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Comments 129251 to 129300:

129251. Patrick 027 at 16:04 PM on 10 December 2008
        Arctic sea ice melt - natural or man-made?
        Rossby Wave Wrap-up 1a. Linear superposition: For any amplitudes, multiple sets of vorticity anomalies have multiple wind fields associated with them, and each adds linearly to produce a total vorticity anomaly field with a total wind anomaly (which can be added to the basic state vorticity and wind to get total vorticity and wind). For relatively weak amplitudes (where displacments are relatively small compared to wavelength and variations in the basic state), the changes in vorticity over time due to potential vorticity advection by the wind field (which results in propagation of the vorticity anomaly patten) can also be approximated with linear superpositions of multiple vorticity anomaly patterns - each propagating in it's own way. However, the changes in potential vorticity anomalies are due to the displacements of potential vorticity contours. When displacements by all waves are along the same direction (with anomaly wind vectors purely parallel to that direction, such as occurs with vorticity waves with no variation in amplitude along the length of infinite phase lines), and with the basic state PV gradient (or at least the component parallel to the wind anomalies) constant along the same direction, and assuming constant ratio between PV anomaly and RV anomaly (it could vary due to different degrees of divergence and convergence due to ...), then the total displacement is equal to the sum of displacements of individual waves and the total resulting change of PV is the same at any x,y point, so the waves can still be linearly superimposed. However, more generally, there can be nonlinearities that arise because, 1. if the PV gradient varies along the direction of displacement, then the PV gradient can be changed at a fixed location by that displacment; an additional wave acting at the same location is no longer acting on the same PV field. 2. as the PV field is displaced by the anomaly wind, changes in the PV gradient can be produced (such as by variation in anomaly wind along phase lines) so that the change in PV produced by the next anomaly wind added are not proportional. 3. variation in amplitude of a vorticity wave along phase lines requires some closed streamlines - the anomaly wind varies in direction. PV contour displacements in one direction can alter the PV gradient in another direction. 4. Maybe some other things I haven't thought of yet. ** In particular, in the case (**CASE C1a** for future reference; **CASE C1b** will refer to a case when the PV gradient is not entirely in the y-direction) of a vorticity wave phase lines aligned in the y direction, phase propagation in the negative x direction, basic state PV gradient in the y direction, where the vorticity wave amplitude is a maximum at y = 0 and decays to 0 toward y = A and y = -A (while being symmetrical about the x axis), then, at y = 0, the anomaly wind only has components in the y direction, but away from the x axis, the anomaly wind also has x components. As the wave propagates in the negative x direction, setting aside the basic state wind, the air flows through the wave in the opposite direction at the phase propagation speed at y = 0, but the x component of the wave alternately varies the flow through the wave, causing the air to spend more time within one phase of the wave and less in the other, and affecting the resulting displacements of PV contours; the result is to sharpen and intensify the vorticity wave crests and spread out and weaken the vorticity troughs on one side of the x axis and the reverse on the other side. Obviously this effect must increase when the x component of the anomaly wind is large compared to the phase speed in the x direction. (Some analogy might be made to water gravity waves when the back-forth displacements are large in comparison to the wavelength; in which case the crests are sharp and the troughs are broad). Of course this change in wave form could modify the propagation itself... ---------- The vorticity wave has a wind wave, with components u' and v', in the x and y directions respectively; they will be (below somewhere) be refered to as the u' wave and the v' wave. 1b. wave numbers, phase speeds, group velocity: Remember that the wave numbers (k in the x direction, l in the y direction (though I've also seen l,m instead of k,l used), which add as vector components to give the wave vector (k,l)) are inversely proportional to the wavelength (1/k in the x direction, 1/l in the y direction, 1/(wave vector magnitude) in the direction of the wave vector, which is *THE* wavelength, in the direction perpendicular to phase lines). Because phase speeds are the speeds of phase lines and thus proportional to wavelength (equal to wavelength times frequency); the phase speeds don't add like vectors; but their inverses do. But if I ever refer to 'phase velocity', that might not be a correct term, but what I am refering to is the phase speed in the direction of the wave vector (perpendicular to phase lines). Group velocity is the motion of a pattern of amplitude variation of a wave (for a wave pattern with amplitude varying in space); group velocity is a vector that is the sum of group velocity components in the x and y direction (or any two orthogonal dirctions, such as parallel and perpendicular to phase lines). 2a. Linear superposition and patterns, group velocity: Consider waves of constant amplitude with wave numbers k and l. For waves with l = 0, phase lines are in the y direction. Waves with l = 0 but different k form an interference pattern with amplitude varying in the x direction. If the two k values are only slightly different, then the interference amplitude pattern moves in the x direction at the group velocity of the wave with a k equal to the average of the aforementioned two k values. This can be seen using one of the trigonometric relationships: 2 * cos(a) * cos(b) = cos(a+b) + cos(a-b) = cos(a+b) + cos(b-a) 2 * sin(a) * sin(b) = cos(a-b) - cos(a+b) = -[cos(a+b) - cos(a-b)] 2 * cos(a) * sin(b) = sin(a+b) - sin(a-b) = sin(a+b) + sin(b-a) OR, where sum = a+b and dif = a-b: 2 * cos(a) * cos(b) = cos(sum) + cos(dif) = cos(sum) + cos(-dif) 2 * sin(a) * sin(b) = cos(dif) - cos(sum) = -[cos(sum) - cos(dif)] 2 * cos(a) * sin(b) = sin(sum) - sin(dif) = sin(sum) + sin(-dif) ---------- 2b. So the linear superposition of: cos[(k+dk)*x - (w+dw)*t] and cos[(k-dx)*x - (w-dw)*t] is: 2 * cos(k*x - w*t) * cos(dk*x - dw*t) Which can be seen (assuming |dk| << |k|, |dw| << |w|) as: a wave cos(k*x - w*t), which has x-direction wavenumber k and angular frequency w, and phase speed in the x direction equal to w/k, (we expect w/k to be negative for PV gradient in the positive y direction), modulated by an 'amplitude wave': 2*cos(dk*x - dw*t), which has wavelength 2*pi/(dk), and moves in the x-direction with the x-component of group velocity dw/dk. There is no variation in the y-direction of this pattern. Call this **CASE C0** (This is nicely explained in Appendix A of Cushman-Roisin.) ---------- 2c. MORE GENERALLY, The linear superposition of: cos[(k+dk)*x + (l+dl)*y - (w+dw)*t] and cos[(k-dx)*x + (l-dl)*y - (w-dw)*t] is: 2 * cos(k*x + l*y - w*t) * cos(dk*x + dl*y - dw*t) Which can be seen (assuming |dk| << |k|, |dl| << |l|, |dw| << |w| **(actually, the last condition may not be necessary, but in the limit of small dw, dw/dk and dw/dl can be treated as partial derivatives of w as a function of k and l, in other words as the components of the gradient of w in k,l space) as: a wave cos(k*x + l*y - w*t), which has wave vector (k,l) and angular frequency w, and phase speeds in the x direction equal to w/k, and in the y direction equal to w/l; the phase lines have slope dy/dx = -k/l modulated by an 'amplitude wave': 2*cos(dk*x + dl*y - dw*t), which has wavelength 2*pi/[(dk^2 + dl^2)^(1/2)], and has ** group velocity (dw/dk,dw/dl) **. ----- 2d. **???(PS why is group velocity given as a vector with components in the x and y direction? These components are the velocities in those dimensions of a point on a 'phase line' of the 'amplitude wave' that doesn't (in this case, at least** - more generally the group velocity is the velocity of an 'amplitude region' which may not be infinitely long and straight) move along the length of the 'phase line', only perpendicular to it, keeping up with it. The reason why phase speeds in x and y directions don't add as vectors to give the 'phase velocity' is because they are not generally the components of motion of such a point on the phase line; rather they are the speeds of motion of the points that are the intersections of a phase line with a line parallel to the x-axis and then a line parallel to the y-axis. )???** ---------- 2e. When l = 0 and dk = 0, the pattern is: the linear superposition of: cos[k*x + dl*y - (w+dw)*t] and cos[k*x - dl*y - (w-dw)*t] which is: 2 * cos(k*x - w*t) * cos(dl*y - dw*t) Which can be seen (assuming |dl| << |l|, |dw| << |w|) as: a wave cos(k*x - w*t), which has wave vector (k,0) and angular frequency w, and phase speeds in the x direction equal to w/k, modulated by an 'amplitude wave': 2*cos(dl*y - dw*t), which has wave vector (0,dl), and has group velocity (0,dw/dl). Call this **CASE C2** **CASE C2a**: Now, in this case, if the basic state PV gradient is in the y-direction (the 'default setting' for this overall discussion), then for Rossby waves, dw/dl should be zero at l=0. There is 'amplitude wave' propagation in the y direction; the phases propagate in the negative x direction. **CASE C2b**: But if there is a basic state PV gradient in the x-direction as well, then dw/dl can/will be nonzero and there will be 'amplitude propagation' in the y direction. Physically, without reference to the motion of the linearly-superimposed components that create the pattern (though it could be understood that way as well for small amplitudes), the reason for this is qualitatively the same as **PART OF** the reason for 'amplitude propagation' in the same direction in **CASE C1b**, which is that, as the amplitude varies along phase lines, there are vorticity maxima and minima that are maxima and minima in both dimensions x and y. This means that the anomaly wind streamlines are closed loops; not only is there a v' wave but also a u' wave. u' is positive where the vorticity anomaly decreases in y and is negative where the vorticity anomaly increases in y. When the basic state PV contours are not parallel to the x-axis, this x-component of the wind displaces those contours so as to propagate variations in amplitude along the phase lines. If the x-component of the PV gradient is toward positive x, then this along-phase-line propagation is toward positive y; it is in the negative y direction for a PV gradient x-component in the negative x direction. Notice if we realign the axes with the PV gradient then the phase lines are tilted and this describes the component of group velcocity parallel to phase lines. In **CASE C2b** in particular, the u' wave has crests and troughs at the nodes of the 'amplitude wave', just as v' has crests and troughs at the nodes of the vorticity wave that occur at discrete x values (at any one time). The nodes of the wind waves pass through the vorticity maxima and minima - which is a quick way to make the judgement that the vorticity maxima and minima keep the same amplitude as they propagate along phase lines ('amplitude propagation') while the phase lines also propagate. In **CASE C0**, the group velocity is perpendicular to phase lines and generally of different magnitude and/or direction as phase propagation, which requires that, following individual phase lines, the vorticity maxima and minima grow and shrink, and reverse sign; this requires that the wind wave nodes not pass through the vorticity wave crests and troughs except at the 'crests' and 'troughs' of the 'amplitude wave'. Notice that in **CASE C2**, rather than refering to one wave field modified by 'amplitude waves', the pattern instead can be described as a checkerboard pattern of rectangularly shaped vorticity wave phases (with u' and v' wave phases also rectangular). The along-phase line 'amplitude propagation' can also be desribed as the y-component of phase propagation of this checkerboard pattern. This becomes more obvious if |dl| is not much smaller than |k| (in which case it doesn't make sense to keep the 'd' - call it l instead of dl). What is also true is that the the identification of the 'amplitude wave' can be assigned to the other part of this pattern (the part with wavenumber k), which becomes more obvious when |l| is larger than |k|. Another point that is interesting, which applies to all cases **CASE C1** and **CASE C2**, is that because -du'/dy makes a contribution to vorticity anomalies (generally with the same sign as dv/dx for the cases as described) , dv'/dx will be smaller for the same vorticity anomalies, which means that, for the same vorticity wave amplitude and wavelength in the x direction, v' wave will have smaller magnitude than otherwise, more so as the magnitude of dl increases (as the wavelength in the y direction shrinks, or more generally, as the spatial scale of the vorticity variations in the y-direction shrinks, for a given vorticity variation). (and the same for u' when the x-direction wavelength shrinks for a given y-direction wavelength, etc.) This means that for the conditions so far and for the same ratio between anomaly PV and anomaly vorticity, the propagation in the x direction will be slower for given vorticity variation over shorter y direction distances (and so on for y-direction propagation with shorter x direction distances). to be continued just a bit more... _______
129252. Wavelength at 20:58 PM on 9 December 2008
        Water vapor is the most powerful greenhouse gas
        Somewhere around 50% of the world’s CO2 and 75% of the AWV is produced by large point sources, in contrast to natural evaporation from oceans or lakes - so to me it seems reasonable to ask if this is likely to affect climate models. I have not seen it mentioned in the reading I have done. Since your previous response, I have looked on the web and found some information, such as: http://ams.confex.com/ams/88Annual/techprogram/paper_136670.htm This shows an average height of plumes above wildfires to be 2.3 km worldwide with 3 km for North America. This presumably only refers to the visible plume from particles/cloud formation, but is quite a bit below the 10-15 km that I had in mind. Also, the updraft from wildfires is probably hotter than from cooling towers, although with a lower relative humidity. The point-source question remains to niggle me. I suspect it is not significant, but still have no definitive argument to dismiss it.
129253. HealthySkeptic at 11:41 AM on 9 December 2008
        Evaporating the water vapor argument
        #27 Douglas, LOL! It is very ironic that your comment "its humor depends on the listener being scientifically illiterate or willing to make oneself temporarily illiterate for the sake of an ideology" applies equally well to the vast majority of AGW alarmists.
129254. HealthySkeptic at 11:30 AM on 9 December 2008
        Global warming stopped in 1981... no, wait! 1991!
        #16 I agree with your point (i), however I think unwarranted fear is what's being generated by some people's interpretation of the evidence... that and the media sensationalisation of the extreme, potential consequences of that evidence.
129255. Mizimi at 05:54 AM on 9 December 2008
        Human CO2 is a tiny % of CO2 emissions
        "Likewise with the Earth's atmopheric CO2 concentration. For millions of years the earth's atmospheric CO2 concentration has been in dynamic equilibrium...." So what is the 'equilibrium position' of CO2 over these millions of years? 200ppm? 1500ppm? 4000ppm?
129256. Mizimi at 05:16 AM on 9 December 2008
        Was Greenland really green in the past?
        #5 'Iceland' is from the old Norse word meaning 'isle' co-joined to 'land' thus giving (phonetically) 'iceland'
129257. paledriver at 02:09 AM on 9 December 2008
        There is no consensus
        #88 Can you provide some links for your claims? Thanks in advance.
129258. Mizimi at 01:14 AM on 9 December 2008
        Water vapor is the most powerful greenhouse gas
        Wavelength: Air temperature decreases with altitude..this is called the 'lapse rate' and is approx -6.5C/km, so at around 5km the air temp is -13C and the pressure is about 0.5bar (half surface pressure). As WV content of air is temperature/pressure related then the amount of WV decreases as you ascend. Both these factors influence how high the plume can ascend without 'external' help from air turbulence or other factors. Therefore I would expect a greater warming effect from WV at surface level ( say up to 500metres)and then a steady decline towards zero at around 3000m
129259. Quietman at 05:15 AM on 8 December 2008
        Arctic sea ice melt - natural or man-made?
        Arkadiusz At least you are a scientist. Many of us posting here can't even say that. Personally I find your comments (and Patricks) quite interesting.
129260. Quietman at 05:10 AM on 8 December 2008
        It hasn't warmed since 1998
        Mizimi Yes and it's always GISS data used by the alarmists.
129261. Quietman at 05:06 AM on 8 December 2008
        Latest satellite data on Greenland mass change
        Mizimi Actually I would love to see it extended back to 1975, just before the current bout of tectonic activity.
129262. Steve L at 07:25 AM on 7 December 2008
        Latest satellite data on Greenland mass change
        Thanks for keeping this excellent resource up to date!
129263. Mizimi at 04:48 AM on 7 December 2008
        Water vapor is the most powerful greenhouse gas
        Wavelength: The answer is : It depends! I live 26km from a coal fired power station/cement works and when the prevailing wind is northerly I can see, out at sea a horizontal band of brown haze..the plume. On other days with higher winds it disperses more quickly and does not appear here. On still winter days smoke from local bonfires rises straight up and flattens out at around 100m and is dispersed by around 200m How high and far the plume goes depends entirely on 'local' weather conditions. Back a few years the scandinavian countries suffered 'acid rain' from british power stations.
129264. Mizimi at 04:31 AM on 7 December 2008
        Temp record is unreliable
        Your quite right Chris; apologies.
129265. Mizimi at 04:24 AM on 7 December 2008
        There is no consensus
        #88 Yes we have a lot of facts, some hard, some soft (paleoproxies for example), some incorporated into models and some unable to be included in detail (clouds and water vapour); do we know all the facts or even enough to make decisions that will adversely affect the lives of millions of people? Are those models sufficiently close to reality to act upon? Ah but, you will no doubt say, global warming will affect millions of people too.........according to those imprecise models. Recent GMT history says different. I don't disbelieve in human induced warming, I just don't accept the projected figures because it doesn't appear to be happening at the rate predicted, and those models are unable to incorporate components that have a major impact on the resultant. So why would I trust them?
129266. Wavelength at 00:31 AM on 7 December 2008
        Water vapor is the most powerful greenhouse gas
        A fine debate! Thanks to both of you. The questions are probably as important as the answers. If cooling towers are significant contributors to global warming, the alternatives to coal-fired power stations need to be reassessed. Surely there is a complication, though. The effluent from chimneys and (probably) cooling towers forms plumes, which are not only blown down-wind but also rise up through the atmosphere, cooling as they do so, remaining warmer and lighter than the surrounding atmosphere until completely mixed. I have a vague (and unsubstantiated) idea that these plumes rise to considerable altitudes – so is it possible that a large part of the AWV (and CO2) mixes into the atmosphere at the middle or top of the troposphere? Here, the influence of the AWV might be more significant… I have limited knowledge of climate modelling, so find it difficult to progress this idea. Any comments would be gratefully received.
129267. chris at 11:19 AM on 6 December 2008
        Global warming stopped in 1981... no, wait! 1991!
        Well yes HS. I'm sure we would all agree that: (i) fear isn't "the greatest behavioural driver of mankind" and: (2) that when it comes to understanding the greenhouse effect, the consequences of massive enhancement of greenhouse gas concentrations, and so on, we should consider the scientific evidence and not resort to conspiracy theorising, or pseudo-psychoanalysis. It's all about the evidence isn't it...? I hope we would all agree on that. We don't pretend that these aren't serious issues by raising ludicrous shcoolboy psychoanalytical notions about "externalising" our "untenable" "perpetual state of fear"! What's your opinion?
129268. chris at 11:02 AM on 6 December 2008
        Models are unreliable
        Come off it Dan.. 1) re "quiet sun". We're smack at the bottom of the solar cycle. Nothing surprising, or out of the ordinary, about that. For the last couple of years the very small reduction in solar irradiation has been opposing greenhouse-induced warming a tad...in a couple of years it will be supplementing greenhouse-induced warming. Not sure what point you're attempting to make about the fact that the sun is at the bottom of its solar cycle! 2) re Milankovitch cycles. No one says that "all temperature trend direction changes are brought about by Milankovitch cycles", so let's not make stuff up! Otherwise, I suspect that you haven't read the papers I cited. You need to come to some decision about whether you want to understand this stuff or not. Remember that the 100,000 year, the 41,000 year and the 23,000 year cycle are out of phase. So it's quite straightforward to understand how the net insolation effect can produce a pattern of cyclical temperature variation as observed in the record. So, for example, if the delta T or delta 18O records from the Dome Fuji or Vostok cores are Fourier transformed to extract their power spectra, the three dominant Milankovitch cycles stand out rather clearly (111 kyr; 41 kyr; 23 kyr). see, for example, Figure 2 of: Kawamura et al (2007) "Northern hemisphere forcing of climate cycles in Antarctica ove rthe past 360,000 years" Nature 448, 912-919. It really is difficult to see your problem....insolation changes due to Milankovitch cylces seem to have dominated temperature (and atmospheric CO2 concentration) variations during the ice age cycles. I suggest you have a more careful read of the article whose url you cited. It gives a pretty good account: http://www.physics.ohio-state.edu/~wilkins/energy/Companion/E16.7.pdf.xpdf Sadly, I suspect you're never going to get the simple and obvious truth that significant insolation changes due to the slow cyclical orbital properties of the Earth, can result in temperature changes that result in slow drops in temperature in advance of changes in atmospheric CO2 concentrations. Happily, competent scientists and policymakers don't seem to share your mental blockage! One of the things that you haven't commented on with respect to the temperature and CO2 changes due to Milankovitch effects, is the really very, very small changes in atmospheric CO2 concentrations [see for example: http://www.skepticalscience.com/co2-lags-temperature.htm]. So some of the changes over which you are very confused involve extremely small changes in atmospheric CO2; e.g. reductions of 10 or 20 ppm of atmospheric CO2 during several thousands of years. These changes are very likely a consequence of the very slow temperature drop that results from insolation changes. The amplify the cooling as expected from the basic physics of the greenhouse effect. But these changes are pretty small (i.e. changes within the major glacial-interglacial transitions). There the sorts of changes occurring over thousands of years that we are now seeing in 4-5 (10 ppm) or 8-10 (20 ppm) years at the current rate of expelling massive amounts of greenhouse gases into the atmosphere. So the Earth is warming at a rate that massively exceeds the very slow temperature changes due to the very, very slow Milankovitch cycles. During ice age cycles insolation changes dominated temperature changes with warming effects resulting in water vapour, CO2 and albedo feedbacks. Now during an extraordinarily miniscule time period in relation to the vast millenia of the ice age transitions, a rapid increase in temperature is occurring during a period of relatively constant insolation as a result of a massive hiking upwards of the atmospheric greenhouse gas concentration (with water vapour and albedo feedbacks as we can measure in the real world). It ain't rocket science Dan! And I'm afraid that blanket dismissal of scientific research that doesn't accord with your agenda, is taking conspiracy theorising too far!
129269. Mizimi at 06:30 AM on 6 December 2008
        Water vapor is the most powerful greenhouse gas
        The article concerns itself with radiative forcing and positive feedback and does not address basics.... The mass of CO2 in the atmosphere is around 3x 10E15 kg. The mass of WV is around 12.7 x 10E15 kg. The specific heat of CO2 @ 275K is 0.819kj/kg The specific heat of water @ 275K is around 4.2kj/kg Simplistically ( I can see the objections coming!) the heat content increase for a 1C temp increase is thus: CO2: 3x10E15 x 0.819 x 1 = 2.45 x 10E15 kj Water: 12.7 x 10E15 x 4.2 x 1 = 53.3 x 10E15 kj IE: the heat content available from wv is 22 x greater than CO2 disregarding any IR effect.
129270. Mizimi at 05:54 AM on 6 December 2008
        Latest satellite data on Greenland mass change
        It would be interesting to see the graph enlarged and extended back beyond the Gakkel ridge event in 1999, and a comparison with NA current flow and temps.
129271. Mizimi at 05:18 AM on 6 December 2008
        It hasn't warmed since 1998
        Interesting that only GISS still indicates a +ve trend whilst the other three show negative. roughly a +1C for GISS and -0.5C for the rest.
129272. Mizimi at 04:49 AM on 6 December 2008
        Can animals and plants adapt to global warming?
        Ps: Chris; I am not 'propagandising' against the science that 'might' find a solution to this problem. I am unconvinced that the 'problem' exists in the magnitude that is being proposed, especially since the 'science' is currently incapable of modelling what is going on to a reasonable degree of accuracy. In addition, the GMT ( which is actually a mathematical artefact and does not exist) 'record' indicates a rise of less than 2C by the end of this century. Hardly enough to cause panic attacks. Not only that, but I am skeptical that a)the root of the problem is just CO2 from fossil fuels and b)that even if it was, the chances of getting global action to reduce FF usage are pretty slim ( politicians being what they are). We already have countries pulling out of or ignoring agreements to reduce emissions ( The US, Canada, Australia to name but three, one of which is the biggest consumer...guess which) so either they don't care OR they know something we don't.
129273. Dan Pangburn at 12:26 PM on 5 December 2008
        Models are unreliable
        In post #68 Chris says “What quiet sun?” There are several agencies that report on solar activity that Chris could have accessed to find out. NOAA has revised several times their predictions of the magnitude and delay of the start of cycle 24. An animated display of the revisions can be viewed at http://wattsupwiththat.com/2008/10/05/nasa-moves-the-goalposts-on-solar-cycle-24-again/ . A day-by-day report of solar activity is available at http://www.dxlc.com/solar/ and http://www.swpc.noaa.gov/forecast.html. Numerical monthly sunspot averages since 1749 are at ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/MONTHLY. As can be observed, the sun remains quiet, even for a solar minimum. The assertion that all temperature trend direction changes are brought about by Milankovitch cycles is rejected by history and logic. The longest Milankovitch cycle is about 100,000 years and has been associated with the glacial/interglacial cycle. Most have determined that it accounts for about half of the glacial/interglacial climate change. The shortest and much weaker 23,000 year Milankovitch cycle explains only about 10% of the variance (http://www.physics.ohio-state.edu/~wilkins/energy/Companion/E16.7.pdf.xpdf) . There is no mechanism by which any Milankovitch cycle could cause the observed temperature trend changes that last only a few millenniums or so. Chris has finally (albeit inadvertently) conceded that average global temperature uptrends and downtrends take place irrespective of the atmospheric carbon dioxide level with the statement in post #78 “a temperature downtrend at high/highish atmospheric CO2 levels only means that the particular driver of the temperature trend at that particular time is variation in insolation”. Think about it. A temperature downtrend continuing for a millennium or so with the carbon dioxide level higher at any given temperature than it was during a prior uptrend. The Vostok data show repeatedly a temperature uptrend changing to a downtrend with the carbon dioxide level during the downtrend higher than it had been during the uptrend. The NOAA data are graphed at the Middlebury web site given at post #41 or at http://www.roperld.com/science/CO2_Temp.pdf . No amount of spin or deception can alter that this proves that significant net positive feedback does not exist. Without the imposition of significant net positive feedback by the GCM users, the GCMs do not predict significant global warming. The many references that Chris likes to list are evidence of the group-think mentality that permeates the climate scientist community who benefit from dire predictions.
129274. Mizimi at 06:22 AM on 5 December 2008
        Can animals and plants adapt to global warming?
        Chris: Whether an extinction of a species is 'good' or 'bad' really depends on whether it's you or not, in other words, on your personal perspective. From a world view, the best thing might just be the extinction of Homo Sapiens Civilis!
129275. Mizimi at 05:57 AM on 5 December 2008
        What does CO2 lagging temperature mean?
        Philippe; In general I agree with what you are saying, but life started with very low biodiversity and until cyanobacteria started putting O2 into the atmosphere remained so. Since then, as Chris has adequately pointed out, various catastrophes have severely affected life in terms of diversity and quantity. Curiously,most of the life forms on earth seem hell-bent on overwhelming anything else ( particularly the smaller varieties) regardless of the consequencies? And you final comment is in agreement with my view that life adapts to fill any and all possible vacuums, so that loss of one species is an opportunity for another to take over that niche.
129276. paledriver at 00:59 AM on 5 December 2008
        There is no consensus
        #83. Yes that claim WAS made..."The American Physical Society, an organization representing nearly 50,000 physicists, has reversed its stance on climate change and is now proclaiming that many of its members disbelieve in human-induced global warming. " from Daily Tech.. so you got it wrong, again. and Mizimi, scientists have come to a consensus BECAUSE of the haed, irrefutable facts. and it's a growing consensus because of there continues to be more hard, irrefutable evidence uncovered. meanwhile, the other side consists mostly of former big tobacco schills who once told us there is no science to link smoking with lung cancer. remember that when you're picking your team.
129277. Mizimi at 06:02 AM on 4 December 2008
        Water vapor is the most powerful greenhouse gas
        Some figures from the World Water Council on evaporation from human sources (not abstraction which is much much higher) 1940 1950 1960 1970 1980 1990 2000 50...80..155..245.. 285..320..515 figures in cubic k's and exclude agriculture and domestic/municipal usage. Including these quadruples the figures. It is clear from the data that AWV has been steadily increasing since 1940 and thus the average global atmospheric water content will have risen since the atmosphere is not saturated. This addition occurs at low altitudes...precisely where one expects the warming effect of GG's to be the greatest.
129278. HealthySkeptic at 15:01 PM on 3 December 2008
        What 1970s science said about global cooling
        Re #17 That's nonsense of course. To critically question scientific evidence is not the same as denying it. It's part of the scientific method. However;- To deny a scientific fact is indeed undeniably stupid. To deny an unproven hypothesis is healthy skepticism. Let me know when AGW becomes a scientific fact.
129279. HealthySkeptic at 14:30 PM on 3 December 2008
        Global warming stopped in 1981... no, wait! 1991!
        Re #14 That's rubbish of course. What has that load of "schoolboy pseudo-psychoanalysis" have to do with "atmospheric, ocean and radiative physics"? -)
129280. HealthySkeptic at 14:09 PM on 3 December 2008
        The Mystery of the Vanishing Ocean Heat
        Chris, Get down off your high horse for a minute and calm down a bit. Wildly accusing people of having "creepy agendas" is in itself more than a bit creepy. The source you ask about is Dr. Nils-Axel Mörner. Specifically, comments he made in an interview which appeared in Executive Intelligence Review, June 22, 2007 An abridged version can be found here;- http://www.ourcivilisation.com/aginatur/sealevel.htm No doubt you will denegrate the poor man severly, as you seem to do with any researchers who disagree with your AGW paradigm. Yet, it still seems strange that if there is such a supposed “scientific consensus” on AGW that so many prominent scientists (especially those in directly-related fields of research) are having second thoughts. Perhaps it's the early signs of a forthcoming paradigm shift. ;)
129281. HealthySkeptic at 13:03 PM on 3 December 2008
        Misinterpreting a retraction of rising sea level predictions
        Re #16, Chris, Despite a very verbose reply in refering to #14, you totally ignored the point of my post, which was in direct response to John's claim that; "They (Fawcett and Jones) find the linear trend over 1998 to 2007 is a warming trend in all three data-sets." My point was that, based on the data sets presented in figure 2 above, the linear trends only appear to trend very slightly upward because of the skewing effect of the two lowest points in 1999 & 2000. There is therefore no credible warming trend in the data presented at all.
129282. chris at 09:57 AM on 3 December 2008
        Global warming stopped in 1998, 1995, 2002, 2007, 2010, ????
        Yes there's no doubt that the effects of the solar cycle are "overshadowed" by internal variations in the climate system. After all the peak to trough surface temperature variation between the solar cycle max and min is around 0.1 (maybe as much as 0.18) oC. Since year on year variation in the Earth's temperature anomaly can easily be 0.1 oC, the solar cycle doesn't really show up in the surface temperature record without efforts to deconvolute this. In general we expect the sun to contribute a little cooling during the solar minimum and a little warming (supplementing greenhouse gas warming) around the solar max. But just like the damped solar cycle contribution to the Earth's surface temperature, so the seasonal temperature variation is damped. For example if, rather than a seasonal drop in insolation where you live, the sun changed its output to give a constant insolation corrsponding to the cold season insolation, the water in the sea where you live would get a whole lot colder than 17 oC. But it would take a while for this new horribly cold temperature to settle at a new chilly equilibrium temperature.....
129283. chris at 09:41 AM on 3 December 2008
        It's the sun
        Not really Mizimi. The chemistry performed by living organisms is catalyzed by enzymes. Enzymes can be exquisitively sensitive to the chemical nature of their substrates, able to distinguish between stereoisomers (e.g. L- or D-amino acids) and showing rather significant preferences in relation to different isotopes of atoms such as 1H/2H; 12C/13C; 16O/18O and so on. The deposition of carbonates, for example, is thermodynamically controlled by the solubility properties of the salts which are very little affected by isotopic composition (12CO3-- cf 13CO3--). That's not to say that physical process don't result in some useful "fractionation" of molecules according to their isotopic composition. For example during cold periods, snow and rain from evaporated water tends to be very, very marginally enriched in 16OH2 since it takes a tiny bit more thermal energy to evaporate an 18OH2 molecule cf a 16OH2 one, and this can be used to determine paleotemperatures in ice cores, for example. However the fractionation of 12C over 13C by photosynthesising organisms is much larger.... We don't expect to see a measurable difference in 12C vs 13C in sea water except to the extent that the exchange of aqueous CO2 [CO2(aq) <--->H2CO3] and atmospheric CO2 results in a tendency for the oceanic CO2 to equilibrate with the continually-less-depleted 12C in the atmosphere that results from the return of long, long-sequestered 13-C-depleted carbon back into the atmosphere from burning massive amounts of fossil fuels.
129284. chris at 09:17 AM on 3 December 2008
        Human CO2 is a tiny % of CO2 emissions
        Not really Mizimi... Our understanding of the natural world is not defined by one individual's ignorance! If you don't know very much about a topic why not make an effort to inform yourself befoe sounding off? Try googling "dynamic equilibrium". Far from being an "oxymoron" it's a fundamental descriptor of phenomena that involve the summation of a number of (opposing) processes whose net effect constitutes a balance to an extent that is further definable by the amplitude of variation around the equilibrium position. When applied to reversible chemical reactions the variation around the equilibrium (concentration of reactants and products, for example) can be small small. When applied to Earth processes it can be somewhat larger.. ...it would be foolish to "invent a new word" for such a well-characterized phenomenon as "dynamic equilibrium". The temperature in a room that results from the opposing forces of heat loss and heat input controlled by a thermostat is an example of a "dynamic equilibrium". If one needed further description of the nature of the fluctuations around the equilibrium one could explore/measure these. Likewise with the Earth's atmopheric CO2 concentration. For millions of years the earth's atmospheric CO2 concentration has been in dynamic equilibrium between the forces of volcanic influx into the atmosphere and the efflux from weathering and carbonate "fixing" (supplemented during the last couple of million of years with glacial cycles that temporarily perturb the equilibrium CO2 concentration downwards during glacial periods). In other worlds, since the atmospheric CO2 concentrations haven't varied very much during this period as far as we can tell (apart from the ice age excursions), the evidence indicates that the atmospheric CO2 levels have been in "dynamic equilibrium" (until recently, when they've started progressing upweards at a very very fast rate). Incidentally your misinformed request for semantic rigour on the subject of equilibria is rather out of keeping with your craven acceptance of the most ludicrous and blatant tosh on plaeotemperature data or pre-present atmospheric CO2 data, and so on. You need to come to some decision about where your "standards" lie science/evidence-wise, and then apply these across the board!
129285. chris at 08:27 AM on 3 December 2008
        Temp record is unreliable
        We're not talking about modeling Mizimi. We're talking about measuring.
129286. Mizimi at 23:08 PM on 2 December 2008
        It's the sun
        Question: plants show a preference for C12 - true. But plants only have chemistry to work with ( not nuclear processes) so how do they manage that? And if they do it solely by chemistry then it follows other chemical processes can do it too.?? Oceanic plant life also prefers C12, so we should see the amount of C13 dissolved in sea water increase in respect of C12....is this the case??
129287. Arkadiusz Semczyszak at 21:43 PM on 2 December 2008
        It's ozone
        „while temperature trends continue upwards” - I don’t see it. And I looking in: the 1996-2008 period ( see for example http://wattsupwiththat.com/2008/03/11/to-tell-the-truth-will-the-real-global-average-temperature-trend-please-rise-part1/)) GISS , HadCRUT, UAH_MSU and RSS_MSU - cumulative seasonal differences temperature. The trends is reverse, not upwards, but same decreased or = 0, ± as exactly the ozone trend. All arguments for “It's the ozone…” are on: http://omsriram.com/GlobalWarming.htm. About UV radiation on the Earth surface, decide a ozone concentration with lover stratosphere, so temperature in this layer (http://www.atmosphere.mpg.de/media/archive/1385.jpg - it’s same different than above-mentioned Figure).
129288. Patrick 027 at 15:18 PM on 2 December 2008
        Arctic sea ice melt - natural or man-made?
        "Thus it makes some sense that a 'gradient wind balance',"..."total effective local f value (f_loc, see Bluestein p. 190) equal to f + 2*V/R"... Actually it is some aspect of the gradient wind balance, and of course, to make complete sense of that requires some other math...
129289. Patrick 027 at 15:14 PM on 2 December 2008
        Arctic sea ice melt - natural or man-made?
        I just realized I made a mistake in describing vorticity in comments 284, 287: pure orbital/curvature vorticity is NOT equivalent to solid body rotation. Solid body rotation requires a shear vorticity that is equal to the orbital/curvature vorticity, so that the total vorticity is equal to twice the value of either component. But it is true that fluid motion locally equivalent to solid body rotation occurs when dv/dx = - du/dy and regionally equivalent over some region in which both are constant in space. Suppose an x,y system is chosen not with respect to north and south but with respect to wind direction at a point O, so that the wind is in the x direction; v = 0 at O. If the wind is along concentric circlular streamlines (or locally fit a portion of such a pattern) centered at distance R in the y direction from O, so along the y axis, the wind is in the +/- x direction. If the wind speed does not vary along streamlines, then in this case, the shear vorticity is -du/dy. For solid body rotation, it can be shown that along y, u is linearly proportional to the distance R from the center of rotation (the center of curvature of the streamlines), so that -du/dy = u/R. For solid body rotation, the wind speed is the same along a streamline, and thus the spatial rate of change of wind direction along a streamline is proportional to dv/dx at the point O where the axes were defined. In this case dv/dx is the orbital/curvature vorticity. If A is the angle around a circle about the center of streamline curvature, then dx = R*dA; the change in the wind dv over a differential angle dA for constant wind speed equal to u is dv = u*dA; hence, dv/dx = u*dA/(R*dA) = u/R. The total relative vorticity = dv/dx - du/dy, which for solid body rotation is u/R + u/R = 2u/R. The coordinates defined above are called natural coordinates, and in general distance in the direction of the wind velocity is s and distance to the left (when the wind blows from back to forward) is n (See Holton and/or Martin). In general, when V (note the change in variable) is the wind speed, and R is the radius of curvature of a streamline, positive if the streamline curves to the left and negative if to the right, then the orbital/curvature vorticity = V/R and the shear vorticity = -dV/dn, and for equivalent solid body rotation, -dV/dn = v/R. planetary vorticity f could also be said to have an orbital/curvature and shear components, but they should at any one location always be equal since the Earth (and many other such bodies) spins essentially as a solid body (for atmospheric and oceanic dynamics purposes). Thus it makes some sense that a 'gradient wind balance', which is a balance in which the acceleration of the wind perpendicular to itself (proportional to orbital/curvature vorticity) and the coriolis acceleration and pressure gradient acceleration all sum to zero, can be defined and mathematically expressed using a total effective local f value (f_loc, see Bluestein p. 190) equal to f + 2*V/R (as opposed to f + V/R). But it is important to note that R in this case must be the radius of curvature of a trajectory - which may be different and often opposite the curvature of a streamline, although trajectories match streamlines in steady-state flow (in which streamlines do not vary in time over some region).
129290. Mizimi at 05:57 AM on 2 December 2008
        Temp record is unreliable
        Chris: we cannot adequately model climate right now, let alone model climate 'that was' millions of years ago. We assume land mass distribution, oceanic currents, atmospheric conditions and movement, biomass activity etc and then use proxy records to pin down climatic conditions. The best we can actually expect is an intelligent estimate of trends.
129291. Mizimi at 05:47 AM on 2 December 2008
        Water vapor is the most powerful greenhouse gas
        Sorry!! got my powers screwed up again, and having re-checked the sums there appears to me to be some overestimates in the AWV basic data, especially in respect of agricultural 'evapotranspiration' and the total for evaporation from reservoirs. So let's drop these out and concentrate on industrial figures which are a lot 'harder'. 90 billion tonnes of WV from industrial use ( excluding water from combustion) is 9 x 10E13 kg /annum or 3 times that produced by CO2 warming. AND it is increasing. There is still the 30% rise in usage recorded from 1980 to 1990 which just happens to coincide with the upturn in GMT. Just a coincidence? Also your figures comparing the 'turnover' of WV in the atmosphere (5 x 10E17kg/annum) only use the WV reckoned to be evaporated from cooling towers, not ALL AWV.
129292. chris at 03:39 AM on 2 December 2008
        Does model uncertainty exagerate global warming projections?
        Re #12: In fact we do know quite a bit about climate, atmospheric composition, temperatures and so on in the deep past. There are two points about the "graph" in post #8. First of all it's obviously incorrect, even for someone with an interest in these issues (anyone that posts here), but lacking detailed knowledge of the subject. For example we all know that the temperature hasn't dropped smoothly from "22 oC" to "12 oC" during the past several million years! And if we were skeptical we might question those long, long 10's and even 100's of millions of years of rock steady temperature. We might want to see the data points! The second point about the "gaph" is that it bears very little relationship to our real knowledge of any link between the Earth's temperature in the deep (and not so deep) past and the atmospheric CO2 levels determined from paleoproxies. In fact, these show a rather strong correspondence between atmospheric CO2 and the Earth's temperature over more than 500 million years. The data that informs us (anyone who wishes to be informed, including policymakers and their advisors) is cited below (see bottom of post). And anyone can find out about this themselves, for example by looking at University researcher or research institute web sites, or the IPCC reports, or even going to their local university library. It really depends on: (a) how well-informed one wishes to be (b) whether one wishes to address the science on these issues, or whether one has other agendas to pursue! --------------------------------------- The paleoproxy data for contemporaneous CO2 and temperature data is reviewed in detail here: D.L. Royer (2006) "CO2-forced climate thresholds during the Phanerozoic" Geochim. Cosmochim. Acta 70, 5665-5675. Even more recent studies supplement the information in Royers compilation and cover additional periods with new data sets right through the past several hundreds of millions of years: R.E. Carne, J.M. Eiler, J. Veizer et al (2007) "Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era" Nature 449, 198-202 W. M. Kurschner et al (2008) “The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of the terrestrial ecosystem” Proc. Natl. Acad. Sci. USA 105, 499-453. D. L. Royer (2008) “Linkages between CO2, climate, and evolution in deep time” Proc. Natl Acad. Sci. USA 105, 407-408 Zachos JC (2008) “An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics” Nature 451, 279-283. Doney SC et al (2007) “Carbon and climate system coupling on timescales from the Precambrian to the Anthropocene” Ann. Rev. Environ. Resources 32, 31-66. Horton DE et al (2007) “Orbital and CO2 forcing of late Paleozoic continental ice sheets” Geophys. Res. Lett. L19708 (Oct. 11 2007). B. J. Fletcher et al. (2008) “Atmospheric carbon dioxide linked with Mesozoic and early Cenozoic climate change” Nature Geoscience 1, 43-48.
129293. Arkadiusz Semczyszak at 01:39 AM on 2 December 2008
        Arctic sea ice melt - natural or man-made?
        …about “historical paleotemperatures in Fontainebleau” - The delta 13C indexes according to IPCC experts opinion, they are very reliable. Gamon, Fraser (1985) in “History of carbon Dioxide in the Atmosphere” writing about this method: separating periods - annual (for example ice core 20-300 y), accurate to 5 percent (2% in future). Many of papers are cited in the IPCC experts publications: Freyer, Balacy - 1983; Marino et al. 1992, Lauerberger 1992, Ferency 1998; Arus et al 1993, 7; Ferio et al., 2001; Keeling, C. D. m. fl., 2005: (Monthly atmospheric 13C/12C isotopic ratios for 10 SIO stations). More Data is in tree, but They are also at shallow water (Pedro Bank), deep water (Jamaica 150 m). However no about this dates don’t have annual separating periods, as in Fontainebleau… δ13C in research “crude” dates by Fontainebleau its very interesting: increase 1950 to 1960 has shape as increase 1985 - 2000; and the “slump” after around 1960 identically as Beck analyses. Becks picks specially: 1860, 1920; they are in Fonteinbleau too! Here also (as in Beck) increase of temperature (δ18O) preceded a δ13C increase… In the Beck analyses are a few errors - too higher CO2 level in 1820, no have s. d.…, However better that it’s, then nothing… Recollecting Gamon, Fraser (1985) writing about chemical methods: accurate to 3 percent…, besides the Results of research in 1920 - 1935 y, are very concentration - they have very small deviations - it’s confirm only 3% errors; as majority Becks date included in a photosynthesis researches - confirmed by photosynthesis product. Meijer and Keeling said, at Beck analyses: no background: “A quick tour through my car-traffic-saturated home town, Paris, can give us a good first impression: • Jardin Luxembourg (major but still tiny green spot in the center of Paris) 425ppm • Place de la Bastille: 430ppm • Place de l’Etoile (the crazy huge roundabout around the Arc de Triomphe): • 508ppm • And the winner was Place de la Nation: 542ppm (160ppm over background!).” (measurements by David Widory and Marc Javoy) but They give arguments for Beck. The differences dated only from present enhanced traffic of car !!! Difference between Mauna Loa - Jardin Luxembourg about CO2 concentration = 40 ppmv. Before 1950 y I think a background was not higher then 20 ppmv. Even however 40 ppmv background, gives for around 1940 y, 360 - 370 ppmv CO2… Besides, old universities were from car traffic, in the distance. "The persistency of the late 20th century warming trend appears unprecedented." writing i.e. N. Etien et al. I see on Fig 3b. - only “trend appears unprecedented” only in 1970 - 2000 period (likely: http://gsc.nrcan.gc.ca/geomag/nmp/long_mvt_nmp2_e.php), but temperature records are in 1911; 47; 49. 2003 is only fourth. Average in around 1950 is smallest in comparison 2000, only about 0,2oC… And here it is not possible to blame only “metal type screens “… The temperature biases in Fontainebleau are likely as in USA (by NASA)… “against the use of delta-13C measurements for long term temperature reconstructions” - I’m against too… None too big warming = more activity soil microorganisms - more CO2, 12C (correlations T - delta 13C, is high); only the big warming is can starts up the oceanic - TH circulations (= no correlations T - delta 13C). Unprecedented here is it, that delta 13C in 1950-60 period, violently fall off, as CO2 at Becks analyses, as mass moments the largest planets… - this last is accidentals ? Maybe, I don’t known… I’m only applied scientist – adviser for agro-meteorology…
129294. Arkadiusz Semczyszak at 01:37 AM on 2 December 2008
        Arctic sea ice melt - natural or man-made?
        Thanks, Patrick, Chris, Philippe Chantreau I can’t agree with You, The stomatal pores, their density in fossil plant leafs, it’s a fundamental legal instrument (not only in ice core context), that We not have a real unbalanced surplus of anthropogenic CO2, that CO2 don’t have long live of atmosphere, likely as present, variability of GHG was always; in finish: confirm it that first growing temperature, later CO2 concentration of air…, summary: not only man-mode melting glaciers… The density of stomata varies with such factors as: the temperature, humidity, and light intensity around the plant and also the concentration of carbon dioxide. The mature leaves on the plant detect the conditions around them and send a signal that adjusts the number of stomata that will form on the developing leaves. Not all plants We can take on experiments. Only some species have of the line relationship CO2 – stoma. They are tested in greenhouse - very wide range conditions – calibrated. First research works about it, makes in 1974… The results reported by Gregory Retallack (in Nature , 411 :287, 17 May 2001), his study of the fossil leaves of the ginkgo, was cited in the IPCC elaborations… “The reliability of this method testing on a total of 285 previously published SD and 145 SI responses to variable CO(2) concentrations from a pool of 176 C(3) plant species.” – Wagner said for students… A resolution this method is limited and "smoothed" because “…although the mechanism may involve genetic adaptation and therefore is often not clearly expressed under short CO(2) exposure times.” – “…don't show wild and massive up and down jumps…” (Wagner et al, 2002) “…to vary by around 295 +/- 10 ppm over a period of around 2000 years” – It is inadmissible “shortening”. Observed the variability in Fig. 2. is between ~ 275 – 330 ppmv CO2, and with standard deviation ~245 – 340 ppmv (the greatest down - certainly + s. deviations; in a few years ! ~7750 BP = 280 – 340 ppmv CO2, in a ~30-40 years 250 – 320 ppmv around 8700 BP; at the greatest grove – ~ 245 – 320 ppmv CO2 in < 150 years - ~ 8450 – 8600 BP). The range of variability in analyzed period for ice core is ~10 ppmv…, even around 55 ppmv (95 ppmv to vary range with s. deviation) contra 10 ppmv, is it: “relatively small disagreement”? Very interesting is comparison it with Fig. 3C in Baker at al. 1998. Correlation, even r-squadron, between a Europe fossil stoma and % C4 in America should be > 80 percent… If its true the range of variability CO2 in Holocene will be between ~200 – 340 ppmv CO2 with specially very quickly and big change between 4800 – 3400 BP. It is fine confirmation by the δ13C composition of stalagmites calcite (Fig. 3A) and… … for example, from news - about this variability; but “sedimentary total organic” is in „Holocene weak summer East Asian monsoon intervals in subtropical Taiwan and their global synchronicity” (http://www.clim-past-discuss.net/4/929/2008/cpd-4-929-2008.pdf - see specially Fig. 3). The four centennial periods: ~8–8.3, 5.1–5.7, 4.5–~2.1, and 2–1.6 kyr BP – “of relatively reduced summer East Asian monsoon” having a very interesting mark of reference whit all index in Baker et al., and Wagner at al.… Finished, I think percentage C4, maybe will by “fairest” proxy for reconstruction CO2 level (small influence of warm, rain, other falls, etc.) E. Steig i J. Severinghaus 27.04.2007 y. on RealClimate say: However very important is it, then concentration CO2 in last 650,000 years wasn’t never above 290 ppmv…, “I'd be very interested to know what they thinks will be achieved trying to cheat us in this way”… T. B. van Hoof et al (2008) – “CO2 levels varied by around +/- 10-15 ppmv” (often > 30 ppmv - more in s. d.; by a few years !) to base at early studies: “Coupling between atmospheric CO 2 and temperature during the onset of the Little Ice Age (van Hoof 2004)”. There is one: the shapes confirmations by D 47 core (however it’s only ± 6 ppmv); both: comparisons in other researching studies at fossil stoma (into L. Kouwenberg dissertation). Interesting is Fig. 2.6 (chapter 2) – growing of temperature with reconstruction Man and Jones 2003 (likely Moberg, Esper, etc.) ~ 1180; 1250; 1320 AD preceded a increase CO2 level… - “a temperature response rather” ? Kouwenberg in here research conclusion, said: “Four native North American conifer species (Tsuga heterophylla, Picea glauca, P. mariana, and Larix laricina) show a decrease in stomatal frequency to a range of historical CO 2 mixing ratios (290 to 370 ppmv). [!]” Well, well…
129295. chris at 00:34 AM on 2 December 2008
        It's the sun
        Not really Mizimi. The GISS update for October erroneously included September data for a number of Russian stations. The error was highlighted and the data corrected. So it's not a big issue is it! There are always errors in every endeavour in life. Science isn't an exception...it doesn't proceed without errors. The important point is that errors of substance are identified (they were) and corrected (they were).
129296. Mizimi at 06:10 AM on 1 December 2008
        Does model uncertainty exagerate global warming projections?
        As a reconstruction of past T and CO2 levels I would ignore it as it is predicated on a lot of (intelligent) guesswork. We simply do not know what the climate system as a whole was really like in the dim distant past. In addition, distribution of land mass was totally different and that affected climate. As an indication of trend (no absolutes here) it has uses.
129297. Mizimi at 05:48 AM on 1 December 2008
        Can animals and plants adapt to global warming?
        FYI; The sea of Cortes, off the coast of California, has been seriously overfished for many years, resulting in the loss of predators for the Humboldt squid. Because of this, and the squid's own predatory nature, its population has 'explode' to an estimated 20million+. (Much dismay and gnashing of teeth amongst marine biologists) However, the Right whale, which uses this sea as a stopover on its annual migration considers this squid as a great delicacy...as a result, Right whale numbers are increasing...........serendipity? Or 'nature' doing a balancing act?
129298. Mizimi at 05:36 AM on 1 December 2008
        Water vapor is the most powerful greenhouse gas
        "a significant part of the water vapour contribution arises as a feedback to CO2-induced warming," If we allow CO2 alone is responsible for a 0.17C rise/decade in GMT as per GISS data, and we allow ALL of the heat associated with that temp rise to evaporate water then an estimate of the increase in WV is around 0.07gm/kg of dry air. The atmosphere contains an estimated 5.135x10E18 kg of dry air (National Centre for Atmospheric research) which gives us a possible 5.135x10E18 x .07x10E-3 kg of WV added by this temp rise. Which ( providing I get my powers sorted out his time!) amounts to some 36x10E13 kg, PER DECADE. The current estimate for mm WV additions is 2360 cubic k's which is 2.36x10E12 kg....PER ANNUM. So over a decadal period we would add WV equivalent to 6.5% of that caused by CO2. Not insignificant. Dismissing AWV on the basis it precipitates out within 7-14 days does not do away with the fact that it does have a warming effect during that time period and it is a continuous effect at that.
129299. Mizimi at 04:40 AM on 1 December 2008
        It's the sun
        "What errors have there been in the GISS record?" Had a look at October's Giss data? Trivail? I don't think so. Look up Wattsupwiththat latest post on Russian data included by GISS.
129300. virbots at 04:12 AM on 1 December 2008
        CO2 lags temperature
        Has anyone discussed the possibility of bias between the two different ways of measuring CO2 and temperature as the source of the big jump near the end of the hockey stick graph? Thanks.

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