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Comments 87201 to 87250:

87201. Marcus at 18:25 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       "Give me a grant of a few hundred thousand dollars and a few research scientists and I'll give you 500 new versions of Rubisco Activase, or more if you want. Give me another ten years funding and I'll give you a field trial on x number of genetically modified crops with a new Rubisco Activase gene." Yes, HR, & can you guarantee that *any* of them will perform better than what nature has already provided after millions of years of evolution? As someone with more than 2 decades of experience in Molecular Biology, I've become a little bit more realistic about the potential for molecular biology to solve all our problems. All GMO's have done is to give certain Corporations far too much control over our agriculture, yet with far fewer benefits for farmers & consumers than were originally promised. So forgive me if I still say that it is *more* cost effective to stop stuffing up our climate than it is to use science to adapt our crops to the conditions we're creating.
87202. Marcus at 18:15 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       "but there is no logic to your suggestion that in vitro work trumps controlled in vivo work in helping us understand what will happen to this gene in the real world." That is *not* what I suggested-so please stop trying to misrepresent my position. My position is that, from an historical basis, our observations of plant physiology in the real world (outside of a controlled environment) has been backed by what we know at the cellular & molecular level-& vice versa. The same cannot always be said for glasshouse trials-as the FACE trials clearly show. The difference between them becomes even more stark when you factor in the known impacts of soil-borne diseases, competition from weeds & predation by insect pests-yet all 3 of these factors can be understood, & well predicted, by our knowledge of plant physiology gained from In Vitro work. With that in mind, I'd say Dawei is far less guilty of making "speculative leaps" than those who rely on results taken *purely* from Glasshouse trials. I'd also say that he is emphasizing a *realistic* conclusion regarding the future impact of rising CO2, whereas people such as yourself continue to push a blindly optimistic conclusion-only because that's the conclusion which will require the smallest action to be taken on CO2 emissions in the future.
87203. JMurphy at 17:57 PM on 28 April 2011
       Antarctica is gaining ice
       RyanStarr wrote : "I recall a picture from the 50s showing a submarine poking through slush at the north pole." Could you post further details on the thread suggested by scaddenp.
87204. JMurphy at 17:55 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       HumanityRules wrote : "Give me a grant of a few hundred thousand dollars and a few research scientists and I'll give you 500 new versions of Rubisco Activase, or more if you want. Give me another ten years funding and I'll give you a field trial on x number of genetically modified crops with a new Rubisco Activase gene." This seems to be a common refrain, and not just with reference to Climate Studies - people have written about 'pots of gold', 'rivers of cash', 'showers of coins', etc. However, when the banks hear similar stories, and various grant organisations hear similar stories (and even when they hear such stories in Dragons' Den), the answer is the same, unfortunately : "If you can prove that your idea has value and potential, the money is yours. If you can't...NEXT". That's life, I'm afraid, and (just as with the other examples I've given) you'll get very little sympathy for wishing, especially from those of a certain political persuasion : who will go on about grant-dependency, people expecting money for nothing, etc.
87205. Argus at 17:51 PM on 28 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       Quick answers: Moderator: "Do you agree with Lindzen or not, per the topic of this post, that we should have seen more warming?" -- Answer: it is still too early to say; time will tell. #90 pbjamm -- not worth an answer. #91 dana1981: " "I like Lindzen therefore he must be correct" isn't exactly a very compelling argument." -- Answer: you are right, and that quote misrepresents what I wrote; read again! #92 Rob Honeycutt: "Is there any basis for this belief? If so I'd like to hear it." -- Answer: the basis is that 20 years is too soon state definite answers about climate. #93 JMurphy: "That comment from Argus..." -- Answer: an excellent compilation of invectives, insults and foul language, other than that deserves no answer ( -Inflammatory snipped- ).
       Moderator Response: [DB] JMurphy was making a generality about your comment being emblematic of stock "skeptic" responses and tactics. I see no personal insults or foul language. Any invective I read is directed at the argumentation style and mindset in general, not in specific.
87206. RSVP at 17:03 PM on 28 April 2011
       Waste heat vs greenhouse warming
       To KR Comparing your remarks... exhibit A "Think of a pot on a stove. Adding AHF is equivalent to turning up the burner. The stew gets hotter, more steam comes out, it recovers equilibrium (stops changing temperature) when in = out. " exhibit B "In fact, if waste heat was the cause of warming, we would see an increase in outward IR due to the planet being over equilibrium temperature, rather than the observed decrease as the climate catches up to the GHG forcing. " In B, with respect to the analogy in A, you are basically saying less steam is observed to be coming out. If as you say, "Adding AHF is equivalent to turning up the burner.", it holds that AHF is contributing to warming. Up to there we appear to agree, but you go on to say that AHF is not the "primary" cause. This would be possible if at the same time AHF were not accumulating, but since energy cannot be destroyed, I am very afraid this needs to be accounted for before considering GHG effects.
87207. HumanityRules at 16:50 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       29 Marcus My 25 years as a molecular biologist says the reason you do in vitro work on a gene is because you can further control the conditions in which the gene is operating. You are taking it one step further away from even the slightly messy conditions of a whole organism in a controlled setting. You can certainly get a more refined understanding of how a gene works but only within the artificial setting of a plastic tube. For example there are numerous co-factor and subtle transcriptional and tranlational modifications that are potentially at work in the in vivo setting that have been lost by working in vitro. There are pro's and con's to both in vitro and in vivo work that's why scientists do both but there is no logic to your suggestion that in vitro work trumps controlled in vivo work in helping us understand what will happen to this gene in the real world. I just want to emphasise I'm not critising the science. The science is the right approach. I'm questioning how much we consider these results as speculative in relation to the real world. I think Dawei has clearly taken a speculative jump here. He has rightly highlighted the speculative jump made in extrapolating from greenhouse work but has ignored the even greater speculative jump made from extrapolating from in vitro work. I think that has the effect of emphasising a more pessimistc conclusion.
87208. Marcus at 16:46 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       "I don't think anyone should be writing off what may be possible, nor discounting the ability of those involved in such work, it is all really only beginning, and so little is known." As someone who is 'involved' in such work (amongst others), John D, I can tell you that you are pinning *way* too much hope on the beneficial effects of eCO2 on crop yields-over the longer term-for several reasons. 1) If the protein yield-in g/kg of total biomass-is reduced, then humans & animals will need to consume greater amounts in order to get the same benefits in terms of protein. The same is true of trace elements like iron & zinc, which have also been shown to fall under eCO2 conditions. 2) Under more stressful conditions (lower water, greater warmth), there was almost *no* significant difference in grain yield between those plants grown at eCO2 vs aCO2 conditions-but the drop in N remained about the same. 3) The FACE trials in Horsham have indicated that acclimation sets in after just 3 short years of cropping at eCO2 conditions. 4) We still don't know *exactly* what impact root-pathogens & insect pests will have on total & grain biomass under eCO2 conditions-but the evidence we have to date does *not* bode well. 5) Back on the issue of N, you seem to forget that the quantity of the enzymes that determine the rate of photosynthesis, as well as the amount of chlorophyll in the leaves, is highly dependent on the levels of nitrogen in the plant. Decrease the levels of N, & this would *suggest* that-in the longer term-you'll also get a decrease in total levels of photosynthesis-that might well suggest that any biomass gains will be short-lived. What it keeps coming back to is this-is it going to be *more* cost effective to keep adapting our agriculture to suit humanity's "tinkering" with the atmosphere/climate, or is it more cost-effective to simply *stop* with the tinkering? From everything I've read at this site for the past 2 years, I'd argue that the *latter* is true.
87209. Marcus at 16:33 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       "1) All the FACE trials Dawei lists here and mentioned in the review linked in #6 suggest mainly positive, sometimes neutral and never negative effects from increased CO2 from what I can see." Do some research then HR, there are several FACE trials which have shown that eCO2-alone-will increase the susceptibility of crop plants to insect pests & increase the levels of certain soil-borne pathogens in the soil-both of which I'd define as a *negative*. There are also FACE trials which show that eCO2 can lead to decreased levels of protein, Zinc & Iron in plants. Given that nitrogen is a key component of chlorophyll, the "power-house" of photosynthesis, I'd say that greatly undermines the foundation of the "CO2 is plant food meme". All of that before we even *begin* to consider the impacts of changed hydrology & increased warming on crop yields. "2) It seems a little unfair that I should be held responsible for possible conclusions people might draw from falsely interpreting what I said." If you make overly simplistic claims, without offering up caveats, then you're actually making it more likely that people will "falsely" interpret what you said-which suggests that this is the outcome you're hoping for, & therefore you *can* be held responsible for making misleadingly simplistic claims.
87210. johnd at 16:32 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       Ian Forrester at 12:29 PM, each time the subject of CO2 enrichment, and particularly FACE trials for wheat is raised, the most common response is, that despite the indicated yield increases, it is the lower protein levels that is the issue. Given that, I think something needs to be clarified in the minds of those who have little or no background knowledge on the subject. The inverse relationship of crop yield and protein levels is not, repeat, not something new, nor specific to CO2 enrichment. Instead it is a well understood, well measured response that happens every year, and has been happening forever, or at least must seem like forever for those growers whose payment is structured not only on weight delivered, but on protein content. Routinely, years of high yields show lower protein levels, whilst the lower yields of drought conditions can be offset somewhat by higher protein levels. In fact there is even a standard formula that is used to determine the nitrogen requirements of a crop that explains the relationship. Using the grain yield (t/ha), the grain protein (%) and the appropriate grain protein factor, (for wheat it is 1.75, and for all other grains it is 1.6), multiplying the yield in t/ha by the % protein by the factor gives the nitrogen requirements in kg/ha. For example a 3 t/ha crop of wheat at 12.5% protein removes 66kg N/ha (3 t/ha x 12.5% x 1.75 = 66 kg N/ha). This formula is used by growers to anticipate the amount of nitrogen that they may need to apply if they want to achieve a certain crop yield. http://www.agric.wa.gov.au/PC_92452.html However other factors may overtake the planned outcome with the eventual yield higher or lower, but the protein will also have varied inversely if the intended amount of nitrogen was taken up by the crop. Another point that is also overlooked is that if calculations are done using the increased yields achieved under CO2 enrichment, and the lower protein levels, it is clear that the amount of protein produced per hectare actually increases. Where such limits may be is yet to be determined, but it may eventually be found in the ability of the plants to take up the nutrients, or it could be in the ability of the soil to give them up. I don't think anyone should be writing off what may be possible, nor discounting the ability of those involved in such work, it is all really only beginning, and so little is known.
87211. From Peru at 16:25 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       There are FROZEN FROGS with a label saying "domain unregistered" in place of the figures. I hope the glitch is fixed soon
       Moderator Response: [DB] Glitch fixed; thanks for pointing that out!
87212. HumanityRules at 15:49 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       11 Phil 1) All the FACE trials Dawei lists here and mentioned in the review linked in #6 suggest mainly positive, sometimes neutral and never negative effects from increased CO2 from what I can see. The extra information is certainly thought provoking but I don't see that any sufficiently undermine the findings of these trials. If you don't want to go as far as saying this points to better agricultural yields in the future that's fine, I don't think I ever put that forward. But it doesn't seem to undermine 'CO2 is plant food'. 2) It seems a little unfair that I should be held responsible for possible conclusions people might draw from falsely interpreting what I said.
87213. scaddenp at 15:21 PM on 28 April 2011
       Models are unreliable
       A lot to learn here. For the attribution question, see Schmidt et al. There is two issue though. One is current state - how much of the greenhouse effect is attributable to each gas in their current concentration in the atmosphere. The other is what happens when change CO2. The other greenhouse gases do not stay in same concentration (especially water varies with temperature) so feedback must be accounted for. Temperature change affects albedo as well and to lesser extent aerosols so this is not a trivial calculation. Why would you suspect something about what you dont know? Firstly, the modelling is physical not statistical. Codes like calculating the absorption of GHGs are improved slowly but code write and rewrite happens all the time as computer speed allows more and more physics to be added to the model. Realclimate has a good FAQ on modelling; I suggest you read it, rather than suspecting. Milankovich is irrelevant to DO and there is a large literature on what the causes actually are. But relevance to modern climate is???
87214. Marcus at 15:09 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       "If Dawei is happy to put a big question mark over the greenhouse work then I'd argue that conclusions drawn from this in vitro work should be in the region of complete speculation. Nothing wrong with that either as long as it's well understood." Well, HR, that just proves how little you know about the relationship between In Vitro & whole organism biology. History has shown us that what occurs at a cellular level tells us a great deal about what will occur at the whole organism level. Greenhouse work, by contrast, only tells us about how an organism will survive in carefully controlled conditions. Once again it seems your "skepticism" only stretches to those things which contradict the propaganda of the Contrarian Movement.
87215. Marcus at 15:06 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       "And "your side of the debate" seem to have given up on human ingenuity or forgotten that throughout human history our ancestors have been fighting those problems you list, and generally winning." Tell that to the hundreds of millions of people who are already going hungry-across the world-& they'll probably laugh in your face HR. What do you think the metric will be when ingenious-but costly-solutions to the problems caused by eCO2 & related global warming push the price of basic food-stuffs even *further* beyond their reach? Or what do you think will happen to the price of crops if we have more record breaking droughts, like those in Russia, or massive storms & flood damage to crops, like those here recently in Australia? What's going to happen to the price of crops when some of the most arable land is under half a meter of sea-water? Yet the way you & your ilk would have us believe, with your simplistic reasoning, eCO2 will bring about a New Age of Abundance-whereas the realists amongst us can see that what it will really bring is a whole mess of new problems, in quick succession, that even our most ingenious minds might not be able to solve in time &-even if they do-will come at the cost of much higher prices for staples-like wheat, rice & soy-beans. We realists also recognize that it will be much cheaper-in the Mid to long term-to simply *avoid* this eCO2 scenario altogether, rather than take the chance that the boffins can solve all the problems it will create in time. Still, I guess if your only concern is the profitability of the fossil fuel sector, then you'd be willing to take that chance.
87216. HumanityRules at 14:59 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       25 KR I'm not hiding my head in the sand, I'm standing up against unrealistic pessimism. I suspect under your cloud of doom you can't see that.
87217. trunkmonkey at 14:55 PM on 28 April 2011
       Models are unreliable
       According to NASA the greenhouse effect of CO2 is 10 w/m^2 or 20% of the total greenhouse effect. I don't know where they got this, if it contains feedback assumptions, or if it is just the net absorbtion at 385 ppm. My understanding is that NASA is the custodian of the GISS model. I have effectively zero knowledge of numerical modeling so I haave to treat the model as a black box. First they tell me that Co2 is only 20% of the greenhouse effect, and then they tell me that when they take this 20% out of the box GAT drops six degrees in the first year. I have been lead to believe that the model was tested using hindcasting. I suspect that much of the source code was written before the ice cores were drilled.I assume (this is the weakest, honestly) that during this hindcasting the presumption was that CO2 had temperature on a leash. My suggestion is that until we discovered how much easier life can be if we burn that nasty black stuff, temperature had CO2 on a leash. Apologies for the excessive breadth of 339. I don't really believe in the "cycles". It's just how they are commonly referenced. The tendency on this website has been to say that because there is spectral significance for precessional cycle in the first half of the Pleistocene and eccentricity in the second half, that paleoclimatology is a done deal and it's all Milankovitch. Milankovitch is irrelevant in both the millenial DO and the billion year "cycles". I believe these "cycles" are actually more like the ENSO.
87218. HumanityRules at 14:54 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       8 SNRatio In general I've got no real problem with this article other than it has a bias towards the most pessimistic conclusions. For example "This effect may potentially nullify some of the gains expected from excess CO2 in these plants." Much of the work supporting this is in vitro work performed on isolated enzymes. That is, it's not even in the plant. Earlier Dawei rightly critised greenhouse work for not well representing the real world. How well to you think a couple of isolated enzymes in a tube represent the real world? There is nothing wrong with this scientific approach, it's getting us a basic understanding of these enzymes but it's a long stretch to Dawei's conclusion from this work. If Dawei is happy to put a big question mark over the greenhouse work then I'd argue that conclusions drawn from this in vitro work should be in the region of complete speculation. Nothing wrong with that either as long as it's well understood. In the meantime all the reports of field trials still seem to show increased CO2 is either beneficial or at worst neutral to crop growth that still doesn't seriously undermine the idea of CO2 is plant food idea.
87219. KR at 14:44 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       HumanityRules - "human ingenuity " and "our ancestors have been fighting those problems" are no excuse for short-sightedness, or hiding our heads in the sand while the tidal wave crests. Which, by dismissing the severity of global warming and it's impact on our lives, 'skeptics' appear to endorse.
87220. scaddenp at 14:39 PM on 28 April 2011
       Antarctica is gaining ice
       Ryan, try taking arctic comments to arctic sea ice melt is a natural cycle
87221. scaddenp at 14:31 PM on 28 April 2011
       Antarctica is gaining ice
       Wow - trotting out the old submarine photo. It's in a polynya! For evidence of part arctic sea-ice, see arctic sea ice threads. You can find pointers to the relevant papers on past sea-ice seasonal limits there.
87222. HumanityRules at 14:31 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       7 Marcus And "your side of the debate" seem to have given up on human ingenuity or forgotten that throughout human history our ancestors have been fighting those problems you list, and generally winning. And all that without even knowing Rubisco Activase existed. Not a utopian but certainly a believer in the human spirit, I'd rather that than an utter pessimist. I'm not here to paint utopian visions just to counter unnecessary pessimism. I'm a molecular biologist. Give me a grant of a few hundred thousand dollars and a few research scientists and I'll give you 500 new versions of Rubisco Activase, or more if you want. Give me another ten years funding and I'll give you a field trial on x number of genetically modified crops with a new Rubisco Activase gene. There are always solutions to problem. ( -Questioning of motives snipped- ).
       Moderator Response: [DB] Don't go there.
87223. Philippe Chantreau at 14:26 PM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       Further correction Arch (sorry, it needs to be said): The particles generated by GCR are too small to act as CCN. A plausible mechanism for particle growth is the physical process lacking to give weight to the hypothesis.
87224. adelady at 14:21 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       20 Marcus ".. changes in sowing times are a poor simulation of the kinds of conditions being predicted .." Yes, I noticed that. I realise that it's very limiting trying to do these experiments in the open air - and the equipment budget was probably entirely swallowed by the CO2 delivery and monitoring systems - but temp changes, (un)seasonal conditions and precipitation unreliability need attention. Who cares if the plants themselves do better if crops are ruined by two weeks of wet/ hot/ windy/ plague conditions just before harvest? I've seen grown men bravely blink away tears over rust ruining a thriving wheat crop - and that was a long time ago. Rust one year, locusts the next - following several drought years, makes Hanrahan look hopeful.
87225. RyanStarr at 14:09 PM on 28 April 2011
       Antarctica is gaining ice
       Muoncounter, we've always had and always will have seasons, climate change isn't changing that. Look at photo above showing March and September extents for both the Arctic and Antarctic. Point me to some evidence which shows arctic ice extent used to be a more static quantity than it is now. I recall a picture from the 50s showing a submarine poking through slush at the north pole.
87226. RyanStarr at 13:57 PM on 28 April 2011
       Antarctica is gaining ice
       @ 80 "...rising ocean temperatures have cleared out sea ice.." Cleared out sea ice in Antartica? You need to read the article above, it attempts to explain why the observed rising sea ice in Antartica can occur in a warming climate.
87227. Ian Forrester at 12:29 PM on 28 April 2011
       CO2 is plant food? If only it were so simple
       Grain quality is decreased under high Co2 concentrations:

       Based on the modified physiology and biochemistry of wheat plants under CO2 enrichment, the concentration of total protein in grain was significantly decreased by 7.4% in the FACE treatment. The reduction in grain protein due to elevated CO2 is consistent with previous reports (Kimball et al. 2001; Taub et al. 2008; Wieser et al. 2008; Ho¨gy et al. 2009), resulting in potentially far-reaching consequences for the nutritional value and use by the processing industry........... ....Among the grain proteins, the N- and glutamine-rich gliadin fraction was significantly decreased under CO2 enrichment, thereby lowering the gluten concentration that is fundamental in determining physical properties of dough formation and product quality

87228. jyyh at 11:59 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       A complex subject, and good overview (with citations).
87229. muoncounter at 11:52 AM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       arch #43: "significant more (and more convincing) evidence that it does not." I suppose that depends on what it takes to convince. We're now far enough from the solar min to make some observations. From Mewaldt et al 2010: In the energy interval from ~70 to ~450 MeV nucleon^–1, near the peak in the near-Earth cosmic-ray spectrum, the measured intensities of major species from C to Fe were each 20%-26% greater in late 2009 than in the 1997-1998 minimum and previous solar minima of the space age (1957-1997) ... Cosmic-ray intensity variations at 1 AU are found to lag IMF variations by 2-3 solar rotations That rotation period is 27 1/4 days, as viewed from earth. So the maximum lag, if any, is less than 90 days. According to the model, these elevated GCR intensities should make more clouds. Do 2009-10 or 1997-98 appear to be cloud-cooled? From tamino's adjusted GISS temperature graph ("we remove the el Nino, volcanic, and annual-cycle signals we have what we’ve called the adjusted GISS data"), To summarize (with apologies to Sondheim), And where are the clouds? There ought to be clouds. Well, maybe next year.
87230. Marcus at 11:44 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       "Trials to ascertain the effect of lower CO2 levels see reduced growth, growth apparently almost ceasing around 180ppm, however these obviously have to be conducted in enclosures." Which is ultimately a straw-man anyway, given that the odds of us ever experiencing CO2 concentrations of less than 200ppm are absolutely zero. The fact is that changes in sowing times are a poor simulation of the kinds of conditions being predicted when atmospheric CO2 levels really reach 560ppm-as I've said many times before. As I recall, though, the seed yield increases under those conditions (Rain-fed, slightly warmer) were negligible (when standard errors are accounted for) compared with ambient CO2-& at a cost of reduced nitrogen uptake under those conditions. Of course, other results from FACE trials show that enriched CO2 conditions favor an increase in certain soil-borne pathogens, increase the competitiveness of weeds & make plants more susceptible to attack by insect pathogens. All of which suggest, as I've said before, that the "CO2 is plant food" meme is *dangerously* simplistic.
87231. arch stanton at 09:47 AM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       Okay ;-) There is evidence that GCRs can trigger particles that can act as cloud condensation nuclei. There is little evidence that this has any influence of our climate, and significant more (and more convincing) evidence that it does not. Better?
87232. Ken Lambert at 09:07 AM on 28 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       dana1981 Perhaps you could explain to the readers how an imbalance of 1.5W/sq.m at the surface becomes 0.9W/sq.m at TOA and still complies with the first law.
87233. KR at 08:49 AM on 28 April 2011
       CO2 effect is saturated
       Berényi - I will also note that incorrectly using a graph from Anderson 2004 does not invalidate either Griggs 2004 or Chen 2007 (referenced in the original post), which fully support Harries 2001. The changes in TOA spectra over the satellite era from increasing CO2 are detectable, as predicted by modeling, and indicate that CO2 is not saturated.
87234. KR at 08:44 AM on 28 April 2011
       CO2 effect is saturated
       Berényi - Several points from those two papers. - From Anderson 2004, final comments: "...there is an increase of greenhousegases from 1970 to 1996 that gives rise to recognizable bands in the observed spectrum." - Anderson makes no claims about invalidating Harries, and in fact notes/thanks him in the Acknowledgements. - Most importantly; Anderson's spectra are not corrected for global warming, to the equivalent black body temperatures. Anderson is showing the raw differences between the two satellite spectra with some fairly impressive corrections added. But this is not corrected for the equivalent black-body spectra (Brightness Temperature) as Harries did, and hence does not show what you claim it does. It would be stunning if there was no difference in IR spectra over 25 years given warming. But your superimposition of Harries black-body corrected spectra over raw differencing is invalid. The elephant has put on weight - but you can't compare that directly to a chart of how it's proportions have changed.
87235. johnd at 08:32 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       Martin at 04:22 AM, the FACE trials that concentrate on food crops best replicate real world conditions regarding pests and diseases in that they are conducted alongside control plots generally in zones where the crops that are being trialled are normally grown. Rainfall and temperatures are replicated by changing the time of sowing, or by conducting parallel trials of the same varieties in areas that are warmer and drier than the main trial site. Such areas are readily identified from historic records and may only be a couple of hundred km away. Trials to ascertain the effect of lower CO2 levels see reduced growth, growth apparently almost ceasing around 180ppm, however these obviously have to be conducted in enclosures. Commercial greenhouse growers do have some knowledge of these effects having noted different zones of growth depending on how even CO2 circulation is within the enclosed area, being quickly depleted in those areas least exposed to the extra CO2 introduced, and not able to be replenished as occurs in the open air, but sometimes due to unintended leaks of air from outside do illustrate side by side, how the various concentrations manifest themselves in varying degrees of growth. As far as optimal CO2 levels, commercial greenhouse growers where CO2 enrichment has been utilised for several decades, tomatoes being perhaps the main, but just one of the foods you may have been eating all those years, find the optimal level is about 1200ppm. Whether that is optimal for growth or optimal for economic returns I'm not sure. In commercial cropping, most fertilisers are applied at rates that find the best balance of offsetting the cost of applying the fertiliser against the anticipated increased returns it will provide, so it is almost always a commercial decision, based on the law of diminishing returns. However as far as absolute growth is concerned, application rates for many commonly applied fertilisers more than double the normal rates will still see some growth response over lower rates.
87236. Philippe Chantreau at 08:03 AM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       Actuall, Arch, there is really little evidence to support the hypothesis that GCR affect cloud cover. There is some evidence, but there is little of it and, so far, no confirmed physical process.
87237. Berényi Péter at 07:40 AM on 28 April 2011
       CO2 effect is saturated
       For your convenience I have merged Fig. 1. Harris 2001 into Fig. 8 (a) Anderson 2004. It is easier to compare them this way (click to enlarge). Between 1970 and 1996 atmospheric CO₂ concentration as measured at the Mauna Loa Observatory has increased from 325.68 ppmv to 362.35 ppmv.
87238. Bob Lacatena at 06:59 AM on 28 April 2011
       Clouds provide negative feedback
       154, RW1,

       ...there is really no physical or logical reason why the net cloud feedback would suddenly switch...

       But there is. You're just denying that it exists. Hint: Go to the top of this web page and actually read the post.
87239. Berényi Péter at 06:57 AM on 28 April 2011
       CO2 effect is saturated
       #152 KR at 00:37 AM on 28 April, 2011 But there is no uncertainty in the fact that CO2 is not saturated at current concentrations. Here is later study applying an improved algorithm. Journal of Quantitative Spectroscopy and Radiative Transfer Volume 85, Issues 3-4, 15 May 2004, Pages 367-383 doi:10.1016/S0022-4073(03)00232-2 Absolute, spectrally-resolved, thermal radiance: a benchmark for climate monitoring from space J. G. Anderson, J. A. Dykema, R. M. Goody, H. Hu & D. B. Kirk-Davidoff Compare it to the obsolete one referenced in the article above from Harries 2001 Anderson et al. say the best estimate is the red curve (dof-wtd cells). Pay careful attention to the differences. Measured CO₂ effect can be seen close to the left edge of both figures. The difference between the wavenumber 750-900 cm^-1 range and wavenumber 710 cm^-1 is about 1.5 K in both figures, but in the improved analysis it turns out only 0.4 K is due to decreased OLR intensity in the CO₂ wing, while there is a 1.1 K increase in the low frequency (most transparent) part of the atmospheric window. As surface temperature between 1970 and 1996 increased less than that (and temperature in the mid-troposphere even less), it can only mean photosphere height in this spectral range decreased during this period. It is consistent with balloon radiosonde data, which show decreasing atmospheric specific humidity above the 700 mbar level (while it was increasing closer to the surface). There is an even more striking difference between the two analyses above the O₃ absorption line, in the high frequency part of the atmospheric window. According to Anderson at al. brightness temperature anomaly here is 1-1.5 K less than at lower frequencies (while Harries puts them about to the same level). The same is true for the relative depths of the CO₂ and CH₄ notches. All this boils down to the conclusion that while the CO₂ effect may not be fully saturated at the wings, it is almost negligible compared to methane (which is not saturated) and is counteracted to a considerable degree by water vapor (negative feedback).
87240. John Bruno at 06:23 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       Great post! Iv'e been waiting to see a sophisticated treatment of this. As even the comments make clear, this is a complex issue as it involves not only the factors limiting plant productivity and biomass but also plant consumers and more broadly food webs. Community ecology is a messy business! One issue not really addressed by the post, although touched on in the comments, is how warming will increase plant pathogens and general rates of herbivory. Plenty of work supports the first prediction and the latter is a simple function of physiology: warming increases insect metabolism and thus metabolic demands. Plant photosynthesis also responses positively to increasing temperature, but at a slightly lower rate, eg, see this paper and this summary of it. The end effect, all things being equal and assuming nutrients and water are available, is more primary production and less plant biomass. Of course if you consider what limits insect (and other grazer) populations, things get a lot more complicated; it often isn't plant tissue but rather minerals, disease, weather, climate and predators. Martin #16, I personally don't believe it is possible to generalize like that (ie, is more or less CO2 "better" for all crops) but you can be sure a warmer world will have more plant disease and likely more plant consumption.
87241. scaddenp at 06:22 AM on 28 April 2011
       Models are unreliable
       There is a difference between "this is unexplained" and "there are multiple explanations and current data doesnt constrain them". "nothing we have comes close to explaining the three things" What??? I really dont get this. You invoke million year and 200 million year "cycles" which are controversial to call cycles. I dont actually see anything in any your points which challenge current climate science. There are multiple possible explanations, none applicable to current warming. And yes, perhaps we have missed something but the energy flow to produce current warming shouldnt be hard to miss. Meanwhile we have perfectly good physical theory which accounts for we see and ignoring that while looking for something fanciful seems like extremely poor risk management to me.
87242. jg at 06:13 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       Martin asks a good question. I think this post shows that any rapid change in CO2 is a disturbance that will have complex and numerous effects. Humans can disturb the CO2 level upward faster than natural changes can (barring rare events). I would like to add a question to Martin's: Are there any drawdowns of CO2 that are as fast as the anthropogenic increase? I can't think of a mechanism that would sustain a rapid reduction. I have to dig through my notes to find it, but I remember reading about a theory that the drawdown of CO2 leads to a state where forest die, which in turn reduces the rate that global forests sequester CO2, allowing atmospheric levels to rise. In other words, low CO2 invokes a reverse feedback effect. I'll hunt for that reference. jg
87243. arch stanton at 04:56 AM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       HR @ 27: The number of citations is an interesting metric. The AR4 cites Svensmark several times in their discussion about why the GCR hypothesis is not likely responsible for the observed climate change. Anyone refuting a paper should cite it. arch
87244. arch stanton at 04:23 AM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       Humanity Rules @25: Don’t quote me out of context. Why would you do such a thing? (Rhetorical question- just think about it). What I said was: “I admit that it is an interesting hypothesis, but only folks highly selectively biased by personal belief could possibly believe that galactic cosmic rays have a climate effect greater than that of the change we have seen in atmospheric CO2 levels. Little in the scientific literature supported it then and even less does now.” I never said there was little evidence to support the fact that CR may affect cloud cover. Indeed there is. What is lacking is substantial evidence that the changes in cloud cover are significant enough to affect climate to a degree greater than (anthropoid changes in) CO2 does. I thought this summary was a good one when it came out 2006 at the start of the CERN CLOUD experiments. I think it still is. HTH, arch
87245. Martin at 04:22 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       I'm not quite sure whether I have correctly understood your post. Have there been experiments which include changes in CO2, temperature, water, competing plants (weeds) and pests? Another question: If the effects of higher CO2 are on balance negative, would a lower CO2 be better? Are there any experiments from which one can conclude what an optimal CO2 level would be for the world's major crops?
87246. jg at 03:07 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       Excellent post! I would nit-pick at you choice of words in the paragraph: "Only recently have researchers begun to pull away from these controlled settings and turn their attention to outdoor experiments." I would say that the experiments aren't recent; rather, they were started some time ago but it takes several years before the results can be reported, and the results are recent. Back to the main idea, I've often replied to "CO2 is plant food" by saying "yes, where CO2 is a limiting nutrient" and these same people usually have irrigated and fertilized lawns and gardens but never thought of trying to add CO2. I also like to point out the tree-topped mountains where I live, and ask why do the trees grow up there and not on desert and chaparral? For the thinner air? Reading your post, I'm beginning to think my "where CO2 is limiting" response is too simple. Rising CO2 affects plant growth whether it is or isn't a limiting nutrient. thanks, jg
87247. muoncounter at 02:49 AM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       Going off-topic for a moment. Seems like we have bigger things to worry about than the 'ideologically motivated' demise of GCR/climate research. the House of Representatives proposed budget includes no replacement for the NOAA polar orbiting weather satellites.
87248. dhogaza at 02:28 AM on 28 April 2011
       Cosmic ray contribution to global warming negligible
       "Those that seem to want to kill the CGR/climate connection are as ideologically motivated as the worst sceptics" Yeah, that's why we insist that the GCR/climate connection violates the 2nd law of thermodynamics, just like certain skeptics insist that radiative transfer theory does. /snark
87249. Chris G at 02:24 AM on 28 April 2011
       CO2 is plant food? If only it were so simple
       This is a good article. I would come at it from a different angle. Greenhouse studies are not a good indication of a real world scenario; most people agree on this. FACE studies are a bit better, and show less improvement from CO2 enhancements than greenhouse studies. But if you want a more accurate reflection (although still not perfect) of how CO2 increases will affect crop plants in the real world, you have to account for the shifting climate zones. For instance, you try growing crop varieties commonly used in Missouri, but try to grow them in central Texas, adding all the CO2 you want. Anyone want to bet on whether the results will continue the downward trend on yield improvements seen in moving from greenhouse to FACE?
87250. dana1981 at 01:51 AM on 28 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       KL #94: top of the atmosphere energy imbalance is not the same as radiative forcing at the surface.

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