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Charlie A at 13:47 PM on 17 March 2011Maximum and minimum monthly records in global temperature databases
#36 Shoyemore "Figure 2 is the cusum plot, with expected centering and expected symmetry about 0. This is actually what happens 1880 to 1940s, giving rise to the suspicion that what was going on back then was natural variation. " Is the cumsum plot below what you would get for the 1920-1945 period, with 1925 cumsum set to zero? I'm pretty sure it is. What does your analysis tell us about that period? Natural variation or not? I'm trying to understand the basis of your concluding that recent warming is anything other than a continuation of the warming seen in the rest of the instrumental record.
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RW1 at 13:42 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE: 597), "5) The surface radiation is a function of temperature and emissivity, which is not 1 at any location, though very close to 1 at most." OK yes, temperature and emissivity, which for all practical purposes is 1 because the surface is a near perfect black body radiator. -
RW1 at 13:38 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE: 597), "Saying that 239 w/m^2 becomes 396 w/m^2 is to directly assert the non-conservation of energy." How do you figure? I said the 239 W/m^2 entering the system becomes 396 W/m^2 at the surface. The amount leaving is still 239 W/m^2. Power in = power out = Conservation of Energy.Moderator Response: [DB] Fixed unclosed html tag. -
johnd at 13:37 PM on 17 March 2011Maize harvest to shrink under Global Warming
Rob Painting at 12:20 PM, re "Don't know where you get that idea." Firstly from this comment in the introduction of the paper, "Roughly 65% of present maize-growing areas in Africa would experience yield losses for 1°C of warming under optimal rain-fed management, with 100% of areas harmed by warming under drought conditions." More specifically from this - "For optimal management, at present, maize growing below ~23°C in average growing-season temperature tends to gain from warming, owing to positive effects of GDD8,30, whereas yields of maize grown in areas above this baseline temperature tend to decline with warming." The maps provided in the study identify such areas as well as the % of land utilised for growing maize, it's a simple matter to then correlate the two. With regards to the matter of tolerance to warming. Warming is a very subjective term, do they mean, plus 5°C, 10°C, 20°C, 30°C ? What data is there that identifies the exact degree of warming that it was thought to be able to tolerate, or was it all based on anecdotal stories? -
Philippe Chantreau at 13:35 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Sorry Camburn, it still makes no sense. You say "Gravity is a force." Then you say "That energy is absorbed by gravity." So energy is absorbed by a force. Please elaborate on the physical process there, I'm at a loss. -
L.J. Ryan at 13:34 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RickG @ 591 "Specifically, what is it that you guys don't understand about this diagram? You are trying to make it into something that it is not." I'm not trying to make this diagram into anything. I question the basis by which the energy is stored in the atmosphere...if not temperature. So I ask again how do you know is there...can it be measured? And by what means is the atmospheric energy stored? -
RW1 at 13:31 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE:597), "1) The energy absorbed at the surface is the Incoming Solar Radiation absorbed at the Surface (approx 161 w/m^2) plus the Back Radiation absorbed at the surface (approx 333 w/m^2)." OK, here is my question then to you: If you agree that the atmosphere cannot create any energy of its own, and 78 W/m^2 of the 239 W/m^2 (239 - 161 = 78) entering the system never reaches the surface, then where is the 333 W/m^2 of back radiation coming from if 239 W/m^2 is also leaving the system? 40 + 78 + 121 = 239 W/m^2 leaving. 396 W/m^2 - 239 W/m^2 = 157 W/m^2 emitted down to the surface. 161 + 157 = 318 W/m^2 at the surface (396 W/m^2 required). Also, 157 W/m^2 + 97 W/m^2 = 254 W/m^2 (333 W/m^2 required). -
Camburn at 13:18 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom C@602: 1. Conservation of energy. Gravity is a force. Everything in our atmosphere/earth sphere is affected by gravity. It consumes energy. Without it, we would all float etc. Yes, kinetic energy is kinetic energy. But even kinetic is the result of heat and can be converted to heat. Friction is an example. When two molecules, even tho of minisucle weight, collide, energy is not only transferred, it is expended because they do not bond, rather they collide and go a different direction and they will go in a different direction at a slightly slower speed. That energy is absorbed by gravity. Even our atmosphere, while of atomic weights, requires an expenditure of energy to stay aloft. This energy comes from the sun as I know of no other source. A physics prof was trying to get this into my mind in college. Not sure I ever really totally grasped what he was trying to show, but rattling my old cobwebs I am trying to understand it still. It gets back to including all energy in any equation talking about energy. Maybe he was all wet, but the older I get the more I think he understood something quit clearly that I didn't. -
scaddenp at 13:02 PM on 17 March 2011Examining the impacts of ocean acidification
You might like to read Realclimate on methane eg here and and especially here. Climate looks grim but lets understand the real reasons. -
scaddenp at 12:58 PM on 17 March 2011Examining the impacts of ocean acidification
This reads like science fiction. Can you please substantiate: "Carbon dioxide saturate water in our polar area will contribute to global cooling." Huh? "ice is growing astronomically at the South Pole" it is? The reason for overall decline in artic ice than was?? If its methane driven, then why dont we see it? (Noting the fossil methane has no C14 whereas biogenic does). If anything oil/gas production has reduced fossil methane in atmosphere by reduction in natural losses (but of course our burning of fuel massively increases CO2). "methane emmissions which are the main culprit in global warming" They are? Where is your data to support that? (Try IPCC WG1 for actual contributions of each GHG). -
Philippe Chantreau at 12:57 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
A loss of energy to gravity???!!??? What in the world is that? -
Albatross at 12:51 PM on 17 March 2011Maize harvest to shrink under Global Warming
For those who are critiquing the paper without apparently having read it (and it is linked to), the authors outline the rationale for their research: "New approaches are needed to accelerate understanding of climate impacts on crop yields, particularly in tropical regions. Past studies have relied mainly on crop-simulation models or statistical analyses based on reported harvest data, each with considerable uncertainties and limited applicability to tropical systems. However, a wealth of historical crop-trial data exists in the tropics that has been previously untapped for climate research. Using a data set of more than 20,000 historical maize trials in Africa, combined with daily weather data, we show a nonlinear relationship between warming and yields."Moderator Response: [DB] Fixed html tag. -
andthorne at 12:43 PM on 17 March 2011Examining the impacts of ocean acidification
Good job. But there is another reason to worry. Carbon dioxide saturate water in our polar area will contribute to global cooling. That is why the ice is growing astronomically at the South Pole and prior to the BP breech it had been growing for two years in the Arctic. The BP methane, in the main, stayed in the northern hemisphere until in reached the Arctic, then it dives and goes to the South Pole and it oxidize along the way ending up at CO 2 It takes 22 degrees F to freeze carbon saturated water and the Souith Pole can get it there. Once frozen it is then 60 times stronger than regular ice. The north pole with the aid of hydrate cold seeps can also. We are between the proverbial devil and the deep blue sea. The heat is killing our oceans and speeding up hydrate dissociation, and therefore methane emmissions which are the main culprit in global warming, because they release heat to the water tht used to hold them when they transverse the solid to gaseous state, but my theory is that it is global cooling that will win in the end, unless we can get the oil and gas industry out of our seas, which is needed but is highly unlikely to happe. Yes I agree the planet is dying and doing so very quickly. My theory is it is also shaking apart from hydrate action as well. I have read discussion between hydrate specialist and Japanese scientists discussing hydrates in the trench where the earthquake split the earth open almost five years ago. Andrea SilverthorneModerator Response:[DB] For the 2nd time tonight I have to say: Huh?
I know your words are English but collectively they do not parse.
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Tom Curtis at 12:42 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Camburn @598, the atmosphere does not cause the Earth to accelerate in space, so there is no loss of energy to gravity. In fact, the paths of all molecules are accelerated to towards the surface, but because the atmosphere is evenly distributed over the Earth (to a reasonable approximation), the Earth is accelerated in all directions equally by this interaction, and hence not accelerated at all. The energy gained by gravitational acceleration of particles in the atmosphere is returned by elastic collisions at the surface. Further, collisions do not expend heat energy. You are assuming the statistical properties of a group of molecules must also be the properties of individual particles. The energy involved in the collision of particles is the kinetic energy of the particles, plus their individual rotational and vibrational energies. Collisions can result in the redistribution of energy amongst the particles, and the rotational/vibrational states, and can result in the emission of IR radiation. But there is no "heat energy" as a distinct property from the kinetic energy, and rotational/vibrational energy of the particles; and sum of the energies of the particles (including photons) involved is always conserved. -
scaddenp at 12:36 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
each time a collission occurs, there is a net loss of energy to gravity What?? gravity gains energy? I dont understand this comment at all. -
scaddenp at 12:34 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
We definitely need that that "GHE violates 1st Law" argeument. So RW1, where is the flaw in equations with SoD's simple model on do-trenberth-and-kiehl-understand-the-first-law-of-thermodynamics? -
Tom Curtis at 12:33 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1 @595, all energy "emitted" from the surface is radiative only because we do not talk about "emitting" convection, or evapo/transpiration. Not all energy flux from the surface, however, is radiative. In fact, only 80% of it is. And some of the energy flux carried by convection and evapo/transpiration makes its way to space. Do you deny that? -
Camburn at 12:30 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1: Please continue this discussion. You are doing an excellent job. One thing to remember in the conservation of energy is that each time a collission occurs, there is a net loss of energy to gravity. This also expends heat energy.Moderator Response: [DB] Huh? Source, please. -
Tom Curtis at 12:28 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1 @592: Questions 2, 3, 4, 6 and 7 are all answered "yes". For Question 1 and 5, the answer is "No". 1) The energy absorbed at the surface is the Incoming Solar Radiation absorbed at the Surface (approx 161 w/m^2) plus the Back Radiation absorbed at the surface (approx 333 w/m^2). If you do not include both terms, the result will inevitably show an inequality of energy flows! The energy leaving the surface is the surface radiation plus the convective flux plus the evapo/transpiration flux. Again, if you don't include all three terms, you will inevitably arrive at an inequality. Saying that 239 w/m^2 becomes 396 w/m^2 is to directly assert the non-conservation of energy. Note, your claim that my caclulations do not include the incoming non-reflected solar radiation, the out going longwave radiation, and the surface radiation is simply false. All are included at their appropriate places, as can be easily checked. 5) The surface radiation is a function of temperature and emissivity, which is not 1 at any location, though very close to 1 at most. @594: The incoming and outgoing energies are both radiative. All of the energy comes from the sun, but some of it is shuffled back and forth a bit before it leaves the system. (Total energy from other sources is, I believe, significantly less than 1% of the total, and can be ignored for practical purposes.) -
Camburn at 12:27 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1: Please continue this discussion. You are doing an excellent job. -
RW1 at 12:25 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE:590), "RW1 @586, until you can identify a physical mechanism whereby CO2 or H2O molecules in the atmosphere can determine the original source of the energy they are emitting, your claim is clearly wrong. Bear in mind that the emitting molecule may not have been the molecule that originally absorbed the energy, but may have gained it after a series of collisional transfers in the atmosphere." I'm not claiming trade offs do not occur between radiative and kinetic energy in the atmosphere - they clearly do, multiple times over I'm sure. The point is the net effect of all the trade offs have to be zero, because all the energy leaving at the top of the atmosphere is radiative and all the energy emitted by the surface is radiative. -
Rob Painting at 12:20 PM on 17 March 2011Maize harvest to shrink under Global Warming
Albatross - yes, I agree it is a concern. As you say much of Africa is subsistence, but the findings, which basically confirm some earlier research, indicate there are global implications. John D - it seems that the negative response to increased temperatures was not evident or very low in those areas where maize is more commonly grown. Don't know where you get that idea. if maize was previously thought to be tolerant of warming was there any real foundation for such opinion See Albatross' comment @ 16. Maize is a C4 plant and therefore more heat tolerant than it's C3 cousins. There's a large amount of literature on the topic. Agnostic - the study provides some hard data to back up the obvious implications of a warming world, and drought, on crop productivity. IIRC much of Africa will experiencing conditions 1 degree warmer than now in the 2030's. -
Tom Curtis at 12:07 PM on 17 March 2011What would a CO2-free atmosphere look like?
BP @70, it turns out I did make an error. Proceeding more accurately, the Modtran model is here. The settings are: CO2 exp 1 - 375 ppm, exp 2 0 ppm CH4 1.7 ppm; Trop Ozone 28 ppb; Strat Ozone Scale 1; Ground Temperatures Offest -0.5 Hold Water Vapour "Pressure"; Water Vapour scale 1; Locality 1976 US standard atmosphere Standard Cirrus Model Sensor altitude 70 km; lookdown Except for locality, offset temperature, cloud type and CO2 concentration, these are the default settings. Ground temperature is 287.7 degrees K. With 375 ppm, the OLR (Iout)is 239.582, a close approximation to the 239.8 w/m^2 black body radiation for a temperature of 255 K. With 0 ppm CO2, the OLR is 262.818 The difference is 23.236 w/m^2. The black body radiation of 262.8 degrees represents an effective temperature of 260.9 degrees K, or a change of 6 degrees over the case with CO2. Clearly you and Lindzen are still underestimating even the no feedback case for the removal of CO2.Moderator Response: [DB] Ok, not "utter". :) -
logicman at 12:07 PM on 17 March 2011One of the best climate change ads I've seen
deyanaus: thanks for the links. If you go to Ferdi Rizkiyanto's site and click on the image you get to download a much bigger jpg. The image is clearly marked as copyright of Ferdi Rizkiyanto. However, Ferdi has most generously licenced this image under the Attribution-NonCommercial-NoDerivs 3.0 Unported terms. Links: Ferdi Rizkiyanto Portfolio http://creativecommons.org/licenses/by-nc-nd/3.0/ -
RW1 at 12:01 PM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE: 587), I should also add: Do you agree that all of the 239 W/m^2 entering the system is radiative? Do you agree that because the atmosphere cannot create any energy of its own, 239 W/m^2 of the 396 W/m^2 at the surface has to come from from the 239 W/m^2 entering at the top of the atmosphere? -
Camburn at 11:47 AM on 17 March 2011Maize harvest to shrink under Global Warming
The parimiters of this study do not provide the required details to do a credible analysis. I will leave it at that. -
Eric (skeptic) at 11:31 AM on 17 March 2011Maximum and minimum monthly records in global temperature databases
Shoyemore, thanks for the reply. I think the approach of counting discrete events (ratio of record high over record lows) in a time series is valid, expected values are going to be higher according to your curve and you made a prediction that can be tested. But the way I look at the data prediction is simply that more events is better than fewer for making higher confidence predictions. Let's say there are 20 temperature measurement stations in New England and we count that the number of new monthly record maximums for 2010 is 50 per year and rising according to some fitted curve. Now let's say we just used one station, Boston, and counted 2 new monthly record maxes for 2010. Pick a different station away from the ocean, say Hartford, and there are 3 new monthly record maxes for 2010. Both are similar to the 50 new records for a total of 20 stations, but quite different from each other. The curve might be different for those 2 stations. None of the numbers are invalid, however a better statistical confidence is possible with from the 50 events per year, 20 station data versus 2 or 3 events per year for one station -
Daniel Bailey at 11:29 AM on 17 March 2011One of the best climate change ads I've seen
Prediction: The "skeptics" will be peeved by this one. So keep 'em comin'! The Yooper -
Riduna at 11:16 AM on 17 March 2011One of the best climate change ads I've seen
Not just striking but conceptually brilliant! -
Protector at 11:12 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis @ 590: Yes, this is exactly what I meant as you articulated it in the first paragraph of #590. Also, your reply to RW1 is right on! -
Riduna at 11:11 AM on 17 March 2011Maize harvest to shrink under Global Warming
So, what does this article tell us that we did not already know? To those who are concerned with the broader topic of food security in a warming world with a population expected to exceed 9 billion within 40 years – not much. To those who wonder what impact SLR and salt water flooding of river delta’s and low-lying fertile coastal plains will have on food production – even less. To those worried about the already failing adequacy of freshwater for agriculture in the face of diminishing mountain snow and glaciers – nothing useful. Academic research, publication of papers and debate thereon is undeniably important and is to be encouraged. However sometimes those efforts do seem rather specialised and esoteric in a world facing some very serious, relatively short-term problems, arising from the broader effects of AGW on food production. A dissertation on the effects on maize yield grown where temperature exceeds 30C by 1degree-day is important but does it deal with future real world conditions where average global temperature may rise by 2C by mid-century? -
RW1 at 11:07 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE: 587), "2) At the Surface: Absorbed Solar Radiation + Absorbed Back Radiation ~= Thermals + Evapo/transpiration + Surface Radiation <=> 161 + (10.6 + 48.8 + 50.1 + 222.6) ~= 17 + 80 + 396 <=> 493.1 ~= 493" There is 239 W/m^2 of post albedo coming in, 239 leaving at the top of the atmosphere, and 396 W/m^2 at the surface. Your energy flow calculations do not adhere to this; thus, Conservation of Energy is not being met. You don't seem to understand this, so I'll break it down into a series of separate questions and we'll go from there: 1. Do you agree that 239 W/m^2 of post albedo enters the system and ultimately becomes 396 W/m^2 at the surface? 2. Do you agree that the atmosphere cannot create any energy of its own? 3. Do you agree that 239 W/m^2 is leaving the system at the top of the atmosphere and all of this is radiative? 4. Do you agree that all of the 396 W/m^2 emitted by the surface is radiative? 5. Do you agree that the 396 W/m^2 emitted by the surface is a result of its temperature and nothing else? 6. Do you agree that latent heat and thermals are kinetic energy (non radiative) moved into the atmosphere from the surface? 4. Do you agree that because latent heat and thermals are kinetic, their energy moved into the atmosphere is in addition to or independent of surface emitted radiation? -
RickG at 11:02 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Ryan @ 589
Specifically, what is it that you guys don't understand about this diagram? You are trying to make it into something that it is not.
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Berényi Péter at 10:46 AM on 17 March 2011What would a CO2-free atmosphere look like?
OK, 195 K is -78°C. Still, it is much lower than global effective temperature in the 18-22.5 THz range. -
Tom Curtis at 10:40 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Protector @582, I could have stated (3) better, but it should do for current discussion. More accurately, the GHG concentration determines the altitude of the effective radiation. The need to balance incoming solar radiation with outgoing longwave radiation then determines the temperature at that altitude, which then governs the temperature at the surface by means of the lapse rate. DB, thanks, but I do not have entire confidence in myself. I try though. RW1 @586, until you can identify a physical mechanism whereby CO2 or H2O molecules in the atmosphere can determine the original source of the energy they are emitting, your claim is clearly wrong. Bear in mind that the emitting molecule may not have been the molecule that originally absorbed the energy, but may have gained it after a series of collisional transfers in the atmosphere.Moderator Response: Your first paragraph of this comment helped me a lot. -
JMurphy at 10:39 AM on 17 March 2011Republicans to Repeal Laws of Physics
Gilles, the 'debate' is between Creationism and Evolution, so that should convince you that not everything is settled - as it seems to have done with regard to AGW. Details are unimportant : the debate is all, apparently. As for global warming, please read these threads : The Big Picture Newcomers Start Here They should give you many assertions concerning global warming.Moderator Response: [DB] I appreciate your talents and determination, but hopefully by now you realize what you're dealing with. -
L.J. Ryan at 10:38 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RickG @ 580 "And again, the diagram is about the distribution of energy, not temperature. " Rick in what form can one quantify the "loose" atmospheric energy? As you say, it is not temperature, so how do you know is there...can it be measured? Measured of course, not based on temperature. And by what means is the atmospheric energy stored? -
Berényi Péter at 10:37 AM on 17 March 2011What would a CO2-free atmosphere look like?
#69 Tom Curtis at 05:39 AM on 17 March, 2011 The result was to increase OLR by 27 watts Impossible. You did something terribly wrong. The flux emitted by a black body between 18 THz and 22.5 THz (wavenumber 600 cm-1 & 750 cm-1) at 255 K is 39 W/m2. If current abundance of CO2 would decrease it by 27 W/m2, effective temperature of the photospehere in this frequency range would be 195 K (-102°C), which is way below any temperature ever observed in terrestrial atmosphere. -
Protector at 10:35 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1 @ 586: I think it was Tom Curtis, who made a comment earlier that it's difficult and probably physically not sound to try separating IR fluxes like that, because we are dealing here with absorption/re-emission NOT reflection of radiation. From what I've read elsewhere, these two processes are physically quite different ... But maybe the other experts would not agree. -
deyanaus at 10:34 AM on 17 March 2011Maize harvest to shrink under Global Warming
I'm a bit disheartened by the overall quality of comments, but hey just in case anyone is genuinely interested, here is a link to a similar study done recently for wheat in the conditions of NW Turkey. -
Tom Curtis at 10:32 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1 @583: 1) At the TOA: Incoming Solar Radiation ~= Outgoing Longwave Radiation + Reflected Solar Radiation <=> 341 ~= (40 + (6.4 + 29.2 + 29.9 + 133.4)) + 102 <=> 341 ~= 340.9 Check! 2) At the Surface: Absorbed Solar Radiation + Absorbed Back Radiation ~= Thermals + Evapo/transpiration + Surface Radiation <=> 161 + (10.6 + 48.8 + 50.1 + 222.6) ~= 17 + 80 + 396 <=> 493.1 ~= 493 Check! 3) For the atmosphere: Solar Absorbed by Atmosphere + Thermals + Evapo/transpiration + (Surface Radiation - Atmospheric Window) ~= Back Radiation + OLR emitted by atmosphere including clouds ~= 78 + 17 + 80 + (396 - 40) = (10.6 + 48.8 + 50.1 + 222.6) + (6.4 + 29.2 + 29.9 + 133.4) <=> 531 ~= 531 Check! All units in w/m^2. Slight errors introduced by rounding, and a slight inequality exists because the Earth is accumulating energy. Other than that, it all adds up if you make sure to use the correct figures. -
deyanaus at 10:26 AM on 17 March 2011One of the best climate change ads I've seen
The author is apparently Ferdi Rizkiyanto, an Indonesian (according to this site). His blog is here. -
johnd at 10:20 AM on 17 March 2011Maize harvest to shrink under Global Warming
Rob Painting at 09:00 AM, whilst I understand the purpose of the trials which is reflected in the majority of trial sites being in areas where maize is less commonly grown, it seems that the negative response to increased temperatures was not evident or very low in those areas where maize is more commonly grown. The two main areas seem to be are the region in the vicinity of Johannesburg and southern Nigeria which interestingly have different average growing temperatures with southern Nigeria at about 25°C being about 5°C higher than the main area near Johannesburg. If the findings of the study were applicable to those areas, then the yields of those crops in southern Nigeria must be only a small % of those around Johannesburg If it is not rational for technology to fix everything, is it rational to expect that maize should like temperatures over 30°C when, whilst it is grown in a wide range of conditions, the area where the greatest % of land is utilised for maize in Africa is in a more temperate zone? Also, if maize was previously thought to be tolerant of warming, was there any real foundation for such opinion, and if so on what was it based? -
adelady at 10:18 AM on 17 March 2011One of the best climate change ads I've seen
Excellent, John. Some people are really clever. I wish I'd thought of such a simple illustration - how to link heat-> melt-> sea level rise. And have it attractive enough for people to look at it long enough for the image and its message to stick. -
Gilles at 10:18 AM on 17 March 2011Republicans to Repeal Laws of Physics
JMurphy : I am not working with analogies. Each issue is to be examined separately. Do you have a precise assertion concerning creationism that you would try to convince me about ? do you have a precise assertion concerning global warming that you would try to convince me about ? I will examine each one seriously and I will tell you what I'm thinking of them. I never said that the existence of a peer-reviewed journal was a proof of veracity - me. "Well, one more try... Gilles, when you say that you are unable to make the determination yourself, but these people say X, that is a style of argument called an appeal to authority, whether you recognise it or not." No it's not, because I not claiming that something is true because somebody said it. I said some issues are open. That's different. " a) That's not true; Jim Hansen has proposed a phased-in carbon tax that would provide the mechanism to wean us off of fossil fuels without causing a crash." May be Hansen is a magician. I suggest him to teach chinese people how to develop without coal. b) "It's irrelevant; it's not really the climate scientists primary responsibility to say how we should reduce FF use. Their primary responsibility is to determine if there is a serious problem, and the consensus is 'yes', there is." I think there is a serious problem with car crashes , which kill a million people a year. It's scientifically proved - actually very easy to prove. Nobody contests it ! no contrarians, no denialist, for sure it's true. So i deduce that we should immediately ban all cars and stop making them. Do you agree ? what does Jim Hansen think of it ?Moderator Response: [DB] This has strayed far enough off-topic. -
RW1 at 10:14 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Protector (RE: 585), "I mean total down-welling long-wave radiation ..." It has to be separated, because what is determining the GHE and surface temperatures is precisely the amount of surface emitted that is coming back from the atmosphere. -
Albatross at 10:11 AM on 17 March 2011Maize harvest to shrink under Global Warming
Rob @15, It is worrying that a C4 crop (i.e., maize) does not fare well under high temperatures, b/c C4 vegetation has (up until now at least) tended to cope quite well with high temperatures. It also struck me in their Figure 3, that the Sahel region (an important crop producing region) is also expected to suffer yield losses under higher temperatures. Also, AFAIK, maize is also a staple crop in Africa. People also tend to forget that much of the farming in Africa is subsistence-type farming, and thus much more at the whim of heat, drought and flood. As an aside, apparently Canola also does not like temperatures above 30 C. From a paper by Kutcher et al. (2010, Agricultural and Forest Meteorology): "Iterative Chi square analysis and iterative principal components analysis both showed that the beginning of July, which coincides with the early part of the flowering period of the crop in SK [Saskatchewan, Canada], was the critical time in which high temperatures (>30 C) and low precipitation led to yield loss." -
Protector at 10:04 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1 @ 584: I mean total down-welling long-wave radiation ... -
RW1 at 09:50 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Protector (RE: 582), "1) Back radiation has a marginal influence on surface temperature due to the effect of convection;" If by 'back radiation' you mean downward emitted radiation that last originated from the surface emitted, then NO. -
RW1 at 09:46 AM on 17 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE: 559), "the total IR radiation from the atmosphere to space is 199 w/m^2. Of that, 6.4 w/m^2 will have been transported to the atmosphere by thermals, 29.2 would have been absorbed SW radiation, and 29.9 would have been carried into the atmosphere by convection." Let's run these numbers and see if they work: If 40 W/m^2 passes through the atmosphere, that leaves 199 W/m^2 emitted by the atmosphere, yes. 199 W/m^2 - 36.3 W/m^2 (6.4 + 29.9) emitted out to space from thermals and evaporation = 162.7 W/m^2. That leaves an additional 162.7 W/m^2 to be emitted. If you assume 29.2 W/m^2 (37.4%) is emitted directly from the 78 W/m^2 of the energy the atmosphere absorbs from the Sun, that leaves 133.5 W/m^2 that must come from surface emitted IR. It also means 48.8 W/m^2 (out of 78 W/m^2) total is radiated down to the surface. 161 W/m^2 is absorbed directly by the surface. 396 W/m^2 - 133.5 emitted to space = 262.5 W/m^2 emitted down to the surface. 161 W/m^2 + 262.5 W/m^2 + 48.8 W/m^2 + 60.7 W/m^2 = 533 W/m^2 (396 W/m^2 required). These numbers don't work.
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