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factfinder at 07:52 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Well John here is a report from a Ph.D. physicist that does not agree with you or your readers that still believe that the "greenhouse gas effect "exists. Lets see how John butchers some real physics. 30 June 2010 On Some Flaws in Greenhouse Gas Global Warming I have just finished reading an excellent article by Alan Siddons called The Hidden Flaw in Greenhouse Theory on American Thinker from way back on 25 February 2010. The article is a little slow in developing, but finishes with a death blow to the usual theory put forth by catastrophic anthropogenic global warming advocates. I intend to explain more concisely what Siddons explained and to add comments of my own in this post which make the deathblow much more gory. First of all, I am going to enlarge the context of the discussion. The primary source of heat for the surface of the Earth is the radiant energy of the sun. The solar wind of the sun, materials dumped into the atmosphere from space, heat from the deep interior of the earth, and the interplay of changes in the Earth's magnetic field and the sun's magnetic field are also contributors of heat, though the sum of these is much less than that from the sun's radiant energy spectrum of ultraviolet (UV), visible, and infra-red (IR) light. The entire catastrophic greenhouse gas hypothesis ignores effects upon the incident IR portion of this spectrum of light from the sun. This is foolish. UV light is 11% of the radiant energy from the sun. The UV light variance of 0.5 to 0.8% with the solar cycle is much larger than is the visible light variance of 0.22%. UV light is absorbed throughout the atmosphere, but much still reaches the ground and is absorbed there. The amount of UV radiation absorbed in the upper atmosphere is highly dependent upon the amount of ozone there. The amount of ozone is highly dependent upon the solar wind, CFCs, and volcanic activity. When UV light is more absorbed in the stratosphere than the ground, its surface warming effect is diminished. The absorbed energy is re-emitted as IR radiation and much of that energy is quickly lost to space. The entire atmosphere is transparent to visible light which is the form of 44% of the radiant energy from the sun, so aside from reflection from clouds and aerosol particles, the visible light reaches the ground or oceans and warms them near their surfaces. Finally, the IR radiation is not absorbed by nitrogen, oxygen, and argon gases which make up 99% of the atmosphere, so a large fraction of it directly warms the Earth's surface. Some, is absorbed by the dominant greenhouse gas, water vapor, and small amounts are absorbed by carbon dioxide and other greenhouse gases. The incoming IR radiation absorbed in the atmosphere is less effective in warming the Earth's surface than is that which is absorbed by the Earth's surface directly. This is because some this energy absorbed in the atmosphere then is radiated again in the form of IR radiation, but now half or more of that is directed out to space. In other words, more water vapor and CO2 in the atmosphere results in a less effective warming of the surface than does less of these gases with respect to the incoming IR energy from the sun. The greenhouse gases have a cooling effect on the original solar radiance spectrum for the 45% of the solar energy in the form of IR. In each case, whether UV, visible light, or IR, not all of the radiation of that form striking the Earth's surface is absorbed. Some fraction is reflected and the fraction is very dependent on whether the ground is covered with snow, plowed earth, grasses, forests, crops, black top, or water. There are two real ways that man does have some effect on the Earth's temperature. He changes the surface of the earth over a fraction of the 30% of its surface which is land. He also converts fossil and biomass fuels into heat. Compared to the overall natural effects, these man-made effects are small, yet they are probably large compared to the effect of his adding CO2 and methane to the atmosphere. Wherever the atmosphere is heated, there is transfer of heat. In the outer, very low density atmosphere, the primary means of heat transfer is radiant transfer by IR emission from an energetic molecule or atom, since collisions of molecules and atoms for direct energy transfer are rare. In the denser atmosphere, most energy transfer is due to collisions and the convective flow of masses of warmed air. Near the Earth's surface, almost all of the energy lost by the warmed surface is due to gas molecules striking the surface and picking up heat and then colliding with other molecules to transfer heat from one to another. Once a body of air is so heated, then masses of warmed molecules are transported upward into the cooler atmosphere at higher altitudes or laterally toward cooler surface areas by convection. Any warmed molecule, most of which are nitrogen, oxygen, and argon will radiate IR radiation. However, no molecule or atom at a low temperature such as that near the Earth's surface is a very effective energy radiator, since the Stephan-Boltzmann equation depends upon the fourth power of the absolute temperature, which commonly near the Earth's surface is about 290K. Thus, gas molecule collisions and convection are the very dominant means of heat transfer. These processes on balance cool the surface of the Earth and redistribute some of the heat back into the upper atmosphere and cooler places such as those shaded from the sun or the arctic regions. The favorite claim of the catastrophic greenhouse gas global warming people is that an increase of carbon dioxide and methane gas in the atmosphere will cause energy radiated into the atmosphere from the ground to be absorbed by these molecules and they will radiate half of it back toward the ground, where that energy will warm the surface again and reduce the cooling due to the ground originally radiating that heat into the atmosphere. According to Alan Siddons, less than 1% of the cooling of the Earth's surface is due to IR emission of the surface or the gases near the surface. More than 99% is due to direct contact and convection. Since the dominant source of energy warming the surface of the Earth is the sun, let us do a simple calculation based upon the facts presented above. Let us say that greenhouse gases absorb a fraction f of the incoming IR radiation from the sun, which is 45% of the sun's incoming energy. Thus the energy absorbed by greenhouse gases from the incoming spectrum of solar energy is 0.45f and a fraction of this, say k is radiated back into space without coming near the surface. NASA says k is 0.5, but it is actually slightly larger than that given that much of this absorption occurs at appreciable altitudes. The total cooling due to greenhouse gases, somewhere in the atmosphere, is now 0.45fk. Of this energy, had it become incident upon the surface as IR radiation, a part would have been reflected rather than absorbed. The fraction that would have been absorbed is q. The net energy then lost to the warming of the surface is then 0.45fkq. Now, let us suppose that a fraction g of the total energy from the sun is absorbed in the Earth's surface or in the very lower part of the atmosphere. We know that g is a larger fraction of 1 than is f, since most of the solar radiation does reach the ground, including that part in the IR part of the spectrum. Of the energy g absorbed in the surface, only 0.01 times it is emitted as IR radiation according to Siddons. Since the greenhouse gas content of the atmosphere is unchanged the amount of outgoing radiation, serving to cool the surface, is now 0.01gf. A fraction j of this energy will be emitted by the IR warmed greenhouse gas molecules back toward the ground. NASA has said this fraction is 0.5. Let us then say j is about 0.5. The greenhouse gas warming of the surface due to absorbing IR radiation from the ground would then be about 0.005gfq, where q is the fraction of back-reflected IR radiation that was incident upon the surface and absorbed. Remember that some radiation is reflected. Now we will compare the greenhouse gas cooling effect upon the incoming solar radiation of 0.45fkq to the re-warming of the surface due to 0.005gfq times the total solar radiant energy. Breaking down the parts: 0.005 is much less than 0.45, in fact it is 0.011 times as large. f appears in both factors, so the comparative effect is cancellation. The factor q appears in both the cooling and the warming quantities, so it cancels. k is somewhat more than 0.5, while g is the surface absorptivity for the entire solar spectrum and is likely to be near 0.7, or quite comparable. So let us say g and k are an approximate trade-off. Thus the net cooling effect of greenhouse gases is very greatly dominant because the re-heating effect is approximately 0.01 times the cooling effect. In sum, using a simple calculation we can approximate the effect of greenhouse gases on the surface temperature of the Earth. It turns out that the cooling effect due to keeping incoming solar IR radiation away from the surface is about 100 times the re-heating effect proclaimed by greenhouse gas alarmists. Now, if the effect were very large in either case, this might be cause for concern. We would likely be better off heating our planet than cooling it. But, then we are heating with land use changes and the release of energy from fossil fuels, so the generation of cooling CO2 may simply be compensating for these other small effects. Much more important to this issue than CO2 and methane is water vapor in any case. So, most of this cooling effect is due to water vapor and only a small part is due to CO2 and methane. Now, of course so much is going on here that this calculation is but an indicator of the likely net effect of greenhouse gases. A more careful calculation would consider the different weight of IR frequencies in the original spectrum of the sun and in the Earth surface emission spectrum. But, any changes due to these secondary issues are likely to be small compared to a factor of 100. In any case, this calculation makes mincemeat of the usual simple rationale for greenhouse gas warming alarmism. It is insane to focus only on the outgoing IR radiation from the Earth's surface while ignoring the large part of the sun's total incident radiation which is IR from the get-go. It is also insane to ignore gas collisions and convection currents as mechanisms for heat transfer. I used the greenhouse gas term in the presently conventional way, but in reality, all gases when warm radiate IR energy and as pointed out by Alan Siddons, they are all really greenhouse gases. But, here I used the term only for those gases that absorb IR energy. Posted by Charles R. Anderson, Ph.D. at Wednesday, June 30, 2010 Labels: Alan Siddons, CO2 emissions, greenhouse gases, solar radiationResponse: The evidence for the greenhouse effect comes from multiple lines of direct measurements. Airplanes measuring the infrared radiation escaping out to space find a big bite taken out of the spectrum at CO2 wavelengths. This is confirmed by surface measurements that find that big bite of heat returning to the Earth's surface:
We cover this topic at Has the greenhouse effect been falsified?. Please continue any discussion there. -
Berényi Péter at 07:38 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Here is Fig. 2. from Long 2006. He goes for a hyperbolic fit, but it looks more like logarithmic (at least for realistic values of [CO2]), C4 plant response under normal (not drought) circumstances being a scaled down version of C3 plants'. In open air (FACE) the results are a bit more controversial.
Fig. 2. Effects of elevated [CO2] on crop yield. Data are yields at elevated [CO2] relative to those at ambient [CO2] (arrow) for (A) soybeans in chambers (solid blue circles) and FACE (blue square, hidden behind red square) and wheat in chambers (red circles) and FACE (red square); and (B) C4 crops (maize and sorghum combined) in chambers (green circles) and FACE studies (green square). Error bars indicate mean ±90% confidence intervals around the means for the FACE studies. The chamber studies included 115 independent measures of soybeans (21), 211 of wheat (36), and 14 of maize and sorghum (table S3). These measures were divided into 10 classes of growth [CO2] in 100-ppm increments. Plotted values are the class means of growth [CO2] and yield. Solid lines are the least-squares fits for the nonrectangular hyperbolic response of yield to growth [CO2] from these enclosure studies of soybeans (blue line, r2 = 0.98), wheat (red line, r2 = 0.88), and C4 crops (green line, r2 = 0.99). The yield response of soybeans in chambers to growth [CO2] of 900 to 999 ppm [open blue circle in (A)] was an outlier and was excluded from the curve fitting. Full details of the meta-analysis methods and results from FACE are presented in the SOM and table S2.
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Doug Bostrom at 07:26 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
JohnD, you've made an assertion about how fruits and vegetables are cultivated and brought to table, namely that we may expect to see a plethora of mainstream foods in our markets that have been grown using C02 enrichment. So far you have done nothing to support that assertion with facts other than to cite a single opinion piece positing essentially the identical argument you're making and with no numerical information on how often consumers actually encounter products cultivated with C02 enrichment. Here's what you said: Perhaps the next time anyone visits a supermarket and salivates over the well grown fresh produce, and admires the beautiful flowers, just check out how much of what has been admired, or has been put onto your dinner plate in recent decades has been grown in an enriched CO2 environment. You're attempting to convey an impression in support of your thesis that C02 enrichment is a great thing even when it's not being engineered and instead is out of control. In support of that you'd like us to believe that we're already benefiting in a significant way from C02 enriched cultivation. So far you have produced no data to support your assertion. At the end of the day folks have to be able to form an estimation of what is more or less useful information, or has any useful information content at all. You are casting an impression about what we might expect to find in our markets but so far you've not conveyed any actual information. Repair your problem by posting some numbers on market penetration of fruits and vegetables cultivated with C02 enrichment techniques. -
VoxRat at 07:24 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Ah - you mean that Wittwer article. I didn't find it terribly useful, in that it lacked any references. But I gather that greenhouse nurseries, have in fact, used CO2 enrichment to boost the production of certain plants. Which would make sense. However, extrapolating those results from the highly controlled artificial environment of a greenhouse nursery, where soil nutrients are not limiting and where competing plants (i.e. weeds) are not an issue, to farm and prairie land would be pretty naive. these guys for instance, found that though grass grew faster in increased CO2, the nutritional content (specifically nitrogen, i.e. protein) was degraded. And these guys (among others) say that increasing [CO2] may already be responsible for shrubland encroachment into pasture lands. -
Ned at 07:16 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
caerbannog, all of Tamino's posts from before March of this year seem to have disappeared. I'm not sure what happened over there. -
johnd at 06:39 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
VoxRat at 06:25 AM , the article linked to in a previous post in my discussion with doug. -
johnd at 06:37 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
doug_bostrom at 05:51 AM, I wasn't asking you about CO2 enrichment, I was asking you if you know where the food you eat comes from. Most consumers are quite ignorant on the matter. In Australia labelling laws are being gradually tightened to keep consumers better informed, I don't know what the situation is in America. It may not be politically correct there to knowingly eat anything produced under enhanced CO2 conditions. It reminds me of the mad cow scare, how many USA consumers continued to eat meat rejected from export markets? Did they know it wasn't meeting export standards? -
VoxRat at 06:25 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
johnd at 5:45 ""... CO2 enrichment has been used commercially for decades and is as widespread as indicated in the article" What article? -
johnd at 06:23 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Albatross at 02:33 AM, understanding the role CO2 plays in plant growth for food production is essential in order to obtain optimum growth. Optimum growth means greater efficiency in terms of nutrient usage, water usage and land usage. That has been proved by those commercial green house operators that adopted the practice long ago. As has always been the case, there are many different varieties of most plant species, and they all respond in different ways under different conditions. The trials being done under enriched CO2 levels are identifying ahead of time which varieties respond best allowing scientists to concentrate on further development on the desirable genetic makeups. What seems to be overlooked is that all plants are not going to be exposed to higher CO2 levels starting tomorrow, levels began rising over 100 years ago. Any negative aspects of higher levels of CO2 should be detectable now, but I don't see that being discussed. It seems that current ambient levels are considered optimum by some and that it will be all downhill from here on. Of course greater growth means increased inputs, it seems that it is only some posters here think otherwise. A backyard carrot grower might be able to continually grow carrots year after year without putting any nutrients back into the system and think he is getting something for nothing, but that is not the case with commercial growers. -
johnd at 05:56 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Marcus at 00:18 AM, if you read and understand the results so well, then perhaps you can explain what was the difference between the TOS1 and TOS2 trials, and what the results of each indicated. Only then will I be confident that you have read and understood the report. Can you also confirm whether the protein produced per unit area increased or not under the higher CO2. -
Doug Bostrom at 05:51 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Why are you asking me about C02 enrichment, JohnD? You suggested I'd find my grocery store shelves richly supplied with fruits and vegetables grown using C02 enrichment but you cannot supply any data to support that claim. Don't ask me about enrichment, it's your impression you're trying to convey. -
caerbannog at 05:46 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
#18 Tamino (tamino.wordpress.com) had a very nice explanation -- unfortunately, it doesn't appear to be on-line now. For the time-being a copy can be fished out of the Google cache here: http://webcache.googleusercontent.com/search?q=cache:jbljNoHoUZIJ:tamino.wordpress.com/2007/07/16/lapse-rate/+lapse+rate+global+warming&cd=1&hl=en&ct=clnk&gl=us&client=firefox-a Excerpt: As we add more CO2 to the atmosphere, it becomes optically thicker for those wavelengths of infrared. This means that to escape the atmosphere, it must be radiated from ever-higher altitudes. The temperature at the altitude at which the infrared actually escapes to space is determined by the incoming energy from the sun, and so does not change as we add more CO2 to the atmosphere. But the temperature at the surface will be higher than the temperature of this high-altitude air, by an amount which is governed by the lapse rate (which doesn’t change much) and by the height of that radiating layer. So, even if the atmosphere has so much CO2 that it is saturated in those infrared wavelengths, adding more CO2 raises the altitude at which those wavelengths of infrared escape to space, increasing the distance to the ground, and therefore increasing temperature difference between the radiation layer and the ground (which is the product “lapse rate” x “distance”). That’s one of the reasons that arguments that CO2 absorption of infrared is saturated, and hence adding more CO2 won’t increase global warming, are mistaken. Because of the lapse rate, raising the altitude of CO2 radiation escaping to space will still warm the surface. -
johnd at 05:45 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
doug_bostrom at 19:18 PM, you are starting to sound as if you think there is a conspiracy involved. However, do you accept that the practice of CO2 enrichment has been used commercially for decades and is as widespread as indicated in the article? -
villabolo at 05:31 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Argus at 18:25 PM on 1 July, 2010 A comment to #6 villabolo and #7 Bern: "Animals and humans use oxygen primarily to get energy to keep us going through the day. Plants use CO2 to keep building biomass. They get energy from sunlight. Therefore it is more correct to call CO2 "food" for plants than "air" for plants. CO2 does not give them energy" **************************************************************************************** I was not referring to the metabolism of the organism but to an appropriate description of what it consumes in terms of whether it's in a gaseous state or solid state. Since this post was written in reference to simplistic phrases used as propaganda for the masses, my idea was to find a simple counter phrase that could be used in rebuttal to members of the general public who say that "CO2 is plant food". The best one I can think of is the old phrase "Too much of a good thing is a bad thing". Examples: Too much food, for humans that is; too much oxygen in the atmosphere (double the % of Oxygen and you'll burn even the wettest jungle down). This response should come before the basic explanation as to what too much CO2 would do. The issue I'm trying to stress is not semantics, as was brought up by carrot eater #14, but the best response to people who simply do not understand the issue. Since they are being instructed (brainwashed) in what are essentially "memes", I am suggesting counter memes such as the previously mentioned one, "Too much of a good thing is a bad thing". As far as I'm concerned, the main issue is that of communicating with the Public and doing so at THEIR LEVEL. We cannot expect them to absorb even the simplest of explanations. To the extent that they may be able to, it would be necessary to use a label (the counter meme I suggested above) to make a simple rebuttal of ours more easily accessible to the overloaded "filing cabinets" of their minds. Our statements to the general public have to ALWAYS be understood in the context of the Denier propaganda they are susceptible to. The issue of communication to the Public is not merely about the LOGICAL but the PSYCHOLOGICAL. My apologies if I seem to be quibbling over an issue separate than those being discussed at the moment but I believe that communication with the manipulated Public, on their level, is of utmost importance. -
Peter Hogarth at 05:19 AM on 2 July 2010Sea level rise is exaggerated
daniel at 17:15 PM on 1 July, 2010 I accept the data points on the chart are sparse, and have temporal uncertainty and height uncertainty. The time series trend developed from these samples is a simple low order curve fitted through them, which is common practice when trying to extract trends. This assumes low long term variation of the variable in question. An alternative fit involving high short term variation which still explains the limited data points would involve undersampling and aliasing. Is this likely? You do not suggest it is, but you propose it is possible. I have spent some hard earned cash looking at over a dozen recent site specific salt marsh studies related to sea level. Without exception they display the poor resolution which you would rightly criticize if any study was the single source of our evidence. One of the best that is free (I honestly did not select by author!) is Donnelly 2006. It is possibly close enough geographically to the 2004 data set so that gaps in the record in each could be reduced, which makes short term variations far less probable. Likewise, archaeological and historical evidence on sea level changes, from around the world, taken in isolation, means little - and could easily be written off using local crustal depression etc. It is the integrated wider evidence based picture that emerges when researchers try to put all this stuff together that proves persuasive to many, and to me. A further point is that researchers like Donnelly cannot help but acquire a great deal of background knowledge or expertise, and will be aware of large amounts of evidence that might not even be in publication, but nevertheless adds to the overall common sense probability based conclusion. Is this conclusion overwhelmingly robust? I couldn’t say without analysis, but it is consistent with the majority of recent and emerging published data. daniel at 17:15 PM on 1 July, 2010 I accept the data points on the chart are sparse, and have temporal uncertainty and height uncertainty. The time series trend developed from these samples is a simple low order curve fitted through them, which is common practice when trying to extract trends. This assumes low long term variation of the variable in question. An alternative fit involving high short term variation which still explains the limited data points would involve undersampling and aliasing. Is this likely? You do not suggest it is, but you propose it is possible. I have spent some hard earned cash looking at over a dozen recent site specific salt marsh studies related to sea level. Without exception they display the poor resolution which you would rightly criticize if any study was the single source of our evidence. One of the best that is free (I honestly did not select by author!) is Donnelly 2006. It is possibly close enough geographically to the 2004 data set so that gaps in the record in each could be reduced, which makes short term variations far less probable. Likewise, archaeological and historical evidence on sea level changes, from around the world, taken in isolation, means little - and could easily be written off using local crustal depression etc. It is the integrated wider evidence based picture that emerges when researchers try to put all this stuff together that proves persuasive to many, and to me. A further point is that researchers like Donnelly cannot help but acquire a great deal of background knowledge or expertise, and will be aware of large amounts of evidence that might not even be in publication, but nevertheless adds to the overall common sense probability based conclusion. Is this conclusion overwhelmingly robust? I couldn’t say without analysis, but it is consistent with the majority of recent and emerging published data. -
DarkSkywise at 05:17 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Ned #14 - I originally wanted to say "Thank you Ned, nice stuff!" but in that case I'll make it "Thank you, Nick! (And Ned.)" And yes, the Guide booklet is nice-looking stuff too! *ponders what it would look like in Dutch* *ponder ponder ponder* -
hengistmcstone at 05:17 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Hi John, I'm still a bit new to this so forgive me if this is a point made before. Why do skeptics need a handbook ? Seems to me it's more "the habitual contrarian's handbook" Salutations Hengist -
citizenschallenge at 04:43 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
caerbannog #16 can you offer some links to this information? thanks -
citizenschallenge at 04:39 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Regarding the Handbook, in light of my visit at jonova and her commentators, there is much ridicule about scientists now using wind speed voodoo, to get the results "we expect." from the handbook: “Confirmation of the hot spot comes from measurements of wind trends. As there’s a direct relationship between temperature and wind shear, this gives us an independent way to calculate temperature trends. This method finds peak warming above the tropics, just as we expect.” Is there someway to give an explanation of how this works, perhaps a link. In fact, all the way around a little more meat, or citations would have been good. Although with handbook like this we almost need three different grade levels: simple: high school; college. Nice job though, with a great look too.Response: The general plan will be the Handbook is the shorter, broader version - the website will contain the longer, more detailed, more technical explanations. This is probably preferable to having multiple versions of the Scientific Guide, particularly if I want to get any sleep at all :-) -
caerbannog at 04:34 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
It should be pointed out that even if the CO2-effect were "saturated", additional CO2 would still warm the Earth. As CO2 concentrations increase, the altitude of the "top of the atmosphere" (TOA) increases. (The TOA is defined as roughly where most of the outgoing IR can escape directly into space instead of being absorbed/reradiated by CO2 above it). As the TOA altitude increases, its temperature decreases (thanks to the lapse-rate that deniers have been flogging recently). Since the amount of IR escaping into space from the TOA is a function of its temperature, the new, "higher altitude" TOA will have to warm up so that the energy leaving in the form of IR balances the incoming solar radiation (first low of thermo). Since we now have a greater distance from the TOA to the surface, the lapse rate means that the Earth's surface must warm as the TOA warms in order to restore the incoming/outgoing energy balance. This will happen whether or not the CO2-effect is "saturated" at lower altitudes. Deniers keep forgetting that "CO2-saturation" at the surface does not mean "CO2-saturation" at high altitudes. They also keep forgetting that CO2 doesn't just absorb IR; it reradiates it. -
citizenschallenge at 04:30 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
I looked at your Handbook this morning I liked it for the first production draft. I agreed with much of the constructive critique in the above posts so didn’t add anything. Being the kind of guy who's always trying to get inside the thinking of others, I found myself at the jonova website and have spent the last couple hours being frustrated and I will admit getting a bit overwhelmed. Especially, after down loading and looking over that masterpiece poster "Climategate: 30 years in the making" Quite the profession production... but with one thing in mind - to win their point of view. The spooky part is when "winning" becomes everything, where does that leave learning and adapting. When so much of the story must be ignored to prop up ones own point of view, where is the value in that? -
What causes the tropospheric hot spot?
Baa Humbug > The charts presented by numerous organizations do not show warming across all latitudes for ghg forcing. They distinctly show warming at 30N to 30S at 8-10km aloft (yes along with stratospheric cooling) The models show enhanced warming at tropical latitudes (the hot spot), but there is also a clear overall warming of the lower atmosphere, which is also clearly visible in the satellite data. I think what you are really looking for is a chart showing what modeled results would like if a non-GHG forcing was causing the warming and comparing it to the actual model predictions and the empirical data. This isn't what the IPCC charts - or the other charts you cited - are doing, though that's the way they are often misinterpreted. I don't know if such a chart exists, but the key difference would be a cooling stratosphere, which should be visible with GHG warming but not solar or other warming. Both GHG and non-GHG charts would show a hotspot, which is why the hotspot is not a signature of GHG warming. The observed cooling in the stratosphere is therefore very strong evidence for the current warming being GHG driven, and a strong falsification of other attributions. If this cooling didn't exist, it would be a very strong falsification of GHG warming. In contrast, if the hot spot really didn't exist, it would shift our understanding of the process of global warming, but not the cause (since the hotspot is predicted for all causes of warming.) -
Ned at 04:03 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
I should note that I learned about that from Nick Stokes at his blog. -
Ned at 04:02 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
John, you probably already know about this ... but if not, check out the booklet Climate sceptic arguments and their scientific background. It's similar to what you do here, and what the US EPA did earlier this year. What makes this one interesting, however, is that it's put together by a large corporation that sees climate change as a serious threat to its financial future. -
chris at 02:46 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
HumanityRules at 23:25 PM on 1 July, 2010 Argus at 01:15 AM on 2 July, 2010 It takes a certain bravery to discuss second-order consequences of global warming like changing precipitation patterns and extremes, and wildfire prevalence and risk, since these can be easy to "pooh-pooh". I think Mariana’s analysis is a justifiable reflection of the scientific data. On precipitation patterns and extremes It is pretty clear that the predictions on changing precipitation paterns in a warming world are being borne out by real world observations [*]. Argus, you asked “In the Amazonas it is already warmer than in most places, but is it dry?”. The answer is that in Northern Amazonia, global warming has been accompanied by drying (reduced precipitation). The latitude band from around the equator to around 30 oN has become drier as the Earth has warmed during the 20th century, much as predicted. This latitudinal band of reduced precipitation will widen as the Earth continues to warm, and so Amazonia is expected to dry progressively towards the South as the Earth continues to warm. The higher latitudes (especially above 50o N and below 10 o) have seen enhanced precipitation. Global warming and shifts in precipitation regimes is expected (and already observed) to lead to amplification of extreme precipitation events [**] (one could cite more papers on this, but Allen et al. 2008 is a decent starting point). [*] X. Zhang et al. (2007) Detection of human influence on twentieth-century precipitation trends Nature 448, 461-465 abstract [**] RP Allen et al. (2008) Atmospheric warming and the amplification of precipitation extremes Science 321, 1481-1484 abstract On wildfire prevalence and risk Again real world observations support the expectation that global warming and shifts in precipitation patterns will (and are) lead(ing) to major changes in local hydrological cycles [***]. These effects lead to enhanced wildfire prevalence [****, *****] [***] e.g. TP Barnett et al (2008) Human-induced changes in the hydrology of the western United States Science 319, 1083-1086. abstract [****] AP Westerling et al (2006) Warming and earlier spring increase western US forest wildfire activity. Science 313, 940-943. abstract [*****] YQ Liu et al. (2009) Trends in global wildfire potential in a changing climate Forest Ecol. Management 259, 685-697 paper -
Alexandre at 02:44 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Captain Pithart #5 Well spotted. I'll try to find some time to do the Portuguese one, as well. I'm not very good at formatting the text to make it look like the original, though. -
Albatross at 02:33 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
I really do not see the point of debating in circles about the "CO2 is plant food" meme. CO2 is, of course, a micro nutrient required for photosynthesis, no argument there. Plants have been doing well at relatively low concentrations of CO2 for over 800 000 years now. Whether or not doubling CO2 is going to help crops and forests is all rather irrelevant when sea level is going to rise by over 1.5 m, and when heat waves and drought are going to continue increasing in intensity and frequency in agricultural certain regions. There are other, much more relevant limiting factors on plant growth and yield, the permanent wilting point being one of them. The portions of the USA are currently experiencing a heat wave, and despite CO2 being at their highest levels in almost a million years, the high CO2 does not seem to be helping the plants much. As noted by Mariana, those arguing that CO2 is plant food relying on the fact the CO2 plant food argument "rests on a simple logical fallacy--the fallacy of exclusion". IMO, that is the end of the debate right there as it pertains to AGW. JohnD are you maintaining that we should double or more than double CO2 in the hopes that the alleged gains in crop yield will offset the myriad of negative impacts associated with a global warming of at least +2C occurring in an incredibly short time? That seems a rather poor reason/motivation to go on to more than double CO2. -
Albatross at 01:57 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Great effort John, and an excellent idea! Have you emailed a copy to Ms. Nova? Perhaps one could consider this version 1, and it can be updated as new information comes along? Maybe one could expand on this sentence a bit "So the hot spot is the result of surface warming and is not unique to the enhancd (?) greenhouse effect. For example, surface warming from increased solar output would also cause a hotspot." I say "enhanced", because some might argue "well why is there not a tropical hotpsot before CO2 increased?" Well, there probably has been there ever since we've had a greenhouse effect, it all depends what baseline you use to calculate the anomalies. Also, I agree with others that the quality of some of the figures is not the best, but I realise that you may have had to grab them from low-res PDFs. You say that "As there are no air conditioners or cars in space to..." Maybe I'm being picky, but while the satellites are in space, the measurements are being made in layers high above the ground in the earth's the atmosphere, and yes up there there is no impact from the UHI. Conceding up front that one simply cannot cover all the bases in such a short booklet, I am disappointed that there is no reference to the increase in OHC or SSTs (did I miss it?). That would, however, tie in nicely with the "reality of global" warming-- no UHI over the oceans. Other have noticed this too, but is there any chance of "fixing" the x-axis labels in the Alexander figure? That is just the kind of thing to get Ms. Nova hopping. You know, falsum in uno, falsum in omnibus. And one last observation, perhaps it is worth noting that some of these "skeptical arguments" were trotted out in the early 20th century, over 100 years ago in some cases. The theory of human-caused global warming is robust and held up to immense scrutiny and new observations from satellites etc. PS: Will people be able to view this on their Blackberries or iPhones? Yes, I know, I am technically challenged....Response: When I first mentioned "enhanced greenhouse effect" to Wendy, she thought enhanced made it sound like a good thing. Ditto for positive feedback. Nowadays, I called it the increased greenhouse effect.
Re expanding on sentences, there is a lot more content that could go in there (and indeed was in there on the first draft). But as you say, you simply can't cover all bases in such a short booklet. And I don't think you should cover too much if you're trying to reach a broad audience. I would love to have got the Murphy ocean heat graph in there but well, there's only so much real estate. Basically, the website offers longer, more comprehensive versions of all these arguments. I'll eventually set up a page that makes all these longer webpages easily accessible from the one place.
BTW, have fixed the x-axis labels in the Alexander figure and the low-rez graphics.
Lastly, sorry, no plans for an iPhone version. But all this content is there in longer form in the iPhone app complete with all the goodies mentioned above. -
Alexandre at 01:55 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
JC #1 said: How does a layman deal with one side that says balloons have found a hot spot and the other side that says balloons have failed to find a hotspot? This is a very good question that most laypeoble should ask themselves, and persue it if they really want to have an informed opinions about this subject. My own attempts to overcome this problem were these: - Check the credibility of the claimer. Very subjective, and in principle nothing more than an authority argument. In practice, though, I think it's reasonable to attribute more credibility to NASA or NOAA or some Nature papers (specially if they concur with each other) than some loose claim in a blog. Or loose claim in many blogs. Understanding the difference between general media and peer reviewed papers helps, too. - Try to really understand the basics. The basic science involved is (to a large extent) accessible to, say, a good high school graduate. There's tons of information in the internet in research organizations and universities. Even some blogs (like this one) usually explain the basics including the relevant references (which is the important bit). -
Mythago at 01:44 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
Hello John, Have to agree with a poster who was concerned with the reproduction quality of the graphs. Also I noted on p11 'The Trend in Downward Infra-red Radiation' had an absence of data from the USA. Was this because the USA doesn't cause climate change? :-) Maybe your country is distancing themselves from responsibility for climate change? :-) Or is it another attempt by the USA to blame everyone else on the planet for the crisis? :-0) Yes, I am joking but some people will read the evidence, just like they do the sceptical arguments, (and read it exactly as I have suggested, albeit I was being tongue-in-cheek with my interpretations here) and believe the evidence as proof of blame should they finally lose the battle to say its all a con. The arguments can cut both ways like any good sword. Maybe also some explanation about the data source would suffice to dissuade the critics from being to literal. I also believe some reference to the original book would be justifiable. What is the point of a rebuttal without a target?Response: It's not my country, I'm Australian :-)
Re the downward infrared radiation figure, here is the original pic from Wang 2009:
The reason for the lack of observations in the USA is explained on page 9. The figure shows the trend over a 25 year period. Over this period, the US and Canada changed their way of observing clouds from a human visual assessment (someone looking out a window?) to instrument measured. So there's no single continuous data series lasting 25 years in the US or Canada. -
barry1487 at 01:44 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
I get a 404 error message when I click on the Climate Crock video link. Good post. -
chris at 01:41 AM on 2 July 2010Astronomical cycles
Ken Lambert at 00:32 AM on 30 June, 2010 Ken Lambert at 00:33 AM on 2 July 2010 Ken, I suggest that you really need to find a way to address these issues with a little more scientific rigour. You were shown in some detail the manner in which the Topex and Jason data were merged here. Yet you continue to make unscientific and unsupported assertions about "offsets", and other unsubstantiated judgemental statements about the data. You are pushing your prejudices far too hard over this issue; kdkd is quite right to keep pointing this out. The bottom line is that the current sea level is pretty much smack on the level that one would have predicted 17 years ago by extrapolating forward in time with a rise somewhat above 3 mm.yr-1 as simple analysis of the data shows (dispassionate readers should also read Peter Hogarths nice description ). Your continued misunderstanding of the nature of the Earth response to enhanced greenhouse gas concentrations isn't helping you. Incrementally increased [CO2] doesn't necessarily equate to incrementally increased TOA radiative forcing, and neither of these (incrementally increasing [CO2]; incrementally increased forcing) necessarily result in incremental changes in the parameters (like sea level rise) of the Earth/climate response. That is so obvious as to be trivial. The TOA radiative forcing waxes and wanes as contributions from natural variability (solar; volcanic; clouds; albedo) modulates the greenhouse-induced forcing. In addition to these contributions, natural variability affects specific parameters of the Earth response. So sea level rise responds both to the variability in TOA forcing, as well to specific factors related to the temporal distribution of ocean heat that enhances and decreases the progression of sea level rise (e.g. during El Nino and La Nina events). Because the temporal progression of Earth responses to enhanced greenhouse gas is poorly predictable, both in its general trend and due to this natural variability, the effect of enhanced greenhouse forcing on the Earth system is normally assessed in relation to the surface equilibrium temperature response, once the climate system has re-equilibrated with the forcing. "CO2GHG theory" (as you call it!) has rather little to say about the exact progression of climate-related parameters (like sea level) other than that these will fluctuate around the trend on the progression towards equilibrium. It is a total fallacy (and a strawman argument) to think that one should observe continuously incremental changes in any parameter of the climate system, as the latter progresses to a new equilibrium state. -
bobp at 01:39 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
It is a red herring and has no bearing on how much enhanced co2 levels are warming the earth, but dismissing the fertilization effect out of hand seems to me mistaken when it is still a matter of scientific debate,see the article linked to by chris @41. I saw a lecture by david archer where he suggests fertilization could explain the missing sink (more co2 is emitted by mankind than absobed by atmosphere and ocean) http://geoflop.uchicago.edu/forecast/docs/lectures.html BTW this is my 1st post though I've enjoyed reading your site for about a year and found it informative and scientific but, I'm sorry to say this article seemed much more(in tone) like an article on a"skeptical" site,and I hope this is just a typo " A rise in CO2 levels is not the only consequence of climate change" -
Berényi Péter at 01:27 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
What the science says: Journal of Experimental Botany Vol. 60, No. 10, pp. 2859–2876, 2009 doi:10.1093/jxb/erp096 Advance Access publication 28 April, 2009 REVIEW PAPER Elevated CO2 effects on plant carbon, nitrogen, and water relations: six important lessons from FACE Andrew D. B. Leakey, Elizabeth A. Ainsworth, Carl J. Bernacchi, Alistair Rogers, Stephen P. Long and Donald R. Ort- carbon uptake is enhanced by elevated [CO2] despite acclimation of photosynthetic capacity
- photosynthetic nitrogen use efficiency increases at elevated [CO2]
- water use at both leaf and canopy scales declines at elevated [CO2]
- dark respiration is significantly stimulated in soybean leaves grown under elevated [CO2]
- stimulation of carbon uptake by elevated [CO2] in C4 plants is indirect and occurs only in situations of drought
- the [CO2] ‘fertilization’ effect in FACE studies on crop plants is less than expected
-
Argus at 01:15 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Thank you, HumanityRules (#47)! Those were two of the blunders in the post that I was about to comment on myself. The paragraph about rain also says: "With the global increase in temperature caused by the various factors affecting our climate's balance, increased evaporation means decreased soil moisture." So, if it is warmer, the soil is drier? In the Amazonas it is already warmer than in most places, but is it dry? The simple fact is that the earth has hot and dry places, hot and wet places, cold and dry places, and cold and wet places. Whether the ground is dry or humid depends on other factors than just the temperature. The paragraph about how more and denser forests and other vegetation would be a problem causing forest fires, is indeed preposterous. We know that on the shorelines and islands in and around the Mediterranean once were full of forests. When they cut down too many trees to build ships or make fire, the soil was washed down into the sea, and the last trees died. The soil is needed to keep the moisture in the ground, and together with the trees, they form the basis for more rain. Now we have dry macchia instead around most of the Mediterranean, which is really conducive to supporting forest fires. Would't it be better to have the forests back? No matter what grows in the soil, it is at least always better than barren ground. -
Ken Lambert at 00:33 AM on 2 July 2010Astronomical cycles
kdkd #115 It seems that the 17 year record is a splicing together of a chain of 3 satelite records (TOPEX, Jason1, Jason2) with differing accuracies and precisions. This chain is only as good as its weakest link. If short links are involved (ie Jason 2) then they should probably be deleted from the composite to give a consistent year on year record. Confine your comments to these technical issues rather than judgements of truth or untruth. -
Marcus at 00:31 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Here is part of an abstract which highlights that an enriched CO2 will lead to problems in photosynthesis & plant health in many cases: "Young bean plants (Phaseolus vulgaris L. cv Seafarer) grew faster in air enriched with CO2 (1200 microliters per liter) than in ambient CO2 (330 microliters per liter). However, by 7 days when increases in overall growth (dry weight, leaf area) were visible, there was a significant decline (about 25%) in the leaf mineral content (N, P, K, Ca, Mg) and a drop in the activity of two enzymes of carbon fixation, carbonic anhydrase and ribulose 1,5-bisphosphate (RuBP) carboxylase under high CO2." This does highlight that-even in the absence of the other detrimental impacts of CO2 enrichment-the significant increases achieved in *vegetative*-not SEED-biomass will most likely be increasingly short-lived as CO2 concentrations continue to rise, & will probably come at the price of overall plant health & nutritional value. This is something that the "CO2 is plant food" crowd never like to dwell on too much. -
Marcus at 00:18 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Wow, John, way to prove that you *didn't* read the results of that Horsham Trial too well. I read the results & understood them clearly-better than you did at any rate (apparently you can't even read a graph too well). I also paid close attention to the final comments that you also linked to. Looking at the graphs regarding GRAIN YIELD (not total biomass-that's completely different), we see in most varieties there is no significant increase in grain yield. In the remaining varieties, the increase in grain yield was significant but very small. By contrast, the decline in protein content-across the board-was significant, & not offset by the increase in grain yields in most cases. The experimental design included nothing simulating about hotter & drier conditions-they only compared rain-fed to irrigated systems, which is a far cry from simulating the conditions expected later this century if global warming gets worse. That you missed this PROVES you didn't bother to give this trial anything more than a casual glance, cherry-picking the bits you felt agreed with your viewpoint. The researchers admitted that, whilst protein levels in the grain decreased, the amount of nitrogen required was signficantly higher in the enriched CO2 conditions. Trust me, no farmer is going to choose to purchase even *more* expensive fertilizer to achieve little to no significant increase in grain yield. Other FACE trials from across the world show an equally disappointing increase in grain yields (5% to 8% maximum)-even in optimum conditions, & they have also noted a decrease in the *nutritional quality* of those seeds. That you haven't discovered that fact proves that you've clearly not looked too deeply into any FACE trials outside of the one in Horsham. Also, the great leaps forward in agricultural production have been as a result of increased use of pesticides, herbicides & fertilizers-& the move towards greater mechanization, not increases in CO2 in the atmosphere (which, need I remind you-yet again-is NOT the limiting factor in plant growth). It has, though, also made farming much more expensive-& marginal. Which is exactly why most farmers won't buy a significant increase in costs just to produce a very small increase in grain yield-at the cost of quality. At the end of the day, John D, you can keep repeating these falsehoods about the *wonders* of future CO2 increases, but repetition won't ever make it the truth! This tactic might work with all your denialist mates, but it doesn't cut the mustard around here. Now, go back & read the results of the FACE trial PROPERLY! -
boba10960 at 00:15 AM on 2 July 2010A Scientific Guide to the 'Skeptics Handbook'
John Your Scientific Guide to the Skeptics Handbook is a terrific resource that will be of great value in setting the record straight. However, there is one point that is misleading if not erroneous. On p. 4 the guide states “In the past when the ocean warmed, this caused more CO2 to be released to the atmosphere.” This is true, but it implies that changing ocean temperature was the primary cause of past changes in CO2 observed in ice cores. This is not the case. Holding everything else constant, atmospheric CO2 will increase about 10 to 12 ppm for every degree C that the entire ocean (i.e., mainly the deep ocean) warms due to the temperature dependence of CO2 solubility in seawater. From the peak of the last ice age, about 20,000 years ago, to preindustrial times the deep ocean warmed approximately 2.5 to 3°C. Therefore, given the temperature dependence of CO2 release noted above, warming of the ocean can account for 25 to 36 ppm 1/3 to less than half of the 80 ppm rise in CO2 after the last ice age ended. However, all else was not held constant. The ocean also became less salty as the ice age ended. Melting of ice on land lowered the salt content of seawater by about 3%. The solubility of CO2 in seawater increases as the salt content decreases. The decrease in salinity of the ocean as the ice age ended lowered atmospheric CO2, offsetting about half the effect of rising temperature. Considering the combined effect of changing temperature and salinity, one can account for only a small (albeit significant) part of the rise in atmospheric CO2 since the end of the last ice age. Other processes must have controlled most of the change in CO2 seen in ice cores. Although there is still no consensus among scientists about the relative importance of various processes that regulate atmospheric CO2 levels, the processes are known. Two recent papers provide nice summaries of these processes, one in Science last week and one in Nature this week. Denton et al. (The last glacial termination, Science, 25 June 2010) describe the sequence of events that cause an ice age to end, including processes that raise the CO2 content of the atmosphere. This paper provides evidence of why temperatures in Antarctica began to rise before CO2 levels rose detectably as the last ice age came to an end. Sigman et al. (The polar ocean and glacial cycles in atmospheric CO2 concentration, Nature, 1 July 2010) reviews the various ocean processes that are thought to affect atmospheric CO2 concentrations. These processes are most important in the ocean around Antarctica, and they are linked tightly to climate. This coupling accounts for the tight correlation between CO2 and temperature that is clearly evident in the Antarctic ice core records. -
JMurphy at 00:05 AM on 2 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
HumanityRules, perhaps you should read some IPCC : 3.3 Changes in Surface Climate: Precipitation, Drought and Surface Hydrology How is Precipitation Changing? See also, for the UK : Changing intensity of rainfall over Britain -
johnd at 23:46 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Marcus at 12:14 PM. information from Monckton? ROTFLMAO. The only things that I know about Monckton is what I have read from his many fans on this site. Given the attention paid to him they obviously see him as being very influential. -
Arkadiusz Semczyszak at 23:41 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
The Polish Institute of Environmental studies (2006): "Previously it was thought that increased CO2 concentrations deteriorate the quality of agricultural products [eg protein cereal - gluten], but accurate, many studies have not been found. Detailed studies have shown that the plants quickly, because within a few weeks acclimated to elevated carbon dioxide. " "... Photosynthesis, especially the most common type of C3 plants increases significantly with increasing concentrations of carbon dioxide (CO2). Simultaneously with the acceleration of photosynthesis, the optimum temperature shifts to higher temperatures. [...]"A particularly positive effect on the "fertilization" of CO2 [700 - 1500 ppmv] to react: "... plants growing in a greenhouse [which] at elevated carbon dioxide concentrations, it’s have higher yields on average by 33% ..." In addition, there is: - Reduction of stomatal conductance and transpiration increase efficiency of water use, - Reduce the amount of protein enzymes involved in carbon reduction cycle, which increases the efficiency of nutrients, - - Accelerate growth and increase the number of leaves and flowers, - Better regeneration of plants breeding - by tissue culture [in vitro], - In some cases reducing costs of light made [greenhouse] ... " CO2 is warming - the area of deserts and areas affected by natural disasters is to be increased, but ... "The prevailing view that the overall scale of expected changes involving global warming will bring positive effects in the rural economy. Indeed, if the sum of effective temperatures will increase it and increase yields of most crops - not only thermophilic. " Previous natural hunger, " ... were correlated with solar activity minima. The probability of randomness of this compound was calculated on an extremely small, ie the order of one ten-thousandth (King 1975). " Therefore, "... Always one of the best determinants of the old warm climates have been and are low prices for cereals and especially wheat. (quoted from above). " “Assessing the importance of expected climate change y its impact on world agriculture, we can conclude that growing anthropogenic global warming and, in particular, the increase in carbon dioxide concentration in the atmosphere can HAVE A FAVORABLE EFFECT on crop productivity in many regions of the earth. However, we should not forget that these estimates for DIFFERENT REGIONS COULD BE SIGNIFICANTLY DIFFERENT.” (The Close Relationship between Climate and the Global Food Problem, Budyko, 1998). "Old growth forests may actually still be accumulating carbon, in defiance of Odum's equilibrium hypothesis, explains Philippe Ciais, Deputy Director of LSCE, and co-author of the study. More than 30% of the planet's total forested area is unmanaged primary forest, half of which is located in temperate regions in the northern hemisphere. The database established for this study reveals that these ancient forests fix between 0.8 and 1.8 billion tonnes of carbon each year, and that 15% of the total forest area that has until now been totally IGNORED IN CARBON BALANCES is in fact responsible for at least 10% of all carbon sinking activity." (ScienceDaily, Sep. 14, 2008). -
johnd at 23:38 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Marcus at 12:31 PM, most of the answers to your questions were in the Horsham FACE trial link I provided originally, but it required understanding the content, not merely the reading of it. 1) does an enriched CO2 environment generate long-term, increased plant growth in the absence of ideal conditions? .......... The only long term trial under such conditions has been over the last 100 years. Given the CO2 levels were stable for 1000's of years, a sudden 100 years of a constantly increasing CO2 levels indicates that at this stage, further increases in CO2 still accelerate the response with little indication of acclimation or any other adverse effects. Indeed some experts are crediting some of the huge leap in agriculture production over that time, in part to increased CO2 levels. ------------- 2) does an enriched CO2 environment generate a significant increase in the quantity of *edible* biomass (usually seeds or fruit)? .......... As indicated in the Horsham FACE trials, grain yields increased, significantly. The long established horticultural practice of CO2 enrichment in commercial greenhouse operations also support significant increases in edible biomass, why else would it have been done for so long? -------------------- 3) does an enriched CO2 environment generate a significant increase in the nitrogen content of the edible biomass? ........ Don't get too hung up on this point. Grain protein levels and yield are often the inverse of each other. Some of the highest grain protein levels are found during the driest years when grain yields are down. Whilst the grain protein level was down slightly in the FACE trials, that was offset by a significant increase in grain yield which most importantly means that the amount of protein produced per hectare increased, and that is the most relevant factor in needing to produce enough food to feed the worlds population. ---------------- 4) does an enriched CO2 environment lead to a decrease in demand for other limiting factors (like fertilizer & water)? ....... This is a really silly question. If plants are to grow bigger and better, for whatever reason, they require more nutrients, that is one of the most basic truths. If you want anything to increase growth, it requires extra inputs irrespective of what stimulates the extra growth. Do kids grow more if you feed them less? It appears however that water is utilised more efficiently when CO2 is the stimulating agent. --------- 5) does an enriched CO2 environment have any other positive or negative impacts on cropping *in the real world*? ...... See (1) above. No-till farming and stubble retention has meant that it is now possible to produce viable crops in more marginal conditions. Increase plant efficiency in the utilisation of moisture is a further positive. -
JMurphy at 23:36 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
This is an interesting read from the Journal of Experimental Botany (2009), mainly going on about the use of models (ooerr) but also giving a good round-up of current knowledge : Crops and climate change: progress, trends, and challenges in simulating impacts and informing adaptation -
HumanityRules at 23:25 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
"Another effect of global climate change is erratic precipitation patterns" "balanced rainfall drastically reduced" Taking the first quote what do we have now, or what did we have 100 years ago? Non-erratic rainfall? Consistent rainfall? It's a blatantly obvious rainfall will be erratic in the future. It's always been erratic that's the nature of weather. There is no optimum, climate is chaotic whether it's under the influence of man-made or natural forces. You seem to fall into the trap that nature is in someway harmonious except when interferred with by man. These statements seem to wander away from science and dangerously close to the Gaia theory. Or an equally poor idea that man-made change is bad, presupposing that natural change is fine. "For one, the increased density of forest vegetation could increase the risk of wildfires, which have reared their ugly heads in California all too often in the past few years, wreaking devastating damage" PURE ALARMISM!! Suddenly dense forests are bad. Maybe we should chop them all down? In fact the whole thing wreaks of emotionalism rather than science, sorry. -
tobyjoyce at 23:22 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Think I found the Climate Crock video here: http://www.youtube.com/watch?v=vFGU6qvkmTI&feature=player_embedded -
VoxRat at 23:18 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
@ #44 Hey that is a compelling argument! Now that I think about it, my sister used to have a mosquito repellent machine in her mosquito infested backyard. It worked by pumping out a lot of CO2, which confused the heck out of the little buggers trying to chemotax to their next blood meal. Coming soon to a climate skeptic site near you: huge increases in CO2 will be a good thing, because it will cut down on mosquito bites and West Nile disease and malaria! (Or at least mitigate the increase in the geographical spread of those things due to increasing temperatures.) -
Berényi Péter at 22:34 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Looks like CO2 Generators are standard equipment indeed in commercial greenhouses. I don't know if it is good for plants or not, but there is a market for the gadget anyway. -
Lassesson at 22:23 PM on 1 July 2010A Scientific Guide to the 'Skeptics Handbook'
John, Thank you for providing us with this material. I will definitely hand it out to my denying friends. I am just curious if you (or Alexander et al) didn't get the years wrong in the figures for Human Fingerprint #3, Nights warming faster than days. It seems to be a bit too many 1950's.Response: You can check out the full paper of Alexander et al 2006 (refreshingly, the full paper is freely available online). I pulled the graphs from Figure 2 on page 7.
UPDATE: okay, I see what you mean, thanks for pointing out the glitch with the years in the Alexander x-axis. Have fixed it. -
chris at 22:18 PM on 1 July 2010CO2 is Good for Plants: Another Red Herring in the Climate Change Debate
Mac at 21:51 PM on 1 July, 2010 Mac that is a truly dismal, scientifically illiterate, and rather nasty site.... Do you really think that misrepresentation and ad hominem argumentation combined with poorly constructed sarcasm is a useful way of addressing scientific issues? BTW, I don't see where the "lost" "irony" applies to Mariana's article and comment. Can you please clarify
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