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Comments 100301 to 100350:

  1. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Sorry, the paper's presumably not nonsense, but the WUWT post interpreting them is. Has WUWT ever been right about *any* paper they claim proves portions of climate science to be wrong?
  2. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    "This is not the tipical nonsensical stuff found in blogs like WattsUpWithThat. " Actually, yes, it is, and a couple of the more knowledgeable denialists over there point out why. Ferdinand Engelbeen's response, for instance.
  3. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    What about this post in WUWT: CO2: Ice Cores vs. Plant Stomata http://wattsupwiththat.com/2010/12/26/co2-ice-cores-vs-plant-stomata/ It states that: -Plant stomata suggest that the pre-industrial CO2 levels were commonly in the 360 to 390ppmv range. (source: Kouwenberg, 2004. APPLICATION OF CONIFER NEEDLES IN THE RECONSTRUCTION OF HOLOCENE CO2 LEVELS. PhD Thesis. Laboratory of Palaeobotany and Palynology, University of Utrecht.) -Plant stomata data show much greater variability of atmospheric CO2 over the last 1,000 years than the ice cores and that CO2 levels have often been between 300 and 340ppmv over the last millennium, including a 120ppmv rise from the late 12th Century through the mid 14th Century. (source: Kouwenberg et al., 2005." Atmospheric CO2 fluctuations during the last millennium reconstructed by stomatal frequency analysis of Tsuga heterophylla needles". GEOLOGY, January 2005.) -A recent study (Van Hoof et al., 2005) demonstrated that the ice core CO2 data essentially represent a low-frequency, century to multi-century moving average of past atmospheric CO2 levels.The stomata data routinely show that atmospheric CO2 levels were higher than the ice cores do. (source:Van Hoof et al., 2005. Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis. Tellus (2005), 57B, 351–355.) This is not the tipical nonsensical stuff found in blogs like WattsUpWithThat. John Cook, what do you think about these studies that show high levels of CO2 in recent past? (By the way it seems like an interesting material for a post)
  4. Lindzen and Choi find low climate sensitivity
    RW1, The extra power from the sun will be distributed the same as the sun's power: highest at the equator, during the summer and only increasing during the day. The power from CO2 will be distributed differently: all seasons, at night as well as day and at all latitudes. Since the forcing is distributed differently, the effect is different. This difference has been measured. The night warms more than the day, the winter has warmed more than the summer and nights have increased more than days. All this information has been discussed on this site in the last month. Most of this is discussed in the Scientific Guide to Global Warming linked on the top of this page. Give it a good read and you will know more of the background information.
  5. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    "rising CO2 is isn't safe" - should be "rising CO2 isn't safe".
  6. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    @archiesteel: um, that's not how science works. science needs to show that recent extreme weather events have been made worse. so far, if it seems to support the AGW theory, then AGW proponents claim that weather events have to do with changing climate. if they don't support the AGW theory, AGW proponents claim 'that's weather, not climate'. witness the dismissal of last winter's record snowfalls in the US, and dismissal of this winter's crippling snow in europe - all called "just weather". a heatwave? why, that's not weather, that's clear and present proof of global warming! it's for those claiming that there is harm to show that harm has occurred. just like this article - which claims that it's about showing that rising CO2 is isn't safe, when all it addresses is that CO2 has risen. the sources in intermediate seem to all be talking about 'expected' harm. a typical example iis http://www.sciencemag.org/content/323/5913/447.short - "are the likely cause". i want science, not guessing.
  7. Lindzen and Choi find low climate sensitivity
    scaddenp, "Of course they can. The forcing term is global annual average. The energy flux (NOT power - please note that this term is normally used in context of energy transformation) produces the same temperature rise without feedbacks." This is what I'm referring to - the intrinsic response only. And what triggers the feedbacks? The intrinsic temperature rise - which you just said was the same for solar power and power from CO2. "However, for considering feedbacks, the energy flux is different spatially, temporally, and spectrally between solar and GHG (and aerosols and albedo if it comes to that)." Why? A watt is a watt - a joule is a joule, is it not? Explain to me how the surface, whose temperature is directly tied to the total power flux via Stefan-Boltzman, is going to 'know' the difference from increased power from Sun or CO2? Even further, even if it were to somehow 'know' the difference, for what physical reason would it respond differently to the same amount of heat increase? (*Please understand that this is not the same question as additional power from CO2 on top of all the current solar power. I think many in this thread are confusing the two, and from that, deriving that I somehow don't understand this distinction.)
  8. Lindzen and Choi find low climate sensitivity
    As an off-topic note, it would be nice to be able to vote (or at least register our agreement/disagreement) on comments. Some sort of "real ID" registration would also help weed out sockpuppet accounts (not aiming this at anyone in particular, mind you). Skeptical Science 2.0, anyone? ;-)
  9. Lindzen and Choi find low climate sensitivity
    @RW1: sure, you can start by responding to chris at #222. I'm also curious to see if you will acknowledge you were wrong when you said: "If this is true, then power from the Sun and power from CO2 cannot both be expressed in W/m^2 as they are." scaddenp and I both revealed your misconceptions about what the W/m² figure means. Will you admit you were wrong about this, and thus about the 4 W/m² having to be cut in half to calculate sensitivity? A simple yes or no will suffice.
  10. Lindzen and Choi find low climate sensitivity
    "If this is true, then power from the Sun and power from CO2 cannot both be expressed in W/m^2 as they are." Of course they can. The forcing term is global annual average. The energy flux (NOT power - please note that this term is normally used in context of energy transformation) produces the same temperature rise without feedbacks. See the chapter in the IPCC on why you calculate forcings in this way and evidence that it can used for arithmetic. However, for considering feedbacks, the energy flux is different spatially, temporally, and spectrally between solar and GHG (and aerosols and albedo if it comes to that).
  11. Lindzen and Choi find low climate sensitivity
    archiesteel, When someone offers a cogent counter-argument and you don't respond, then you have been successfully rebutted. I'm hardly the first one to note this here, either. I know I have missed a few things and haven't responded to everything. Again, I stated that in the middle of the thread somewhere. Please point me to the specific counter-argument presented that I have failed to address and I'll respond to it.
  12. Lindzen and Choi find low climate sensitivity
    Re: RW1 (274, 276 et al) You said:
    archiesteel, "I'm just pointing out that your arguments have all been rebutted. No, you're just declaring they have been successfully rebutted.
    Thanks for clarifying that. Other than being argumentative, do you still have a purpose in continuing this conversation? After all, you point out that your position has been successfully rebutted. This site contains a plethora (lovely word, that) of science-based information substantiated by links to actual peer-reviewed sources for those interested in learning about climate science. Even, for example, on working out climate sensitivity from satellite information (the subject of this post the nature of which this conversation abandoned any pretense at following long ago). Usually I'm the one catching flack for using the appellation "dude". :) The Yooper
  13. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    @anastrophe: please show me proof that the many recent extreme weather events have not been made worse by the increase of energy in the global weather system caused by AGW. Thanks. BTW, the Intermediate version of the "It's not bad" argument provides ample sources for you to educate yourself. @gallopingcamel: a pollutant is not simply determined by toxicity, but also by the harm it causes in large concentrations. Increased CO2 is harmful, and won't by itself help plant growth. As for the net effect of AGW, experts may disagree on details, but they pretty much all agree it will be bad.
  14. Lindzen and Choi find low climate sensitivity
    @RW1: "No, you're just declaring they have been successfully rebutted." When someone offers a cogent counter-argument and you don't respond, then you have been successfully rebutted. I'm hardly the first one to note this here, either. Therefore, I am simply pointing out something everyone already recognizes. "Whatever, dude. If you're not going to specifically address anything in a way that facilitates any genuine scientific give and take discussion, I'm not going to respond anymore." Go ahead, "dude", it'll make my job of pointing out errors in your arguments a lot easier. :-)
  15. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    anastrophe (@59), You make excellent points. Like you I want to improve the environment by limiting the pollution of our air and water. However, I don't see CO2 as a "Pollutant" given that all plants would die without it. From basic physics it is clear that CO2 concentrations in the atmosphere have an effect on radiative heat transfer but the experts are still arguing about the net effect on global climate after "feedbacks" are taken into account.
  16. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    @dhogaza, you offer nothing but rote dismissal of my comments. is it really necessary for you to attempt to dismiss my thoughts, rather than actually addressing them? @archiesteel, i just skimmed the article you directed me to. it has a lot of "might" and "may" and "could" to it; it provides no science to back up the anecdotal claims it makes. again, show me the proof that the small warming that has occurred has actually caused harm. not speculations about what might, may, could happen if we warm further. evidence of harm that has occurred. there is none as yet. only anecdote. and i'll note that the word alarmism well predates your colloquial claim that it's used to denigrate 'those who understand the scientific consensus'. show me what harm has occurred. show me how screaming that the sky if falling is useful.
  17. Lindzen and Choi find low climate sensitivity
    archiesteel, "I'm just pointing out that your arguments have all been rebutted. No, you're just declaring they have been successfully rebutted. You also keep repeating obvious things I already know, such as the increase from 2xCO2 will be in addition to (or on top of) seasonal and orbital eccentricity cycles, each of which average out and don't contribute to long term warming. Whatever, dude. If you're not going to specifically address anything in a way that facilitates any genuine scientific give and take discussion, I'm not going to respond anymore.
  18. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    @gallopingcamel: looking at past values of CO2 is useless if you don't adjust it for lower solar input, as was the case when it was in the high end of that range. The last time CO2 concentrations were this high with a similar solar output, temperatures were 5 to 7 degrees warmer than today. So the answer to the question is really "NO". The "CO2 lags temperature" argument is also junk, as shown elsewhere on this site. Also, it would be nice if you admitted you were wrong about increased atmospheric CO2 automatically being good for plants.
  19. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    I was trying to answer the question "Is it safe to double atmospheric Carbon Dioxide over a 200 year period" but rather than get bleeped, I will try a different approach. Atmospheric carbon dioxide concentrations have varied over a wide range since life appeared on land. For the sake of argument I suggest a range of 190 to 7,000 ppm, although the error bars at the high end leave plenty of room for debate. Modern CO2 levels are quite close to the low end of the range and even with a doubling will remain at levels that have been well tolerated by living things over hundreds of millions of years through both climate optimums and ice ages. So the answer to the question is "YES". The arguments for CO2 driven catastrophe arise from an inclination to see only negative consequences from changing conditions as if the status quo represents some kind of "golden age". The "fingerprinter" is guilty of making all kinds of statements that are contrary to what the science tells us. For example: "The first place to look is of course the paleoclimate record. Over the last several decades of research, the sensitivity of the climate system to changes in carbon dioxide has been established through ice core samples and other proxy climate indicators." The ice core records such as Vostok and GISP/GRIP show no such thing. To the contrary they show the sensitivity of carbon dioxide concentrations in the atmosphere to changing temperatures.
  20. Lindzen and Choi find low climate sensitivity
    @RW1: "You're not engaging in scientific argument - just shouting down anyone who presents any contradictory information and repeating things you've already concluded." I'm not shouting down anyone, I'm just pointing out that your arguments have all been rebutted, and yet you continue repeating them as if saying a false thing often enough would make it true. Unlike you, I'm more than welcome to be shown wrong about AGW. I don't *want* it to be true. However, I must conced when faced with the mountain of evidence supporting it, and the absence of evidence supporting the contrarian view. That's what science is about, not your purposefully-confusing attempts at minimizing the reality of AGW in order to satisfied you preconceived, politically-motivated opinions. "If that is all you're interested in doing, then why even participate on this site - let alone this thread?" Because that's not what I'm interested in doing. I'm interested in honest scientific debate, not whatever it is that you're doing.
  21. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    @Anastrophe, I refer you to the It's not bad for a few examples on how a 0.15C rise per decade is dangerous. BTW, it's "alarmism" to be prepared to deal with bad stuff, it's survival. "Alarmism" is the term contrarians use to denigrate those who understand the scientific consensus. The truth of the matter is that alarmism is much less of a threat right now than is apathy.
  22. Lindzen and Choi find low climate sensitivity
    archiesteel (RE: 273), You're not engaging in scientific argument - just shouting down anyone who presents any contradictory information and repeating things you've already concluded. If that is all you're interested in doing, then why even participate on this site - let alone this thread?
  23. An overview of Greenland ice trends
    #38. Camburn. A more recent paper that cites the one you mentioned and has a 168 year trend. http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2816.1 In contrast to the 1920s warming, the 1994–2007 warming has not surpassed the Northern Hemisphere anomaly. An additional 1.0°–1.5°C of annual mean warming would be needed for Greenland to be in phase with the Northern Hemispheric pattern. Thus, it is expected that the ice sheet melt rates and mass deficit will continue to grow in the early twenty-first century as Greenland’s climate catches up with the Northern Hemisphere warming trend and the Arctic climate warms according to global climate model predictions.
  24. An overview of Greenland ice trends
    @Camburn: since you are citing an AGU study, I'm sure you also agree with the AGU's official position on AGW, right? Here it is, in case you weren't awayre of it: "The Earth's climate is now clearly out of balance and is warming. Many components of the climate system--including the temperatures of the atmosphere, land and ocean, the extent of sea ice and mountain glaciers, the sea level, the distribution of precipitation, and the length of seasons--are now changing at rates and in patterns that are not natural and are best explained by the increased atmospheric abundances of greenhouse gases and aerosols generated by human activity during the 20th century."
  25. It's Pacific Decadal Oscillation
    @NETDR: "Is this divide and conquer time ?" Just stick to making rational arguments that are on-topic and you won't have any problems. For isntance, there is no evidence AFAIK that the PDO and the LIA are directly related, therefore trying to link the two in some sort of "grand unified denier theory" is off-topic. The truth is that contrarians are forced to resort to the logical fallcy known as "changing the subject," because they do not have arguments that withstand scrutiny, and therefore are forced to flee to another topic whenever they are confronted with the weakness of their position. My personal suggestion to you is that, if you don't like the moderation on this site, then just stop commenting. Maybe then we'll be able to have more constructive discussion, such as what we should actually do to mitigate the very real effects of AGW.
  26. Lindzen and Choi find low climate sensitivity
    @RW1: "Just repeating generalities doesn't make them true." They're not generalities, they're the actual current level of scientific understanding on the matter of AGW. You have failed so far to demonstrate why we should believe in a unreviewed theory that runs counter to current science *and* observations. "If you don't desire to or not able to engage in genuine scientific discussion in this thread, then why participate?" I am both able and eager to engage in genuine scientific discussion, but apparently you're not, since you continue to latch on a dubious theory while ignoring the very thorough counter-arguments presented to you. As I said earlier, you're not really interested in learning the truth, but simply "muddy the waters", i.e. create confusion and force people to spell out obvious scientific truths in order to bog down the scientific debate. Hey, when even self-avowed skeptics disagree with your argument, you know you have a problem.
  27. An overview of Greenland ice trends
    You would be better served to include at least a 100 year trend analysis. There is data for the period. As an example, here is data in ref to temperatures: http://meteo.lcd.lu/globalwarming/Chylek/greenland_warming.html
  28. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Anastrophe's post is nothing but a rote recapitulation of standard denialist dogma. Do we really need it here? Can't we at least have some creative skepticism?
  29. It's Pacific Decadal Oscillation
    It is almost impossible to post coherent arguments on skepticalscience.com because all arguments slide between threads and part of every response is O T. The so called skeptical arguments are straw-men which don't cover my reasons for not believing in catastrophe at all. Consequently my posts are O T wherever I post them Ocean currents can not cause overall arming but they can cause short term [20 - 30 year like the 78 – 98 ] warming which fools the scientist into thinking there is a bigger trend than there is. Solar variation did not cause the 78 – 98 warming but it can cause the 1880 to 2010 trend when long term positive feedback is factored in. Some treat positive feedback as if it only operates on CO2 caused warming but no scientist really believes that. By breaking the two arguments apart they are both O T on two different threads. Is this divide and conquer time ?
    Moderator Response: If you would bother to read the Climate Time Lag post to which you were pointed, you would learn why your contention about solar contribution is wrong.
  30. Lindzen and Choi find low climate sensitivity
    archiesteel, Just repeating generalities doesn't make them true. If you don't desire to or not able to engage in genuine scientific discussion in this thread, then why participate?
  31. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    this article actually doesn't address what it claims to address. in the argument 'is it safe', this article merely addresses whether or not increased CO2 causes warming - not whether that warming is safe or unsafe. i am a skeptic. the holes in the alarmism arguments are large enough to drive a CO2 belching truck through. there has been no verified, demonstrable evidence yet presented that there have been any harmful effects due to the less than one degree C of global warming over the last century. there has been considerable anecdotal evidence suggested. much of it wrong. we here in the US were relentlessly warned after hurricane katrina that this was a sign of 'things to come'. we all know how that turned out. rising sea levels have not been empirically demonstrated to date. anecdotally yes. south sea islands going under? no. subsidence, yes. there has been no statistically significant increase in global temperature in the last *fifteen years* - all while china has increased its belchings of CO2 by many orders of magnitude. no, all i ask is that climate "science* give me something more concrete than ridiculous computer models with no basis in reality. all i ask is actual, verifiable PROOF that harm has occurred. now, does my skepticism mean i'm against reducing dependence on petroleum, that i'm against clean air? not in the slightest. it's likely that oil will run out someday. as a feedstock for a huge number of extremely important products that have made life better for all humans, i'm in favor of conserving petroleum for uses more constructive than driving about on a sunday afternoon. we need power to run our modern world - and we need to find alternatives. what i am against is extreme policies that can harm just as many people as global warming is claimed may be harmed. alarmism is harmful in itself. it does not advance the science or the argument. running about, screaming that the sky is falling, is not having the effect the promulgators desire. encourage conservation. work on creating the ultimate solar panel. be constructive, rather than alarmist, and you'll accomplish a hell of a lot more, and alienate a hell of a lot fewer people.
  32. Lindzen and Choi find low climate sensitivity
    @RW1: I'm sorry, I wasn't clear enough. I meant to ask why, considering you agree that CO2 is an additional forcing, do you keep trying to insinuate that the CO2 effect is not significant, when the science clearly indicates it will be, and observations confirms what the science says? This is the crux of it: we know it is warming, and we know why it's warming. That warming is within projections that indicate an increase of about 3C (including feedbacks) for a doubling of CO2. So far you have failed to clearly demonstrate *anything* that challenges this, relying on a single source that has not been peer-reviewed, and which to makes some glaring mistakes (if we are to believe your interpretation - the fault may lie there instead). Again, please stop wasting everyone's time.
  33. Lindzen and Choi find low climate sensitivity
    archiesteel, Also, why won't you acknowledge the fact that the seasonal change represents a cycle, while CO2 forcing represents a supplementary increase... Because I already have acknowledged it - multiple times in this thread I might add. I'm well aware of it, and I have been long before I ever posted anything here. I'm trying to now take things in a step by step basis. I'm using the information from that website because it's empirically derived from satellite data and it makes the fewest assumptions about how the climate system behaves globally or hemispherically - each of which reveals critically important characteristics. Also, the Lindzen and Choi feedback study has been criticized as only being localized in the tropics, where as this analysis is global and gets roughly the same sensitivity. If you're not interested, then don't participate and continue to believe whatever you want.
  34. Lindzen and Choi find low climate sensitivity
    @RW1: why do you keep citing the same website as reference? Is that your only source? Also, why won't you acknowledge the fact that the seasonal change represents a cycle, while CO2 forcing represents a supplementary increase, i.e. raising the "AVG" value of those irrelevant graphs? In short, why do you keep wasting our time? You're not going to convince anyone here with marginal theories that haven't been published and/or peer-reviewed, and which run counter to actual observations. You're also not going to convince those who are still learning the science with your convuluted, purposefully confusing arguments. The only people you are going to "convince" are those who have already decided they don't believe in AGW, i.e. who seek positive reinforcement of their preconcieved opinions. This begs the question, then: why are you doing this?
  35. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    It’s probably futile to draw your attention yet again to the science that informs our understanding on these issues gallopingcamel, but in the seasonal spirit let’s have another go.
    gallopingcamel:”You don't need university researchers to tell you this kind of thing. Enhancing the CO2 in greenhouses has been a common practice for decades.”
    Sadly, that only works under conditions of optimal water and fertilization supplementation. In the real world that’s not how the vast majority of food crops are grown. If you were to properly assess the FACE experiments that aim to characterize the effects of CO2 supplementation under field conditions, the picture isn’t so rosy: S. P. Long, et al (2006) Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations Science 312, 1918-1921 abstract A. D. B. Leakey et al. (2009) Elevated CO2 effects on plant carbon, nitrogen, and water relations: six important lessons from FACE J. Exp. Botany 60, 2859-2876
    “More broadly, the stimulation of seed yield in response to growth in elevated [CO2] is ~50% lower in FACE experiments than in enclosure studies for the world’s four most important crops (Long et al., 2006; Ainsworth, 2008; Ainsworth et al., 2008a). With the caveat that FACE experiments have been limited in number and geographical coverage, the much lower elevated [CO2] fertilization factor on yield observed under agronomicaly relevant conditions has potentially serious implications for projections of world food supply……………. Most important though will be understanding why our major food crops fail to achieve the improved production under elevated [CO2] that can be achieved in protected environments and by some non-crop species.”
    J.A. Langley & J. P. Megonigal (2010) Ecosystem response to elevated CO2 levels limited by nitrogen-induced plant species shift Nature 466, 96–99 abstract This reiterates that any [CO2] effect requires enhanced N (nitrogen) nutrient as is well known, but the combined effects of [CO2]/N are likely to be counterproductive with respect to plant growth in natural ecosystems due to CO2/N-induced shifts in plant species. So natural ecosystems may respond poorly to enhanced [CO2] due to water and nutrient limitation and species shifts. In other words the terrestrial ecosystem is likely increasingly to falter as a sink to "mop up" large amounts of enhanced anthropogenic [CO2]. Managed agricultural production may cope with enhanced [CO2] but is likely to become more expensive to support due to nutrient and water limitations, as indicated by FACE studies (e.g. as in the first two papers above).
    gallopingcamel: ” However, you are in error to link desertification to increased temperatures. It is falling temperatures that increase desertification, while rising temperatures cause increased precipitation”
    Wrong. The predictions on changing precipitation patterns in a warming world are borne out by real world observations. The latitude band from around the equator to near 30 oN has become drier as the Earth has warmed during the 20th century, much as predicted, and will continue to do so. This latitudinal band of reduced precipitation will widen as the Earth continues to warm (and so Amazonia, for example, is expected to dry progressively towards the South as the Earth warms). The higher latitudes (especially above 50o N and below 10 o) have seen enhanced precipitation. Global warming and shifts in precipitation regimes is expected (and already observed) to lead to amplification of extreme precipitation events (one could cite more papers on this, but Allen et al. 2008 is a decent starting point). In other words those parts of the world that are water-limited are becoming more susceptible to drought as global warming proceeds…those areas of the world that don’t need more rain (higher latitudes) are getting more: X. Zhang et al. (2007) Detection of human influence on twentieth-century precipitation trends Nature 448, 461-465 abstract RP Allen et al. (2008) Atmospheric warming and the amplification of precipitation extreme Science 321, 1481-1484 abstract
    Moderator Response: Since there already is a history of comments on this topic on the thread CO2 Is Not a Pollutant, how about everybody respond over there.
  36. Lindzen and Choi find low climate sensitivity
    Eric, "New power flux is added which causes an increase to T+delta, "gain" is much higher. That's because "gain" is not a constant as KR explained in 210." The reason I ask is because I think you are saying that the gain increases as temperature and surface power increases. Actually, the gain decreases as radiative forcing and surface power increases. This is very clear from the graphs, where the gain is out of phase with solar input: http://www.palisad.com/co2/eb/g/gain.png This is true in both hemispheres as well: http://www.palisad.com/co2/eb/nh/gain.png http://www.palisad.com/co2/eb/sh/gain.png Do you see how/why this clearly illustrates negative feedback? That is as radiative forcing and power increases, the proportional amount of surface power increase is reduced, and as radiative forcing and power decreases, the proportional amount of surface power increases. This means that increases in radiative forcing and temperature are being opposed rather than reinforced by the climate system.
  37. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    @gallopingcamel: as others have pointed out, it's not just as simple as doubling CO2. In a greenhouse you control temperature, moisture and the amount of nutrients the plants get. You are the perfect example of the old saying, "a little knowledge is dangerous." I suggest you learn more about growing plants (I myself have spent a lot of time working in a greenhouse at my sister's farm) before pushing the myth that "increased atmospheric CO2 will have a beneficial effect on plant growth" when there is *no* indication this would be the case.
    Moderator Response: As GP perfectly well knows, there are other threads that are appropriate for his repetition of these arguments. Deletions will commence soon.
  38. Renewable Baseload Energy
    An interesting article on use of microgeneration in developing countries: African Huts Far From the Grid Glow With Renewable Power
  39. It's freaking cold!
    An interesting take on the extreme winter by a weather guy in 26 Dec NY Times: As global temperatures have warmed and as Arctic sea ice has melted over the past two and a half decades, more moisture has become available to fall as snow over the continents. So the snow cover across Siberia in the fall has steadily increased. The sun’s energy reflects off the bright white snow and escapes back out to space. As a result, the temperature cools. When snow cover is more abundant in Siberia, it creates an unusually large dome of cold air next to the mountains, and this amplifies the standing waves in the atmosphere ... He goes on to explain how this forces the jet stream into a more N/S configuration, resulting in deeper, wetter cold fronts. Which is as reported here and here and shown below. Similar results published in JGR: This causes a continental-scale winter cooling reaching −1.5°C, with more than 3 times increased probability of cold winter extremes over large areas including Europe. Our results imply that several recent severe winters do not conflict the global warming picture but rather supplement it, being in qualitative agreement with the simulated large-scale atmospheric circulation realignment.
    Moderator Response: [muoncounter] Note: original image was from intellicast and updated daily. Conditions referred to here occurred in late Dec 2010; jet stream map now shown for 12/26/10 from archive at http://squall.sfsu.edu/crws/archive/jetsat_arch.html
  40. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    #53: "Enhancing the CO2 in greenhouses has been a common practice" And we are comparing the artificial, closed environment of commercial greenhouses to the open atmosphere because ...? Does it occur to you that moisture content in a commercial greenhouse is also controllable? "in error to link desertification to increased temperatures." Or not: "more arid conditions" "Increased drought frequency will likely cause major changes in vegetation cover." "An Australian study offers further confirmation of the climate change phenomenon – arid regions are indeed becoming drier and higher rainfall regions wetter" Interestingly, there seems to be reports of both extreme drought and floods. Are we up to 7 out of 10 yet?
  41. Philippe Chantreau at 02:42 AM on 27 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    It's also worth mentioning that commercial greenhouses using CO2 enriching maintain between 800 to 1200 ppm CO2 content. If we have to get there to see any "benefit" we'll end up with quite an interesting geo-engineering experience, especially if it's done in just another few decades.
  42. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Re: gallopingcamel You need to read Dai et al 2010, then. Hope your Christmas was merry, The Yooper
  43. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    archiesteel (#48), According to the FACE experiment (Nicolas School of the Environment), CO2 does make plants grow more. When CO2 concentrations are increased, plants grow faster until scarcity of some other nutrient intervenes. You don't need university researchers to tell you this kind of thing. Enhancing the CO2 in greenhouses has been a common practice for decades. If you are right, global temperatures will rise as a result of doubling the CO2 concentration in the atmosphere. However, you are in error to link desertification to increased temperatures. It is falling temperatures that increase desertification, while rising temperatures cause increased precipitation.
  44. Ice isn't melting
    Over on Neven's Arctic Sea Ice blog, a reader has done an analysis of the Arctic sea ice loss, with a log-fit (R2=0.933253) showing 2011 as the last full-ice year: So much for the "recovery". The Yooper
  45. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    #46: "The plants are going to love it but nobody listens the them ... " Nice of gc to entertain with his Lorax imitation. Unfortunately, messing with Mother Nature can produce surprising results: The direct, physiological response of plants to elevated CO2 generally acts to weaken the earth’s hydrologic cycle by lowering transpiration rates across the globe. Lowering transpiration alone would tend to enhance soil moisture. However, reduced recirculation of water in the atmosphere, which lowers precipitation, leads to more arid conditions overall (simulated global soil moisture decreases by 1%), particularly in the Tropics and midlatitudes. And if altering the hydrologic cycle isn't a big enough gamble, here's evidence for another unintended consequence: Elevated levels of atmospheric carbon dioxide (CO2), a consequence of anthropogenic global change, can profoundly affect the interactions between crop plants and insect pests and may promote yet another form of global change: the rapid establishment of invasive species. So that could add famine, locusts and probable cattle diseases to our list. Just how many Biblical-style plagues do the deniers consider 'safe'?
  46. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    it sounds very much like the cheapest and most reliable nightmare.
  47. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    To be fair to the skeptics, reducing our dependence on fossil fuels will be difficult. It won't be the end of civilisation as we know it, which is what skeptics think. But we do need to make the judgement, "Are the risks of global warming sufficient to justify the cost of abandoning fossil fuels?" I think it is worth it, but others may differ. It does bug me when they argue that global warming isn't happening, and our CO2 emissions aren't causing it.
  48. Lindzen and Choi find low climate sensitivity
    @RW1: "The graph clearly shows the solar power fluctuting by about 20 W/m^2 from perihelion in January to aphelion in July" Who cares? It's a fluctuation, as you point out yourself. The additional 4 W/m³ for a doubling of CO2 is an actual increase (and raises temperatures in both seasons). Seriously, go read a book or something.
  49. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    "Small uncertainties in the conventional science are used to reinforce the notion that doubling atmospheric carbon dioxide is entirely safe." Not only that, but skeptics want us to think doing something about climate change will be unsafe.
  50. Lindzen and Choi find low climate sensitivity
    @RW1: "If this is true, then power from the Sun and power from CO2 cannot both be expressed in W/m^2 as they are." Sure they can. The fact they have different signatures doesn't mean they can't all be reduced to relative W/m² values. RW1, it's clear you have some serious issues understanding simple scientific fact. Rather than waste everyone's time here, I suggest you start taking science classes (and pay attention, this time).

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