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Tom Curtis at 13:03 PM on 19 April 2011CO2 effect is saturated
novandilcosid takes on basic physics on the CO2 lag thread. He writes:"1. The undisputed absorption figures for CO2 mean that an increase in concentration cannot directly greatly (I mean by more than 0.5W/m^2) increase the absorption of surface energy by the atmosphere."
novan calculates this by calculating the change in brightness temperature of the back radiation assuming the atmospheric temperature profile remains constant, and that the increased CO2 concentration reduces the average altitude from which the back radiation is emitted. The problem with this is not that it is in error, but what it ignores. Specifically, what heats the surface is not the back radiation but the sun. The way the back radiation effects the surface temperature is only by modulating the rate at which heat escapes, but it is a minor player in that role. Far more important is convection, which carries heat rapidly to the upper atmosphere. In the event that the upper troposphere warms, as for example, because of reduced IR radiation because of increased CO2 concentrations, that will slow the rate of convective heat transfer, and because heat is being carried away from the surface slower, the surface will warm until equilibrium is reestablished. This will result in an increase in back radiation, but because the lower atmosphere has warmed, not because of the lower effective altitude of emission of back radiation."4. All very well, but what about the rest of the CO2 band? At STP 50% of wavenumber 650 emissions are absorbed in the first 25m of atmosphere. At say 17km the same number of CO2 molecules occupy about 250m. The pressure decrease over these 250m means only a small narrowing of the emission/absorption lines, so absorption rate will not be greatly affected: at 17km just under half the wavenumber 650 photons are absorbed within 250m. 5. I calculate that the published absorption data for CO2 means that the great majority of emissions from CO2 must be coming from above the Tropopause."
It is odd that novan concentrates his discussion on the 650 wave number. It is well known that at that wave number, CO2 absorption is at its peak, and that as a result the majority of CO2 emissions to space at that wavenumber come from the stratosphere. However, the CO2 absorption band in the atmosphere is approximately 350 cm^-1 wide, with most of that band being much weaker absorption than at 650^-1. Science of Doom has calculated the change in transmission at the troposphere for a doubling of CO2:
This is total change in transmittance, and does not take into account the emissions by the CO2, but the effect of the stratosphere and above on transmittance or emissions in the wings (<625cm^-1, >715cm^-1) is negligible. The consequence of including all the line numbers in your calculations (rather than just one, and done by novan) is to show that increasing CO2 concentrations reduces total emissions to space from the upper troposphere, requiring a compensating warming of the surface to restore the energy balance.
Moderator Response: [DB] Closed blockquote tag. -
CO2 lags temperature
novandilcosid - This thread discusses the fact that CO2 has lagged temperature changes in the past, often used as a 'skeptic' argument that changing CO2 concentration now won't be a problem. The Milankovitch cycles driving the repeated glaciation of the Earth only supply a very small forcing (both up and down), not enough to change temperatures very much by themselves. They do induce CO2 feedbacks (vegetation changes, but primarily changes in solubility of CO2 in the oceans, which is inversely related to temperature); these act as positive feedback, amplifying the Milankovitch changes. The ocean CO2 feedback takes 500-1000 years due to deep circulation - hence the lag seen in the ice cores. Both also affect water vapor (more powerful a greenhouse gas than CO2), which takes a matter of weeks or so to respond. Further amplification occurs (in both directions) with changes in ice coverage and albedo. Once a swing in base forcing occurs, that change is greatly amplified. The total effect with feedback amplification (each feedback having it's own time frame) is to produce the temperature swings seen in the glacial cycle. --- Now we're inducing a very large and very fast temperature forcing by artificially increasing CO2 levels to amounts not seen since the Pliocene, when global temps were 2-3°C higher than today, global sea level 25 meters higher than now. This forcing is larger than the Milankovitch cycle changes. And that can't be good. -
novandilcosid at 12:46 PM on 19 April 2011CO2 effect is saturated
My take on the science is this: 1. The undisputed absorption figures for CO2 mean that an increase in concentration cannot directly greatly (I mean by more than 0.5W/m^2) increase the absorption of surface energy by the atmosphere. 2. The increased absorption of sunlight by the upper atmosphere means a drop in insolation at the Surface of about 1W/m^2. The increased back radiation due to the decreased average altitude of the CO2 surface-bound emissions is about 0.5W/m^2, so the NET direct effect of doubled CO2 on the Surface is a cooling forcing of 0.5W/m^2. 3. At the other boundary, it is clear from the outgoing spectra that CO2 is responsible for between 15 and 18W/m^2 of the emissions to space. It is also very clear that the emissions at the stronger wavenumber 670 are stronger than the rest of the CO2 band. Because emissions to space have to get through the overlying gas, it is also clear that the more strongly absorbed wavenumber 670 emissions are coming from higher in the atmosphere than say the wavenumber 650 emissions. So in this case, Higher = hotter, ie the wavenumber 670 emissions are definitely coming from the stratosphere. 4. All very well, but what about the rest of the CO2 band? At STP 50% of wavenumber 650 emissions are absorbed in the first 25m of atmosphere. At say 17km the same number of CO2 molecules occupy about 250m. The pressure decrease over these 250m means only a small narrowing of the emission/absorption lines, so absorption rate will not be greatly affected: at 17km just under half the wavenumber 650 photons are absorbed within 250m. 5. I calculate that the published absorption data for CO2 means that the great majority of emissions from CO2 must be coming from above the Tropopause. 6. If so, then we would expect a doubling of CO2 to have a COOLING effect on the planet. -
novandilcosid at 12:40 PM on 19 April 2011CO2 lags temperature
I thank the moderator, and apologise. The headline post makes the assertion that CO2 amplifies temperature. It is my view that the ice core data shown does not support that assertion. If temperature was being amplified proportionately to CO2 concentration then we would expect to see some influence of this on falling temperatures. I don't see this effect at all in the data. -
RW1 at 12:39 PM on 19 April 2011Clouds provide negative feedback
Sphaerica (RE: 27), "Yes, it is coincidental. That is, both are true, but neither mean anything." The AGW theory seems to require an awful lot of coincidences. "Yes it does, every time the seasons change. That is, the change in temperature in the temperate zones is greater than could be accounted for by the mere change in hours of insolation and angle of incidence of the sun (and change in albedo from winter snow to bare ground). Humidity also rises, and the GHG effect from this amplifies the temperature. This happens, any you experience it, every spring." I generally meant globally - not seasonal or more local temperature change. I'm well aware that seasonal change is due to significant hemispheric insolation change. "But to give your question a more direct answer, you seem to be describing a runaway. As long as the feedback is less than the original forcing, it is positive, but not a runaway. This is the simple case of a convergent versus a divergent series in mathematics." I'm not describing a runaway effect. "So if they had a moderating effect they would be a serious damper in the system. But they don't. And if they were, because they operate so quickly, you would see their effect instantly. Which is exactly why clouds cannot be a major factor. On the time scales over which clouds vary, if in fact they were a moderating influence, then the temperature of the earth would never, ever vary by more than a fraction of a degree (or the clouds would quickly step in and stop it)." But it generally does not vary by much at all. The global mean average temperature tracks very, very tightly - rarely is there a difference from year to year more than 2 or 3 tenths of degree. "Anything which operates on that fast a time scale is either the primary control, or it's not a control at all. All evidence points to "not at all." OK, so then what is the mechanism controlling the energy balance? What is keeping the global average temperatures so tightly in check from year to year? From decade to decade? From century to century? Why don't we see much larger variation - like multiple degree C per year, per decade, per century? The climate system as a whole is remarkably stable. "Which is exactly why clouds cannot be a major factor. On the time scales over which clouds vary, if in fact they were a moderating influence, then the temperature of the earth would never, ever vary by more than a fraction of a degree (or the clouds would quickly step in and stop it). You'd never have ice ages, Medieval Warm Periods, Little Ice Ages, or any notable variations. And yet over the history of the earth the temperature has varied by as much as 10˚C" Most of these changes, except the MVP and LIA, are much longer term and driven by very large external forces - not relatively small internal forcings. External influences aside, just topographical differences alone due to plate tectonics had a huge impact on surface albedo over the Earth's history, which in turn had a huge influence on temperature and climate. The ice ages and interglacials are driven by changes in the Earth's orbit, etc. "It may be a slightly positive or slightly negative feedback, but it's not a control, and not even a major feedback (compared to H2O, CO2, and albedo)." I don't know how you can say this. A very large amount (if not most) of the enhanced warming from the climate models comes from positive cloud feedback. "Look here for further information on how we know that climate sensitivity is not low, so any moderating influence of clouds cannot be a major, fast acting factor. 'For example, between glacial and interglacial periods, the planet's average temperature changes on the order of 6°C (more like 8-10°C in the Antarctic). If the climate sensitivity is low, for example due to increasing low-lying cloud cover reflecting more sunlight as a response to global warming, then how can these large past climate changes be explained?'" Very simply. The large change and increase the distribution of the Sun's energy in the northern hemisphere combined with a positive surface albedo feedback is enough to overcome the negative cloud feedback. -
ranyl at 11:22 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
As CO2 rises and the world warms, weather patterns change (dry to wet and wet to dry) geographically as the tropics widen and in essential character as drought and deluge becomes the way of the weather. There will be winners and losers in the eco-systems present, as exampled by this years Amazon drought and (in some areas) drought breaking rains in Austrialia. Yet overall it appears the sinks are shrinking and going to shrink further. "Their efficiency in removing CO2 emissions from the atmosphere is expected to decrease in the future under increasing atmospheric CO2 because of their response to elevated CO2 levels, warming and other climate changes. Recent evidence from observations and models suggests that the efficiency of the sinks could have already decreased in the past few decades, but the uncertainties are very large" Trends in the land and ocean carbon uptake Corinne Le Que´ re´ 1,2 Current Opinion in Environmental Sustainability 2010, 2:219–224 Also keep in mind that all the models used to estimate safe CO2 emissions and future carbon cycle behaviour don't include permafrost release and keep increasing the sinks. Then add in ocean warming, rain_forrest droughts, ozone effects, pest increases, the nitrogen situation (reactive nitrogen additions to the land have been a net negative radiative forcing for the 50 years and have significanlty increase primary production), etc...etc Then consider that the Pliocene was 3-5C (1.8-3C in a hundred years of 350ppm or 2090) than present on 350ppm and we're at 390ppm. Stop all emissions today and the gradual uptake by the sinks (~100-200years) will remove another 10-20% of the 110ppm addition of Co2 there has been, so taking it down to an equilibrium of ~370ppm a level at which it will then stay at for eons. Of course as always it is slightly more complicated for as the atmospheric CO2 falls the sinks re-release the carbon they stored, meaning we don't get away with that easy and will still have take all the CO2 out of the atmosphere to get to 350ppm (40ppm or 20 years of current emissions). Then add in the 7-14ppm release per 1C that occurs as the world warms and massive losses to biodiversity that are occuring due to other human past times (meaning eco-systems are unhealthy and vulnerable) making biosphere carbon release much more likely. So the reality is to get anywhere near 2C, and not be facing traumatic change, there is a need to at get least 40ppm of CO2 out the atmosphere as of now, i.e. forget having a carbon budget the human race already has a huge carbon debt and every ounce of carbon from now on just adds more to it. Prevention is better and cure and more effective the earlier it is done so means stopping all fossil carbon emissions asap and transforming land use such that, it not only becomes an enhanced carbon sink but also provides sustainable food, fuel and materials. Even with all that the temperature rise is still likely to rise to at least to 1.5C so major adaptations are already necessary and they will have a carbon cost. Everything that needs fossil fuels to exist (e.g. wind turbines) are extra carbon costs, and as to have any chance of reachign 350ppm all FF emissions really have to stop asap so payback Fossil carbon displacement is a false accounting. Considering basically everything is totally fossil fuels dependent at present and to date CO2 emissions just keep going up (yes 2009 dipped but 2010 rose to the challenge again) both suggestive that all actions so far have been futile; Does anyone have any suggestions?Moderator Response: Converted to hyperlink -
Marcus at 11:19 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
Might I also suggest, John D, that you stop misrepresenting what I said before. I clearly said they did *little* to simulate future conditions-I did *not* say they did nothing at all to simulate it. In fact, as poor a simulation as I believe this to be, it went further than any of the other FACE trials I looked at-which seem to look strictly at eCO2 alone. Again, all the yield boosts you mentioned came from the more ideal conditions + eCO2, yet still the message they present is grim-with future soil-borne disease issues, acclimation issues, poor nitrogen use efficiency & predicted drops in yields across the majority of Victoria between now & 2070. Of course, being in denial, you've chosen to focus only on the numbers which you think "prove" your case. -
Marcus at 11:05 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
"Why then are you now claiming they did little to simulate expected changes in temperature and precipitation when it so clearly was a integral part of the trials" Yes I recall the study, & I remember thinking at the time that it was a pretty poor recreation of the kind of conditions that we expect to see in 20-40 years time. You've clearly forgotten that. You've also clearly forgotten that the yield increases you cited were *only* seen under the more ideal conditions (regular sowing times & under irrigated agriculture). Likewise you forgot how they mentioned that they were already seeing the impacts of acclimation after just 3 years. Lastly, you seem to forget that the leader of the project was incredibly downbeat about the results in the summary he presented at the time. I think you should make a better effort to understand the FACE trial, & its implications, yourself before you accuse me of a lack of understanding. -
scaddenp at 10:31 AM on 19 April 2011Christy Crock #4: Do the observations match the models?
rhjames - a perfectly valid model result can give you 15-20 years of little warming. Look at Keenlyside & Motif fuss for an example. Each model run is an instance of a possible climate. No way at moment to know which one we will get. The grey area is boundary of all model runs in the example. The actual should lie in there. More on this at realclimate. Note particularly their graphic with the many model runs on it. -
LukeW at 09:55 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
Villabo - you remain unread as to how major droughts break in Australia, decadal influences, and the importance of major floods in recharging rivers and groundwater. Sorry but it's our underlying lot in life and our natural ecology (exclude Europeans) is adapted to it. Las Ninas are not evenly spread either. So good luck finding a climate change signal in there with the current time series ! Sorry to harp on off-topic. But more to the point extrapolating from CO2 fertilsation to other AGW doom and gloom issues is also off topic. As for CO2 - all I have said is that the jury is still out and things are quite complex. FACE experiments are indeed equivocal and not as good as laboratory studies. As for declines in quality of foodstuffs - well let the plant breeders work at it. You'll be surprised. Don't assume that the current varieties are all you'll have in the future. Same would have been said 100 years ago. I would be more concerned about natural systems - unknown interactions of C3 woodies overtaking C4s by basic metabolic efficiency. Impact of frost from CO2 sensitivity on natural species. But some nation states may win out of AGW on crops and extra CO2. It's Liebig's law of the Minimum. In general I think extra rainfall and temperature will help C3 crops. The way things are going - hope you're one of those nation states. There won't be a global deal on CO2 mitigation and adapation is where we're at. Time to prepare. -
johnd at 09:30 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
Marcus at 09:20 AM, we've discussed the Horsham FACE trials in depth some time back in another thread, and you claimed to have studied and understood the results. Why then are you now claiming they did little to simulate expected changes in temperature and precipitation when it so clearly was a integral part of the trials? Do you recall that, or didn't the results make it clear enough for you? -
Marcus at 09:28 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
That map in the Horsham FACE trial is also nothing to be optimistic about. Almost the entire map shows areas with declining yields between now & 2050-with some areas only expected to decline by 2070, & only a few smatterings of areas that expect to see a yield increase between now & 2070. Again, what the people running the FACE trial are telling us is *very* different from what John D is trying to sell it as. -
novandilcosid at 09:27 AM on 19 April 2011CO2 lags temperature
CBDunkerson wrote: "That CO2 causes higher surface temperatures (aka 'the greenhouse effect') was first proven by John Tyndall more than 150 years ago. Articles explaining how this works and correcting other fundamental errors in your analysis above can be found on this site at; Has the greenhouse effect been falsified? and The greenhouse effect and the 2nd law of thermodynamics" I thank CBD for his response to my post. I would be grateful if he would identify all the "fundamental errors" in my post rather than referring me to vague and unspecific articles. My main ponts are: 1. The undisputed absorption figures for CO2 mean that an increase in concentration cannot directly greatly (I mean by more than 0.5W/m^2) increase the absorption of surface energy by the atmosphere. 2. The increased absorption of sunlight by the upper atmosphere means a drop in insolation at the Surface of about 1W/m^2. The increased back radiation due to the decreased average altitude of the CO2 surface-bound emissions is about 0.5W/m^2, so the NET direct effect of doubled CO2 on the Surface is a cooling forcing of 0.5W/m^2. 3. At the other boundary, it is clear from the outgoing spectra that CO2 is responsible for between 15 and 18W/m^2 of the emissions to space. It is also very clear that the emissions at the stronger wavenumber 670 are stronger than the rest of the CO2 band. Because emissions to space have to get through the overlying gas, it is also clear that the more strongly absorbed wavenumber 670 emissions are coming from higher in the atmosphere than say the wavenumber 650 emissions. So in this case, Higher = hotter, ie the wavenumber 670 emissions are definitely coming from the stratosphere. 4. All very well, but what about the rest of the CO2 band? At STP 50% of wavenumber 650 emissions are absorbed in the first 25m of atmosphere. At say 17km the same number of CO2 molecules occupy about 250m. The pressure decrease over these 250m means only a small narrowing of the emission/absorption lines, so absorption rate will not be greatly affected: at 17km just under half the wavenumber 650 photons are absorbed within 250m. 5. I calculate that the published absorption data for CO2 means that the great majority of emissions from CO2 must be coming from above the Tropopause.Moderator Response: Your comments regarding the physics of the greenhouse effect are off-topic for this thread and are covered elsewhere. Per this site's Comment Policy, please review the appropriate posts and place your comments there. In addition to the links provided by CBD you may find the CO2 effect is saturated thread relevant. Future off-topic comments will be removed. -
Ed Davies at 09:23 AM on 19 April 2011Christy Crock #4: Do the observations match the models?
This Standford video of a Ben Santer talk is a very illuminating introduction to the problems with the Douglass paper. Thanks to whoever referenced it originally - I'm fairly sure it was in a comment on this blog. -
Marcus at 09:20 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
Back to the issue at hand-in spite of all the hand-waving & obfuscation being done by John D, BP & Luke, the fact remains that attempts to claim that enriched CO2 will be beneficial for agriculture are overly simplistic-as they ignore all the other negative impacts that might well result from either enriched CO2 directly, or from changes in hydrology & temperature that will result. These facts are backed up even by the results of the FACE trials in which they place so much faith-even though said trials do little to simulate expected changes in temperature & hydrology. Drops in nutrition, resistance to insect pests & increased soil-borne pathogens have all been shown to occur under eCO2 *alone*-which will almost certainly have a negative impact on crop yields & increase the cost of cropping for farmers. Certainly, just the known dangers to agriculture posed by increasing CO2 emissions should be sufficient to make us want to pursue a more prudent approach to the burning of fossil fuels. In Denial World, however, the risks are entirely worth it if it means a continued reliance on fossil fuels. -
rhjames at 09:20 AM on 19 April 2011Christy Crock #4: Do the observations match the models?
I have to agree with Gilles - even if the temperature had trended strongly downward over the past 15 years, it would still be within the grey area. If I simply look at the trend over the past 15 years, it certainly looks flat, rather then increasing. If I further consider the first quarter of this year thrown in, it further supports a flat trend. GISS is so far removed from all other data this year, that it's hard to take it seriously. However, let's leave it in as a source of data. If I look at the IPCC prediction, the direction is stongly upwards. However, if I blank out the gray area, and just look at the three data sets over the past 15 years (about the time the IPCC as predicted future data), I don't see a convincing upward trend. Therefore, I have to say that, at this stage, the actual data doesn't support the IPCC model trend in recent years. -
johnd at 09:12 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
JMurphy at 08:34 AM, once again you've overlooked the obvious. It is a University of Melbourne project, coincidently it was they who provided the FACE PowerPoint presentation I referenced earlier. Given the objective is to collect data that is beyond that contained in the official BOM records, BOM will be more of a beneficary rather than a contributor. -
Waste heat vs greenhouse warming
RSVP - Re: my rhetorical question about cherry-picking from the middle of publications: "For the same reason you didnt answer the question about the social security analogy?" I didn't answer your social security analogy because it's a horrible analogy, one that doesn't map to the climate system. Sunlight puts energy into the climate, adding to the surface air temperature (SAT) and ocean heat content (OHC), which then radiate increased IR to space. Waste heat also does the same, but at a level only 1% that of sunlight. It's not measurable as a climate effect until it shows up in the OHC and SAT, at which point the same temperature^4 radiation feedback applies to both. You're still treating waste heat as a separate pool of energy that somehow doesn't affect surface radiation (which it could only do if it didn't affect surface temperatures!), which is quite an unjustified and unphysical position to hold. -
Albatross at 08:34 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
Luke, John and Villabolo, If I may be so bold--could we please move the discussion back to the topic at hand? Arguing about what ifs and the IOD and ENSO (yes, I was guilty of that earlier too) is not helpful. -
JMurphy at 08:34 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
johnd wrote : "If you are not already aware of it these addresses should lead you to information about it. http://www.australiangeographic.com.au/journal/first-fleet-logs-reveal-climate-patterns.htm http://climatehistory.com.au/2010/12/02/volunteers-dig-up-tales-of-wild-weather-and-insect-plagues/" This is pure gold, as far as so-called skepticism is concerned. Any project involving the BOM and Met Office (two of the organisation most hateful to the so-called skeptics - due to their important leadership in that all-encompassing conspiracy, apparently), has a built-in rejection clause when the results are not as desirable as required for continuing obfuscation, i.e. "It was always going to be biased, fraudulent and untrustworthy - the BOM and Met Office are involved !" -
johnd at 07:52 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
villabolo at 07:34 AM, the flooding event you are referring to was not due to the La Nina alone, but rather to the combination of La Nina and a negative IOD. That combination merely replicated the conditions last bought in 1975, but also to some extent in 1942, 1933, 1917, 1916,1909,1906, and yet to be established prior to that. The difference now is that the ENSO and IOD are very close to being able to be accurately forecast 2 years out, and as has been happening, those who follow such forecasts are able to plan ahead with more confidence than those who don't, and so not everyone got caught out. -
johnd at 07:38 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
LukeW at 05:33 AM, good to see someone with their feet firmly on the ground and enough nouse to know whether it is dry or wet. There is a project that is collecting all available anecdotal evidence from journals etc to reconstruct as best possible, the early climate of Australia prior to the official record period. If you are not already aware of it these addresses should lead you to information about it. http://www.australiangeographic.com.au/journal/first-fleet-logs-reveal-climate-patterns.htm http://climatehistory.com.au/2010/12/02/volunteers-dig-up-tales-of-wild-weather-and-insect-plagues/ -
villabolo at 07:34 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
@100 LukeW: ""And you want those La Ninas to get stronger?" YES PLEASE !! Would make us billions ! (with some collateral damage too but life wasn't meant to be easy)" (Emphasis mine) Luke; concerning your response at #141 to my post #115. I am very well aware of Australia's variable climate throughout history. You are assuming my ignorance, in what I believe is an attempt to dodge my basic premise. As you yourself stated, La Ninas will become stronger and more frequent. I was simply stating that there will be more devastation than blessing as a result. An obvious example is what you saw happen to your wheat crop last season. That you admitted that production in Australia is problematic runs against the grain of your original statement in #100. You were describing the heightened effects of La Nina as if it were a cornucopia while grossly downplaying the destructive side. Recent events and rational intuition should give you an idea of what you country's future really has in store. More severely fluctuating weather than before, with more drastic effects than before. By the way, you can try out this thinking experiment: All percentages are based a previous average. Year 1: 130% bumper crop. Year 2: 50% crop devastation. Year 3: 70% harvest; 10% complete crop loss; 20% crop dwngraded to animal feed status. Question. What is the average harvest of crop fit for human consumption? -
Rob Honeycutt at 07:28 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
As far as more surface stations is concerned, that's the whole upshot of the Berkeley Earth Surface Temperature study. They are incorporating 39,000 stations into their data. But, the initial findings are showing exactly what all the other data sets are showing. We need to wait to see what the full BEST study says but indications are that more stations is not going to change the result. -
RSVP at 07:27 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
KR #146 For the same reason you didnt answer the question about the social security analogy? -
johnd at 07:25 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
dhogaza at 06:23 AM, for your analogy to be true, it means you are referring to fans watching replays of a season oblivious that the games were played a decade earlier. I can certainly see how that might actually be happening. -
johnd at 07:21 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
KR at 06:06 AM, I'm not sure what crop amplification you think I have suggested, as all my arguments in this thread and all others previously have always been based on what the FACE trials indicate. Unlike perhaps yourself and many others I don't have a lot of faith on modeled projections that have not, or cannot be validated by real world observations. The only exception to the FACE trials has been the use of CO2 enrichment in commercial greenhouses where it has been an established practice for several decades. -
Dikran Marsupial at 07:21 AM on 19 April 2011Christy Crock #4: Do the observations match the models?
dana1981@10 If Christy is not mentioning the Santer paper because he doesn't thing Santer's paper refutes Douglass, that would if anything be worse as the Douglass paper is so obviously wrong. When I first saw it I was amazed that it made it through peer review. Statistically the argument is equivalent to saying that rolling a die 100 times the mean is 3.5 with a standard error of the mean of 0.1. I just rolled a 4 on another die. That means the first die is statistically inconsistent with the second. Yes, the statistical error is that bad! -
dana1981 at 07:03 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
Nick #26 - yes, you've got it right there. Evans didn't word the sentence very clearly. -
Albatross at 06:56 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
Jay @34, "but I would be more at peace if they added more surface stations" I'm sorry, but you being at peace does negate the findings that one does not need a needs a plethora of data to adequately monitor the global mean surface temperature as was so nicely shown by CCC and as was eloquently stated by Dr. Schmidt. But if you feel strongly, then I encourage you to please contact your government and ask them to stop cutting funds to monitoring programs. Now to get back to the topic at hand, you have still to condemn Evans for his misleading statements, so I can only assume then that you support said misleading statements. -
dana1981 at 06:56 AM on 19 April 2011Christy Crock #4: Do the observations match the models?
Dikran - agreed, Christy's continued references to Douglass et al. without even mentioning that Santer et al. refuted it is a major issue. Composer99 - the Climate Graphics resource consists of graphics that Skeptical Science created ourselves. It's not meant as a collection of everyone's useful climate graphics. -
Dr. Jay Cadbury, phd. at 06:35 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
"The assumption is simply that the Arctic Ocean as a whole is warming at the average of the stations around it. What people forget is that if you don't put any values in for the areas where stations are sparse, then when you go to calculate the global mean, you’re actually assuming that the Arctic is warming at the same rate as the global mean. So, either way you are making an assumption." Albatross I understand his point about having to put in values for where stations are sparse but I would be more at peace if they added more surface stations. And this is what is frustating to me, at the last congressional hearing, Lindzen was arguing with the scientists on the other side about the surface station measurements and the issue went unresolved. -
More Carbon Dioxide is not necessarily good for plants.
A rhetorical question: Why do some people think that cherry-picking quotes and numbers from the middle of presentations and papers, while ignoring the summary and conclusions sections that provide the take-home message for all the data, is in any way an acceptable tactic? -
Alec Cowan at 06:28 AM on 19 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
@Ken #136 Quit spamming, Ken! You simply cannot find K&D saying their own figures are for any deeper than 0-700m. If you could, you simply have showed it and pointed a finger at me. The fact that you didn't but you still have time for playing ping-pong here is self explanatory. -
More Carbon Dioxide is not necessarily good for plants.
johnd - My apologies; I had looked at the second reference you made in this post, defending BP, not your earlier post the day before. From that PowerPoint on Australian FACE experiments (only), Slide 14: "Increases and Decreases in Yield BUT Despite experimental yield increases, due to future predicted changes in rainfall and increases in temperature: - Semi-arid zone: Yield LOSS (-10 to -20%) in North West Victoria - HRZ: Yield GAINS (+10 to +20%) in the South West" (Capitalization as in original) Looks like a wash to me - any CO2 based increases nullified by resulting temperature and hydrology shifts. You are not making your case. -
dhogaza at 06:23 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
"As to redneck commercial growers and new seed varieties - great" Reminds me of the Chicago Cubs fan who, every fall, says "just wait until next year!" -
Rob Honeycutt at 06:10 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
Jay @ 29... Regarding the satellite data and the surface station not matching, I wonder if you're pulling up old data somehow. Or maybe someone else you're reading is referring to old data. For quite a while there was a discrepancy between the satellite data and the surface station data. There was a big rift where no one was understanding why the two methods were returning different results. This went on for quite a while. Then an outside group was reviewing the UAH satellite data and discovered that they (Spencer and Christy at UAH) were not accounting for orbital decay of the satellite. That decay introduced a cooling trend (or less of a warming trend) into the UAH data. Spencer and Christy finally had to admit that their data was in error and correct it. Once they did their data matched the surface station data sets almost perfectly. -
More Carbon Dioxide is not necessarily good for plants.
johnd - "KR at 04:35 AM, you obviously missed the results of the FACE trials I referred to in johnd at 19:31 PM on 18 April, 2011" Actually, I did look at the second article you linked. From their conclusions: "Overwhelmingly, this has shown that data from laboratory and chamber experiments systematically overestimate the yields of the major food crops, yet may underestimate the biomass production of trees." More wood, but less food? Again - the FACE experiments you have pushed, with more realistic testing then lab/greenhouse work, do not show the crop amplification you have suggested will occur. As to redneck commercial growers and new seed varieties - great, let us know when they have something. In the meantime, the data indicate that CO2 is not going to boost crops the way skeptics have claimed. -
Alec Cowan at 06:00 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
@Berényi Péter #103 Speaking of real science and given that you speak of every branch of science as if you know it. Can you explain how those FACE experiments could keep the CO2 enrichment in wind conditions, which accounts for a great deal of water strain? Also, can you comment the fact that the vegetation studied is mainly for human use, directly or indirectly, that is, varieties have been enhanced to maximize growth and productivity and to resist drough by every possible way, thus they might "be expecting" more CO2? Why don't we humans enrich our environment with 28% Oxygen just to feel good? Why don't we add some 30% food to our diets, just to thrive? (Oh, we do! and the only thing that thrives is our spare tyres -those in the middle and with a navel in front-)
The fact is that the brochure is a very poor one and unfortunately some very serious works are misinterpreted or depicted in a wrong fashion. There are also not so serious works, but all of that is outside the importance of that brochure to the present topic. On the practical side, the image equals you simply saying "raising CO2 has made soils and vegetation richer in Carbon during the last +100 years". How do we know? Just because if you have had a better source you would have used it, and that, sir or madam, that almost equals a confession.
About your snippets -the sort of figures and phrases that you are recently laying in any imaginable nest- you selected the image on the right from a brochure that also contains the image at the bottom.
At this time you should know better and get some graphic with margin errors in it, proper attribution and a dataset. Also checking the source, a very poor one -no matter who did it- no matter it is just a brochure. In the image below they only speak of drought. No single place becomes any wetter and even a new dessert is born in southern Chile ... wait! the scale is wrong: 40% doesn't mean 40% less rainfalls, just a 40% probability of the place going dryer, hence a 60% probability of it going wetter. How do I know? Because it's what Mahli et al (2008) says, and that's why a source is needed. I can also tell that the season name is the NH's though most of the area represented is in the SH.
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Albatross at 05:49 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
Interesting, Jay, you do realize that the GOP want to slash NOAA's budget, right? And now we have contrarians arguing that the station dropout is an issue. Anyways, the station dropout has been demonstrated to be a non issue by the CCC. This is not big nor is it recent news. Please, instead of obfuscating, your credibility would be much better served by actually calling Evans on the myriad of errors in his speech/essay. Why are "skeptics" so unskeptical of their own, and so reticent to critique their own or call them on their errors? Mind you I should not complain, it is for this very reason that "skeptics" will probably always have a huge credibility issue. PS: Re the station issue, please read this (see last question). -
Dikran Marsupial at 05:39 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
It is also worth noting that the various surface station products measure slightly different things (e.g. coverage of poles), which are again slightly different from what the satellite products measure (surface rather than lower trophosphere), so you wouldn't expect them to be exactly the same anyway. -
LukeW at 05:33 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
Albatross - be careful interpreting the increased variability. Land clearing in reef catchments has increased runoff which is what the coral proxy study is based on. And land clearing itself can accentuate droughts when they occur. Villabolo - you really are trying to stop the tides - yes I am Australian and your basic knowledge of our climate history isn't very good. (1) don't build homes and infrastructure on flood plains - lessons of 1974 forgotten to be rediscovered in 2011 (as the lessons from the 1800s were also forgotten). Is it that surprising that flood plains ... errr ... flood ! It is absolutely stunning that Australians are surprised by the floods. (2) any Aussie crop physiologists and modellers worth their salt knows that episodic droughts and floods make production problematic. We live on the receiving end of ENSO - you HAVE and WILL get episodic droughts and floods. And any ecologist knows the big wets are the resets for decades of low rainfall years. If you don't like it - don't live here. Are you trying to suggest none of this has happened before. In fact probably historically much worse in the 1800s. Those who don't learn from history are doomed to repeat it. And the ENSO x IPO story is written large in the rainfall history, sediment cores and corals. Not enjoying such variation Aussies mitigate against drought and flood using a thing called "dams". How many billion dollars do you think full dams and rivers are to agriculture? -
Albatross at 05:33 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
Jay @27, Your questions have been answered in the main post. The long-term trends in the satellite data and surface data are in good agreement, especially the between the RSS products (which are superior to the UAH data that the contrarians are so focussed on) and the surface temperature data. Why don't you look at the data yourself (trends for 1980-2010) at woodfortrees.org? Tamino also has a good post on this issue, well worth the read. Either way, Evans was completely wrong to state that the "official" science do not track the satellite data. I'm sure that we can agree that Evans was demonstrably wrong on that point. And be wary of uncritically citing "information" from political lobby groups like the SPPI-- recall Monckton is with them too, and he has been debunked more times than I care to recall. -
Dr. Jay Cadbury, phd. at 05:31 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
Here is a pull quote from the article that concerns me. "The world’s surface observing network had reached its golden era in the 1960s-1980s, with more than 6000 stations providing valuable climate information. Now, there are fewer than 1500." This concerns me because 1500 stations does not seem adequate enough to measure the entire system. Secondly, what range are these stations accurate up to? -
Dr. Jay Cadbury, phd. at 05:28 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
He sent me a pdf, which you can download here. http://scienceandpublicpolicy.org/originals/policy_driven_deception.html -
les at 05:21 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
128 Johnd "modeled projections are... at best only theories based on opinions." No. Some are based on well understood models and data while other are not so good. BPs assertion that the famous clipped diagram shows an exponential rise was clearly a theory based on opinion which the data in the FACT paper didn't uphold. Personally, I think he did a great job of correcting himself and supporting the blog post. -
Dr. Jay Cadbury, phd. at 05:18 AM on 19 April 2011David Evans' Understanding of the Climate Goes Cold
@Chris Extremely interesting and informative post. Evans: "Why does official science track only the surface thermometer results and not mention the satellite results?" "This would be a good question, if it were remotely true. In reality, "official science" pays very close attention to satellite temperatures. For example, they're discussed in great detail in the IPCC report and highlighted every single month by NOAA." I am confused here because I have read some scientists who say that the surface and satellite data does not match. "The satellite data shows little long term warming. Ground station data shows a lot of warming. The ground-station data has serious systematic problems with the urban heat island effect and station dropout over the years. I put much more faith in the satellite data. “Satellite data” normally means the temperature of the lower troposphere, not the surface temperature. Have a look at the attachment."-Dr. Happer I will post his attachment shortly, as I am waiting for it to finish downloading. -
johnd at 05:08 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
KR at 04:35 AM, you obviously missed the results of the FACE trials I referred to in johnd at 19:31 PM on 18 April, 2011. The science isn't settled just yet, plant genetics is moving at a fast pace. The irony is that some red necked croppers involved in commercial seed trials is going to know where the science is at years before you get to read about it in some peer reviewed study available free online. -
villabolo at 04:52 AM on 19 April 2011More Carbon Dioxide is not necessarily good for plants.
#133 Volunteer: "Increased carbon dioxide in the air actually decreases the amount of water needed by plants, because most water lost by plants is lost by transpiration. When plants can access carbon dioxide more efficiently, they "breathe" less and emit less water vapor." I and others have already responded to that issue. If you do not believe that are responses are accurate, by all means, tell us why. To return to the original statement, however, is to communicate with the rest of us as if we never responded. Please pick up your discussion of the issue from where it was last left. There is no need to reinvent the wheel. "In response to the questioning of the "clipped" chart -- obviously the author cut it off where he did because everything past that point was a projection, not a measurement. Proponents of global warming are learning that projections can't be trusted." Volunteer; it is totally irrelevant that BP cut out a section that he believed did not apply to his point. That is grossly unprofessional. If he does not believe in its relevancy or accuracy, the proper thing to do is to post the entire image and then to explain why he believes that particular portion of it is not relevant. To do as he did is to represent the evidence in a way that the originator of the did not intend. It also causes those who look at the chart to have faith in the assumption that nothing has been taken out of context; intentionally or not. Finally, your quote marks on the word clipped is disingenuous. -
Rovinpiper at 04:36 AM on 19 April 2011Earth hasn't warmed as much as expected
Daniel Bailey@11 That is exactly what I was looking for. Thanks.
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