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Tom Curtis at 12:45 PM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Bob, I don't know if this helps, but you seem to be thinking of the interactions as entirely a radiative story. In fact, it is a radiative/colissional story. Instead of: UVin + IRin = IRout, we have: UVin + IRin + Collisionalin = IRout + Collisionalout. In the stratosphere, for O3, UVin >> IRout > IRin; so O3 is a net absorber of radiation, with the excess energy being distributed to other components of the atmosphere by collission. With CO2, IRout >> IRin, with UVin being zero. The energy defecit is drawn from the surrounding atmosphere by collisions. If we simply doubled the CO2 in the stratosphere, leaving that in the troposphere untouched, then initially IRout and IRin would double. Because IRout is larger than IRin, that results in a net energy deficit which the CO2 draws from colisional energy, in the process cooling the surrounding atmosphere until a new steady state is reached. If we instead doubled the tropospheric CO2, leaving the stratospheric CO2 untouched, that would reduce IRin, again creating an imbalance restored by local cooling of the atmosphere. If we do the actually possible, and double CO2 at both levels of the atmosphere, both factors will come into play. However, I believe, the first has the larger effect. More importantly, the second is a cooling effect only because IRout larger than, or equal to IRin. If IRin >> IRout, as would be the case in the absence of O3, then doubling both IRin and IRout would have a significant warming effect, more than sufficient to compensate for the small reduction of IR radiation from the troposphere in the 15 micron band. -
Tom Curtis at 12:17 PM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio @115: Question: I understand what lapse rate and adiabatic means but what is meant by the adiabatic lapse rate? Is there another kind of lapse rate? The Lapse rate is the change of temperature with change of altitude, and more specifically the lapse rate = -dT/dz. Because convection and latent energy dominate heat transfers in the troposphere, the lapse rate in the troposphere approximates to the the dry adiabatic lapse rate or the moist (or saturated) adiabatic lapse rate depending on relative humidity. At 0% humidity, the adiabatic lapse rate equals the dry adiabiatic lapse rate. At 100% humidity it equals the saturated adiabatic lapse rate. The adiabatic lapse rate is the rate of fall of temperature with increasing altitude predicted by the fall in pressure with altitude, as adjusted by release of latent heat as moisture condenses due to falling temperature. In practise, the environmental lapse rate rarely equals the adiabatic lapse rate because energy release from condensation and energy absorption of sunlight by clouds is rarely gruadual. However, the adiabatic lapse rate dominates only in the troposphere (and possibly mesosphere). At the tropopause, the lapse rate is zero; and in the stratosphere it is negative. It is again zero at the stratopause, positive in the mesosphere, zero at the mesopause, and negative again in the thermosphere. Even if we exclude convection as a means of transfering energy in the atmosphere, and hence exclude the adiabatic lapse rate as a temperature profile, radiative transfer in an optically absorbing atmosphere will generate a lapse rate, indeed, typically a shallower (greater change in temperature for a given change in altitude) lapse rate than the adiabatic lapse rate. Therefore this reasoning should still hold. Question/Comment: To me, shallower means a more gradual or lower lapse rate. Please clarify. Also, less shallow than what? The lapse rate is generated by the radiative transfer of energy so it seems as if you are comparing something to itself. A shallower slope is one with a greater change in the x axis for a given change in the z axis. In this case, the x axis is temperature and the z axis is altitude. In speaking of slope I am speaking of dZ/dX, whereas the lapse rate is measured as - dT/dZ; so I can see how this can cause confusion, for which I apologise. In a grey atmosphere, ie, one which is uniformly absorbing of IR at all wavelengths and has no convective heat transfers, the lapse rate is much greater than that determined by convection, ie, the adiabatic lapse rate. (As the lapse rate is the negative inverse of the slope of the plot of altitude against temperature, that means it has a much smaller slope.) As the IR absorption is restricted to fewer wavelengths, the radiative lapse rate will decrease; but in Earth's atmosphere it is still greater than the adiabatic lapse rate (I believe) although not much greater. I believe it is because of this that at the 60th parralel, the convectivion that drive the polar cell forms. Quesion/Comment: But I think that the portion of the IR spectrum that would be absorbed by the stratosphere has less IR energy in it after going through and being absorbed by the troposphere. It does, or more correctly that portion has less IR energy after being absorbed by CO2 and reradiated at a lower energy level because the CO2 is at a lower temperature. However, most of that energy escapes to space, so it is quite possible for there to be less energy coming from the troposphere in that band of the spectrum, but more energy being absorbed by the stratosphere in that band. It just means that less of the energy from the troposphere escapes to space in that band. -
Berényi Péter at 12:10 PM on 4 December 2010We're heading into an ice age
#147 muoncounter at 03:54 AM on 4 December, 2010 Once the ice is fully frozen, why would there be any further aging of the air? How credible are these reported age discrepancies between ice age and air age? It is explained here. Basically it's because ice is cold & accumulation rate is low. Bubbles are enclosed only near the firn-ice transition zone, about 90 m below surface. I am not sure however, that gas diffusion is stopped as soon as bubbles get enclosed. There's a microscopically thin boundary layer between ice grains where impurities get concentrated and supercooled liquid water is retained even at temperatures well below freezing. -
actually thoughtful at 12:00 PM on 4 December 2010Renewable Baseload Energy
Bibliovermis -really? What CO2 intensive activities are associated with: solar thermal wind PV wave geothermal ? The ongoing CO2 comes from fuel processing - none of that is required for renewables. I don't know how the concrete/watt metrics come out. If, as I suspect, nuclear has a huge disadvantage here (more concrete per watt than renewables), then there is only CO2+ for nuclear when you compare them. Maybe apples to apple slices. -
Renewable Baseload Energy
Bibliovermis - Quite true, all power plants will require concrete, raw material mining, and (except for non-biomass renewables) continuing fuel mining/collection, CO2 emission from the vehicles used, etc. But nuclear is definitely far from carbon neutral. Uranium (especially the fissionable isotopes) is a pretty diffuse fuel, and you have to move a lot of rock to get significant quantities. -
Bibliovermis at 11:51 AM on 4 December 2010Renewable Baseload Energy
That's an apples to apple cores comparison unless the same full life cycle analysis is applied to the other electricity generation methods. -
Spaceman Spiff at 11:49 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio at 10:52 AM The answer to your first question is "yes". The up and down transition rate equations contain many terms (spontaneous radiative decay, radiative absorption, induced emission, collisional excitation and de-excitation, ....). Collisional excitation followed by radiative decay via a photon that escapes is an important process in the stratosphere. Radiative absorption is not dominant (excepting in the ozone bands and the central CO2 transitions very near to 15 microns). I am not sure I know what you mean by, "The energy in the absorbtive portion of the band has been depleted after going through the troposphere." What you see in the main CO2 band isn't due to Beer-Lambert's law. What you are seeing is largely due to light emerging from the layer at which the optical depth (dimensionless measure of matter's ability to absorb or scatter light) has fallen to ~1 (the "photosphere"). Deeper down, the optical depth is too large (the photon mean free path too small), and most of the light is absorbed (and "re"-emitted) locally. The thermal emission is very sensitive to temperature, in that higher T gas emits more strongly. So where in wavelength the atmosphere is most opaque, the emitting layer (photosphere) lies high up in the troposphere where the T is low and so the thermal emission intensity is also low. Where it is less opaque, it arises from deeper layers in the troposphere where T is higher and thus is the thermal emission intensity. An exception to this is the set of very, very optically thick transitions of CO2 lying very near 15 microns. Here the atmosphere is so opaque (due to the strength/probability of the transition) that this light's effective photosphere lies up in the stratosphere, where T is substantially higher than in the troposphere below (due to O3 dissociation by UV sunlight). The escaping emission there is therefore brighter than in surrounding wavelengths within the surrounding CO2 transitions, and thus the sharp, narrow, reversal you see at 15 microns at the center of the main CO2 "trough". Does that help at all? -
actually thoughtful at 11:35 AM on 4 December 2010Renewable Baseload Energy
Money quote from Rob's link: "In the paper "Nuclear Power : the energy balance" by J.W. Storm and P. Smith (2005) download here, the authors calculate that with high quality ores, the CO2 produced by the full nuclear life cycle is about one half to one third of an equivalent sized gas-fired power station. For low quality ores (less than 0.02% of U3O8 per tonne of ore), the CO2 produced by the full nuclear life cycle is EQUAL TO that produced by the equivalent gas-fired power station." -
Rob Honeycutt at 11:08 AM on 4 December 2010Renewable Baseload Energy
Here is an interesting take on the CO2 involved in nuclear energy. -
Tom Dayton at 11:05 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
damorbel, I can't get past even your second paragraph, which seems to be gibberish. -
Bob Guercio at 10:52 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Spaceman Spiff - 113 Please help me understand. There are many mechanisms that populate the upper level of a radiative transition. One is by absorbing a photon having (virtually) that wavelength. But another possibility is collisional excitation. If the collision rates (gas density) aren't too large relative to the rates of radiative decay, then the collisional excitation has a chance to radiatively decay, rather than redistributing the energy back out into the thermal pool of gas due to a subsequent collisional de-excitation. So the thermal energy of the gas is converted into radiative energy -- and if that radiative energy escapes, this is a net cooling process. This is what is meant by a "net emitter". Questions: I think what you are saying here is that sometimes during a collision, the kinetic energy of motion is lost and reappears as internal energy of a molecule. That molecule then emits radiation. Do I have this correct? The point is that with exception of the CO2 transitions lying near the very strongest ones near 15 microns, the stratosphere is largely transparent to radiation from below (in particular, that which arises in wavebands corresponding to transitions in C02). Run the default model from David Archer's website (70 km, looking down), linked within the OP. See that sharp reversal in the spectrum within the center of the CO2 band? That light is emerging from an effective "photosphere" that lies within the stratosphere. Nearly all of the other light you see in that spectrum, including that within the C02 band is emerging from an effective photosphere somewhere within Earth's troposphere (but in the 800-1200 cm^{-1} spectral region it's emerging mainly from near Earth's surface, excepting the O3 trough near 1050 cm^{-1})-- and passes largely unscathed through the stratosphere. Question: Isn't this kind of what I'm saying. The energy in the absorbtive portion of the band has been depleted after going through the troposphere. To be continued. The stratosphere emits escaping radiation at a rate (that's the cooling rate) that is balanced by the energy deposited via absorption of short wavelength solar radiation by O3 and O2, resulting in molecular dissociation (that's the heating rate). One of the most radiatively active gases in the stratosphere is C02. Increase its abundance, and the cooling rate will exceed the heating rate until a new (lower) equilibrium temperature is reached. -
damorbel at 10:35 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
Re #287 Ned you write:- "... at a particular wavelength. Part of the problem with damorbel's argument here is that the incoming solar radiation has a very different spectral distribution from the outgoing longwave radiation." The wavelenth difference is indeed great but what that count for? Sure it indicates that the Sun/Earth system is in considerable disequilibrium. But the only significance of this is the nature of the disequilibrium, which is precisely what we are talking about, the contradiction of AGW/GHE 'science' and the 2nd Law of thermodynamics, exactly the OP topic of this thread. Further you write:- "Absorptance in the visible/near-IR is not necessarily equal to thermal infrared emissivity. A statement like that just confirms what I am arguing. If they weren't equal there wouldn't be an equilibrium temperature of any sort. If emissivity always was different from 1-a (a is albedo) then the temperature would never be stable, rising or falling according to the sign of the difference. -
Bob Guercio at 10:31 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Tom Curtis - 83 Please help me understand. I went only so far so once I understand this I'll continue and probably have more questions. Thank you, Bob After carefull consideration, I believe the explanation of stratospheric cooling given in the original post is simply wrong. To see this, consider a hypothetical planet whose atmosphere is completely transparent at all wavelengths of electromagnetic radiation. In this case, its surface temperature will be its temperature as measured from space, ie, its effective temperature. The temperature at any point in the atmosphere above the surface will be less than the effective temperature, and the temperature profile of the atmosphere will be defined by the adiabatic lapse rate up to the thermosphere. (Like Venus, see graphic in 80 above, it will have no stratosphere.) Question: I understand what lapse rate and adiabatic means but what is meant by the adiabatic lapse rate? Is there another kind of lapse rate? Now, as we introduce CO2 into the atmosphere, what happens is that the altitude of the effective temperature gradually increases in height. As the temperature profile is still defined by the lapse rate, the temperatures at every altitude up to the thermosphere will also increase. Question/Comment: Yes. CO2 absorbs IR in accordance with the greenhouse effect. Even if we exclude convection as a means of transfering energy in the atmosphere, and hence exclude the adiabatic lapse rate as a temperature profile, radiative transfer in an optically absorbing atmosphere will generate a lapse rate, indeed, typically a shallower (greater change in temperature for a given change in altitude) lapse rate than the adiabatic lapse rate. Therefore this reasoning should still hold. Question/Comment: To me, shallower means a more gradual or lower lapse rate. Please clarify. Also, less shallow than what? The lapse rate is generated by the radiative transfer of energy so it seems as if you are comparing something to itself. Looked at differently, and using Earth as our model, we need to consider that the effective altitude of radiation, ie, the average altitude from which radiation reaches space, lies several kilometers below the tropopause. Therefore most outgoing radiation at the tropopause reaches space, and the Beer-Lambert law is an appropriate approximation of the effect of changing CO2 concentrations in the stratosphere. Given that, then if we double the CO2 concentration we also double the amount of IR radiation absorbed by CO2 in the stratosphere. The amount of IR radiation outgoing from the tropopause will not itself double, but infact will slightly fall because the atmosphere is optically thick below the tropopause. Consequently, although the net radiation entering the stratosphere will fall in this scenario, the amount absorbed in the stratosphere will increase. Quesion/Comment: But I think that the portion of the IR spectrum that would be absorbed by the stratosphere has less IR energy in it after going through and being absorbed by the troposphere. Comment: To be continued. Of course, the amount of IR radiation emitted at a given temperature will also double with doubling of CO2 in the stratosphere. The result is that, if the temperature of the stratospheric CO2 is less than the brightness temperature radiation emitted by CO2 in the troposphere, it will warm. If it is greater it will cool. Of course, had the temperature in the stratosphere followed the adiabatic lapse rate, it would have been less than that of the troposphere; and increasing CO2 would warm the stratosphere, all else being equal. But all else is not equal - the stratosphere is much hotter than the upper levels of the tropospere because of the absorption of UV radiation by ozone. Therefore, I would have to conclude that stratospheric cooling with increased CO2 is primarilly due to increased efficiency at radiating away energy absorbed by ozone due to increased concentration of CO2. There would be a small additional boost due to reduced outgoing radiation of IR in the 15 micron (CO2) band; but that is ony a secondary cooling effect, and would have been a warming effect where it not for the presence of ozone in the stratosphere. Having said all that, I now hope some one will knock some holes in my reasoning. -
Spaceman Spiff at 10:21 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
A point of clarification to my last post (#113): Yes, light emitted by CO2 in the stratosphere is escaping upward, but the low gas density there makes it a weak emitter (except near the center of the band at 15 microns) compared to the light emerging from the troposphere via CO2. In some ways, Earth's stratospheric properties and spectrum are much like those of the Sun's chromosphere, that lies just above its photosphere. -
Spaceman Spiff at 10:06 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio @105 et al.: There are many mechanisms that populate the upper level of a radiative transition. One is by absorbing a photon having (virtually) that wavelength. But another possibility is collisional excitation. If the collision rates (gas density) aren't too large relative to the rates of radiative decay, then the collisional excitation has a chance to radiatively decay, rather than redistributing the energy back out into the thermal pool of gas due to a subsequent collisional de-excitation. So the thermal energy of the gas is converted into radiative energy -- and if that radiative energy escapes, this is a net cooling process. This is what is meant by a "net emitter". The point is that with exception of the CO2 transitions lying near the very strongest ones near 15 microns, the stratosphere is largely transparent to radiation from below (in particular, that which arises in wavebands corresponding to transitions in C02). Run the default model from David Archer's website (70 km, looking down), linked within the OP. See that sharp reversal in the spectrum within the center of the CO2 band? That light is emerging from an effective "photosphere" that lies within the stratosphere. Nearly all of the other light you see in that spectrum, including that within the C02 band is emerging from an effective photosphere somewhere within Earth's troposphere (but in the 800-1200 cm^{-1} spectral region it's emerging mainly from near Earth's surface, excepting the O3 trough near 1050 cm^{-1})-- and passes largely unscathed through the stratosphere. The stratosphere emits escaping radiation at a rate (that's the cooling rate) that is balanced by the energy deposited via absorption of short wavelength solar radiation by O3 and O2, resulting in molecular dissociation (that's the heating rate). One of the most radiatively active gases in the stratosphere is C02. Increase its abundance, and the cooling rate will exceed the heating rate until a new (lower) equilibrium temperature is reached. -
actually thoughtful at 09:52 AM on 4 December 2010Renewable Baseload Energy
So, to support my claim that I am a greenie who is just fine with higher electric prices, what happens if we use LCOE's most expensive energy the evil photovoltaics? I live in the state of Arizona. Our warm, fuzzy, lovable profit-driven electric monopoly charges us $.14/kwh (take the bill total, divide by the kwh used). Of that cost, 46% is fuel, the rest is "not fuel". So if my baseload power averages 110/unit (using figures above (mine are probably higher - we are still paying for the Palo Verde nuclear plant built in the 1970s & 1980s - the most delayed, most expensive electricity in the history of the universe (not that I am bitter))). So, using the figures above solar PV* (the most expensive way to get electricity) costs 396.1/unit, then to switch to all PV, my electricity bill would go from 78.78 (typical (and actual) electricity bill) to 127.62 (396.1/110*45%*78.78)/month. $51 a month or 612 bucks a year to avoid climate change. Does anyone else see this as a bargain? I pay more for that to insure my home, health and automobile (each). * Now it is obvious that RIGHT NOW we can't switch to all PV. Both logistically, and due to grid-level storage. And we wouldn't use all solar PV, we would use a mix (including nukes), so while my renewables-only cost is WILDLY inflated, I will leave it as is to easily cover the grid-level storage issue. But that should pretty much kill the solar is too expensive argument. It fails because it isn't true (a painful death, surely). Oh, and the zombie-like follow on argument - energy increases apply to ALL sectors of the economy - everything, everywhere: 78.78 is 2.3% of my monthly budget. So factor in a one time economic inflation of 2.3%. Still cheap by any rational standard. -
Albatross at 09:42 AM on 4 December 2010A basic overview of Antarctic ice
Hi Bill, "..... it would seem the winner is no statistically significant change." Umm, no. I'm afraid that you seem to have completely missed the point of that statistical analysis exercise. Anyhow, the graph @89 is the net result of all the changes/processes and it is showing a distinct downward trend in global sea ice since about 2001. Global sea ice coverage and volume is down. Continental glacier and ice sheet volume is down. Greenland ice sheet volume is down. Antarctic ice sheetvolume (mainly WAIS)is down. -
Chris G at 09:21 AM on 4 December 2010The human fingerprint in the seasons
To this end, I played with some graphs at Wood for Trees. I got this far before running out of time. Four plots of January,July versus Southern, Northern hemispheres. Ran out of time before figuring out how (or if it is possible) to aggregate between series, but the test is basically: "Are red and purple rising faster than blue and green?" I believe the answer is "yes". I smoothed over best-guess of the time interval for 6 solar cycles. -
actually thoughtful at 09:14 AM on 4 December 2010Renewable Baseload Energy
I looked deep into my crystal ball and determined the following: *In 2011 the levelized cost of nuclear will include a 25% higher overnight cost. *In 2011 the levelized cost of solar PV will include a 25% LOWER overnight cost. You can look into my crystal ball too! http://www.eia.doe.gov/oiaf/beck_plantcosts/index.html (click on the table 2 link) So now we can debate the rate of change and burn up another 200 or so messages. My take away is that DOE is having to eat a little bit of crow for being so far from reality (but all you renewable haters good news for you, too: geothermal doubles and burning methane out at the dump triples!) Beyond the crystal gazing above to support my "doubt the DOE" theme - riddle me this: Why does it cost almost DOUBLE to run a solar thermal plant compared to running a nuclear plant? Yes, we wash the panels (with a machine). Given the downside to things going wrong, wouldn't you almost hope it cost more to run the nuke? What are they doing with all that O&M money down at the ST plant? I might enjoy burger and beer night over at the ST plant - sounds like they have the funds to do it right! -
mars at 09:13 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Re Daniel 109 Thanks that is the one. -
Paul D at 09:11 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
I understand the points Tom Curtis was making and I agree I made a mistake in 88. I'm thinking that in Toms scenario, because all the Suns energy would get to the surface, like the Moon, the surface would get hot (like the Moon) it would also emit a lot of radiation, which would go straight back out to space. However assuming the atmosphere was able to warm by conduction, the atmosphere would get warmed at the surface, and that warmed atmosphere would behave roughly as Tom described (lapse rate as described). The question would be how warm? I guess the warmed atmosphere would help to increase the temperature of the surface which would emit more, thus removing energy and keeping a balance between incoming and outgoing energy. Apologies that it took so long for me to get my brain around it. -
mars at 09:07 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
It comes from this site. The image I wish to refer to is the 4th from the top of the page Heat loses and gains in the atmosphere This is the site if the link does not work http://lasp.colorado.edu/~bagenal/3720/CLASS14/14EVM-5.htmlModerator Response: [Daniel Bailey] You've been including an extra / at the end of the URL. Make sure you use the preview function before submitting; formatting errors in URLs and posting of images are by far the most common errors in posting. Most would have been caught by previewing. -
Daniel Bailey at 09:05 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Re: mars (108) This one?
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mars at 09:01 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Hmm I don't seem to be able to post the image It comes from this site. The image I wish to refer to is the 4th from the top of the page Heat loses and gains in the atmoshere -
Daniel Bailey at 09:01 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
And took hits for not observing the Skeptics' "Code Duello" The Yooper -
Rob Painting at 08:58 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
Ned @ 290 - there's always the exception to the rule, albeit very minor, BP waded into Ken Lambert a few weeks back over a "theoretical observed" comment. -
mars at 08:54 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
The image above shows how the Ir emission from of CO2 and other GHG
produces cooling in the stratosphere. This suggests that Bobs explanation is inadequate.
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actually thoughtful at 08:48 AM on 4 December 2010Renewable Baseload Energy
On to this post: Peter Lang version 1 "Better to stick with Levelised Cost of Electricity (LCOE)." But WAIT, read on in this post Peter Lang version 2 "Gemasolar (Spain) ... Cost per average kW = $34,587/kWy/y For comparison nuclear = $4,500/kWy/y" So it seems that LCOE is what one ought to do, but if a particular renewable project exceeds the budget - let's focus on that instead for the rhetorical points. For the record - I've already pointed out why and how the DOE is slanted in favor of existing, polluting industry and against renewables. But even using their data, the results speak for themselves. (no subsidies, no carbon pricing - the free market in its current busted state) [2008$/megawatt hours] least to most expensive: Natural gas (NG) advanced combined cycle 79.3 NG combined cycle 83.1 coal 100.4 advanced coal 110.5 Biomass 111 NG advanced CC with CCS 113.3 Geothermal 115.7 advanced nuclear 119 Hydro 119.9 NG advanced combustion turbine 123.5 advanced coal with CCS 129.3 NG conventional combustion turbine 139.5 Wind 149.3 Wind-offshore 191.1 Solar thermal 256.6 Solar PV 396.1 This is from the DOE, by way of wikipedia - you can trace out the veracity yourself if you want. I trust wikipedia to cut'n'paste the DOE data. clickable link - check out UK and by energy source down below the DOE bit - DOE is NOT the only possible source of credible data I suggest anything within 10% is basically equivalent. I don't know what overnight (OK, now I do $3,902/kW) or all in cost they used for nuclear. So using the cost ONLY, but avoid carbon (and claims about future efficacy are accepted (like advanced nuclear is cheap, CCS works, etc)). We would, as rational optimizers of baseload power avoiding fossil CO2, choose: Biomass 111 NG advanced CC with CCS 113.3 Geothermal 115.7 advanced nuclear 119 Hydro 119.9 Wind 149.3 Wind-offshore 191.1 Solar thermal 256.6 Solar PV 396.1 [As a certified "greenie" I am able to state the obvious - electricity is too cheap because it does not factor in the cost of CO2 - once you do that, you don't just re-arrange preferences on the chart above - the chart itself will change.] -
Chris G at 08:09 AM on 4 December 2010The human fingerprint in the seasons
Doh, regarding my first point, I now see that the data are for NH only. So, my concern is moot. However, I think it would make for a stronger case if SH temps were included as well. -
Chris G at 08:05 AM on 4 December 2010The human fingerprint in the seasons
A few things I've noticed: #12 TIS says: "There is no time when the Earth is in winter or in summer." This is a valid concern. It would be pretty easy to aggregate summer as NH June-July-August and SH December-January-February, and vice versa for winter. However, I can't tell if this has been done within the spreadsheet since I don't see a column for hemisphere. TIS's comment about orbital obliquity is of dubious merit; it just doesn't change much over the course of decades. That effect operates over millenia. #39 Tom Curtis: "Fourth, water vapour is largely confined to the troposphere, so the water vapour feedback will not result in stratospheric cooling. " I agree with other points, but I'm not sure I'm following this. Most of the atmosphere in general, including CO2, is within the troposphere. The average height of emission of a photon to space is around 5-6K, and the tropopause is mostly above that. My understanding is that any GHG effect results in tropospheric warming and stratospheric cooling. The atmosphere is heated from above by whatever SW radiation is absorbed and it is heated from below by whatever LW radiation is absorbed, plus conduction. The tropopause exists where these balance each other. #36 Sphaerica, An excellent point regarding water vapor and climate sensitivity. You can't have it both ways. #45 TOP: "For 6 months out of the year the solar radiation input and hence the effect of any GHG on blocking radiation to space there is minimal to non-existent." This is wrong at the conceptual level. The surface of the earth is above 0K at all times and at all locations; therefore, it is always emitting radiative energy at all times and at all locations. See Planck's Law. General comment regarding comments on water vapor versus CO2 effects: The phase state diagram of H20 is different from CO2. Humidity varies a lot by both altitude and latitude because the temperature and pressure where it precipitates is common within our atmosphere. CO2 precipitates at temperatures and pressures not common within our atmosphere; so, it varies a lot less with altitude and latitude. I'm pretty sure one could define different warming, 3D spatial signatures to be expected dependent on which was changing more. However, since the two are linked via the physical properties of the system, it is not clear to me how the data could be unobfuscated. (Hmm, on another read, I see that #4,22 Mike has already made this point, and asked the same question I'm leading to.) -
Daniel Bailey at 07:52 AM on 4 December 2010Renewable Baseload Energy
Re: All concerned parties The reason I stepped in and made nuclear off-topic on this thread was to try to prevent what we saw happen on the other thread (and I was asked by a commenter to do so). As has been pointed out, this action (policement by moderation) had only limited effect. If I may suggest a different tactic: the community active on this thread simply ignore any and all comments from Peter Lang that you disagree with. In effect, the problem goes away. This thread belongs to all of you. Unite, and take ownership of it. The Yooper -
Bob Guercio at 07:45 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Joe, There are two situations. One is what is going on now. The stratosphere is cooler and the earth is gaining more energy than it is emitting. This cannot go on forever. Let's say we stabilize the CO2 level to what it is now. The earth continues to heat and in a few decades the energy entering the earth will be the same as that leaving. That is the second situation. And there too, the stratosphere will be cooler than what it was before more co2 was put into the atmosphere. We have to be clear which situation we are talking about in order to understand each other. My blog that was posted by John Cook addresses only the steady state solution. Bob -
Bob Guercio at 07:24 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Joe, That paper is heavy. Can you explain it in your own words or point to the salient portions of that paper. I'm not sure if this is going to work but I have an image on the CO2 spectrum here. If it doesn't appear, please go to the URL that you see. The spectrum is almost entirely in the IR region. So how can it be a net absorber or emitter of IR. Or is the little amount in the visible region enough to make it that. Bob
Moderator Response: [Daniel Bailey] - Fixed HTML -
Philippe Chantreau at 07:23 AM on 4 December 2010A basic overview of Antarctic ice
"it would seem the winner is no statistically significant change" The above graph of global sea ice anomaly shows a significant decline. One has to go back to 1988 to find a positive anomaly comparable, albeit smaller, to the negative anomalies experienced on a regular basis in the past 10 years. And the baseline includes all years to 2008. Global sea ice area coverage is decreasing. -
Bob Lacatena at 07:22 AM on 4 December 2010The human fingerprint in the seasons
39 (Tom Curtis), When you say:direct solar heating would make days hotter than night, summers hotter than winter, and tropics hotter than the poles, while to a first approximation, the water vapour feedback would have the reverse effect. Because the initial forcing and feedback have effects opposite in sign, they would cancel each other out (to a first approximation), thus resulting in no signal.
I'm not entirely sure that this would be true. It would be a question of degree (i.e. is one strong than the other), and I think the H2O forcing would stand out, although not to the same degree as with solar versus CO2. To be a little more specific, if we assume a 3C total warming from a doubling of CO2, which itself contributes 1C to the 3C, then feedbacks (primarily H2O, or follow-on CO2, but also including changes in albedo due to ice retreat) are responsible for roughly 2C of warming. This implies that a change in insolation which causes 1C of warming will in turn cause 2C of feedback (primarily in the form of GHG). As a side note, as the topic of different forcings has come up often of late, I'm finding myself annoyed at the previously convenient definition of climate sensitivity in terms of doubling of CO2 -- it implies that CO2 is necessary, and provides no yardstick for other forcings. A definition of "X degrees of change per Y degrees from external forcing" would be more workable. Oh, well... So the GHG signal would be stronger than the insolation signal, and should stand out as described in the original post, just not to the same degree as pure GHG forcing would (by a factor of roughly 3:1). But there would be no way (without a trial run of each) to be able to tell whether what we are seeing now is or is not a result of insolation forcing (1C) + GHG feedback (2C), or GHG forcing (1C) + GHG feedback (3C). Except, of course, for the differences in stratospheric cooling, and numerous other methods not mentioned in or relevant to the original post (Dan listed a number of them), such a the need to explain why the globe somehow isn't warming from CO2 emissions if another cause were found.In particular, direct solar heating would result in a significant increase in humidity in the tropics, but not the poles.
I'm not sure that this is true, either. Transport of moisture from the tropics to the poles is an important part of both climate and weather, and changes in such transport are one of the biggest dangers of a warming world (expansion of the arid subtropic zones), so I don't think a blanket statement could be made in this regard. -
scaddenp at 07:00 AM on 4 December 2010We're heading into an ice age
BP, the rate of change associated with YD type events is also assessed from lake records but I dont have reference handy - but read it in recent review by Wally Broecker. cjshaker - I agree that emerging from ice age, there is good evidence for very fast changes - too fast I think for modern agriculture to cope. We have too many hypotheses and insufficient data to start with total certainty the causes are but we take comfort from fact that these effects appear to only happen as climate emerges from glacial and not during interglacial, and that these appear to be hemispherical events not global events. The review in IPCC WG1, Chapter 6 on this is well worth reading. -
Ned at 07:00 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
KR writes: damorbel - The last 15-20 postings you have presented have made it increasingly clear that you do not have a firm grasp of the physics involved. That's not an insult - we all start somewhere. Yes. And I would note that, as we saw with the Evil Waste Heat Thread, the usual SkS "skeptics" are once again standing by on the sidelines. Apparently they're willing to quibble endlessly over things like UHI, who wrote what in a snippet of somebody's email, etc. But they're not willing to speak up and help address the problems with even the most appallingly confused argument coming from the "skeptic" side. As always, it turns out that "climate skepticism" is rather asymmetric around here. The unwritten rule seems to be that "No SkS skeptic shall ever publicly disagree with another SkS skeptic." IMHO that's pretty depressing. -
scaddenp at 06:53 AM on 4 December 2010Renewable Baseload Energy
"n New Zealand you, like Australia, have a ban on (unprintable), so we have no way of knowing if your generating system is the least cost option." Commonly believed but I as pointed out on another thread, false. The ban on nuclear-powered ships and weapons, does not extent to a ban on nuclear power. The last ministerial statement I heard on the subject ruled out nuclear on economic grounds, based Electricity Commission research, looking at small scale of electricity requirement compared to infrastructure needed to support it. -
Joe Blog at 06:46 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio At equilibrium, how can a group of molecules be net absorbers or net emitters. Because the energy is brought into the stratosphere by O3, through UV and 9-10micron LW absorption, but emitted by co2 and h2o. CO2 does absorb some LW, but emits twice what it absorbs. I'll be the first to admit it seems counter intuitive. I did not get this until i came across this paper paper Its about variable O3 effects, but it quantifies all the radiative exchanges involving the stratosphere/troposphere very clearly. -
Billhunter at 06:44 AM on 4 December 2010A basic overview of Antarctic ice
Albatross at 05:11 AM on 4 December, 2010 Bill, "Please read my post @74." Tests of statistical significance may or may not return strong results. In the case of your analysis you returned statistically significant change in two different directions. The fact that you got a distribution of 3 statistically significant ice shrinkage, 1 statistically significant ice gain, and 6 cases of no statistical significant change, it would seem the winner is no statistically significant change. I suspect that if fall and spring was included the number of cases of no statistically significant change would greatly increase. Thus what is happening with ice on the planet would only be remarkable under the assumption that statistically significant change is the rule. -
Bob Guercio at 06:39 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Joe Blog 102 At equilibrium, how can a group of molecules be net absorbers or net emitters. If CO2 is a net absorber, that would mean it is constantly absorbing more than it is emitting. That can't be. Now ozone is different. It absorbs and emits both IR and UV. So it could absorb UV and emit IR so I guess you could say it is a UV absorber and an IR emitter in the stratosphere. But I don't believe that CO2 reacts appreciably with visible light so at equilibrium, it cannot be a net absorber or a net emitter. Bob -
Joe Blog at 06:30 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio at 06:21 Bob, i dont disagree with much in this post, except your understanding onb the mechanisms of stratospheric cooling, O3 is a net absorber, CO2 & H2O are net emitters in the stratosphere, and they do balance. In my first comment @ 44 i linked a paper by Ramanthan and Dickenson, it quantifies the radiative exchanges between troposphere and stratosphere... the stratosphere is a net emitter to the troposphere, not the other way around. -
Ned at 06:23 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
damorbel writes: Another application of this principle is multilayer insulation Multilayer insulation stacks up reflective surfaces and is extremely effective. Good grief! Did you even read that wikipedia page you linked to? How could you not have noticed that their explanation of how multilayer insulation works is exactly the process whereby backradiation from CO2 in the atmosphere raises the temperature of the earth above what it would be in the absence of that CO2! The process that you yourself cite as "extremely effective" is the exact same process that you claim violates the second law of thermodynamics! -
Bob Guercio at 06:21 AM on 4 December 2010Stratospheric Cooling and Tropospheric Warming
As I see it: Conservation of energy must be considered at all times. At equilibrium, the energy into a system must equal the energy out. Consider a box of CO2 with infrared coming in and leaving. CO2 molecules are constantly emitting and absorbing infrared; however, at equilibrium the number of absorbers equals the number of emitters. Now imagine that the incoming IR is cut in half. Suddenly there is less IR to be absorbed and for a while there will be more emitters than absorbers until equilibrium is reached. Again, emitters will equal absorbers with less energy coming in and less energy going out than before it was cut in half. My intuitive guess would be that equilibrium occurs very quickly and at any time the stratosphere is in equilibrium. The same holds true for sunlight coming in and interacting with the ozone. Ozone molecules are constantly absorbing and emitting radiation with the amount of energy coming in equaling the amount leaving. Fortunately for us, the UV energy absorbed is at a different frequency from that emitted but for the total energy spectrum, the amount coming in equals the amount leaving. At present, more energy is coming into the earth than is leaving. This energy is being absorbed by the earth and, were the CO2 in the air to miraculously stabilize today, the earth will continue warming up for another few decades. As the temperature increases, more heat energy will leave the earth until such time that the temperature is warm enough so that the IR energy leaving is equal to the sunlight energy entering. The troposphere will be warmer and at equilibrium so that the IR energy leaving the troposphere will be the same as the IR energy entering. The IR entering the stratosphere will be the same as that leaving but the stratosphere will forever be cooler than it was before CO2 levels increased. This is because the IR spectrum leaving the troposphere is different. Even though there is the same amount of IR energy leaving, less of this energy is able to react with the CO2 in the stratosphere which keeps it at whatever temperature it is. Bob -
2nd law of thermodynamics contradicts greenhouse theory
damorbel - The last 15-20 postings you have presented have made it increasingly clear that you do not have a firm grasp of the physics involved. That's not an insult - we all start somewhere. I, like Ned, strongly suggest you go check with your local university or other institute of learning, and find out some more of the basics. -
Ned at 06:15 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
Tom Dayton writes: damorbel, at face value your statement is correct that "the absorption capacity is always equal to the emission capacity." ... at a particular wavelength. Part of the problem with damorbel's argument here is that the incoming solar radiation has a very different spectral distribution from the outgoing longwave radiation. Absorptance in the visible/near-IR is not necessarily equal to thermal infrared emissivity. -
Tom Dayton at 06:14 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
damorbel, the reflective outer surface of an inner layer of multilayer insulation does not help by reducing that layer's emission. It helps instead by reducing that layer's absorption of the radiation emitted by the next-most-outer layer--radiation that this inner layer emitted, that was returned by the outer layer. -
h pierce at 06:12 AM on 4 December 2010The human fingerprint in the seasons
ATTN: muoncounter at 13:22 PM on 3 December, 2010 The wind is by far the most important mechanism that transports surface water into the atmosphere. Evaporation of water in still air is a slow process. Set out a shallow dish with water and determine how long it takes for the water to evaporate. Refill the dish to the same level and have a fan blow a gentle current of air over the water. The water level will decrease much faster in the presence of the wind from the fan. Clouds are another source of water vapor. Since they can move about freely and quickly, they can alter the local humidty --like to 100% of they bring rain or snow. -
Ned at 06:10 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
damorbel writes: So thermos (vacuum) flasks don't work this way? Care to explain how they do? The problem is that planets don't work this way. Read the rest of my comment. The point is that the incoming and outgoing radiation fluxes have different spectral distributions. A change in the visible/NIR albedo doesn't imply a corresponding change in thermal infrared emissivity. A lot of your comments in this thread seem to involve trying to analogize the earth-sun radiation balance to some object, like a thermos or asphalt or a coffee pot. With all due respect, that's not necessarily the best approach. -
damorbel at 05:50 AM on 4 December 20102nd law of thermodynamics contradicts greenhouse theory
Re #280 Tom Dayton you wrote:- "But emission from that inner chamber is not reduced by making the outer surface of that inner chamber reflective." A polished metal outer surface is an excellent insulator, the old fashioned silver coffee pot is a a good example, the modern chrome model is just as good because it doesn't need polishing so much. Another application of this principle is multilayer insulation Multilayer insulation stacks up reflective surfaces and is extremely effective.
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