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Comments 88151 to 88200:

  1. More Carbon Dioxide is not necessarily good for plants.
    Take note readers, Villabolo is changing his/her post in the face of criticism. Note too that that is something "skeptics" rarely, if ever, do. So for someone her to make the comment that Villabolo has "descended into rampant pro-AGW defensive posture" is simply false. I would also contend that it is an ad hominem and therefore violates the house rules.
  2. More Carbon Dioxide is not necessarily good for plants.
    Luke @65, May I point out the irony of you lecturing Villabolo on being more thorough when you did not provide a single source from the reputable literature to support your assertions. Not one. A recent pamphlet prepared by the Royal Canadian Geographic Society (based on findings in the scientific literature) has this to say about conditions on the prairies, Canada's bread basket: "In fact given the IPO change - expect a cracker decade for Australian rainfall ahead - more Las Ninas and stronger ones. Boom time for producers?" And what do you base the above statement on? And what about this one: "If as some suggest the Pacific becomes a more El Nino like mean state and the world warms - the thermocline the Canadian/US wheat belt moves north, temperature nearer C3 optima for wheat, higher rainfall and more CO2" And a note of caution, Oz is not the centre of the universe when it comes to providing grains. I do agree with you that this is complex, and that the impacts may not all be bad, at least up to a point. Fortunately, those darn scientists (bless them) have been working on this for a long time, and the over whelming evidence is that a little warming (typically <2 C may benefit crops), but that beyond that things really start to tank. Listen to this (also click on "wheat" and "maize". Note that they are talking about local change sin temperature, not global, and that mean summer temperatures are projected to increase by 3 to 4 C. And if you doubt that droughts have a negligible impact on crops, then think carefully what happened in Russia last year, in 2007 in Europe in 2003, on the Canadian prairies in 2002. And there are many more examples. I have said this before, all the CO2 in the world is not going to help is the soil moisture drops below the permanent wilting point and under heat stress. Also, as others have pointed out, plants may be able to move, but people cannot necessarily, and then one is assuming that there is viable land to move to-- that last point should be obvious to someone living in a place like Australia, well at least it is to adelady. Oh, and what Marcus just said @70.
  3. Clouds provide negative feedback
    Sphaerica (RE: 25), "They are not "greatly amplifying" small temperature changes. They do have some impact, but there's no reason to exaggerate things with "great" and "small" to try to score points." OK, fair enough. The point is the AGW theory claims the net effect of clouds is to amplify warming rather than attenuate warming. The mechanisms available for altering climate are: * Solar insolation (barely changes) * Orbital forcings (changes predictably on huge time scales) * CO2 (changes on any of 3 time scales, geologic=very slow, natural feedback=medium, anthropogenic=very fast * H2O (changes relatively quickly in direct proportion to temperature, and so it is the primary amplifier in power, but not a controller since it exerts no independent control of its own) * Albedo (can change relatively quickly, or slowly, but almost always as a response to other factors) * Clouds (change almost instantaneously, and positive/negative effects are arguable, but relatively inconsequential compared to the bigger factors)." If the Sun is the source energy and ultimately heat in the system, and if H2O changes so quickly in response to temperature - specifically warming, and water is the primary amplifier but not a controller, what is the controller? If the Sun is the only real heat source, and water concentration (the primary amplifier) is driven by heat from the Sun, the primary controller would need to modulate the amount of the Sun's energy allowed to enter the system. Clouds definitely do this since they make up about 3/4ths of the albedo and are constantly changing spatially and in time - all the time. Is it also a coincidence that clouds are made up of H2O and water vapor concentrations drive cloud formation? It is also another coincidence that water vapor is removed from the atmosphere from precipitation that emanates from clouds? If the net cloud feedback was positive in conjunction with positive water vapor feedback, what would prevent the temperature from rising significantly higher and higher from even just a few days or few weeks of abnormally warm weather? Yet this never happens - abnormally warm weather periods end and normal or colder weather inevitably commences. This is probably because the forces that drive evaporation/water vapor are not as strong as the combined forces of clouds and precipitation. This is fundamentally why net positive cloud feedback is so illogical. "* Land mass dispositions (which greatly affect albedo and the results of orbital forcings, but which only themselves vary on massively long timescales) Which is primary? At the onset and termination of glacial periods, the orbital forcings, but only through an albedo feedback, and in conjunction with a strong CO2 feedback, which in turn operates in conjunction with the strong H2O feedback. Outside of those periods of orbital forcings, under natural conditions, CO2 is the main long term driver, amplified by albedo, cloud and H2O feedbacks. During anthropogenic pollution, CO2 is the only control mechanism that operates on the time scales that we are witnessing, again amplified by all of the usual feedbacks." But clouds operate on even shorter time scales than CO2, and temperature fluctuations occur on much shorter time scales too. Let's not forget that the surface of the Earth is over 2/3rds water. The cycle of water -> water vapor -> clouds -> precipitation -> water is enormous.
  4. More Carbon Dioxide is not necessarily good for plants.
    The point remains, Luke, that claims of "CO2 being plant-food" are incredibly simplistic & inaccurate, yet the Contrarians want to take a chance with our agricultural future based *entirely* on this simplistic attitude-with what amounts to a grand experiment on the only atmosphere we have.
  5. More Carbon Dioxide is not necessarily good for plants.
    "You've descended into rampant pro-AGW defensive posture" Sorry Luke, but that's exactly the kind of language I've come to expect from someone who has descended into a "rampant pro-denialist defensive posture". If you want to be taken seriously, try removing some of the invective first.
  6. More Carbon Dioxide is not necessarily good for plants.
    I think (not that my opinion should count for much) the original and the edited version are both fine. You can't get too nuanced in a basic version of this material without loosing the audience. FWIW, I found the article referenced by my first link. Hansen et al, 2006 Relevant information is in and around Figure 6.
  7. More Carbon Dioxide is not necessarily good for plants.
    @51 Chris G: Not a problem, Chris. I'm just a non scientifically trained enthusiast. I change point #4 in my post to the following below. Tell me what you think. 4. The worse problem by far is that increasing CO2 will increase temperatures throughout the Earth; making deserts and other types of dry land grow. While deserts increase in size, other eco-zones, whether tropical, forest or grassland will try to migrate towards the poles. However, soil conditions will not necessarily favor their growth even if the temperatures are optimum. There will be some other minor changes throughout the post.
  8. More Carbon Dioxide is not necessarily good for plants.
    villabolo #57, I'm not trying to take anything away from what you said, and I am sure that you in particular understand shifting climate zones. I'm trying to add to what you said for anyone interested in further reading, and also somewhat responding to the mistaken meme that our agricultural systems can adapt and continue to feed us all without substantial cost. Adelady, Yes, that was kind of my point. There is no land on which to develop agriculture south of, say, Victoria. If the climate zones shift 400-500 km southward, agriculture is over in that region.
  9. More Carbon Dioxide is not necessarily good for plants.
    villabolo You've descended into rampant pro-AGW defensive posture Woodland thickening across savanna biomes - apart from frozen area is about 14% of the world's area - thickening or shrub encroachment is happening across Australia, the southern USA and southern Africa. Less fire is why (with CO2 also assisting C3 trees and shrubs over C4s grasses. That's less fire and more tree/shrub thickening and so less grass means less fire. In terms of the latest floods - what rampant silliness compared to facts - in fact the land surface condition away from water courses in very good. No massive erosion at all. As for low and zero tillage at odds with mechanised agriculture - ye gods man ! - do you ever get out and see what is happening around Australia. Major transformations in last 20 years. Minimum tillage is a first world revolution ! In fact machinery especially designed to cope with minimum tillage. Tell Monsanto there is no market for minimum tillage (they'll ROFL).Away from broad scale cropping sugar cane industry almost now universally trash blankets after a green harvest - not burns - soil surface always well covered. Yes Australian floods may have taken out some production temporarily - but what like they've done for 100s of years with La Nina by cool IPO combination ! Come on AGW influence ?? .... in fact Australia is set for a record cotton harvest. Cotton Australia estimates the crop will top four million bales this year, smashing the previous record. But floods also fill dams and replenish aquifers - and thank heavens ! "Winners and losers" means this - ENSO means rainfall is already not uniformly distributed. If as some suggest the Pacific becomes a more El Nino like mean state and the world warms - the thermocline the Canadian/US wheat belt moves north, temperature nearer C3 optima for wheat, higher rainfall and more CO2 - perhaps the CIA already know something we don't ! :-) (in this scenario eastern Australia gets the drought end of the oscillation). In fact given the IPO change - expect a cracker decade for Australian rainfall ahead - more Las Ninas and stronger ones. Boom time for producers? And of course with increased CO2 we haven't let the conventional breeders and genetic engineers loose yet? I would assume plenty of potential based on track record. My point is this issue is very complex and a universal assumption of worse on food security is not a well thought through response. If you are going to the do the CO2 fertilisation review - need to be much more thorough.
  10. More Carbon Dioxide is not necessarily good for plants.
    "...look at where major agricultural areas are now, there are a fair number which will not be readily migrated poleward." That polewards movement notion is very much a northern hemisphere idea. Look at a map and draw a line around the globe. Start at Capetown, then across to Perth, Adelaide, Hobart, Dunedin and finish up at Montevideo or Buenos Aires. Apart from that sharply narrowing tongue of southernmost South America, there _is_ no poleward land to replace any of those productive areas of South Africa, Australia, New Zealand and Argentina.
  11. A Flanner in the Works for Snow and Ice
    Ken Lambert @81, if your read the OP about Flanner, you will sea that, "A new paper by Flanner et al in Nature Geosciences tries to estimate the so called ‘cryosphere albedo feedback’ since 1979." (My emphasis.) It's right there in the first sentence. Therefore if we want to do a plausibility check on Flanner (which is technically what this exercise is), we need to compare the change in summer incoming energy flux from 1979 to 2008. That is, by a very conservative approximation, 1.35*10^21 Joules. If we extent the comparison period to 2010, the change is 1.51*10^21 Joules, again very conservatively estimated. What is more, even the original post by Sphaerica from which this debate sprung is clearly considering the change in arctic forcing between the 1978-2000 average and the present, ie, effectively 2010. So why you should suddenly be interested in the mean annual change in the change in the ice albedo forcing during the Arctic summer rather than, as we have been discussing, the mean annual change in the ice albedo forcing during the arctic summer is almost entirely mystifying. It does not even make much sense as mere passing curiousity. After all, as revealed by Piomas, the total ice volume has not been recovering each winter. The Ice does not need to melt back from the March of 1979 position each year. Therefore the change of the change is not a predictor of how extensive the ice melt will be each summer. This is a genuine feedback situation, with each summers melt making each successive summer's melt easier, and likely to be more extensive. (Note, likely, not guaranteed - there are other factors here.)
  12. More Carbon Dioxide is not necessarily good for plants.
    1. Plants will need extra water. Where will it come from? Rainwater is not sufficient for current agriculture and aquifers are running dry throughout the Earth. Actually some plants, or should I say trees do better with more CO2. It has been proposed to reforest the Sahara which is possible because of increased CO2. The key attribute certain trees have is that CO2 causes the pores that transpire water to close, reducing water requirements. A side effect of this reforestation is to consume the so called AGG solving another problem.
  13. Clouds provide negative feedback
    24, RW1,
    If clouds... are instead acting to greatly amplify relatively small temperature changes...
    They are not "greatly amplifying" small temperature changes. They do have some impact, but there's no reason to exaggerate things with "great" and "small" to try to score points.
    ...what is the primary mechanism controlling the energy balance of the planet?
    I'm not sure why there must be a primary mechanism, and because there are multiple mechanisms, they all interact, they are all difficult to "force," and it becomes a question of semantics in arguing over which is "primary." The mechanisms available for altering climate are:
    • Solar insolation (barely changes)
    • Orbital forcings (changes predictably on huge time scales)
    • CO2 (changes on any of 3 time scales, geologic=very slow, natural feedback=medium, anthropogenic=very fast
    • H2O (changes relatively quickly in direct proportion to temperature, and so it is the primary amplifier in power, but not a controller since it exerts no independent control of its own)
    • Albedo (can change relatively quickly, or slowly, but almost always as a response to other factors)
    • Clouds (change almost instantaneously, and positive/negative effects are arguable, but relatively inconsequential compared to the bigger factors).
    • Land mass dispositions (which greatly affect albedo and the results of orbital forcings, but which only themselves vary on massively long timescales)
    Which is primary? At the onset and termination of glacial periods, the orbital forcings, but only through an albedo feedback, and in conjunction with a strong CO2 feedback, which in turn operates in conjunction with the strong H2O feedback. Outside of those periods of orbital forcings, under natural conditions, CO2 is the main long term driver, amplified by albedo, cloud and H2O feedbacks. During anthropogenic pollution, CO2 is the only control mechanism that operates on the time scales that we are witnessing, again amplified by all of the usual feedbacks.
  14. A Flanner in the Works for Snow and Ice
    Tom Curtis #78 - #1 "I have then multiplied by the total area.' Yes, but that is the total area lost relative to 1979. You need to look at the total area in 2010, relative to the total area in 2009 to ascertain the ice lost and the *annual* heat gain. And 2009 relative to 2008, 2008 to 2007 and so on...
  15. More Carbon Dioxide is not necessarily good for plants.
    Another thing which isn't considered by so-called "skeptics" is what impact increased CO2, combined with associated changes in temperature & moisture, will have at the root-soil interphase-especially as regards the incidence of root-borne diseases. Its not an area that's been researched at length, but what little info I've seen suggests that disease incidence will become worse under AGW conditions.
  16. More Carbon Dioxide is not necessarily good for plants.
    @ Ian Forrester. Yes, I'd read that very recently myself. Kind of puts the whole "CO2 is plant-food" argument into perspective!
  17. Ian Forrester at 12:29 PM on 18 April 2011
    More Carbon Dioxide is not necessarily good for plants.
    If we want to see the effects of higher CO2 concentrations and hence higher temperatures on plant growth we should look and see what is happening at the molecular level. All of plant metabolism is controlled by various enzymes, literally thousands in any one organism. The key step in plant growth is the fixation of CO2 via the enzyme Rubisco (Ribulose-1,5-bisphosphate carboxylase oxygenase). Here are some recent findings on the biochemistry of Rubisco. The older studies showed that the enzymatic activity of isolated Rubisco (the enzyme responsible for the fixing of CO2 into organic metabolites) was increased at higher temperatures and higher CO2 concentrations. This allowed deniers to argue that this would be good for agriculture since it would allow for higher yields (forget about water and available nitrogen for now). However, there were always problems in getting reproducible levels of Rubisco activity (preparations had to be aged and/or treated to give maximum activity). Later research has shown that there is another layer of regulation affecting Rubisco activity (as is common with many enzyme system). A new enzyme, Rubisco activase, was found to be responsible for converting “inactive” to “active” Rubisco. And, surprise surprise, this new enzyme was found to be inhibited by higher temperatures and also inhibited by higher CO2 concentrations. This finding is probably responsible for the contradictory results found in experiments where varying temperatures and CO2 concentrations on plant growth have been conducted. http://www.ars.usda.gov/is/AR/archive/nov02/plant1102.htm http://www.pnas.org/cgi/content/abstract/97/24/13430
    Moderator Response: [DB] Hyperlinked URLs.
  18. More Carbon Dioxide is not necessarily good for plants.
    So we have at least one FACE trial that shows that Rice grown under conditions of increased CO2 will have a decrease of N, on average, of 14%, P by 5%, Fe by 17% & Zn by 28% (according to Seneweera and Conroy, 1997). Ziska et al (1997) have reported a drop in protein content in crop plants when you combined increased temperature & CO2. Although I'm struggling to find a peer-reviewed reference, there is a general belief that warming will lead to a shortening of crop growing cycles, thus resulting in reduced crop productivity. Also, I've read that increased CO2 tends to boost *vegetative* growth at the expense of *reproductive* growth. As was pointed out above, as we tend to eat the reproductive material of most crop plants (like corn, rice & wheat), this is *not* a good thing.
  19. More Carbon Dioxide is not necessarily good for plants.
    I want to be clear that Berényi linked to the original graph and publication in the image hyperlink. However, the graph as presented here was Photoshopped to remove 100 years of predictions that completely contradicted how he presented the information. I consider that deliberate distortion. The graph itself (unnumbered in the Hadley PDF) is something I couldn't find discussion of in that document - I don't know if it's talking about forests, all vegetation, what the sources are, etc., so I don't consider it a great reference in the first place. But much much worse when clipped and distorted.
  20. A Flanner in the Works for Snow and Ice
    Ken Lambert @79, no I am not - and that is a ridiculous accusation. I have taken a conservative estimate of the difference of ice coverage between circa 1979 and circa 2010. I have taken a conservative estimate of the energy flux in that area measured in Watts per square meter. I have multiplied the energy gain measured in Watts per square meter (= Joules per second per square meter) and multiplied it by 60 (60 seconds in a minute), then by 60 again (60 minutes in an hour), then by 24 (24 hours in a day) and then by 90 (three months at 30 days per month). I have then multiplied by the total area. Now you suggest that 60*60*24*90 Watts is "30 to 32 years of heat gain". Absurd!
  21. More Carbon Dioxide is not necessarily good for plants.
    @51 Chris G: "If you pull out a globe, or open Google Earth, and look at where major agricultural areas are now, there are a fair number which will not be readily migrated poleward. Geographic features and political boundaries will make it so that this problem is much more difficult than the base cost of relocating farmers and the cities they are based out of." Yes Chris, I am very much aware of the constraints of migration. Particularly agriculture. However, I was referring to biotopes in general. Canadian boreal forests have soil that is thin, nutrient poor and acidic. Then there's the Siberian permadefrost which will basically become muck, swamps and a million methane bubbling lakes. I believe I can resolve this issue by adding one word to point #4. That word is "mostly". "While deserts increase in size, other eco-zones, whether tropical, forest or grassland will [mostly] migrate towards the poles; shrinking in land area as they do.
  22. A Flanner in the Works for Snow and Ice
    Tom Curtis #77, #78 "That is only 3 to 4 times Trenberth's figure, but Trenberth did not calculate the average amount of energy absorbed in annual (not seasonal) ice melt over 1979, but only over 2004 to mid 2008, over which period there was an average of around 1.8 million square kilometers of additional ice lost relative to 1979." That is your error. You are taking the ice melt area 'relative to 1979' which means that you have 30 or 32 years of heat gain (energy) in your calculated number of Joules. A Watt is a Joule/sec so if you use forcings (energy flux) in Watts you must introduce the unit of time. ie Joules/year - which is what Dr Trenberth is calculating.
  23. More Carbon Dioxide is not necessarily good for plants.
    "KR at 10:06 AM on 18 April, 2011, I am constantly perplexed by claims such as yours that many charts are doctored or not properly referenced, when it is a simple matter of clicking on such charts to go to the original source." Oh, what a surprise-members of the Denial-o-sphere coming to each other's defense. The issue here, John D, is *why* do people like BP & Gilles always choose to clip or modify the charts they post, in such a way as to give a false impression of what those charts are actually telling us? You, too, have a habit of reporting only *half* of a story-like the story regarding your beloved FACE trials. The FACE trials really don't properly mimic what a CO2-enriched world would look like. Even the Horsham Trial only looks at current conditions for rain-fed vs irrigated agriculture. Yet even those people running the Horsham Trial have conceded that increased CO2 leads to a decrease in nitrogen uptake by the plants-& that any gains in biomass are short-term, with acclimation setting in within 2-3 years. Yet you only mention the rather modest "benefits" of the FACE trials-why is that?
  24. More Carbon Dioxide is not necessarily good for plants.
    @44 LukeW: "This post on CO2 is dreadfully simplistic and naive." Simplistic yes. That's what you get with a basic level rebuttal. Naive, I think not. In the Australian context of savanna woodlands increased vegetation in terms of trees will decrease not increase fire. Grass is what makes fire carry in the world's vast area of savanna biomes. "Most detailed crop physiology modellers will now take CO2 fertilisation into account when simulating crop growth. If there is enough water and nutrients growth will be enhanced. At the levels of CO2 enhancement practically experienced in the field is CO2 really having any impact of yield quality?" Please see the video (1:58; also, focus on 2:21) for a global perspective. That is observation as opposed to modeling. "At a whole landscape scale increased CO2 will improve transpiration efficiency and greater water runoff will result." Since I try to be as thorough and detailed as possible, you some of your statements and questions have already been covered in previous posts. As far as water depletion, irrespective of the benefits of transpiration, is concerned; I responded to that in the post right before yours (#43). I responded to the issue in the context of mechanized agriculture. Please refer to the second to last paragraph in that post. "Climate change will have winners and losers. If North America became warmer and wetter - their wheat yields would be boosted considerably, especially with some CO2 turbo-charging. As for more intense rainfall causing greater loss of soils and nutrients - I wonder - there is this thing called soil conservation - contour banks, minimum tillage or zero tillage. Great advances have been made in these areas over the last 40 years." "Winners and losers." Are you referring to plants in general or mankind in a rapidly changing world with famine; infrastructure damage; economic collapse and mass migration? Did I forget wars? As far as advantages in soil conservation, three points can be brought up. First; how much time and extra resources will we have to adapt with? How much time to adapt to worsening conditions for crops and socio-economic situations? IMO, expect serious trouble beginning this decade and escalating from there on. Second; overwhelming flooding like Pakistan and Australia will overwhelm the positive effects of soil conservation. Pakistan, for example, was so inundated over 20% of its landscape that some farmers could not even distinguish their former land from the rest of the terrain. That was due to the massive floods changing the landscape altogether. Third; low and zero tillage are at odds with mechanized agriculture, as far as I know. "What could have been mentioned at the other end is that CO2 can increase frost sensitivity (deniers would chip in here and exclaim it will never frost again)." That should be mentioned in a more advanced post. It is simply too much detail for the basic level reader to digest. It's best not to overload them with too much information. I feel I've already done that to a certain extent. "Anyway the case for winners and losers needs to be made. At nation state level, land use, biome, and ecological patch level. The article here is far too simplistic." The summation above has been covered in the previous statements IMO we will need a drastically different civilization to adapt to CAGW. A network of self-reliant villages, numbering no more than 500 persons each; is what I envision. But that's a different story.
  25. Daniel Bailey at 11:19 AM on 18 April 2011
    More Carbon Dioxide is not necessarily good for plants.
    @ Albatross and KR: 'Tis a Travesty the Tricks employed by the Deny-O-Sphere to Hide the Decline...
  26. The e-mail 'scandal' travesty in misquoting Trenberth on
    Alec Cowan #133 Alec, stop being coy and tell us all what is wrong with the K&D paper.
  27. More Carbon Dioxide is not necessarily good for plants.
    May I second Adelady? Nature Does Not Care in the slightest about your survival, or any other species survival for that matter. If you survive - great. If you don't - equally great. Organisms comfortably adapted to a particular set of surprisingly stable conditions poke those conditions with a sharp stick at their peril. (How this can be done in the name of 'Conservatism' is beyond my comprehension - and parody!) Liebig's law puts the lie to the idiot 'CO2 is plant food - therefore more must be good' mantra full stop. You only have to demonstrate any substantial exception to such a glib fallacy in order to disprove it. If the initial meme is inane quibbling that the anti-meme is insufficiently nuanced is just captiousness. You can get too much of a good thing; quibbling about the complex (indeed, Chaotic) boundary of this 'too much' as if this somehow invalidates the general principle is pointless at best. 'Yellow doesn't exist because you can't define the point in the spectrum at which it becomes orange' is not a valid argument.
  28. More Carbon Dioxide is not necessarily good for plants.
    KR at 10:06 AM on 18 April, 2011, I am constantly perplexed by claims such as yours that many charts are doctored or not properly referenced, when it is a simple matter of clicking on such charts to go to the original source. I do it as a matter of course. If I can do it, how come others cannot. What is the problem, lack of research skills or what?
  29. More Carbon Dioxide is not necessarily good for plants.
    I was thinking there are at least two ways of thinking of this issue. In the post above, mostly the discussion is about how plants respond to changing conditions. The other way is to think of it as where conditions exist. Expanding on item #4: Poleward movement of terrestrial surface isotherms is expected to average between 3.8 km and 5.9 km per year if current trends of global climate change continue (1). If you pull out a globe, or open Google Earth, and look at where major agricultural areas are now, there are a fair number which will not be readily migrated poleward. Geographic features and political boundaries will make it so that this problem is much more difficult than the base cost of relocating farmers and the cities they are based out of.
  30. More Carbon Dioxide is not necessarily good for plants.
    villabolo at 09:45 AM, just FYI the other thread was available from the time you first made it. I noticed it then,but didn't have time to respond, only earlier seeking it out again to follow up. Perhaps you should have it removed entirely as it only serves to clutter and confuse. The only link you provided is to an abstract regarding, IIRC, a laboratory study. I believe I have read some of that paper somewhere previously. However, given we are talking about the real physical world, laboratory studies are of limited value. At the very least it should be the results of FACE trials that you are referencing as these provide the closest data simulating future real world conditions. But more important than that they are the only means by which modeling based on laboratory experiments are able to be validated. It appears that the FACE trials indicate that the results produced under real world conditions differ from the expectations of the modeled laboratory projections, requiring the models to be retrained against the results obtained under FACE conditions.
  31. More Carbon Dioxide is not necessarily good for plants.
    KR, Smile. Good sleuthing. There goes BP'S already troubled credibility. I hope that people following this thread note that this is the kind of thing that climate scientists and others who understand AGW to be a concern repeatedly come up against. The 'skeptics' demonstrate highly questionable ethics, yet repeatedly falsely accuse others of same. Again, this is not so much about where things stand now, but where we are headed if we continue on this path consumption.
  32. Clouds provide negative feedback
    Sphaerica (RE: 22), "1) Present your own model more clearly. You skip steps, make leaps, then get frustrated when other people can't figure out where you get your numbers from. You even claimed that you didn't have a model!" What specifically do you want me to explain? I agree with the moderator that a lot of this has been covered in previous discussions, but if you ask any direct question, I'll do my best to answer it. At any rate, I'd like to get back on topic with a question: If clouds are not the primary mechanism modulating the energy balance, and are instead acting to greatly amplify relatively small temperature changes, then what is the primary mechanism controlling the energy balance of the planet?
  33. Clouds provide negative feedback
    As far as I can see RW1 believes that you can infer feedback relationships from the Trenberth state diagram (ie the comments about gain) and then use these no.s to project what the diagram would look like for say doubled CO2. When the no.s dont accord with those calculated properly, then RW1 claims physics is wrong.
  34. More Carbon Dioxide is not necessarily good for plants.
    Moderators - What are the ethics of a carefully clipped chart (pretty obviously edited) without attribution?
    Moderator Response:

    [DB] Given that less than 10% of all readers ever click on an obviously provided link, when said hyperlink is incorporated into an expandable thumbnail (Admission: I hyperlink scaled thumbnails for brevity sake; but I do not only present PART of the original image) with the only way of knowing it IS hyperlinked is to mouse over it/move the cursor over it...you tell me.

    Not warning the reader that the enclosed graphic is an enlarged, windowed version of a much larger graphic certainly opens up the reader to the possibility of taking the totality of the graph out of its intended context.

    In like fashion, it certainly opens up the poster of the questionably presented graphic to many, many questions...

  35. More Carbon Dioxide is not necessarily good for plants.
    Berényi Péter - That's a fascinating chart, Berényi. Why did you clip it? This is from a set of Hadley Center forest predictions, discussing climate change effects on forests. Unfortunately, there is no discussion of that chart in the PDF. One interesting factoid from that PDF - during the 2003 heat wave in Europe, crop productivity dropped 30%. Climate change doesn't seem to be good for crops...
  36. More Carbon Dioxide is not necessarily good for plants.
    @41 Albatross: "One of my main concerns about this post is that there was not meat in terms of referencing the scientific literature-- but some mistakenly take that to mean that such support is missing in the literature." Albatross, John C previously stated, in response to someone with your own concerns on references, that it was not necessary for a Basic Level post to provide such references. The articles cited in the illustrations do provide such sources. In any case, I'll be adding extra primary source references as time allows; but there is no need to elaborate in the main text due to its basic level.
  37. More Carbon Dioxide is not necessarily good for plants.
    @39 Johnd: "villabolo at 06:59 AM, strange you didn't notice the other thread as you have 3 separate posts in it." I did post on what I assumed was a blog post that had not been officially turned in a post for public view. As I said, this is the first post I noticed today, when I went to home page. I assumed that anything on this post would supersede any previous posts. Sorry for any misunderstandings. As for declining nutrition in wheat, mentioned in my rebuttal above, I provided a link. As to other comments on nutritional deficiencies due to mass produced agriculture (Non CO2 related), that was an off topic comment in response to the claim that FF based agriculture is "advanced". I'd rather leave that particular issue at that. Right now I'm backed up with two other responses as well as personal chores, so I can't respond to every question; particularly if they're not directly in reference to CO2 issues.
  38. A Flanner in the Works for Snow and Ice
    Ken Lambert @77:
    You say: "Therefore there is need to divide the 1.51*10^21 Joules by 32. That is the additional amount of energy each summer that would not have been absorbed except for the reduced sea ice area." That is precisely my point.
    Sorry, that was a typo. I intended to write, "Therefore there is no need to divide the 1.51*10^21 Joules by 32."
  39. A Flanner in the Works for Snow and Ice
    Ken Lambert @76, if the additional melt had proceeded smoothly over the years (which is not true), then the arctic ocean would have absorbed 4.7*10^19 Joules more in the summer of 80 than in the summer of 79; and 9.4 more Joules in the summer of 81 than in the summer of 79, and so on. However, in the summer of 2010 it absorbed more than 1.51*10^21 joules more than it absorbed in the summer of 79. If you were to calculate the average additional energy flux in the years between 1979 and 2010, the figure would be 7.55*10^20 assuming (incorrectly) an even progression) or perhaps half that given that the loss of summer sea ice extent between the early 1980's and 2006 was only about 1 million square kilometers. That is only 3 to 4 times Trenberth's figure, but Trenberth did not calculate the average amount of energy absorbed in annual (not seasonal) ice melt over 1979, but only over 2004 to mid 2008, over which period there was an average of around 1.8 million square kilometers of additional ice lost relative to 1979. Hence the additional amount of energy absorbed in that period is conservatively estimated as 1.8/2*1.51*10^21 = 1.359*10^21. As it happens, Flanner did his calculations on the average over the same period, so I should probably accept 1.35*10^21 as my conservative estimate rather than the figure I have been using which includes an additional two seasons of extreme ice melt.
  40. The e-mail 'scandal' travesty in misquoting Trenberth on
    @Ken #131 I forgot. Why have you supposed that the figure in #128 was the only one? Did you want that a group of teenagers evaluated the whole planet? The whole oceans were covered by different groups. Those teenagers understood it, why don't you? There is also another exercise covering different months of a year. Every slice had its own tremendous variability and you can see that in Figure 1 and in the Argo site how all of them amount to a variable total. That is what I'm asking you to comment from figure 1 and by those means that you show a comprehension on the subject.
  41. The e-mail 'scandal' travesty in misquoting Trenberth on
    @Ken #131 You're just repeating yourself, Ken. Why don't you quote exactly every part of Knox & Douglas where they state clearly that the ocean layer is other than 0-700 metres regarding figure 1 and their calculations using those 4 methods? Do that and we'll continue to talk because it looks like you "want" for it to be "the oceans". It looks to me like you see Ocean Heat Content and a flat or slightly negative trend line together and feel a heartbeat rush "That's it!". Read it again, carefully. Then we can move to the others studies and later come back to the cooling periods -the real ones-. That's where the travesty is. Should I conclude that you see Knox & Douglas' figure 1 and have nothing to comment?
  42. Solar Hockey Stick
    @Berényi Péter #75 It looks from your last graphic that UV-A radiation doesn't reach farther than blue light does. It looks like your UV heating is not much different of Blue Light heating. Reading the last figure we got some 1.3 x 10-4 cm-1 for blue light so we keep some 99.987% of light intensity once we penetrate one centimetre in the water -fresh, crystal clean water-. Some 87.8% of this blue light reaches 10 metres deep. Some 27% reaches 100 metres and only 2% reaches 300 metres. But we know we are not talking of distilled crystal clear water but some water with one ion of an heterogeneous kind for each 50 water molecules. Where is the information about how different wavelengths do in filtered sea water? Besides, does somebody remember having sailed far from the shore an having seen clearly the silhouette of other ships' hulls underwater. Sea water is pretty cloudy as it's full with life and every kind of particles. So almost nothing of blue light reaches 100 metres, nor UV-A does, what begs the question, Berényi Péter, what are you up to? Why are you telling us "this kind of radiation can penetrate into the ocean (down to several hundred meters) and deposits its energy there as heat"? Don't you realize most of the energy got converted to heat in a few dozen of meters and almost nothing goes deeper that 100 metres? Why do you talk as if a mermaid go several hundred metres down and lay an egg, and egg containing a secret? Why are you saying that a thousandth of the energy of a band that accounts for 2% of total radiation is a better measurement of what? Didn't you realize that your penultimate graphic tells that 60% of the radiation in your precious UV-A band doesn't even reach the surface?
  43. More Carbon Dioxide is not necessarily good for plants.
    This post on CO2 is dreadfully simplistic and naive. In the Australian context of savanna woodlands increased vegetation in terms of trees will decrease not increase fire. Grass is what makes fire carry in the world's vast area of savanna biomes. Most detailed crop physiology modellers will now take CO2 fertilisation into account when simulating crop growth. If there is enough water and nutrients growth will be enhanced. At the levels of CO2 enhancement practically experienced in the field is CO2 really having any impact of yield quality? At a whole landscape scale increased CO2 will improve transpiration efficiency and greater water runoff will result. Climate change will have winners and losers. If North America became warmer and wetter - their wheat yields would be boosted considerably, especially with some CO2 turbo-charging. As for more intense rainfall causing greater loss of soils and nutrients - I wonder - there is this thing called soil conservation - contour banks, minimum tillage or zero tillage. Great advances have been made in these areas over the last 40 years. What could have been mentioned at the other end is that CO2 can increase frost sensitivity (deniers would chip in here and exclaim it will never frost again). Anyway the case for winners and losers needs to be made. At nation state level, land use, biome, and ecological patch level. The article here is far too simplistic.
  44. More Carbon Dioxide is not necessarily good for plants.
    @24 Steve L: "This is an interesting topic. I get the feeling that several aspects may have been glossed over (as necessary for a blog post) -- one of these is the conclusion that more water will be necessary for plants in a higher CO2 world. Because the stomata won't need to be open so long (due to the higher CO2 availability), there will be less evapotranspiration per carbon molecule fixed. SteveL; It's refreshing to have a meaningful and rational question to respond to. No, it's not so much glossing over as it is keeping the post both on a basic level as well as brief (You can see how long it already is). However, to answer your question from a non-scientist's view, let me make some inspired attempts. Even if plants should become more efficient in water usage they are still likely to require more water. Perhaps in lesser proportion compared to other factors but more nonetheless. Likely to be of more importance is the increase in soil evaporation. This would effect agriculture due to the soil being exposed. Also when the temperature gets too hot for the plant's basic metabolism, aquifer fed sprinklers would have to be used to cool them down. Aquifers are getting depleted throughout the world. Metaphorically speaking, there is a spider web pattern of effects when you pull just one thread.
  45. More Carbon Dioxide is not necessarily good for plants.
    "How do you explain that it seems to be *universally* unfavorable, everywhere?" Unfavorable? Only if you've got some vested interest in things being much as they have been for the last 10,000 years or so. Many millions of years ago, lots of little critters in a different atmospheric arrangement produced a gas that was poisonous to the biota of the time. In the end, oxygen wiped out a whole "nature" that had developed relying on little or no oxygen. In its place, we got the beginnings of the atmosphere that suits us and the other plants and animals that survive and thrive around us. Nature. Does. Not. Care. About anything. It's like a computer or the internet. It is just a set of processes and linkages that work regardless of what we would call the content. A computer does not know or care if it is used to create beautiful art or write a vile book or play mindless games or run a payroll or spread a 'virus' destroying the hard work of millions of people. It just follows its own rules. If something happens to damage or destroy some plants or animals, 'nature' does not know or care that its processes may take thousands or millions of years to establish a new set of successful items. Its got all the time in the world. Literally. We are the only ones that care whether our own lives or the lives of our descendants will be comfortable and successful or difficult and miserable. We are the only ones capable of caring whether the same considerations affect people we'll never know and plants or animals we will never see.
  46. Clouds provide negative feedback
    21, RW1,
    Where does the difference between "established physics" lie ? This is what I don't understand.
    And this is the crux of your problem. You need to do two things: 1) Present your own model more clearly. You skip steps, make leaps, then get frustrated when other people can't figure out where you get your numbers from. You even claimed that you didn't have a model! 2) You are the outlier. You are the one with the unconventional point of view. The burden is yours to explain your position, but more importantly to study (as the rest of us have) to learn what the mainstream science says. If you can't see the difference between what you put forth, and what everyone else already understands, the burden falls upon you to educate yourself to eliminate that gap. You can't just demand that everyone answer your questions, when you don't demonstrate a clear grasp of the established science, or when you make incorrect statements that clearly are not in line with the established science, and yet even when this is pointed out, you can't see the difference, stomp your feet, and get flustered. You can complain that something is incorrect if you can demonstrate that you understand things, and can yourself clearly explain where your position diverges. You cannot, on the other hand, complain that you don't know why people can't answer your questions, and yet refuse to consider other points of view yourself. You also should not be adopting the tone that you are right, all of main stream climate science is wrong, and so everyone else owes it to you to prove to you that you are mistaken. Like it or not, you are the outlier. If you want to "sell" your position, you need to do that, by convincing other people, not by demanding that they convince you.
    Moderator Response: [muoncounter] RW1 has explained his position in considerable detail on the Lindzen and Choi thread; it is not necessary to start that up again. He is correct in expressing an interest in staying on topic.
  47. The e-mail 'scandal' travesty in misquoting Trenberth on
    Alec Cowan #130 "Why? Is some cherry-paper picking out there? Some kind of "editorialized" line of evidence? The papers I was referring in a previous comment are related to the travesty as Trenberth meant it. The papers you picked are related to the a supposedly independent line of evidence "confirming" the 'climategate' paraphernalia." The Knox and Douglas paper was published in Aug10 which showed that 2003-08 data for OHC content was flat or slightly negative (cooling)for the top 700m and *deep ocean* of approx +0.09W/sq.m (Purkey & Johnson). The paper cites five Argo studies for 0-700m OHC by Willis, Loehle, Pielke, Knox & Douglas show **negative** OHC change, while von Schukmann (0-2000m) is the outlier showing +0.77W/sq.m. I note that K&D quoted Willis (a private communication) as a reference in the Aug10 paper. This is pretty recent information. I would like know if the Knox & Douglas paper has been contradicted or its findings overturned by more recent studies. BTW all these numbers quoted in the above papers are 'global'. You can highlight parts of the oceans which are heating or cooling, but what counts about 'global' warming are 'global' numbers.
  48. More Carbon Dioxide is not necessarily good for plants.
    Villabolo, There is much material out there to satisfy the "concerns" raised by the 'skeptics' regarding the nutritional content being diminished for doubled or trebled CO2 levels. One of my main concerns about this post is that there was not meat in terms of referencing the scientific literature-- but some mistakenly take that to mean that such support is missing in the literature. Ironically enough, the only link that you provide in the body text (at point number 3 in your post) is about diminished nutritional quality in some staples, in this case wheat. I'm certain that the "skeptics" do not even bothering reading these posts, they see the title and launch into obfuscation mode.
  49. Glenn Tamblyn at 08:25 AM on 18 April 2011
    More Carbon Dioxide is not necessarily good for plants.
    Several additional points from things I have read in the past - sorry know references, just memory. Increased CO2 levels can result in reduced numbers of Stomata on leaves - with more CO2 available they don't need as many to supply the same metabolic rate. Paleoclimatologists use stomata counts on fossil leaves as a method of estimating past CO2 levels. Stomata are used for evapotranspiration so this may reduce water loss, but this also provides the plants principle source of cooling, so changed stomata count may impact a plants ability to thermo-regulate - an issue in a hotter and certainly more variable climate. Temperature limits are important to plants. They can do quite well up to some temperature limit then declines markedly - the tree-line on any mountainside is the most obvious example of this. With more CO2 available a plant may be able meet its 'food' needs with less consumption of its resources freeing it up to devote more resources to other functions such as protection from predators through the production of more toxins. I believe increased toxin levels have been reported in Cassava. Might we see increased caffeine levels in coffee & tea? Just because a plant may be able to produce more biomass from increased CO2, that does not automatically mean that this increased biomass will manifest as increased yields of the crops we eat. Our food supply is sourced predominantly from the reproductive parts of the plants. Just because a plant is doing better overall does not mean that it will therefore increase its reproductive activity. A common trait is that plants go into increased reproductive activity, more flowering etc when under stress. If the plant is thriving it might devote more resources into enhancing its own survival rather than reproduction. There could even be a reduction in yield from some plants because of this. Finally the response of a plant species to an environmental change can be two-fold: Adaptation to the changed environment via changes to its metabolism or Migration to remain within its preferred environment. The capacty of plants to adapt to an environmental change depends on whether they have the metabolic pathways and behaviours that allow that change or whether they can evolve new traits as a response. If it doesn't have the pre-existing metabolic/behavioural response availabe, then evolution is its only viable response. Which then raises the question of speed of adaptation. With the rate of CO2 change being nearly unprecedented in Earths history, how fast a plant can adapt to a change may its key survival problem. Annuals such as grains may fare better here than larger long lived species that take years to reach sexual maturity. So evolutionary rates of change could have huge impacts on the species mix of ecosystems, with all sorts of flow on effects. As far as migration is concerned, this again depends on mechanism and speed. Wind blown seeds that can go huge distances allow rapid migration. Seeds from fruit that drop near the parent only permit very slow migration. And just because migration speed may be sufficient to keep pace with climate shifts, that doesn't mean the other aspects of the environment they need will be available, particularly soil characteristics. And finally, plants face a predator that not only predates them for food, but unusually predates them very effectively if they migrate, just because they are migrating. Us. We call them weeds and kill them. So given the range of possible impacts on plants due to CO2 rise and temperature change, from individual plant composition to ecosystem structure, the fact that some plants may reap some benefits from increased CO2 is far more likely to be overwhelmed by the diversity of negative adaptation pressures for ecosystems. And since some of these ecosystems are critically important to us - we call them farm paddocks - CO2 increase is far more likely to be a negative than a positive for our food supply.
  50. A Flanner in the Works for Snow and Ice
    Tom Curtis #75 You say: "Therefore there is need to divide the 1.51*10^21 Joules by 32. That is the additional amount of energy each summer that would not have been absorbed except for the reduced sea ice area." That is precisely my point. The annual (or per summer) increase in heat absorbed by your calculation is therefore 0.49E20 Joules/year. This compares with Dr Trenberth's 1E20 Joules/year for Arctic Sea Ice comtribution to the global heat imbalance budget of 145E20 Joules/year (equal to 0.9W/sq.m globally)

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