when the system as whole warms to a significant degree like during an El Nino event, it always seems to revert to its pre-equilibrium state fairly quickly afterward? This is hardly consistent with net positive feedback acting on perturbations." So... because the daily cycle of temperature fluxes due to sunrise and sunset returns to its 'equilibrium' state in short order this is evidence against Summer temperatures being warmer than Winter temperatures? That is essentially the 'logic' you are presenting... 'if A shows steady fluctuations around a flat baseline then B cannot possibly show long term increases'. "Also, the temperature rising as the Sun comes up each day is not the result of net positive feedback acting on the increased incident energy." In part, yes... it is. Most of the temperature increase is due to the increased radiation. However, water vapor feedback also plays a part... as anyone who has lived in a very humid area would be able to tell you. A climate 'forcing' is just a change from a baseline. Most often we choose baselines from on yearly averages. However, it is perfectly valid to look at the incoming solar radiation over the course of a day with the daily average as the baseline. In such case, sunrise would represent a massive warming forcing. We can then look at feedback responses to this forcing... specifically, that warming forcing from sunlight will cause water to evaporate. Water vapor is a greenhouse gas. Ergo, this will create a positive feedback. Further, it is a positive feedback that we have known about and studied for centuries. We use the term 'relative humidity' because the amount of water vapor the atmosphere can hold increases as the temperature does... so the relative humidity is the percentage of the possible maximum water vapor content of the atmosphere for the current temperature. If the temperature goes up the amount of water vapor the atmosphere can hold increases as well. A long understood and thoroughly measured phenomenon. Now, if the temperature of the entire planet goes up... why wouldn't the same feedback apply? If the planet's atmosphere is warmer it will hold more water vapor. That water vapor will produce more greenhouse warming. You argue that 'the notion' of positive feedback from water vapor cannot be reconciled with 'tightly constrained' temperature variations in various other cycles (e.g. ENSO, seasons, day/night, 11 years solar cycle, et cetera). I am saying that there is no logical way to conclude that water vapor will not be a positive feedback, because it is always a positive feedback to warming.
  24. Clouds provide negative feedback
    RW1, You have now demonstrated extreme ignorance on climate science (a complete failure to understand Stefan-Boltzmann, the Planck response as a feedback, and the way that we know that this response is 3.3 W/m2 per degree K). At this point, you must recognize the need to study and learn a whole lot more before you "authoritatively" comment any further on things that you clearly do not grasp.
  25. Human CO2 is a tiny % of CO2 emissions
    Sphaerica@212. Exactly. You appear to understand perfectly. The numbers I calculated were based on the assumption that the extra sucking applies only to anthropogenic CO2 and the new magical natural source that looks just like anthropogenic CO2 (i.e., same isotopic signature, etc.). The numbers I present say that if this removal ratio is 99%, then this mysterious natural source is 49x larger than the anthropogenic one - i.e., the 30 Gt anthropogenic source is running in parallel with a natural source of 1470 Gt. Kind of hard to miss in the grand scheme of things, since we seem to be able to identify the long-existing natural sources of much smaller quantity than this. This new source also seems to be rising at the same rate as anthropogenic CO2. Another astounding coincidence. ...but at least you have a conjecture as to the source. Unlike the "skeptics". And as muon points out, the same logical applies to any new sink we haven't noticed - it is "emerging before our very eyes". It has some magical property that allows it to turn on and grow at just the right rate. ...but muon's hypothesis seems a bit far-fetched. I think it is more likely that Sphaerica's alien race has introduced a cap-and-trade scheme, and some enterprising alien has realized that they can make oodles of money by scarfing CO2 out of our atmosphere and get credit for sequestering it. Unfortunately, the same conspiracy that made up the AGW hoax is also hiding the fact that we've made contact with these aliens, and have one of their teleportation devices stored at Area 51. We're not allowed to use it to solve our problem. [Yes, I know that it is inconsistent to have the same conspiracy both make up the problem and hide a real solution to the same problem. In the People's Republic of Made-up-istan, consistency is not a legal obligation.]
  26. Climate's changed before
    Great site! Questions which I swear I have searched for, but this is also a vast site, and I do have a day job: 1 is there any climate model that can simulate in full using natural forcings alone the generally accepted natural temperature variations of the last 1100 years, up to 1850.? (the variations appear to be +/- 0.5 deg c.) 2 if not, what is the magnitude of the gap in degrees c? 3 How much in degrees c is current temperature above the historic mean of the last 2000 years (proxy measurements of course)? Thanks for any answers.
  27. Clouds provide negative feedback
    RW1 - "What I'm asking is why specifically is it 3.3 W/m^2 per 1 degree of warming? Why not 0.33 W/m^2 or 33 W/m^2 (some other number), for example?" I'm more than a bit appalled by this question. You look at the physics, you run the numbers, and you get a result. The only reason the number would be different is if the physics were somehow different, RW1. But reality is a harsh critic.
  28. Clouds provide negative feedback
    188 RW1 The earth radiates energy as E=epsilon*sigma*T^4, where epsilon is the emissivity (0.61) and sigma is the Stefan-Boltzman constant. If you increase the average earth surface temperature (287K) by one degrees you'll increase E by 3.3 W/m^2
  29. Clouds provide negative feedback
    Riccardo (RE: 187), What I'm asking is why specifically is it 3.3 W/m^2 per 1 degree of warming? Why not 0.33 W/m^2 or 33 W/m^2 (some other number), for example?
  30. Clouds provide negative feedback
    RW1 try here, but let's not go offtopic here and choose a more appropiate place to discuss sensitivity.
  31. Clouds provide negative feedback
    Riccardo (RE: 185), "the so-called Plank sensitivity or response is derived from the Stefan-Bolzman law." OK, explain to me how it's derived? Why the 'Planck sensitivity' 3.3 W/m^2 per 1 degree of warming?
    Response:

    [DB] "OK, explain to me how it's derived?"

    Try here:

    http://scienceofdoom.com/2010/10/24/planck-stefan-boltzmann-kirchhoff-and-lte/

  32. Clouds provide negative feedback
    CBDunkerson, Are you aware that the system is almost always in a state of energy imbalance to some degree? Have you noticed that even when the system as whole warms to a significant degree like during an El Nino event, it always seems to revert to its pre-equilibrium state fairly quickly afterward? This is hardly consistent with net positive feedback acting on perturbations. Also, the temperature rising as the Sun comes up each day is not the result of net positive feedback acting on the increased incident energy. You seem to be confusing a causative positive response to an increase in 'forcing' with positive feedback in response to the causative change. They are two different things. No one disputes that increased energy from GHGs or the Sun will cause warming.
  33. Clouds provide negative feedback
    RW1 the so-called Plank sensitivity or response is derived from the Stefan-Bolzman law.
  34. Clouds provide negative feedback
    RW1 wrote: "The global temperature anomaly barely moves by more than a couple tenths of a degree per year..." Which, is a massive amount of heat. You dismiss the idea of positive feedbacks (which BTW are estimated at a 200% increase on the forcings - 300% would be the combined total) because the average annual temperature anomaly is so 'constrained', but that is a completely groundless argument. I could just as easily claim that the massive average annual temperature anomaly shows how large the positive feedbacks must be. In reality, there is no direct connection between the two and thus the argument is meaningless. We know feedbacks are positive because every past and current warming forcing which we can estimate with any degree of accuracy has been enhanced by positive feedback effects. Frankly, it is ridiculous to claim that feedback effects will not be positive given that measurements of forcing and feedbacks from every El Nino, every Summer, and indeed every sunrise prove otherwise. The sun comes up, temperatures rise, dew evaporates, atmospheric humidity increases, that water vapor causes further warming... positive feedback. Happens all the time and not remotely controversial. The idea that this would suddenly just 'stop' happening if the warming comes from increasing atmospheric CO2 levels is without any justification at all.
  35. Clouds provide negative feedback
    Riccardo, I assume you're talking about the so-called 'Planck' response of about 3.3 W/m^2 per 1 degree of warming?
  36. Clouds provide negative feedback
    RW1 given an incoming heat flux, it is the emission of radiation that mainly constrains temperature. Why on earth the Stefan-Boltzman law, the most important negative feedback, is so often forgotten?
  37. The BEST Kind of Skepticism
    "The problems that have been associated with the CRU and NASA data sets" were largely known to be fictional before BEST began, as previous studies had already shown.
  38. Clouds provide negative feedback
    The climate system's energy balance is extremely dynamic. It's constantly changing spatially and in time - all the time, yet long-term averaged it's very tightly constrained. The global temperature anomaly barely moves by more than a couple tenths of a degree per year despite such variability. This is hardly consistent with net positive feedback on imbalances, let alone net positive feedback of 300%. Water vapor and clouds are also not a homogeneous distribution - they are by far most dynamic component of the entire atmosphere. The notion that the feedbacks of water vapor and clouds are both strong net positive cannot be reconciled with physical process and feedbacks that so tightly constrain planet's energy balance as a whole.
    Response:

    [DB] Fixed text.

  39. Should The Earth Be Cooling?
    Dikran#71: "Land use change emissions have indeed being going on for a very long time, and fossil fuel emissions only overtook land use change emissions in the early 60s" Here's a CDIAC graph of emissions from land use change: full scale Here is the current CDIAC graphic of emissions from fossil fuel consumption: full scale The land use graph is scaled in Terra grams C (million metric tons) with values in the hundreds; prior to the post WW2 period, the total is less than 1 Gton. The fossil fuel graph is scaled in million metric tons, with values in the thousands. So it looks like the period of rapid growth immediately following 1945 was the crossover; from then on fossil fuel carbon dominates. Wouldn't it be the case, based on population density alone, that land use changes prior to 1800 are insignificant on these scales?
  40. Should The Earth Be Cooling?
    Additionally, I find Fig 4 from the study fascinating: Figure 4. Comparison of atmospheric [CO2], [CH4], δ13CCO2, δ13CCH4, and population data for the Americas: (A) Concentration of atmospheric CO2 (Etheridge et al. 1996; Meure et al. 2006; blue and black symbols) and CH4 (Ferretti et al. 2005; red symbols from Law Dome; (B) δ13C of atmospheric CO2 (Francey et al. 1999; blue symbols) and CH4 (Ferretti et al. 2005; red symbols) from Law Dome; (C) population estimates for the Americas (Rosenblat 1954; Dobyns 1966; Denevan 1992a; Henige 1998) and Neotropics (this study). Gray vertical bars as in Figure 3.
  41. Should The Earth Be Cooling?
    Sphaerica It is indeed an interesting paper, tying as it does directly into the work of William Ruddiman (author of Plows, Plagues, and Petroleum: How Humans Took Control of Climate). Note that Ruddiman has a very interesting guest post on Real Climate: http://www.realclimate.org/index.php/archives/2011/04/an-emerging-view-on-early-land-use/
  42. Should The Earth Be Cooling?
    I'd like to point out that the original paper cjshaker references is available for free here: The Columbian Encounter and the Little Ice Age: Abrupt Land Use Change, Fire, and Greenhouse Forcing It looks like a very interesting read. I will get to it later today (after I play a little bit of soccer with some other 50 year old men).
  43. Should The Earth Be Cooling?
    69, cjshaker, Thank you for the reference to an enlightening article. I did not realize that there was a measurable drop in CO2 just prior to the Little Ice Age. It would seem that it's possible that CO2 and anthropogenic actions could have been a factor in that event, which would make it all the more probable that a heavily industrialized and technological society like ours could further impact the climate. I like the tongue-in-cheek way that you attribute the entire episode to one man (Columbus), when of course the article clearly shows that the real problem was the entire European arrival, but more importantly the introduction of diseases which are well known to have ravaged the Native American populations, killing as much as 90% of them and completely exterminating them on some Caribbean islands. That this lead to a huge amount of cleared land being abandoned and reclaimed by forest does not seem incredible in the least. The unexpected result that the new forest growth required carbon to grow those trees, and so over time extracted large amounts of carbon from the atmosphere (the exact same amount of carbon that is recorded as vanishing from the atmosphere at that time) is an unexpected but perfectly logical consequence. All in all, a very, very interesting article, which highlights the usefulness of a number of scientific techniques and leads to what at first appear to be unbelievable, fantastical results (as you were able to demonstrate with your cleverly cute misleading synopsis), and yet these turn out to be perfectly logical conclusions. Of course, one never knows if the result will hold up. I have to do the skeptical thing myself, now, and find and read the paper in detail. News articles about science are rarely trustworthy. But thanks for the find! Definitely worth a look.
  44. Clouds provide negative feedback
    177, RW1, Your "intelligent design" approach which requires that the earth's climate system be constructed and constrained like an electrical engineering project imposes any number of requirements (such as the idea that there be a single controller) which are quite simply fabricated. Your "coincidences" are mere observations of known physics. You imply that because they exist, they must be primary factors in the system, but you provide no evidence of such. You imply that because you haven't bothered to list any other mechanisms here, they cannot exist or must be inconsequential. Your position amounts to argument from ignorance. Your argument boils down to "I can only envision things happening this one way, so how can it be anything else?" Your position amounts to recognizing that you cannot touch the sun but it moves through the sky, therefore it must be the flaming wheel of the sky god's chariot. How could it be anything else?
  45. Corals are resilient to bleaching
    cjshaker - note the following from the post: "The critical issue with global warming induced coral bleaching, as it is for many eco-systems, is the speed of warming. They are simply not being given sufficient time to evolve tolerance" As for the Great Barrier Reef (GBR), the worst mass coral bleaching episode was back in 2002/2003. The ocean has steadily gained an enormous amount of heat in that time, and the GBR appears to have been protected by a largely La Nina-dominant pattern - especially since 2005. Sadly this is unlikely to last. I'll have a post on this topic soon.
  46. Dikran Marsupial at 21:33 PM on 23 October 2011
    Ice age predicted in the 70s
    CBDunkerson I have just looked into cjshaker's posting history, and it appears that he asks many questions, but rarely replies to the answers.
  47. Ice age predicted in the 70s
    cjshaker wrote: "Found a much more recent paper, which is talking about a return to ice age conditions in the near future 'This altithermal period may be similar to the Holocene Maximum that began nearly 3,800 years ago. The solar output model suggests that, approximately 20,000 years after it began, the current interglacial period may come to an end and another glacial period may begin.' 20,000 - 3,800 = 16,200 You consider 16,200 years the "near future"?
  48. Dikran Marsupial at 21:14 PM on 23 October 2011
    Should The Earth Be Cooling?
    cjshaker wrote: "According to Professors Reddiman and Kaplan, our climate should be cooling, if not for mankind's CO2 emissions. They say that our CO2 has been modifying the climate since the beginning of agriculture, well before industrialization" Why should that be a surprise? Land use change emissions have indeed being going on for a very long time, and fossil fuel emissions only overtook land use change emissions in the early 60s IIRC. So if the comparatively small CO2 emissions from land use change before the industrial revolution had an non-insignificant effect on the climate, we should expect the vastly larger anthropogenic emissions (both fossil fuel and land use change) since the industrial revolution to have a much more substantial effect. If you are interested you can get data on fossil fuel and land use emissions from the Carbon Dioxide Information and Analysis Center I note that you have been very active today posting a large number of papers for discussion on a wide range of topics. Some constructive criticism: this gives the impression that you are not really interested in the answers, because very few people would be able to hold a worthwhile discussion on so many topics simultaneously. I would advise in future that you stick to a small number of topics at any one time so that you can have an in-depth discussion that science demands.
  49. Dikran Marsupial at 21:06 PM on 23 October 2011
    Freedom of Information (FOI) requests were ignored
    cjshaker I note that you fail to mention that they were ordered to publish the data by the ICO, even if that did violate the confidentiality agreements that they had with national met offices. So there is no contradiction there, you are making a mountain out of a molehill. I note that you have been very active today posting a large number of papers for discussion on a wide range of topics. Some constructive criticism: this gives the impression that you are not really interested in the answers, because very few people would be able to hold a worthwhile discussion on so many topics simultaneously. I would advise in future that you stick to a small number of topics at any one time so that you can have an in-depth discussion that science demands.
  50. Dikran Marsupial at 20:51 PM on 23 October 2011
    CO2 has been higher in the past
    cjshaker wrote "Where is the CO2 going over geologic time?". On geological time scales, the climate appears to be regulated by the "chemical weathering thermostat", where weathering of rocks sequesters carbon dioxide from that atmosphere as carbonates in the lithosphere. There is a very good primer on the carbon cycle by David Archer that does a good job of explaining the behaviour of the carbon cycle on geological timescales and shorter, well worth reading. I note that you have been very active today posting a large number of papers for discussion on a wide range of topics. Some constructive criticism: this gives the impression that you are not really interested in the answers, because very few people would be able to hold a worthwhile discussion on so many topics simultaneously. I would advise in future that you stick to a small number of topics at any one time so that you can have an in-depth discussion that science demands.

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