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Comments 130501 to 130550:

130501. Mizimi at 05:06 AM on 17 December 2008
        Models are unreliable
        Not forgetting that WV is also a GG, and has considerably greater warming effect than CO2. And that during glacial cycles the amount of WV would decrease thus adding to a more rapid/longer cooling cycle. In order to reverse WV driven cooling you need to get more WV into the atmosphere...through volcanic action or increased evapo/transpiration. If you don't increase the WV content significantly CO2 levels would have to rise dramatically to get you out of the glacial cycle. But we don't see such patterns in the CO2 record, so the primary forcing has to be increasing WV.
130502. chris at 03:02 AM on 17 December 2008
        Misinterpreting a retraction of rising sea level predictions
        No, I addressed your point in my response in post #14, Healthy Skeptic. To be specific: The linear warming trend in the Fawcett/Jones data is exactly that. A linear warming trend (or, to be precise, three linear warming trends, two strongish, one weak), is simply a mathematical fact. You consider that the linear trend is "skewed" "by the effect of the two lowest points in 1999 and 2000. But those two points are representative of the global temperature anomaly around that time. The point that "skews" the progression of the global temperature is 1998 which was lifted around 0.2 oC above the long term trend by the strongest El Nino of the 20th century. So there is a very clear warming trend in the data. It's mathematically precise in relation to linear regression of an 11 year running average of the raw data, and is more apparent in the analysis presented in which the effects of internal variations (due to ENSO) are removed. The point that Jones and Fawcett are making is that there is no scientific basis for proposing that there hasn't been any greenhouse-induced warming since 1998. Of course one can argue endlessly over temperature variations during very short periods, and the fact that the temperature anomaly has been steadyish for the last couple of years is cat-nip for those who want to progress spurious "arguments". Fawcett and Jones are just pointing out (yet again!) that those arguments don't have much basis in fact. Of course we'd like to wait a few years to see how things progress. In the meantime the most reliable means of adressing the temperature anomaly trend is to consider substantial running averages in which internal variations are roughly averaged out....
130503. Patrick 027 at 16:43 PM on 16 December 2008
        Arctic sea ice melt - natural or man-made?
        Just to be clear, everything in comments 352 up to here has been focused on (two-dimensional) barotropic Rossby waves. -- For waves that can be described by cos(k*x + l*y - w*t): -- 1. WAVE GEOMETRY (2 dimensions, (x,y)): A WAVE WITH WAVE VECTOR (k,l): phase lines are parallel to: y = -k/l * x because along a phase line: constant = y*l + k*x y*l = - k*x + constant (For y north, x east orientation of x,y: if k and l are both positive or both negative, the phase lines are aligned from northwest to southeast. If they are of opposite sign, the phase lines are aligned from southwest to northeast. If l = 0, the phase lines run from north to south; if k = 0, the phase lines run from west to east.) _______________ wave vector = (k,l) magnitude of wave vector = M = (k^2+l^2)^(1/2) unit vector in that direction = (k,l)/[(k^2+l^2)^(1/2)] = (k,l)/M Direction of wave vector: Angle counterclockwise from positive x direction: A_n cos(A_n) = k/M sin(A_n) = l/M (note: this is the n direction) _______________ unit vector perpendicular to wave vector (to the right) = (l,-k)/[(k^2+l^2)^(1/2)] = (l,-k)/M Direction of (l,-k)/M : Angle counterclockwise from positive x direction: A_s = A_n - pi/2 (radians) cos(A_s) = l/M sin(A_s) = -k/M (note: this is the s direction) ________________ 2. THE DISPERSION RELATION (w as function of spectrum (wave vector)): FOR BAROTROPIC ROSSBY WAVES, with the PV gradient in the positive y direction, and only due to beta, where beta = del(f)/del(y) (Hence, y is north, x is east) (FOR such waves, k is never positive (on a planet with prograde rotation such as most planets, where del(f)/del(y) is never negative) - the wave vector's x component is never positive - the wave vector can be westward, southwestward, northwestward, and in the limit of k=0, it can approach northward or southward - thus, A_n can be between 90 and 270 deg (pi/2 and 3pi/2 radians); A_s can be between 0 and 180 deg (0 and pi radians)). From p.85 Cushman Roisin: w = -beta * R^2 * k / [1 + R^2*(k^2+l^2)] = -beta * k / [1/R^2 + (k^2+l^2)] = -beta * k / [1/R^2 + M^2] = -beta * cos(A_n) * M / [1/R^2 + M^2] where R is the external Rossby radius of deformation, R = (g*H)^(1/2) / f ** NOTICE THAT if 1/R^2 goes to zero (or in the limit of the product (M*R)^2 going to infinity), the dispersion relation above reduces to the proportionality that would occur if the ratio of PV anomaly to RV anomaly were constant: w proportional to -beta * k / M^2, which is equal to -beta * cos(A_n) / M ** w is positive because beta is positive and k is negative. ______________________ PHASE SPEEDS: in the x direction: cx = w/k = -beta / [1/R^2 + (k^2+l^2)] = -beta / [1/R^2 + M^2] (cx is always negative; phase propagation is never eastward.) --- in the y direction: cy = w/l = -beta * (k/l) / [1/R^2 + (k^2+l^2)] = -beta * (k/l) / [1/R^2 + M^2] = -beta / ( tan(A_n) * [1/R^2 + M^2] ) = +beta * tan(A_s) / [1/R^2 + M^2] = (k/l)*cx (cy is positive if l is positive, negative if l is negative; phase propagation is northward for positive l, southward for negative l.) --- in the direction of the wave vector (k,l) (in the n direction): c = w/M = w/[(k^2+l^2)^(1/2)] = -beta * k / ( [1/R^2 + (k^2+l^2)] * (k^2+l^2)^(1/2) ) = -beta * k / [ (k^2+l^2)^(1/2) / R^2 + (k^2+l^2)^(3/2) ] = -beta * k / [ (k^2+l^2)^(1/2) / R^2 + (k^2+l^2)^(3/2) ] = -beta * k / [ M / R^2 + M^3 ] = -beta * k/M / [1/R^2 + M^2] = -beta * cos(A_n) / [1/R^2 + M^2] --- cos(A_n)/c = 1/cx = k/M / (w/M) = k/w cx*cos(A_n) = c sin(A_n)/c = 1/cy = l/M / (w/l) = l/w cy*sin(A_n) = c cy = k/l * cx = cos(A_n)/sin(A_n) * cx ________________________ GROUP VELOCITY x and y components: cgx = del(w)/del(k) = -beta / [1/R^2 + (k^2+l^2)] - -beta * k * 2k / [1/R^2 + (k^2+l^2)]^2 = -beta / [1/R^2 + (k^2+l^2)] + beta * 2k^2 / [1/R^2 + (k^2+l^2)]^2 = -beta / [1/R^2 + (k^2+l^2)] + beta / [1/R^2 + (k^2+l^2)] * 2k^2 / [1/R^2 + (k^2+l^2)] =(-beta / [1/R^2 + (k^2+l^2)] ) * (1 - 2k^2 / [1/R^2 + (k^2+l^2)] ) = w/k * (1 - 2k^2 / [1/R^2 + (k^2+l^2)] ) = w/k - 2*w*k / [1/R^2 + (k^2+l^2)] ) = -beta / [1/R^2 + M^2] + beta * 2k^2 / [1/R^2 + M^2]^2 = +beta / [1/R^2 + M^2] * (2*k^2/[1/R^2 + M^2] - 1) --- cgy = del(w)/del(l) = +beta * k * 2l / [1/R^2 + (k^2+l^2)]^2 = +beta * 2*k*l / [1/R^2 + (k^2+l^2)]^2 = +beta * 2*k*l / [1/R^2 + M^2]^2 _______________ Group velocity vector = [del(w)/del(k), del(w)/del(l)] = [cgx,cgy] Magnitude of group velocity = cg cg = (cgx^2 + cgy^2)^(1/2) = beta * ( 1/[1/R^2 + M^2]^2 * (2*k^2/[1/R^2 + M^2] - 1)^2 + 4*k^2*l^2 / [1/R^2 + M^2]^4 )^(1/2) = beta / [1/R^2 + M^2] * ( 4*k^4/[1/R^2 + M^2]^2 - 4*k^2/[1/R^2 + M^2] + 1 + 4*k^2*l^2 / [1/R^2 + M^2]^2 )^(1/2) = beta *2*k / [1/R^2 + M^2]^2 * ( k^2 - [1/R^2 + M^2] + [1/R^2 + M^2]^2/(4*k^2) + l^2 )^(1/2) = beta *2*k / [1/R^2 + M^2]^2 * ( M^2 - [1/R^2 + M^2] + [1/R^2 + M^2]^2/(4*k^2) )^(1/2) -- IN THE LIMIT of 1/(M*R)^2 = 0, cg = beta *2*k / [1/R^2 + M^2]^2 * [1/R^2 + M^2]/(2*k) = beta / [1/R^2 + M^2] ~= beta / M^2 -- (PS A VECTOR IS EQUAL TO A VECTOR SUM OF all orthogonal components. Any set of orthogonal components can be used.) Component of group velocity parallel to any other vector [a,b]: cg component = cg*cos(angle) = dot product of two vectors = cgx*a + cgy*b cg*cos(angle) = (cgx^2 + cgy^2)^(1/2) * cos(angle) = cgx*a + cgy*b cos(angle) = (cgx*a + cgy*b) / cg ____________ RECAP OF cgx and cgy: cgx = del(w)/del(k) = -beta / [1/R^2 + M^2] + beta * 2*k^2 / [1/R^2 + M^2]^2 cgy = del(w)/del(l) = +beta * 2*k*l / [1/R^2 + M^2]^2 -- Group velocity vector = [ -beta / [1/R^2 + M^2] + beta * 2k^2 / [1/R^2 + M^2]^2 , beta * 2k*l / [1/R^2 + (k^2+l^2)]^2 ] = beta * [ -1 / [1/R^2 + M^2] + 2k^2 / [1/R^2 + M^2]^2 , 2k*l / [1/R^2 + M^2]^2 ] = beta / [1/R^2 + M^2]^2 * [ - [1/R^2 + M^2] + 2*k^2 , 2*k*l ] ________________ Component of Group velocity parallel to wave vector: cgn = (k,l)/M "dot" [cgx,cgy] = beta/M * [ -k / [1/R^2 + M^2] + 2k^3 / [1/R^2 + M^2]^2 + 2k*l^2 / [1/R^2 + M^2]^2 ] = k/M * beta * [ -1 / [1/R^2 + M^2] + 2k^2 / [1/R^2 + M^2]^2 + 2*l^2 / [1/R^2 + M^2]^2 ] = k/M * beta / [1/R^2 + M^2] * [ -1 + 2*k^2 / [1/R^2 + M^2] + 2*l^2 / [1/R^2 + M^2] ] = k/M * beta / [1/R^2 + M^2] * (2*M^2 / [1/R^2 + M^2] - 1) ________________ Component of Group velocity parallel to phase line (to the right of wave vector): cgs = (l,-k)/M "dot" [cgx,cgy] = beta/M * [ -l / [1/R^2 + M^2] + 2*l*k^2 / [1/R^2 + M^2]^2 - 2*l*k^2 / [1/R^2 + M^2]^2 ] = -l/M * beta / [1/R^2 + M^2] *** NOTE: The component of group velocity in the direction of (l,-k) of the wave with wave vector (k,l) is equal to the c of a wave with wave vector (l,-k) (not too surprisingly!). _______________ IN THE LIMIT OF k going to 0, |l| = M, cgs*(|l|/l) = cgx = cx __________________ cgn = 0 when k = 0 or when: 2*M^2 / [1/R^2 + M^2] = 1 2*M^2 = 1/R^2 + M^2 M^2 = 1/R^2 (M*R)^2 = 1 For negative k, cgn is (positive/0/negative) when (M*R)^2 is (greater than/equal to/less than) 1. __________________ group velocity in direction of wave vector relative to phase speed in direction of wave vector cgn - c = = k/M * beta / [1/R^2 + M^2] * (2*M^2 / [1/R^2 + M^2] - 1) + beta * k/M / [1/R^2 + M^2] = k/M * beta / [1/R^2 + M^2] * 2*M^2 / [1/R^2 + M^2] = k/M * 2*M^2 * beta / [1/R^2 + M^2]^2 For waves with negative k, cgn is always less than c. ___________________ IN THE LIMIT OF 1/(M^2*R^2) = 0, cgn ~= k/M * beta / [1/R^2 + M^2] ~= k/M * beta / M^2 cgs ~= -l/k * cgn ~= -l/M * beta / M^2
130504. Mizimi at 09:18 AM on 16 December 2008
        What does CO2 lagging temperature mean?
        An interesting read... http://www.co2science.org/subject/c/summaries/co2climatehistory.php
130505. Mizimi at 08:51 AM on 16 December 2008
        Water vapor is the most powerful greenhouse gas
        Had a quick look at the summary page which talks about measuring total WV content of the atmosphere....but no mention of assigning values to WV from global warming as distinct from WV evaporating from human activities. It;s all lumped together as 'WV'.
130506. chris at 06:32 AM on 16 December 2008
        What 1970s science said about global cooling
        When you start "to critically question scientific evidence" please let us know! Denialist don't deny facts....denialists deny the evidence. And one shouldn't "deny an unproven hypothesis". The mature approach to hypotheses is to assess them with respect to the evidence. We know you're not an evidence sort of chap, but global warming is essentially undeniable, and the role of massive man made enhancement of greenhouse gas concentrations is sufficiently supported by the evidence that it requires some pretty specious argumentation to deny this (and I haven't seen you present any sort of evidence-based argument for anything here, but I haven't read all your posts (!), and perhaps you can point out one or two examples). Of course if you source your information from dismal newspaper "articles" and dodgy graphs from web sites and such like, then you're very likely to be horribly ill-informed on the subject. AGW is strongly supported by the evidence. It's sufficiently strongly supported that mature[*] and well-informed policymakers consider it appropriate to address the problems. [*]by mature I mean those that make an effort to be well-informed on the science, are dismissive of specious arguments and misinformation, and are able to engange in considered discussion on policy implementation.
130507. chris at 00:21 AM on 16 December 2008
        CO2 lags temperature
        Sadly you're wallowing in logical fallacy Dan. Two things we know: (i) the ice age cycles were drived by the slow cyclical variations in the orbital properties of the earth, and the associated variation in the pattern of insolation (solar irradiation at the surface) drove temperature variations. (ii) atmospheric CO2 is a greehouse gas. The Earth has a temperature response to raised CO2 somewhere near 3 oC of warming per doubling of atmospheric CO2. It's fallacious to attempt to insinuate that those two rather well-characterized phenomena are sumehow mutually exclusive! I don't think too many people here are buying logical fallacies Dan!
130508. chris at 00:11 AM on 16 December 2008
        Models are unreliable
        Do you really expect that logical fallacies are going to fool anyone on a skeptics board Dan? The ice age cycles were/are dominated by Milankovitch cycles (insolation pattern variations resulting from achingly slow cyclical variations in the Earth's orbital properties). Carbon dioxide is a greenhouse gas. The Earth has a warming response to raised atmospheric CO2 of the order of 3 oC per doubling of atmospheric CO2. Each of those phenomena apply to the Earth's temperature response and both of the statements are true. They're not mutually exclusive as you attempt to insinuate. It's logically fallacious to attempt to pursue the deceit that only one thing can influence a particular parameter (like the earth's temperature).. the fallacy of the single cause. Here's what the evidence idicates rather clearly: (i) there is a clear relationship between atmopheric CO2 levels and earth's temperature throughout the last 500 million years (see citations in my post #48). (ii) this is entirely consistent with the well-established fact that CO2 is a greenhouse gas, enhanced levels of which contribute to a warming response (amplified by feedbacks like raised water vapour and albedo response that we can observe and measure in the real world). (iii) During the slow, slow ice age cycles insolation effects result in a second-order cyclical temperature variation... it ain't rocket science Dan!
130509. Patrick 027 at 16:13 PM on 14 December 2008
        Arctic sea ice melt - natural or man-made?
        ..."the negative of the cosine of the angle between y and s directions." It implies that the angle between y and s directions is an 180 deg more or less than the angle between x and n directions, which can be confirmed geometrically. The angle between x and s directions is the same as the angle between y and n directions, but the angle between x and n directions is the angle between the y direction and the negative s direction.
130510. Patrick 027 at 16:00 PM on 14 December 2008
        Arctic sea ice melt - natural or man-made?
        CORRECTION of a paragraph above, with changes noted ***: "Say that s*** is the distance perpendicular to n****, that is, perpendicular to the 'wave envelope vector' (dk,dl); such a vector would be in the direction (dl,-dk) (90 deg to the right) or opposite that, (-dl,dk) (90 deg to the left). Let's have it be the FIRST*** one, so that coordinates s,n are a rotation of x,y. "
130511. Patrick 027 at 15:38 PM on 14 December 2008
        Arctic sea ice melt - natural or man-made?
        I figured out the error I made in sections 2c and 2d in comment 352 (PS and I may have made this error earlier as well when discussing group velocity). Recap: The linear superposition of two waves of equal amplitude, with average wave vector (k,l) and average angular frequency w, with wave vector difference between them 2*(dk,dl) and difference of angular frequency = 2dw: cos[(k+dk)*x + (l+dl)*y - (w+dw)*t] + cos[(k-dx)*x + (l-dl)*y - (w-dw)*t] = 2 * cos(k*x + l*y - w*t) * cos(dk*x + dl*y - dw*t) which can be seen as a wave with wave vector (k,l) and angular frequency w (with phase lines with slope dy/dx = -k/l) modulated by a sinusoidal wave envelope with 'amplitude wave vector' (dk,dl) and frequency dw (with 'amplitude phase lines' with slope dy/dx = -dk/dl). The magnitude of the wave vector (k,l) is M = (k^2+l^2)^(1/2), and the wavelength of the wave with that wave vector, measured in the direction of the wave vector (perpendicular to phase lines) is 2*pi/M (and so on for 'amplitude wave vector' (dk,dl) ). Now, here's the error: "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" To borrow a phrase from Ted Stevens, NO! As with w/k, w/l, and w/M (phase speeds in x direction, y direction, and direction of wave vector ("THE" phase speed))for the wave with wave vector (k,l), wave vector magnitude M, dw/dk, dw/dl, and dw/dn are the phase speeds of the wave envelope in the x direction, y direction, and direction of 'amplitude wave vector' (dk,dl), respectively, where dn = (dk^2+dl^2)^(1/2) is the magnitude of half the vector difference between the wave vectors of the two linearly superimposed waves. As with the wave with wave vector (k,l), the phase speeds dw/dk and dw/dl do NOT add as vector components to give a vector in the direction (dk,dl) with magnitude dw/dn - it won't generally have that magnitude nor will it have that direction. The inverses, however, do have the relationship of vector components; (dk/dw,dl/dw) = dn/dw *(dk,dl)/dn, where (dk,dl)/dn is the unit vector in the direction of (dk,dl). So what is the group velocity, and what are it's vector components? This is where it would have helped me avoid a mistake if I had been using the 'del' symbol for partial derivatives; it is important to differentiate (pun intended) among the different kinds of derivatives. The group velocity for a wave with wave vector (k,l) is the gradient of w over wave vector space at the value (k,l), with the component in the k direction being the component of group velocity in the x direction, and so on for l and y, or for any other set of orthogonal components that could be used (the component in the direction of a vector (a,b) in k,l space would be the component of group velocity in that direction in x,y space. The gradient is a vector with components equal to partial derivatives; group velocity = (cgx,cgy) = [del(w)/del(k) , del(w)/del(l)], where del(a)/del(q) is the partial derivative of a with respect to q. The key is that del(w)/del(k) is NOT generally equal to dw/dk, even in the limit of infinitesimal dw and dk such that dw/dk is equal to a derivative. This is because dw is the total difference in w over a specific distance in k,l space in a specific direction. Only if that direction were only in k - that is, if dl = 0, would then del(w)/del(k) be equal to dw/dk (in the limit of infinitesimal dk). More generally, in the limit of infinitesimal differences, dw = del(w)/del(k) * dk + del(w)/del(l) * dl; dw/dn = del(w)/del(k) * dk/dn + del(w)/del(l) * dl/dn That is - only part of dw is due to dk, etc (and so on if we were discussing three-dimensional waves). dk and dl are components of the vector with magnitude dn in the direction of (dk,dl)/dn, which is of course that vector, (dk,dl). dw/dn IS the component of group velocity in that direction, because it is equal to the partial derivative of w in that direction, given how dn was defined. This is the phase speed of the wave envelope in the direction of its wave vector. It has vector components in x and in y, which are equal to dw/dn * dk/dn and dw/dn * dl/dn, respectively. These are not components of the total group velocity, however, because they are components of a component vector. One would have to add to each component the component of the other component of the group velocity to find the total group velocity components in x and y. Say that n is the distance perpendicular to s, that is, perpendicular to the 'wave envelope vector' (dk,dl); such a vector would be in the direction (dl,-dk) (90 deg to the right) or opposite that, (-dl,dk) (90 deg to the left). Let's have it be the second one, so that coordinates s,n are a rotation of x,y. In that case, del(w)/del(s) is the component of group velocity in the s direction, which adds with the vector in the n direction with magnitude dw/dn to give the total group velocity. Of course one won't observe such a group velocity for a wave envelope that does not vary in s. More generally, if a wave envelope has a rectangular checkerboard pattern that is described with two sets of 'phase lines' intersecting at right angles (as the nodal lines would do), then the two 'phase speeds', each of one set of wave envelope 'phase lines' in the direction perpendendicular to those 'phase lines', form a complete set of components of the group velocity. The group velocity will be the velocity of the checkerboard pattern, which can be defined by the motions of points (such as node intersections), as opposed to lines. ... Suppose we instead take s and n as coordinates locally defined in k,l space as being perpendicular and parallel to the wave vector (k,l) (with magnitude M) of a wave, respectively (or parallel and perpendiclar to phase lines of that wave, respectively), with n 90 deg to the left of s, so that n is in the direction of (k,l) and s is in the direction of (l,-k). Then group velocity can be described with components: cgn = del(w)/del(n) in the direction of phase propagation, which is in the direction of the wave vector and cgs = del(w)/del(s) in the direction along phase lines, to the right of phase propagation. The vectors (cgs,cgn) and (cgx,cgy) are the same vector, the group velocity, described in different coordinates - s,n and x,y, respectively. Using dot products with unit vectors that define s and n directions ( (l,-k)/M and (k,l)/M, respectively), cgs = (cgx,cgy) "dot" (l,-k)/M = 1/M * (l*cgx - k*cgy) cgn = (cgx,cgy) "dot" (k,l)/M = 1/M * (k*cgx + l*cgy) which implies that l/M is the cosine of the angle between y and n directions and the cosine of the angle between x and s directions, while k/M is the cosine of the angle between x and n directions and the negative of the cosine of the angle between y and s directions. (which can be confirmed geometrically).
130512. AlecRawls at 15:09 PM on 14 December 2008
        Svensmark and Friis-Christensen rebut Lockwood's solar paper
        There does not need to be a secular trend in solar activity for solar activity to create warming. It simply has to be high. A constant high level of solar activity (averaged over the 11 yr. cycles) will warm the earth, says 500 million years of the geologic record. This idea that there must be an upward trend in solar activity over a period (like 1975-2004) in order for warming to be explained by solar activity is like saying that you can’t heat a pot of water unless you keep turning the flame up. Having the flame set on high is supposedly not enough. This is a bizarre mistake for people to be making. Have we forgotten that the oceans form a vast heat sink? In terms of climate science, the earth is in effect a big pot of water. For as long as there is reduced cloud cover, if that is the mechanism by which solar-magnetic activity warms the earth, this reduced cloud cover will keep feeding energy into the oceans (both directly, and from air warmed up over the relatively sunny land masses). There does not need to be an ever decreasing level of cloud cover for this to occur. But John is right about one thing. Go look at these papers by supposedly competent scientists and they do indeed look at the wrong derivative. Instead of looking at the zero derivative (level of solar activity) are looking at the first derivative (trend). Here is the last line of Usoskin et. al., 2004:

        Note that the most recent warming trend, since around 1975, has not been considered in the above correlations. During these last 30 years, the solar total irradiance, solar UV irradiance, and cosmic ray flux, has not shown any significant secular trend, so that at least this most recent warming episode must have another source.

        Stupidest thing I ever heard! Well, maybe not given the competition, but it is still up there. The only thing I can figure (other than trying to avoid stepping on AGW toes) is that these eminent scientists somehow forgot that they were talking about a pot of water. Of course a continued high level of GCR/ low-level of cloudiness would continue to feed energy into the oceans. What were they thinking? Well, we know what they were LOOKING AT: the simple correlations, and lagged correlations, between solar activity and temperature. Somehow they let themselves substitute these simple correlations for the physical process itself. Lagged correlation is a little better, but it is still does not model the physical process. It would not be hard to estimate, for each level of global temperature, the level of solar activity that tends to create warming rather than cooling. Then estimate, for each increment of solar activity above this level, how much the rate of warming tends to increase. This could easily be combined with a physical model of the heat storage capacity of the oceans. Fitting such a model to the data would yield a picture over time of the heat store (ocean temperature) and the solar driven additions and subtractions from it. Logically, we would expect to find some periods where solar activity was increasing but the earth was still cooling, because the increase still hadn’t brought the level of solar activity back to the level necessary to create warming. These instances would be misinterpreted as counter-evidence to the sun-temperature link if we were looking at trend instead of level. It’s just obvious that looking at trend is wrong. It doesn’t fit how the world works. We have all the data. It’s just a matter of decomposing it more intelligently. Once we realize that we should be looking at level, not trend, the implications of Svensmark’s graph come into focus. You can see from the close fit between the plot of Galactic Cosmic Radiation and the de-trended temperature curve that there is very little trend in GCR over the second half of the 20th century. The average over the 11 yr cycles was consistently high, what Solanki calls “grand maximum,” or as high as anything seen in the geologic record. That’s why we had warming. The flame was turned up under the pot for sixty years. Why wasn’t warming uniform? The Pacific Decadal Oscillation. Take out the PDO and, as Svensmark’s graph shows, the ups and downs of the 11 yr. solar cycle match the ups and downs in the temperature anomaly. If you want, you can look at Svensmark as graphing de-trended temperature against de-trended GCR (where the GCR trend is essentially zero). What the graph shows is that changes in GCR do a very good job of explaining (statistically) the changes in temperature. From here you can see how John’s interpretation of Svensmark’s graphic is wrong. He thinks that because the ups and downs of GCR perfectly explain de-trended temperature, the trend in temperature must be explained by something else. But the “something else” is the LEVEL of GCR. It’s STILL the cosmic ray flux that is at work. 60 years of relatively cloudless skies kept pumping heat into the oceans (or so the evidence seems to indicate). John has a lot of company in getting this wrong. Usoskin and Solanski got it wrong in their 2004 paper and they are AGW skeptics. Thus apparently this is not a motivated error, but just collective incomprehension of something that ought to be pretty easy to sort out. Dang. Who hasn’t used a stove? My posts here and here, My posts here and here, but they don’t go as far into this particular issue as this comment does.
130513. chris at 11:16 AM on 14 December 2008
        Did global warming cause Hurricane Katrina?
        That's incorrect Healthy Skeptic. Perhaps you are unfamiliar with the science on this issue. I've had a look at the newspaper interview (!) you are sourcing your info from and it's pretty poor stuff. Much of the "article" is assertions about the absence of an increase in the number of hurricanes...Gray concludes a section with "The hypothesis that increasing carbon dioxide in the atmosphere increases the number of hurricanes fails by an even wider margin when we compare two other multi-decade periods..." However it's clear from John Cook's top article that the issue isn't about the number of hurricanes but the number of high intensity (cat 4/5 hurricanes), and these have increased in line with raised sea surface temperatures (SST), as Gray acknowledges. So most of the "article" is uncontroversial. Unfortunately Gray's asertions about the source of raised SST doesn't accord with the scientific evidence, since: ONE: The evidence indicates that the global rise of SST has a major component of man-made warming due to greeenhouse gas emissions: e.g. Barnett, T. P. et al (2005) Penetration of human-induced warming into the world's oceans Science, 309, 284–287. Abstract:"A warming signal has penetrated into the world's oceans over the past 40 years. The signal is complex, with a vertical structure that varies widely by ocean; it cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models. We conclude that it is of human origin, a conclusion robust to observational sampling and model differences. Changes in advection combine with surface forcing to give the overall warming pattern. The implications of this study suggest that society needs to seriously consider model predictions of future climate change." [TWO] The AMO (Atlantic Meridonal Overturning) that Gray speaks of is likely to have made only a small contribution to increased SST: e.g.: K. E. Trenberth and D. J. Shea (2006) Atlantic hurricanes and natural variability in 2005 Geophysical Research Letters, VOL. 33, L12704 Abstract:"The 2005 North Atlantic hurricane season (1 June to 30 November) was the most active on record by several measures, surpassing the very active season of 2004 and causing an unprecedented level of damage. Sea surface temperatures (SSTs) in the tropical North Atlantic (TNA) region critical for hurricanes (10° to 20°N) were at record high levels in the extended summer (June to October) of 2005 at 0.9°C above the 1901–70 normal and were a major reason for the record hurricane season. Changes in TNA SSTs are associated with a pattern of natural variation known as the Atlantic Multi-decadal Oscillation (AMO). However, previous AMO indices are conflated with linear trends and a revised AMO index accounts for between 0 and 0.1°C of the 2005 SST anomaly. About 0.45°C of the SST anomaly is common to global SST and is thus linked to global warming and, based on regression, about 0.2°C stemmed from after-effects of the 2004–05 El Niño." [THREE] Analysis of the dominant causative influence on high SST supports the conclusion that GW results in raised SST results in increased tropical storm intensity, rather than the alternative (AMO---> raised SST): e.g. Elsner JB (2006)Evidence in support of the climate change - Atlantic hurricane hypothesis Geophysical Research Letters 33 L16705 Abstract: "The power of Atlantic tropical cyclones is rising rather dramatically and the increase is correlated with an increase in the late summer/early fall sea surface temperature over the North Atlantic. A debate concerns the nature of these increases with some studies attributing them to a natural climate fluctuation, known as the Atlantic Multidecadal Oscillation (AMO), and others suggesting climate change related to anthropogenic increases in radiative forcing from greenhouse-gases. Here tests for causality using the global mean near-surface air temperature (GT) and Atlantic sea surface temperature (SST) records during the Atlantic hurricane season are applied. Results show that GT is useful in predicting Atlantic SST, but not the other way around. Thus GT "causes" SST providing additional evidence in support of the climate change hypothesis. Results have serious implications for life and property throughout the Caribbean, Mexico, and portions of the United States." ...and so on. If we're really intested in understanding these issues, we really should be addressing the evidence from the science, and not unsubstantiated assertions from newspaper articles!
130514. chris at 10:43 AM on 14 December 2008
        The Mystery of the Vanishing Ocean Heat
        You seem to have a problem with the truth Healthy Skeptic. Unfortunately Dr. Nils-Axel Morner is stating something that is not true. He's perfectly within his rights to diseeminate falsehoods in interviews... ..but why listen to rubbish that people say in interviews? We know how sea level measurements are made, and we know how the IPCC report on this extensive research (see papers in my post #27). So what's to be gained from pretending that things are not as they are? I don't really understand your approach to this. On the one hand you want to portray yourself as a "skeptic". However your approach to the science is decidedly unhealthy. You don't seem to care to address the science but prefer unsubstantiated stuff from interviews and dodgy websites. I'm not denigrating Dr. Nils-Morner. I'm pointing out that he is asserting things that aren't true. I accept that you seem to prefer untruths on the subject of climate science (the rubbish on previous CO2 measurements from a German scholl teacher...the nonsense on paleotemperature/paleoCO2 relationships from a wildly inaccurate sketch of "data" and so on...) In science Healthy Skeptic, it's all about the evidence. You choose not to address this. That's fine..it's your choice. But don't pretend that propagating falsehoods has anything to do with "skepticism"!
130515. chris at 04:28 AM on 14 December 2008
        Evaporating the water vapor argument
        Your comment doesn't make much sense Healthy Skeptic. What humor are you referring to with respect to "the vast majority of AGW alarmists"? Can you give us an example please? After all Douglas and I are referring to something rather specific. You seem to be making a generalized assertion about something and it's not obvious what you're referring to. Example please...
130516. chris at 02:35 AM on 14 December 2008
        Determining the long term solar trend
        #16 Some plants grow better with raised CO2 and some don't. Since plants also require water and nutrients, the idea that plants will continue to show enhanced growth in a world with higher CO2 levels, and that this will result in "locking up" of significant CO2, is fallacious. In any case, the limits on plant growth and CO2 sequestration are dominated by land use/deforestation, and not be CO2 levels. The notion that "reaction mass increases roughly 100% for every 10C rise" is an empirical finding from physical chemistry and doesn't apply to biological systems. Your other points about cycles don't really accord with real world considerations either. The rate of drawing excess CO2 out of the atmosphere is very slow, and so there isn't really any significant "draw down" of the vast amounts of CO2 we're pumping into the atmosphere apart from that amount that is partitioning into the oceans. It's plain to see that atmopsheric CO2 levels are rising at a phenomenal rate (over 100 times faster than during the last glacial to interglacial transition which is the most recent example of a natural change in atmospheric CO2 levels)...so your "cycle" clearly isn't acting.. The "small amount of extra CO2 we release" is certainly not "small"! It's enormous. It's an amount that could only be sustained for a truly tiny period (several hundred years), and it's occuring at a rate that were we to carry doing so for several hundred years we would effectively return to the atmosphere all of the CO2 in fossil fuels that took several hundreds of millions of years to form... You are correct 'though, that the massive amounts of extra CO2 that we release "will not substantially affect the cycle". The cycle responds very slowly to enhanced CO2, and so any feedback elements are going to be rather insignificant in their abilities to mitigate our truly massive increases in atmospheric CO2...
130517. chris at 02:08 AM on 14 December 2008
        Determining the long term solar trend
        #15 That's just incorrect Healthy Skeptic. Raised greenhouse gases cause the atmosphere to warm and to increase the concentration of water vapour. That's a straightforward prediction from our understanding of atmospheric physics....... and we can measure this in the real world. There is no evidence that increased water vapour has a "cooling" effect that you speculate on. Since warmer air has a higher capacity for water vapour there is no necessary increase in clouds with enhanced water vapour. In any case clouds don't just reflect solar radiation. They also also efficiently trap outgoing thermal radiation (even an unhealthy "skeptic" must have direct experience of that fact!) and retain heat in the surface and lower atmosphere. Since we have a wealth of paleodata on the relationship between Earth's temperature and atmospheric CO2 levels, and the data indicate a clear correlation between temperature and CO2 (highish temperatures when CO2 is high and lowish temperatures when CO2 is low), a skeptic would have every reason to be skeptical about your proposed cooling efect of water. It's pretty clear that increased water vapour enhances CO2-induced warming. try this, for example: http://www.nasa.gov/topics/earth/features/vapor_warming.html
130518. Dan Pangburn at 01:18 AM on 14 December 2008
        CO2 lags temperature
        During the last and previous glacial periods there were temperature and carbon dioxide up-trends and downtrends. Credible data from Vostok and EPICA showing these trends are readily available (e.g. the first graph above). Close examination of these data shows unequivocally that on many occasions temperature trended down for centuries while carbon dioxide level was higher than it had been during a prior temperature uptrend. This shows that, at least at that time, temperature was not driven by carbon dioxide level. It is well known that added increments of carbon dioxide have less influence than previous increments. This has been elucidated using the added-blankets metaphor. Since there is more carbon dioxide in the atmosphere today than during the glacial periods, added increments of carbon dioxide today have even less influence than they did during the glacial periods when they did not drive temperature. Thus added atmospheric carbon dioxide today does not drive temperature and AGW that is based on increased atmospheric carbon dioxide is a mistake.
130519. Quietman at 16:59 PM on 13 December 2008
        We're heading into an ice age
        Mizimi Plates literally float. They can shift, rise or fall. There are no true continents, what we see is a result of large pieces of lighter material breaking and mergeing or subducting. There is no real difference between sea floor and land other than elevation. So while Australia is relatively free from volcanism it is still subject to plate tectonics which are constantly active but change intensity and speed is cycles.
130520. Tom Dayton at 14:31 PM on 13 December 2008
        Water vapor is the most powerful greenhouse gas
        There's a new satellite-based study of the relationship of water vapor to CO2 by Dessler and colleagues on NASA.gov (the Earth section). It nails down the specific feedback effect's size.
130521. chris at 06:27 AM on 13 December 2008
        Human CO2 is a tiny % of CO2 emissions
        It hasn't been far-off 300 ppm (generally a bit lower)for millions of years (around 20 million years), apart from the glacial periods of the past few million years when atmospheric CO2 dropped towards 180 ppm. That's what the evidence indicates. see papers cited in post #13 above...
130522. Patrick 027 at 16:17 PM on 12 December 2008
        Arctic sea ice melt - natural or man-made?
        CORRECTION " (**The component of Group velocity parallel to phase lines - amplitude propagation along phase lines - is fastest at intermediate tilts between phase lines being aligned with the PV gradient and being perpendicular to it**). " Actually, that's for the group velocity y-component with basic state PV gradient parallel to y. The fastest group velocity component parallel to phase lines occurs when the phase lines become parallel to basic state PV contours. Of course, for finite-width wave envelopes, this should be equal to phase propagation of the same wave described instead as having phase lines aligned with the PV gradient, with amplitude varying sinusoidally along phase lines... etc. ------------ A wave envelope can be limited in multiple dimensions. In **C0** in was limited in the x direction. One could consider the case of a wave envelope limited in both x and y, in which case aspects of **C0** and **C1** would be combined; there could/would be group velocity in both x and y; new phase lines would grow on the outskirts in the x direction (in the direction of group velocity minus phase motion - if the wave envelope is not spreading out too quickly, then old phase lines will decay on the other side of the wave envelope). ---------- Group velocity: THE group velocity of a wave is determined by the frequency as a function of the spectrum - specifically, it is in (x,y) space equal to the gradient of w in wavenumber space (k,l) (and so on for three dimensional waves, etc.) - thus it has components that are partial derivatives dw/dk and dw/dl. ----- (I'm using d for partial derivatives here but partial derivatives are written with a "del" symbol (not the same as the gradient operator symbol, which I believe is called "Del", which is an upside down capital greek letter Delta; the del symbol looks a little like the lowercase greek letter delta, but is smoother - it looks like a backwards '6'. I also used 'd', as in 'dw','dk','dl' above, as values (representing a difference in w, k, or l) that may or may not be infinitisimal in size. The propper symbol to use in that case is the lowercase delta, or particularly for sizable differences, capital Delta. I'm going to continue to just use dw, dk, and dl here, though.) ----- But in order to actually see amplitude propagation (wave envelope propagation) at the group velocity, there must be variation in amplitude. This can be produced by linear superposition of additional waves that or only infinitesimally different parts of the spectrum. In that case, amplitude variations are very spread out in space and the group velocity of the interference pattern is about the same as (dw/dk,dw/dl). However, as the amplitude variations become more concentrated in space, the ratios of the differences of w to the differences of k and l between wave pairs won't be exactly the same as the derivatives dw/dk and dw/dl for each linearly-superimposed component - and each component may have different dw/dk and dw/dl for it's own k and l. While a wave envelope will propagate with some average or effective group velocity, it will also tend to spread and weaken (or contract and intensify up to a point and then spread and weaken - one or the other might happen in one direction while the opposite happens in another direction) and the phase lines may take on different tilts in different parts of the wave envelope, which might then be described by multiple overlapping wave envelopes, etc..., as there are a range of group velocities present. While wave envelope propagation perpendicular to phase lines can always be seen as being at a group velocity component in that direction, the group velocity along phase lines may lose any meaningful distinction with phase propagation, as in the checkerboard pattern example; this suggests (at least for Rossby waves) that the group velocity component parallel to phase lines will get smaller when the wave envelope wavelength in that direction get's smaller, just as phase speed is smaller for smaller wavelengths, and as described for the checkerboard pattern, both propagation of phases or along phases each vary qualitatively the same way with wavelengths in both directions.
130523. Patrick 027 at 16:13 PM on 11 December 2008
        Arctic sea ice melt - natural or man-made?
        ... In **CASE C2**, the checkerboard pattern - the nodes of the vorticity wave, u' wave, and v' wave, form a set of rectangles for each wave. Contours of wave values thus are nearly rectangular near the nodes but become more rounded toward the centers of the rectangles. In this checkerboard pattern, parallel to either set of parallel nodes, wave values vary sinusoidally. In the x direction, the u' and vorticity waves are in phase and 180 deg out of phase (depending on y), while they are 90 deg or 270 deg out of phase in the y direction. In the y direction, the v' and voriticity waves are in phase and 180 deg out of phase (depending on x), while they are 90 deg or 270 deg out of phase in the x direction. Because of the constant proportionality in the x direction of u' with vorticity and in the y direction of v' with vorticity, the propagation in the y direction does not vary with x and the propagation in the x direction does not vary with y. (The propagation of the wave of course occurs as u' and v' act across the PV gradient to increase PV where the PV anomaly gradient is in one direction and decrease the PV where a component of the PV anomaly gradient is in the other direction; a maximum moves toward where values increase and away from where values decrease, a minimum moves toward decreasing values and away from increasing values; the derivative in space of a sinusoidal waveform is another sinusoidal waveform either 90 or 270 deg (depending on view point) out of phase; a moving sinusoidal waveform produces variations at fixed locations that are sinusoidal in time, etc, so propagation of a otherwise unchanging wave pattern will have rate of change of PV, RV, u', v', etc, 90 or 270 deg out of phase (in the direction(s) of propagation) from the wave pattern of the instantaneous values of PV, RV, u', v', etc, respectively, and with the amplitude of the time derivative wave in proportion to the amplitude of the instantaneous value wave - a proportion that can vary in the direction of propagation but does not vary in the perpendicular direction). -- But what about **CASE C1**, or more generally, when a wave does not form an infinite pattern but has only nonzero amplitude (or amplitude above OR below some threshold) in a single limited region that is not part of a repeating sinusoidal variation (or some linear combination of those) of amplitude? (PS this does not describe any propagation of the checkerboard pattern; the modulation of amplitude of one wave by another sinusoidal function has a group velocity but this is not the group velocity of the whole pattern; to illustrate such a group velocity, one must multiply the whole wave form by yet some other amplitude-modulating function, etc...) Take **CASE C1** for example. The vorticity wave is a wave train along the x-axis, symmetric about y, that is nonzero only over some finite range of y. If the basic state PV gradient is not parallel to either axis, as in **CASE C1b**, then the wave is tilted and the 'amplitude wave' (better term - the wave envelope) will move with some group velocity in y that is a function of the wavelength in x (and therefore a function of wavenumber k), where the group velocity y component is precisely the derivative dw/dl for the k value - w is a function of (k,l) for Rossby waves and waves in general; this is how group velocity can be defined for a wave that is not part of a specific interference pattern of specific waves). In **CASE C1a**, the y component of group velocity is 0; the wave envelope doesn't propagate in y. The physical explanation is qualitatively the same as in **CASE C2(b and a, respectively)**. A narrow wave envelope should slow propagation in the x direction for the same reason that k affects propagation in y and l affects propagation in x for the checkerboard pattern. But that is only part of the story. In both **C1a** and **C1b**, as in **C2**, there are closed wave streamlines around the wave vorticity maxima and minima, as there are u' and v' waves. But in **C2**, both u' and v' reach maxima and minima along the nodes of the vorticity wave, and there values go toward zero approaching the next vorticity maxima or minima. In **C1**, in the y direction, there is not other vorticity maxima or minima. Instead, u' and v' values must decay toward zero going away from the center of the wave envelope - Refering back to how the wind field can be determined from the vorticity field, the length scale of this decay to zero will increase with increasing wavelength in the x-direction (note consequences for group velocity, this is somewhat** qualitatively similar to how k affects propagation in y and l affects propagation in x for the checkboard pattern, though perhaps for additional reasons). Outside the vorticity wave envelope, this wind field must also be irrotational; this works because while -du'/dy must reverse sign (in the y direction) in order for u' to decay to zero, dv'/dx can keep the same sign out to large |y| (though it approaches 0 as v' approaches 0). One can get a qualitative handle on this (and some of the other issues discussed above, including group velocity of tilted waves) by considering each phase line as a string of circular vorticies (remember that the wind speed of each is inversely proportional to distance from the center of each). Each contributes to the wind field v' in between vorticity maxima and minima phase lines, and not just at points on the same y value as the vortex; hence, v' is larger at any one y value due to voriticity at other y values (though the vorticity at the same y will have the greatest effect). Meanwhile, the u' fields of any pair of vortices also adds to increase total u' outside the pair but the values partly cancel in between the pair (with the total u' from that pair being of the sign of the u' from the stronger of the two vorticities). And so on... vorticity phase lines of constant amplitude over y has constant v' over y as well, zero u', and if only one line of vorticies, v' would be constant over x on either side of the line. But variation of vorticity amplitude along a phase line allows nonzero u' (as described above for both cases **C1** and **C2**, thus allowing some propagation in the y direction if there is a PV gradient in x ----- [PS another way to look at that: suppose instead of holding x and y oriented to the wave structure, hold x and y so that the PV gradient is just in y, but the wave is tilted. The wind field of each vortex will, by displacing PV contours, increase PV on one side and decrease PV on the other, with zero PV change along a line in the y direction centered on the vortex. In a tilted wave, the vortices along a phase line (along a vorticity wave crest or trough) lie in each other's PV changing regions. Where their is constant amplitude along the phase line or where there is an amplitude minimum or maximum (constant amplitude at that point), provided symmetry about that maximum or minimum, then the effects cancel and there is zero PV change at that point, but where vorticity is not symmetric along the phase line about a point, or generally where vorticity changes along the phase line or changes sign, the effects at the location of one vortex by the other vortices can be or will be unbalanced, so that PV is changing at that point along the vorticity crest or trough, hence there can be or will be amplitude propagation in the direction parallel to phase lines]. -----), and variation of v', but unlike **C2**, where the v' is kept proportional to vorticity over y, for **C1**, the parts of the wave near y=0 may generally have less v' per vorticity as there is on the edges of the vorticity wave envelope - the stronger vorticies have proportionately weaker v' at the same y due to the weaker vortices at other y values, while the weaker vortices have stronger v'. Furthermore, outside of the vorticity wave itself, there is still v' (and u') from the vortices within the wave envelope (that their magnitudes decrease faster with distance from the vorticity wave envelope for shorter wavelengths in the x direction (higher k) can be seen as a consequence of the wind field at any one point depending less on the finer details at some distance). This means that, initially, phase propagation speeds (in the x direction) are slower in the center of the wave envelope as they are on the outskirts. This means the waves bend into V or U shapes (and the wave envelope expands due to the extent of v' (and u' for **C1b**)). The wave is tilted relative to (x,y), above and below y=0, in opposite directions. This bending then allows for amplitude propagation away from the center (where the amplitude falls) and toward the wave envelope edges; for **C1a**, this is symmetrical about y=0, for **C1b**, the variation of basic state PV in the x direction can introduce some asymmetry - the tilts relative to the PV gradient direction won't be equal and opposite; conceivably they might be the same sign; they can't have the same magnitude, though; ----- (**The component of Group velocity parallel to phase lines - amplitude propagation along phase lines - is fastest at intermediate tilts between phase lines being aligned with the PV gradient and being perpendicular to it**). This could be seen as two wavetrains of equal and opposite phase tilts relative to x,y directions, but with wave envelope aligned in the same direction, that were initially linearly superimposed, but then seperated as each had it's own group velocity (and possibly different phase phase speeds, if the PV gradient is not parallel to y). However, each of these wavetrains can be expected to undergo the same process (modified by different phase tilts, etc.) as occured with the original wavetrain. Alternatively, depending on wave envelope form, there might never be complete seperation (thought the amplitude at the center will continually decrease) - the wave might continue to spread with a range of group velocities (corresponding to those group velocities of all linearly superimposed component waves) with the phase lines curving into U shapes. Another way of veiwing this is to consider a string of vorticies of alternating sign (representing the wave train, aligned with the wave envelope); rather than consider the motion of the vorticities, one can think of it as vorticities that are not moving but with each generation of vorticity phase lines continually producing a new generation of new vorticity crests and troughs that are 90 or 270 deg out of phase from the parent generation. The total wave propagates because the third generation is 180 degrees out of phase from the first, as is the forth from the second, etc, so that they cancel each other. But with amplitude confined to a wave envelope centered at y=0, any generation will produce a next generation that is more spread out in y and has lower amplitude at y=0. Thus the third generation does not completely cancel the first at y = 0, but that allows a portion of the first generation to continue to act to produce an additional second generation (generation 2B ?), and so on... so that the first generation might eventually be canceled out, but by that point ... etc...
130524. Dan Pangburn at 12:18 PM on 11 December 2008
        Models are unreliable
        Contrary to the statement in post #80 “No one says that "all temperature trend direction changes are brought about by Milankovitch cycles", so let's not make stuff up”, the statement “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” and several similar statements in post # 80 indicate that Chris seems to realize that temperature up trends and downtrends were not driven by atmospheric carbon dioxide level in the past. In post #73 with the statement “We all know that the Earth's equilibrium temperature response has a logarithmic relationship to the atmospheric CO2 concentration” Chris appears to also understand that added increments of carbon dioxide have diminishing influence on temperature. But then Chris and apparently the rest of the alarmists fail to put the two observations together which would prove to them that temperature trends now are also not driven by atmospheric carbon dioxide level.
130525. Quietman at 11:20 AM on 11 December 2008
        A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
        This is what "State of Fear" is about and like all of Michaels works is based on his investigations and conclusions drawn from same and then voiced in the form of a novel. It was one of, if not his best, works. The following is a paragraph from environmentalism as a religion in a speech at the Commonwealth Club, San Francisco, CA, September 15, 2003 How will we manage to get environmentalism out of the clutches of religion, and back to a scientific discipline? There's a simple answer: we must institute far more stringent requirements for what constitutes knowledge in the environmental realm. I am thoroughly sick of politicized so-called facts that simply aren't true. It isn't that these "facts" are exaggerations of an underlying truth. Nor is it that certain organizations are spinning their case to present it in the strongest way. Not at all---what more and more groups are doing is putting out is lies, pure and simple. Falsehoods that they know to be false. Thank you Michael. R.I.P.
130526. Patrick 027 at 05:28 AM on 11 December 2008
        Arctic sea ice melt - natural or man-made?
        Correction sec.2e.: **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 *** N O T *** 'amplitude wave' propagation in the y direction; the phases propagate in the negative x direction.
130527. Tom Moore at 00:24 AM on 11 December 2008
        Latest satellite data on Greenland mass change
        At face value, the graph suggests that there was a mass gain going on until quite recently, perhaps 2005. If so, this past couple of years doesn't seem like much to worry about.
130528. Philippe Chantreau at 18:46 PM on 10 December 2008
        Arctic sea ice melt - natural or man-made?
        I wouldn't hold it against you Patrick... Quietman, you may be right about Arkadiusz, or not. I am still unimpressed with Beck, especially his fantasy graph on Dansgaard-Oeshger cycles. Has he withdrawn that piece of work from his web site? Has he explained what the change in the x axis mean? Arkadiusz, what degree have you earned from which institution and what are your publications? Those are the things that will tell me if you are a "scientist", as Quietman states. I do applied science too (in another area), and would certainly not consider myself a "scientist."
130529. Patrick 027 at 16:08 PM on 10 December 2008
        Arctic sea ice melt - natural or man-made?
        PS a little unsure of my section 2d above.
130530. 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... _______
130531. 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.
130532. 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.
130533. 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.
130534. 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?
130535. Mizimi at 05:16 AM on 9 December 2008
        Greenland was green in the past
        #5 'Iceland' is from the old Norse word meaning 'isle' co-joined to 'land' thus giving (phonetically) 'iceland'
130536. 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.
130537. 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
130538. 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.
130539. 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.
130540. 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.
130541. 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!
130542. 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.
130543. Mizimi at 04:31 AM on 7 December 2008
        Temp record is unreliable
        Your quite right Chris; apologies.
130544. 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?
130545. 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.
130546. 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?
130547. 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!
130548. 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.
130549. 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.
130550. 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.

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