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Comments 52751 to 52800:

  1. Climate's changed before
    Peter A wrote: "...the fact that water vapour is a greenhouse gas is never mentioned in the mainstream media. That was my point there, and all I did was question why this is the case." It isn't the case. A simple Google News search proves that this 'fact' is fiction. So the real question is... why do you believe things which are plainly untrue? Did you never bother to check?
  2. New research from last week 40/2012
    mike, the paper is open access, so you should be able to download it. yes, rice can be produced with lower methane emissions, but wetland rice production dominates (older paper here) The oil&gas production section does contain a combustion subsection (see Table 1 in paper)
  3. Climate time lag
    Falkenherz @351 Your response shows you are a keen observer and have read through numerous papers, unlike your previous modesty about your knowledge. Your continued playing of devil's advocate starts to look strange to me. I asked about your understanding of the lag mechanism both verbally (again above by Bob) and graphically explained to you. It would help if we knew your answer. To repeat Daniel: The warming mechanism between increased atmospheric CO2 and increased TSI is not the same, hence you cannot infer that you would have to get the same lag times.
  4. Climate time lag
    Falkenherz: I'm a bit busy, so I can only give you a few minutes at the moment. I may be able to follow over to the radiative transfer stuff a bit later, but for now I'm still on the "time lag" issue. Let's look at an analogy. You have a tall tank full of water. You put a small hole near the bottom. Water starts to drain out the hole. The final equilibrium water level is down where the hole is, but that won't happen instantaneously - it takes time. Let's assume the tank is large enough, and the hole is small enough that this will take 40 years. Thus, the time lag to equilibrium is 40 years. ...but water starts to leak out right at the beginning. What is the rate of leakage over time? Well, the leak rate depends on the pressure forcing water out the hole (plus the size of the hole), which is related to the height of the water above the hole (technically, the height difference). At the start, there will be a relatively rapid loss of water and a rapid decrease in the level in the tank, because the pressure is high (the full height of the tank). As water drains out, the height of the water decreases, the pressure decreases, and the flow rate decreases. Near the end, as we approach equilibrium, we only see a trickle of water, and the level in the tank is dropping very slowly. Note that we are committed to draining the tank as soon as we make the hole (unless we find a way to plug it). So someone coming in half way is going to be looking at a leak that is the result of an imbalance (hole) made 20 years ago, and the time lag in fully draining the tank means the leak will continue for another 20 years (time lag). The rest of the leakage is "in the pipeline" already (to make a bad pun, but using a term that is often used in climate change discussions). That person arriving at the 20 year point will be seeing a leak that was faster in the past, and gets slower in the future. What we don't expect to see is a pattern where nothing happens for 20 years after the hole is made, then the leak gradually gets faster and faster as the tank begins to drain. The physics just doesn't work that way. If you arrive at the tank after 20 years, and see the water level dropping at an increasingly faster rate, then you need to look for new leaks, not blame it on the hole that was made 20 years ago. To tie the analogy back to climate and radiation forcing, the pressure in the water tank is the radiative imbalance (sun pushing energy in minus the current IR loss to space). The flow out the hole is the increased loss of IR to space needed to eventually restore equilibrium. The level in the tank is temperature. For climate, the radiative imbalance is largest at the start and gets smaller over time, the temperature rises fastest at the start and slows over time, and the equilibrium temperature change is committed as soon as the radiative imbalance is created. It's kind of a backward analogy, because the water tank is losing water, while the earth is gaining energy (increased TSI, or CO2 reducing IR losses, leading to a net positive radiation balance), but hopefully you can easily visualize the water tank and how it responds, to understand how time and changing fluxes/levels factor in to restore equilibrium. Like all analogies, this one is full of holes (in addition to the one the water is leaking from), so first just try to make sure you understand the physics of the leaking tank, before trying to apply it to the global radiation balance. ...and the TSI increase vs. CO2 increase effects are, to a first approximation, not much different.
  5. New research from last week 40/2012
    That 2030 CH4 chart is very interesting. It tells us that livestock production must be slowed, and vegan diets encouraged. I had no idea that rice harvesting emitted so much methane. Three questions: Can you post current CH4 emissions for comparison? Are there ways to produce rice that do not include high CH4 emissions? Does the oil production section not include combustion?
  6. Climate time lag
    Dikran, Falkenherz - I have responded on the appropriate thread here.
  7. It's the sun
    (Continued from here) Dikran Marsupial, Falkenherz - Foster and Rahmstorf 2011 (discussed here) examined atmospheric responses to various forcings, namely aerosols, MEI/ENSO, and insolation, using multiple linear regression to examine their contributions. The steady increase in CO2 forcing was not associated with a time lag: as a near-linear trend, it doesn't have the necessary variations to be time-matched to temperature changes (no 'teeth' to match). For that component F&R 2011 just used a linear rising trend. [Source] The atmosphere, in particular the upper troposphere (RSS/UAH) responds quite quickly to changes in TSI. Overall effects (larger temperature swings) will occur over longer periods due to the thermal buffering of the oceans, but there is a fairly immediate and detectable atmosphere response.
  8. Climate time lag
    Falkenherz, to make that substitution is inapplicable and demonstrates a lack of understanding on your part between forcings, feedbacks and the physical interconnections of our world. I suggest listening and reading more. I am not the only one doubting the existence of these "other skeptics" you paraphrase.
  9. Climate time lag
    Falkenherz - CO2 did not magically appear as a forcing in the 1960's. Rather, it was around the 1960's when insolation took a downward turn, and when CO2 became the dominant forcing. And continued to rise in forcing strength as it has since the start of the industrial revolution. If you look at net forcings (as I showed here), they have been increasing roughly linearly for the last 40-50 years. Temperatures have also been rising roughly linearly over that time frame - not showing an exponential rate decay towards equilibrium, but rather following the forcings upwards. TSI has decreased over that interval, CO2 forcing has continued to increase. That temporal relationship clearly shows that recent warming (over the last half-century) is not due to the sun - and in fact, decreasing insolation has noticeably slowed the warming. If you wish to chase this TSI windmill any further, I would strongly suggest taking to the far more appropriate Solar activity & climate thread.
  10. Dikran Marsupial at 04:12 AM on 9 October 2012
    Climate time lag
    Falkenherz, radiative physics isn't my strong suit, so hopefully my better informed colleagues can correct me if I am mistaken, but in this context I would have thought there is a difference between CO2 and TSI forcing. For CO2 forcing, increased CO2 raises the altitude in the atmosphere from which IR photons can escape into space. Due to the lapse rate, this higher layer will be colder, and hence the amount of IR radiated into space will be lower. As a result, the Earth will gain energy until the atmosphere warms sufficiently for the emitting layer to warm enough to radiate away as much energy as is coming in. For the atmosphere to warm, the oceans need to warm as well, and that causes a lag. TSI is rather different, imagine the height of the emitting layer remains constant. If TSI rises slightly, so that more energy comes in than is radiated away into space, there will be an energy imbalance, and the Earth will begin to warm. However if TSI then drops back to its equilibrium level, the energy imbalance disappears and the warming relatively quickly stops. Thus it seems to me that the response to TSI should be much more rapid than the adjustment to CO2, unless there is suddenly a way to scrub vast quantities of CO2 from the atmosphere and bring the height of the emitting layer back down again.
  11. Climate time lag
    gws, if global temp follows [cause], but takes time to reach and stabilize at a higher energy level (corresponds to global temperature) as given by [cause], than this applies to both CO2 and TSI. In that case, on that graph above you should move the blue curve (=cause) to the right, or the red curve (=effect) to the left, in order to correlate that lag properly. This whole article here talks about a climate lag of roughly 25-50 years, because of the time for the system to get back into energy equilibrum (which corresponds to a certain level of global temperature). Even the link from Daniel tells of a lag of 40 years for CO2 and states explicitly "With 40 years between cause and effect, it means that average temperatures of the last decade are a result of what we were thoughtlessly putting into the air in the 1960’s." Now delete from "what we were thoughtlessly" onwards and replace with "the TSI increase which started somewhere around 1700 and lasted until the 1960s". BUT, by contrary, when TSI is concerned everybody just seems to state that, since TSI stopped increasing in 1960, then instantly, without any lag, any further rise of global temperature after 1960, the 0,6 Degrees since then, MUST be attributed to CO2. Apparently I am the only one who finds that odd. The only reason I can see as a logical argument is, if TSI rose only by minimal amount since *1700* (why do everybody here seem to assume they can ignore anything that happened with TSI and global temp before 1880?), because in that case, indeed there would be no physical possibility for a lagged increase of an amount of ~0,6 Degree. DSL, Forster and Rahmsdorff 2011 calculate the rate of rise of temperature ("the warming rate is steady over the whole time interval"). This. is. not. my. point. Side remark, the quoted essay of Krinova in the article speaks of going back to the maunder minimum, but the models they create go only back to 1868. That's not the maunder minimum. I can just assess the abstract, though.
  12. Dikran Marsupial at 03:03 AM on 9 October 2012
    Climate time lag
    Falkenherz, my research interests lie in statistics, so I know from experience how dangerous it is to look for correllations first and explanations second. At the end of the day, if the correllation is real it is because of a physical reason, so if there is a correlation, but no physical explanation, assume that the correlation is spurious.
  13. Climate time lag
    Falkenherz, rather than getting sucked into climastrology & curve-fitting, why not examine physical mechanisms potentially involved in lags between causes and effects? Try reading Climate Change: The 40 Year Delay Between Cause and Effect. As always, should you have any questions on that thread, please place them there. The regulars here will see them.
  14. Climate time lag
    It appears to me, Falkenherz, you still have not understood the graph posted by Riccardo @324, and its implications verbally explained to you in detail, have you?
  15. Climate time lag
    Dikran... now I give up, really. :( Can someone please point me towards a graph showing TSI (estimations) since 1700, and another graph showing global temperature (estimations) since 1700? Proxies, reconstructions, I don't care, I just want to know what we have for these two data since 1700 and I want to see how they correlate since the end of the maunder minimum around 1700. Then I can come back to you about "climate" lags.
  16. Climate time lag
    Falkenherz: That would be moving the blue curve to the left, not right ... where does the presumption of a 40something TSI-climate time lag come from anyway?
  17. Climate time lag
    Excuse me, DK, I meant "DK" and not "KR."
  18. Climate time lag
    Agree, KR -- Falkenherz, why not a 140-year lag, or a 260-year lag. There are other similar periods of solar increase. Working back to physical principles from a graph of temperature is a bad idea. Surface temp is a very complex process. You've read Foster & Rahmstorf (2011), yes?
  19. Modelling the permafrost carbon feedback
    Lanfear english is not my first language either, so there is the concrete possibility that I was not very clear. :) Anyway, we should always be carefull when using the word "runaway" because, as you noticed, it may mean similar but different things.
  20. Dikran Marsupial at 00:22 AM on 9 October 2012
    Climate time lag
    Falkenherz please can you specify a physically plausible mechanism that explains why there should be a 40 year lag of global temperature following TSI. The human eye is very good at detecting patterns in data that are not actually there and are merely artefacts of random/chaotic variability (which is why we have statistics). Requiring a plausible physical mechanism guards against jumping to conclusions based on spurious correlations.
  21. New research from last week 40/2012
    Will there be a follow up article - The Influence of Ball Lightning on Climate Change? Or What Ball Lightning Tells us about Global Warming. I'm sure there's something.
  22. Solar Hockey Stick
    The last image in comment #75 is now at http://www.lsbu.ac.uk/water/vibrat.html under "The visible and UV spectra of liquid water".
  23. Arctic Sea Ice Loss Has a Larger Impact than Antarctic Sea Ice Gains
    Jim @3, Thanks for the pointers. Those are very useful posts by Tamino. Refered therein, I found this paper which answered my question in details. Great paper to learn the details of mid-Pleistocene revolution (MPR) when cycles switched from 41ka to 100ka. According to this and other newer studies, eccentricity just paces rather than drives the system while precession+tilt are the drivers. The ‘eccentricity myth’ (or simplified view of the relationship between glaciations and orbital forcings) an artefact of early spectral analysis of ice-core data.
  24. Climate time lag
    Maybe even simpler: Just displace the blue curve in your graph 40 years to the right in order to represent a 40-year lag of global temperature following TSI (i.e. adapting to the new energy equilibrum, ceteri paribus). Does this illuminate what I mean with my speculative point a bit better? Again, all the arguments seem to be there, but for me it does not come together, yet.
  25. 2012 SkS Weekly News Round-Up #4
    For next week's roundup take note of the change on Thwaites Glacier, Antarctica.
    Moderator Response: [JH] Thanks for the tip.
  26. Climate time lag
    KR, the difficulty of non-scientist people like me is to understand the arguments I read about, and clarification is the tool. That's why it is great of you guys to offer a comment function and take the time to answer. Truth will answer to any question, and, in fact, it is only fully revealed by questions. I understand that I misunderstood the paragraph I quoted, and the uncertainity expressed cannot exceed the range of TSI given there. In that case, I was mislead by "...incomplete understanding of solar variability mechanisms over long time scales..." The key issue I was trying to clarify for me is in your No (5). And there, we seem not to understand each other's points, or my understanding is simply too limited. Maybe one last try: I am not talking about anything "hidden", concerning a temperature lag from long-term TSI. I simply believe that the matter of observing a decreasing temperature trend could be a matter of which timescale you are looking at. If you compare 1850 to 2010, and take 1960 as a "breakpoint" (and assuming that the data showing a declining TSI is indeed correct), imo no one can rally dispute your conclusion. But, would that counclusion be so clear if you looked at 1700 to 2010, with the same "breakpoint" at 1960? Relations might be different then, and what we perceive as "linear" (btw, I did not introduce this word and I don't see the relevance of it in our discussion, in fact, the "hockeystick" is far from linear) over the last 50 years might as well be read a slow trailing off if we wait a bit into the future. And CO2 on top might only be able to prolong ("hide"?) the process of trailing off, but not increase much beyond what TSI did on the long term. behold, a core argument of some sceptics.
  27. Modelling the permafrost carbon feedback
    Riccardo@19 "I was referring to the melting permafrost feedback." Ah, yes, then I do agree with you. Sorry for the confusion. With regards to Colose writing, this is largely my understanding too, as there is a whole spectrum of more probable outcomes between what we have now what constitutes a global 'runaway', which I tried to convey in my previous writing (english not being my primary language). wili@20 "Efforts to avoid panic have left us where we are" Again, this may be due to difference in what panic means, but I feel strongly that panic is the least helpful state that people should be in in this (or any) situation, and it seems that this is somewhat reflected in the writings of other people too. Panic IMHO means that individuals throw out their reasoning and goes into a short-circuit mode where the survival instinct rules, resulting in a quick and painful collapse of the society. Nothing can be accomplished in this mode. As a background reference, I am talking as an avid diver and aspiring cave diver where panic equals death. What I would solicit instead is a (rude) wake up call, not much unlike the Samuel L Jackson video 'Wake the f*ck up' backed up with numbers (like what Clinton did). The other part should be a (again rude) confrontation and stripping of any perceived validity of the denialosphere argumentation (maybe in the spirit of Christopher Hitchens). This is why I personally enjoy SkS, but it grieves me that the noise of the lukewarms as well as denialists are assumed by the public as 'equal'. A misanthropist would perhaps think that we deserve what is coming...
  28. Water vapor is the most powerful greenhouse gas
    Ah, nevermind, I think I found a good source: http://www.sciencemag.org/content/327/5970/1219.full
  29. Water vapor is the most powerful greenhouse gas
    I am sorry if that seems so much nonsense that it isn't even worth an explanation to you. I know that this article here starts with the assupmtion of water vapour being dominant, because a lot of sceptics say this. But I think you could discern and explain a bit more between the ratiative processes and the evaporation processes and the clouds caused by more water vapour, alll of which are very strong effects of water vapour. The sceptic I encountered refers to the radiative element, which is the only possible wv process for a positive forcing. My first quote is from Held 2000, p. 446 http://maths.ucd.ie/met/msc/ClimSyn/heldsode00.pdf who is trying to disprove this argument; sadly, I don't get it. The second quote is a translated argument I encountered from a sceptic who seems to know a lot about radiative physics, but then he suddenly comes with queer assumptions like this; and I found so far no source to directly disprove him with a scientific argument (Held 2000, p. 446, was a try, but I cannot quote things which I don't understand myself). As to temperature dominated by stratosphere, I believe this refers to the absorption length, which might not be long enough by just counting the troposphere. Thanks for the referral to Iacono and Clough, but it seem they do not adress this issue directly, but to follow up on it, as they are just "introducing an improved, LW radiative transfer model". I need an explanation why water vapour in the stratosphere is very much driving global temperature. With google I just found articles which report that a recent decrease of water vapour in the stratosphere was the cause of some cooling, but no explanation or experimental proof as to why.
  30. The Economic Damage of Climate Denial
    funglestrumpet - While it's certainly a voluminous writeup on renewables, I would suggest considering that the writer (Leo Smith, MA) has some, shall we say, "skeptic" attitudes:
    ...if you are not Concerned About Climate Change (and let's face it, a world with no electricity at all is a lot more terrifying than one a degree warmer) there's several hundred years of coal, which the Chinese will be burning anyway.
    Curious capitalization... A fairly quick look on the InterWebs indicates that the author of this paper has a history of claiming that AGW is an incorrect theory. That doesn't bode well for his other work. I would suggest that you look at some of the SkS threads and references on renewable baseload power, such as here or here. Many of the opinions expressed in the Smith paper are discussed, and (IMO) shown to be mistaken. You might also look at a very interesting study by Archer & Jacobson 2007 - they found that connecting multiple wind plants (19) over a reasonably large geographic area (MidWestern US) would provide between 33-47% of the average output was reliable as baseload power by current availability standards. Add solar (with different availabilities) and that percentage will only rise. Power density? There's enough area to supply our electrical needs hundreds of times over with either solar or wind power. Widely separated power plants are actually easier to balance than large centralized ones. Intermittency/dispatch? See the Archer et al paper above - distributed sites across more than weather pattern can manage quite well. The McKay study (McKay book) he references is quite worth reading on its own - there he looks at area, power density, and the possibilities of sourcing all UK power from available UK renewable resources (hardly a global perspective). And I believe McKay is quite correct that the UK is too densely populated, too small, and rather too far north for that to be possible within UK borders. On the other hand, there's plenty of space in North Africa, and in Eastern Europe - and if the UK finds itself a net importer of energy, it will hardly be alone in the world in that respect. Note: The myth (which you repeat) that renewables require more fossil fuel use than the original fossil fuel plants they replace is complete nonsense, from (mis)analyzing single-site renewable sources, when a distributed grid is the correct system to evaluate. Finally: On a personal point of view, I would much prefer windmills and solar farms to coal strip-mines - eyesores that poison the local water table, and never ever recover to anything approaching the original land quality. I grew up in coal mining country - portions of it resemble a moonscape. Those mines (and oil fields, and fracking regions, and...) represent an unavoidable land area/power that has to be considered in balance to the area required by renewables. Outside my hometown there are a group of windmills on a ridge across the highway from a strip mine. IMO the choice is obvious.
  31. Nate Silver's Climate Chapter and What We Can Learn From It
    Two Commoner books that I read, as part of the requirements at Columbia's Earth Systems classes at Biosphere II, in 1997, were "Making Peace With The Planet," and "The Closing Circle." Those books, among many, were why I began my serious research into this issue, and Barry will be missed. He left a much-unappreciated legacy.
  32. 93% of Fox News climate change coverage misleading
    Andrew Mclaren@9: That would be "Ailes," not "Aimes." Roger Ailes has a looooooong history of being vehemently anti-liberal and aggressively right-leaning in his stewardship of Fox News. His is an ethic informed by the late Lee Atwater, the modern guru of attack politics, damned the cost.
  33. Doug Hutcheson at 12:59 PM on 8 October 2012
    The Economic Damage of Climate Denial
    funglestrumpet@48, I have read the paper you linked and found it interesting, but the fact that the author quotes material produced by the Global Warming Policy Foundation makes me suspect the integrity of the research. The document is full of typos that would have been picked up by peer review, so it does not impress me with its reliability. Nonetheless, it discusses some genuine problems and provides insights into the thinking of the BAU brigade.
  34. The Economic Damage of Climate Denial
    funglestrumpet@48, I'll read your linked paper, BUT...this line makes me a bit suss, right off the bat. "...and let's face it, a world with no electricity at all is a lot more terrifying than one a degree warmer." That's opinion and sensationalism, not science. I'll get back to ya.....
  35. funglestrumpet at 09:17 AM on 8 October 2012
    The Economic Damage of Climate Denial
    Liquid Fluoride Thorium Reactors surely have to be part of the mix. I know they need some development, but a Manhattan type effort would bring the time for that development down to a few years. (Surely, the problem deserves such an effort.) They are so much safer than the current fleet. Had Fukushima been of the LFTR type, it would have been a non-nuclear event - still awful, of course, but not from a nuclear standpoint. We cannot rely on solar and wind, so if we carry on as we are and still want a stable supply, we are going to have to have fossil fuel plants to follow the loading variations they automatically create, and upgrade the grid in the process to cope with it (not cheap). The more of those ugly wind turbines we have peppering our once beautiful landscape, the more variable will be the renewable input and so the more we will have to rely on fossil fuels. It is difficult to see how that is going to do much good as far as CO2 reduction is concerned. If we go with LFTRs they automatically are capable of load following. For an interesting paper on renewables, I recommend: http://www.templar.co.uk/downloads/Renewable%20Energy%20Limitations.pdf With small modular reactors, which LFTRs can easily be, we can distribute them so that they serve local communities. That way, we will hardly need much of a grid. They don't need the copious amounts of water that current nuclear reactor designs do, they are inherently safe (automatic shutdown), they cannot safely be used to make nuclear weapons, they use 99% of their fuel, which is ubiquitous anyway ... the list goes on. And as for being uninsurable, well, being automatically shutdown in an emergency surely goes a long way to solving that problem. All we need to do is get the Greens to shut up about nuclear for a while and we might, just might, save the planet.
  36. Philippe Chantreau at 06:58 AM on 8 October 2012
    Climate's changed before
    Peter, on the other thread you suggested you had read the litterature. On comparing the radiative effects of water vapor and CO2, that would include Iacono and Clough (1995), the MODTRAN and LBLRTM works, numerous papers using the ERBE data, many more papers treating of absolute and relative humidity and why water vapor can't be considered a forcing. Statements that you made are considerably at odds with knowledge of all that litterature, hence the reactions you got.
  37. Modelling the permafrost carbon feedback
    wili @32 "Anyway, thanks for all the fish." I seem to remember that preliminary to that, there was some sort of guide that prominently said "Don't Panic" on it. To me, SkS is exactly that sort of guide. Best wishes, Mole
  38. There is no consensus
    Peter, I'd just like to point out that your opinion of the IPCC is based entirely on what other people have told you to think, based on their own opinions and misunderstandings.
  39. Nate Silver's Climate Chapter and What We Can Learn From It
    Barry Commoner, a leading environmentalist and some might say the successor to Rachel Carson, died about a week ago. He felt strongly that scientists have a duty to share their knowledge with the public: "Commoner insisted that scientists had an obligation to make scientific information accessible to the general public, so that citizens could participate in public debates that involved scientific questions." Thomas Jefferson would surely agree with that sentiment. That statement and a good summary of Commoner's life, work, and contribution to humanity are in the article Barry Commoner, Pioneering Environmental Scientist and Activist, Dies at 95.
  40. Pete Dunkelberg at 01:52 AM on 8 October 2012
    2012 SkS Weekly News Round-Up #4
    This new paper: Impact of melt ponds on Arctic sea ice simulations from 1990 to 2007, Flocco et al. 2012, Abstract:
    The extent and thickness of the Arctic sea ice cover has decreased dramatically in the past few decades with minima in sea ice extent in September 2007 and 2011 and climate models did not predict this decline. One of the processes poorly represented in sea ice models is the formation and evolution of melt ponds. Melt ponds form on Arctic sea ice during the melting season and their presence affects the heat and mass balances of the ice cover, mainly by decreasing the value of the surface albedo by up to 20%. We have developed a melt pond model suitable for forecasting the presence of melt ponds based on sea ice conditions. This model has been incorporated into the Los Alamos CICE sea ice model, the sea ice component of several IPCC climate models. Simulations for the period 1990 to 2007 are in good agreement with observed ice concentration. In comparison to simulations without ponds, the September ice volume is nearly 40 % lower. Sensitivity studies within the range of uncertainty reveal that, of the parameters pertinent to the present melt pond parameterization and for our prescribed atmospheric and oceanic forcing, variations of optical properties and the amount of snowfall have the strongest impact on sea ice extent and volume. We conclude that melt ponds will play an increasingly important role in the melting of the Arctic ice cover and their incorporation in the sea ice component of Global Circulation Models is essential for accurate future sea ice forecasts.
    discussed at Climate Central, looks helpful for understanding rapid changes in the Arctic.
  41. Dikran Marsupial at 01:47 AM on 8 October 2012
    Modelling the permafrost carbon feedback
    Eric (skeptic) as I have pointed out to you before, the constant proportion taken up by the environment is a result of anthropogenic emissions rising roughly exponentially, it is not a natural law. The carbon cycle can only be roughly approximated as a first order differential equation (implied by your 1/50th assertion). In reality, the carbon cycle is more complex than that, and such simple "spreadsheet" models are useful for qualatative understanding of the very basics, but nothing more than that, especially not quantative analysis.
  42. Climate's changed before
    Peter, you said "The truth of the matter is" -- that never fails to ring the warning bells. You said you were new to the site, but then you made some claims about some really basic stuff. When you ask a basic question about the relative strength of water vapor and CO2, and then you make a broad claim about what climate science doesn't understand, your broad claim can't be taken seriously.
  43. Eric (skeptic) at 01:17 AM on 8 October 2012
    Modelling the permafrost carbon feedback
    Dikran, we have emitted CO2 into the atmosphere far in excess of equilibrium. Nature is absorbing roughly 1/50th of the excess. If we stopped (again I must caveat, completely academic because we are not stopping), then the situation has not changed. We will still have manmade CO2 in the atmosphere far in excess of equilibrium and nature will still absorb roughly 1/50th of it. As you pointed out in your first reply to me, there is now a higher flow of CO2 from new sources, mainly Arctic outgassing. That flow will increase with thermal inertia. What that means is that the nature will absorb less than 1/50th into the future. I don't know how much less. There are a lot of factors involved (e.g. continuing Arctic amplification).
  44. There is no consensus
    Peter, the "peasants" didn't need an interpreter, but when they went off on their own, they still assumed the god of their ancestors existed. In other words, they carried their cultural assumptions with them as they went to try to understand the mind of god. This is precisely why many non-experts doubt anthropogenic global warming. Humans have never had such control over the Earth before, things are developing nicely for us, these guys over here say that some of these scientists are frauds, and everyone knows that sensationalism is the way to catch a buck these days. Business as usual. Not really a rapid shift in climate of the type that humans have rarely had to deal with (and certainly not in the historical period). I find it odd that you would characterize SkS as a "priesthood" site. It has comment streams. You can ask questions. You can go directly to the science itself. On this site, there are more direct links to the science than at any other climate science site on the net, IPCC included. This is, in fact, the best place to inform yourself. All we need are links to atmospheric science textbooks, but there are links to science of doom, which is about the same thing. Now consider sites like WUWT. These are the new priesthood you describe. The owners/mods and especially the news sites that are plugged into places like WUWT assume their audience is incapable of understanding the science. They post articles containing really basic errors, and then sit around while the comment stream cheers them on. They engage in rhetorical games like "climategate." The "climategate" allegations, never formalized, are wholly fraudulent, except for one claim (Jones being mean to Soon and Baliunas, but even then there's much, much more to the story). Yet these people knew that their allegations would be swallowed whole by their congregation. They depended on it. And that congregation did not disappoint. They bleated the news far and wide, never once actually checking the claims against what Jones and Mann (and the various independent investigations) had to say. No, people don't need interpreters. They believe they need interpreters--talk radio, CNN, Anthony Watts.
  45. Arctic Sea Ice Loss Has a Larger Impact than Antarctic Sea Ice Gains
    Slightly off topic but of value for the discussion. I was looking at IPCC's 1st assessment report and spotted this. "Most model simulations suggest that the warming north of 50°N in the winter half of the year should be enhanced due to feedback effects associated with sea-ice and snow cover (Manabe and Stouffer, 1980, Robock, 1983, Ingram et al, 1989) In the Southern Hemisphere, results from simulations with atmospheric GCMs coupled to ocean GCMs do not show this enhancement (Bryan et al , 1988, Washington and Meehl, 1989, Stoutlei et al , 1989)" http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_08.pdf So a divergence is pretty much what was expected by mainstream science from the early 90s.
  46. 2012 SkS Weekly News Round-Up #4
    Interesting to note is that the cranks at WUWT must go back 33Ma in search of some cherry (or rather statistically insignifficant straw-data in this case) to support their pre-conceived viewpoint that CS must be low. We know they deny a well understood and far more accurate, ice-core data supported research for the last 800ka. I don't need to mention how irrational is to look for answers about CS in Miocene hothouse and try to project results at today, as Miocene climate was totally different. I wonder how far those cranks would have to reach for some new straw data, when paleo guys start obtaining better proxies for Miocene and better quantifying the differences between then hothouse and now interglacial climates.
  47. There is no consensus
    @Peter A #518: The body of scientific evidence about anthropogenic global warming is not an “idea”, it is a body of scientific evidence. It would take years for the average person to sift and winnow through each and every cell in this body of evidence in order for him /her to make an informed decision. If your personal physician determines that you have an illness and recommends a course of treatment, do you sift and winnow through the entire body of scientific evidence about that illness and about the recommended treatment before deciding whether to proceed? If your personal physician tells you that a specific treatment for your child’s illness is recommended by the American Academy of Pediatrics, do you challenge him/her to explain why he/she is deferring to a higher authority,
  48. Climate's changed before
    @ PeterA #316: Using a scale of 0 to 10, with 0 being “know absolutely nothing” and 10 being “know absolutely everything”, how do you rate the scientific understanding of the Earth’s climate system?
  49. 2012 SkS Weekly News Round-Up #4
    After a cursory reaading of the paper I noticed the following. The conclusions stands on essentially two choices. 1) the time intervals. In the paper Asten admit it's not based on any sound criterion. He first says: "Following the temperature drop to a minimum at 33.4 Ma a step change of duration about 150 000 yr is evident on the smoothed data." In other words, eyeballing the smoothed curve he sees a step change and that's good enough. Then, assuming the step change, he makes "some subjective choice on the position of time segments labelled a, b, c on Fig. 1, [...]". Again, we have to live with it. 2) CO2 concentration. The three segments are supposed to be "representative samples before, during and after the temperature change associated with the CO2 pulse shown in Fig. 4." But looking at fig. 4 they do not match, segments a and b have the same, higher CO2 concentration. For some reason, Asten averages the CO2 concentration during time intervals a and b (see table 1) contraddicting what he said on the step change between segments a and b. But then he added one more time interval before a to average its CO2 concentration with that of segment c. Either the rationale of this procedure is beyond my comprehension or I'd call the conclusions rather weak.
  50. 2012 SkS Weekly News Round-Up #4
    As Rob has pointed out the Lindzen and Choi analysis is completely unreliable as an estimate of climate sensitivy both because of fatal methodological flaws but also due to the fact that his method (analysis of immediate changes in radiative response at the top of the atmosphere due to changes in surface temperature) can address only the rapid atmospheric response and doesn't say too much about responses occurring on the decadal (let alone 1000's of years!) timescale. Several papers have addressed the flaws in Lindzen's methods and these should certainly be known to a scientist making an honest and informed foray into this topic. The Chylek estimate cited by Asten is highly flawed (cherrypicked timepoints) as described by Hargreaves and Annan in Climate of the Past. The Douglass and Christy estimate is simply silly - they determine their estimate from the temperature variation during the period of satellite observation 1979-2007. …and so on… You simply can’t cite papers in the scientific literature that have been shown to be fundamentally incorrect, as if these still constitute valid elements of the evidence-base that informs current understanding. I expect these aspects of his paper will have to be fundamentally redone before the paper is considered suitable for publishing. And that’s not to address what may or may not be fundamental flaws in the work itself (I’ve only seen the paper for half an hour!). Dr Asten has published a smattering of scientific papers since 1973 largely in fields related to studying microseismic behaviour. No evidence in his published work over 40 years that he has any particular expertise in analysis of paleo data for addressing climate sensitivity, and judging by the work he’s cited he hasn’t got a very good understanding of the strengths and limitations of previous work on this subject…

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