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Paul D at 01:45 AM on 20 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Hi Bob@28. Copyright is a complicated issue. Generally it is best to assume you can't use something unless it is stated you can. On the other hand, if someone wants to 'prosecute' to protect their copyright, it usually is a civil action, not a criminal one. Which means that the person/organisation who is protecting their copyright has to have the money to take legal action (they won't have state aid, criminal prosecutions are usually by the state). But then again, there are fare use exceptions in the US. In many places, if something is used in schools or colleges or in not for profit situations, then the owner may allow the use of the materials, but they usually state that the materials can be used in those situations. You put a copyright notification on your own article, that implies you don't want anyone to copy it without you giving permission. BTW by default every piece of work is copyrighted, I don't believe the notice is required other a reminder to the reader. Creative Commons licensing is a great new way of dealing with this sort of issue. The licenses allow as much or as little flexibility as you want. -
Alec Cowan at 01:44 AM on 20 December 2010Debunking this skeptic myth is left as an exercise to the reader
Speaking of The Hollow Earth, perhaps the warming comes from the internal sun becoming a red giant in spite of its size :) The fact is we live in times when epistemological hedonism[1] is king so any book describing global warming as a hoax will reach larger publics the same way Velikowsky's or Von Däniken's books would sell copies ten times the best selling book devoted to debunk their theories. And in a similar way, Watts' paraphernalia gets 2 million hits a month, while RealClimate gets 360K and this site 220K[2]. People has been swollen by this tide of epistemological hedonism and -placing their necessities, including that of recognition, above everything else- they simply write to the head of a website to share the preposterous theory they took a fancy to. The same about some people commenting and the dumbpiphanies they sometimes provoke. I wonder if analyzing the attitudes behind denialism and the underlying mechanisms is not as important as spreading good science about what causes global warming causes and discussing solutions. [1] THE LIMITS OF CRITICAL THINKING by Jamy Ian Swiss Swift 1-1, page 14 [2] Wattsupwiththat; RealClimate; SkepticalScience -
RSVP at 01:32 AM on 20 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
MarkR #26 "By increasing the temperature of the atmosphere, you increase the amount of heat that it radiates " The increase came from the thing you now say it is heating. "It does 'double time' because it's constantly receiving heat " By double time, I am referring to a single packet of energy. If it gets into the air via CO2,(coming from a hot stone on the ground), the hot stone has just lost that heat. That is not double time. That is heat transfer. -
Bob Guercio at 23:29 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
The Ville -25 What are the rules for using online images? If I see an image that I like, how do I know whether or not I'm allowed to use it? Thank you, Bob -
michael sweet at 21:29 PM on 19 December 2010Renewable Baseload Energy
Actually thoughtful, You pump the water out one well, use the heat/cool and then pump the water down the other well. Since it is a siphon energy use is minimal. There is no net use of water for heat/cool. I get the impression this type of heat pump in only useful where there is a lot of water (like here in Florida). -
MarkR at 21:15 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
#5 RSVP: Increasing the kinetic energy of a system isn't necessarily work. Imagining a closed, fixed piston, you can put in heat through the walls that will increase the kinetic energy of the molecules without doing work. Work is done in an ideal gas by expansion. The tropopause has risen, so the troposphere has expanded, but unless it expands forever then it is not constantly doing work and therefore the flow of energy must be heat. It does 'double time' because it's constantly receiving heat so it has to 'dump it'. Some light heats the molecules, they bump around warming other things which allows the heat to be dumped so that more IR can be absorbed. If it didn't do this, it would just increase in temperature forever and quantum physics/thermodynamics would be broken! -
MarkR at 21:04 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
#5 RSVP: By increasing the temperature of the atmosphere, you increase the amount of heat that it radiates and this can be approximated by Planck's law with a wavelength dependent emissivity plugged onto the end. To an individual molecule acting electromagnetically, there is no 'up' or 'down', all direction are equal. Therefore it will radiate in all directions. CO2 absorbs IR light and transfers much of this to surrounding molecules in kinetic energy (and at the same time collisions will pump energy back into the CO2, such that the output looks more like a greybody). All of these molecules will couple to the vacuum field and decay to lower energy states, emitting light. Warmer temperatures mean more light, and more light going down heats the surface. This is the basic pure radiative effect. There are other complicating factors, but this is the most important. It explains why there is so much longwave radiation coming down to Earth. -
Paul D at 20:16 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Bob love the diagrams, it is clear you spent a lot of time on this. Not sure the 'step 2' diagram works?? My interpretation of that is some sort of fission explosion! I guess without animation it's difficult to show a collision.Response: [from John Cook] That's my fault, I offered to do the diagrams for Bob. Wasn't sure of a good way to portray two molecules colliding - welcome any suggestion of a better version (eg - a link to an image online). -
Riccardo at 19:54 PM on 19 December 2010Lindzen and Choi find low climate sensitivity
RW1 the often quoted 4 W/m2 is the imbalance at TOA, i.e. the amount of energy not allowed to leave the planet after a doubling of CO2. Following your scheme, an equal amount is radiated back to the surface. In this way you get a 1.2 K increase in temperature; incidentally, this is equal to the so-called Plank sensitivity. To know the equilibrium temperature increase you still need to multiply it by the feedback factor, which is not included in the 4 W/m2. -
archiesteel at 18:34 PM on 19 December 2010Lindzen and Choi find low climate sensitivity
@RW1: that site (www.palisad.com) doesn't seem very credible. The best analogy that has been given is the tub filling in vs. ripples. Seasonal variations tend to cancel out over time, while the current warming we are seeing keeps going up. The whole isn't in AGW theory, it's in your understanding of the theory. -
archiesteel at 18:28 PM on 19 December 2010The human fingerprint in the seasons
@Argus: "I also read about severe problems with snow in Canada some of weeks ago." Actually, our winter is quite typical, even a bit on the mild side. Europe does seem to be getting colder, but remember we're talking about Global, not European temperatures. -
RW1 at 17:15 PM on 19 December 2010Lindzen and Choi find low climate sensitivity
muoncounter (RE: post 18), Yes, the oceans have thermal inertia, as evidenced by the roughly one month of "seasonal lag", but the overall response is still relatively fast in each hemisphere every year. This contradicts the ocean thermal inertial taking decades to fully respond. The albedo adjusted gain is just an aggregate empirical measure of the system's response at the surface to incoming power from the Sun. As you can see from that site, it varies a little but is roughly about 1.6 on average. -
muoncounter at 16:33 PM on 19 December 2010Lindzen and Choi find low climate sensitivity
#17: The two paragraphs in your comment don't seem to have any logical connection. Don't the oceans have thermal inertia? Is there any research regarding 'albedo adjusted gain', beyond this website? -
dhogaza at 15:59 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
"You're serious, aren't you ? Can't you see the connection between air getting hotter ergo surface (land or ocean) getting hotter ?" In RSVP's world, if you lie on the ground at Death Valley you'll be just as cold as if you'd laid on the ground in the high desert ... -
RW1 at 15:34 PM on 19 December 2010Lindzen and Choi find low climate sensitivity
Riccardo (RE: Post 15) The hemispheric seasonal responses to large changes in radiative forcing are relatively quick – certainly not years or decades. If they were, we wouldn't see anywhere near the seasonal variability throughout each year. There is a delay or "seasonal lag", but it’s only about one month. This contradicts the notion that a tiny increase in radiative forcing of less than 2 W/m^2 from a doubling of CO2 gradually added to atmosphere over decades will take decades longer after to reach equilibrium. If anything, because CO2 is added incrementally and so slowly over such a long period of time, the response time is a non issue. -
actually thoughtful at 13:48 PM on 19 December 2010Renewable Baseload Energy
Michael - fantastic. It occurs to me that you are concentrating the value you get from your well - which is a good thing. Unless the well goes dry - in which case you wake up with no water and no heat/cool. Actually, I think you will still get heat/cool, even from a dry well (better performance with the water of course). -
RW1 at 13:20 PM on 19 December 2010Lindzen and Choi find low climate sensitivity
Riccardo (RE: Post 15), How am I confusing the surface and the TOA? Are you saying that power from the Sun and additional power redirected from CO2 are not both "forcing" the surface? The energy balance is determined by the rate at which incoming power from the Sun is allowed to leave the planet (at the TOA): The incoming short wave infrared energy from the Sun is mostly transparent to the clear sky atmosphere. Cloudy sky is obviously different, as a lot of the energy is reflected off of and absorbed by the clouds - a much smaller amount makes it through. The short wave energy that hits the surface is re-radiated back up in the form of long wave infrared, which in certain wavelengths is absorbed and re-radiated by greenhouse gases and/or clouds. In effect, the presence of greenhouse gases and clouds delay the release of infrared heat energy by redirecting some of it back toward the surface, which makes the surface warmer than it would be otherwise. The albedo adjusted gain factor of about 1.6 means that due to the greenhouse effect, it takes about 1.6 W/m^2 of power at the surface for each 1 W/m^2 of power to leave the system, offsetting each 1 W/m^2 entering the system from the Sun. In other words, power in = power out. The albedo adjusted solar input of about 238 W/m^2 = 238 W/m^2 leaving the planet, and a power of 238 W/m^2 equates to a temperature of about 255K, which is the so-called effective temperature of the earth as seen from space. There is no difference between power sourced from the Sun and additional power re-directed back to the surface as a result of more CO2 being added to the atmosphere. Afterall, a watt/meter squared of energy and power is watt/meter squared of energy and power, independent of where it originates from. Put another way, the surface doesn't "know the difference" between heat or power sourced from the Sun or additional heat or power re-directed back down from GHGs and/or clouds - all it "knows" is what the total heat and power is at the surface; and the total power at the surface in W/m^2 is directly tied to temperature via Stefan-Boltzman because the surface of the earth is considered to be very close to a perfect black body radiator. At an average global temperature of 288K, the surface emits 390 W/m^2 of power. About 240 W/m^2 of this is from the Sun and the additional 150 W/m^2 is from GHGs and clouds in the atmosphere re-directing infrared power back down toward the surface. If the albedo adjusted power from the sun increases 2 W/m^2, the infrared power at the surface increases 2 W/m^2, plus about an additional 1.2 W/m^2 will be redirected back downward from the atmosphere (due to the presence of GHGs and clouds) for net increase of about 3.2 W/m^2 - raising the surface power total to about 393.2 W/m^2 (or a temperature of 288.6K). If instead, the albedo adjusted power from the Sun is unchanged, but an additional 2 W/m^2 of infrared power is redirected downward to the surface as a result of a doubling of CO2, the most additional power that can amplify (or in effect re-redirect down) the added 2 W/m^2 is only about the same 1.2 W/m^2 because there is no physical or logical reason why an additional 2 W/m^2 of infrared power at the surface will behave radically different from either the original 99+% or an additional 2 W/m^2 from the Sun. -
oamoe at 13:13 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Thank you, Tom Curtis and Joe Blog. I'm impressed by the fundamental science that people on this blog know. -
Joe Blog at 12:59 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
But through O2/O3 UV absorption... -
Eric (skeptic) at 12:39 PM on 19 December 2010A detailed look at climate sensitivity
To RW1 on the Lindzen thread, muoncounter recommended that you visit this thread for evidence of high sensitivity. I second that, but IMO the arguments here come up short in several respects. One is that the average measurement of higher water vapor do not take into account the distribution of WV. If it is higher and evenly distributed then it is a positive feedback to CO2 warming. But if WV is unevenly distributed in a world warmed slightly by CO2, then an average increase in WV will result in less or no amplification. Second, the derivation of sensitivity from paleo studies routinely ignores unmeasured confounding factors. I gave one possibility here: cosmic-rays-and-global-warming.htm but there are others. Typically the response is to treat solar geomagnetic variations as a proxy for TSI and then dismiss it because of poor correlation and low amounts of TSI change. Also the last 30 years of detailed measurements don't show much in the way of GCR related climate effects. However the penultimate interglacial coincides with an abrupt decline in GCR so a relatively small TSI increase could be amplified without the need for CO2 feedback. -
Joe Blog at 12:39 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
oamoe at 12:30 PM Because the stratosphere isnt really warmed by terrestrial LW absorption. But through UV O2/O3 absorption, terrestrial LW does off set loses somewhat, but CO2 is emitting just under twice what it absorbs in the stratosphere. Its a Q of path length, how opaque the atmosphere is to what wavelength. At the tropopause the path length in 15micron is already short enough that it basically just acts to transmit energy. This is a result of the reducing pressure, so for a given area(volume) there are less molecules than at a higher pressure. -
oamoe at 12:30 PM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Let me ask my previous question in a different way, why does the absorption of IR in the troposphere not dominate as the major cause of the cooling of the stratosphere. It seems odd that collisional activation of IR emission by CO2 would be so important. -
Riccardo at 12:04 PM on 19 December 2010Lindzen and Choi find low climate sensitivity
RW1 there are a few pieces that got to be fixed. "All I did was apply the same gain factor for solar power to additional power from CO2." You did it wrong as I explained in my previous post, you're confusing surface and TOA. "Ultimately, what matters is the total infrared power at the surface" The energy balance of the planet is governed by what happen at TOA, not at the surface. What we see (measure) at the surface is the effect of the change at TOA. "The point I was making about the perihelion power increase of about 14 W/m^2 was that a much larger increase in radiative forcing above the average doesn't have anywhere near the proportionally predicted effect as the AGW warming theory says will happen with just a 2 W/m^2 increase in radiative forcing from a doubling of CO2." (emph. mine) You should not expect any proportionality, indeed. When you have a cyclic forcing, the effect depends of the response time of the system. If the response is slow you won't get the full effect of the forcing; you are comparing a forcing with a one year period with a response time of the order of decades. An extreme example is the diurnal cycle, where you have the forcing going from about 240 W/m2 to zero but the temperature doesn't change proportionally. -
RW1 at 11:18 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
I'm asking the question because I think it's a significant hole in the AGW theory that I've yet to see adequately explained. What I'm trying to show is that the CO2 AGW theory is saying that the climate system is all of the sudden going to treat an additional 2 W/m^2 of power at the surface radically different than it does the original existing 99+ percent, and while I suppose that is theoretically possible, there is no physical, empirical or logical reason why it would, especially in a system that is constantly changing everywhere, by relatively large magnitude. Ultimately, what matters is the total infrared power at the surface, independent of where all the power orginates from - the the Sun, GHGs and/or clouds. Both 2 W/m^2 of additional infrared power from the Sun "forcing" the surface and 2 W/m^2 of additional infrared power from CO2 "forcing" the surface are the same - all the surface 'knows' is what the total power is, and the total power is directly tied to temperature via Stefan-Boltzman (*if this was not true, then power from the Sun and additional power from CO2 cannot both be expressed in W/m^2 as they are). The point I was making about the perihelion power increase of about 14 W/m^2 was that a much larger increase in radiative forcing above the average doesn't have anywhere near the proportionally predicted effect as the AGW warming theory says will happen with just a 2 W/m^2 increase in radiative forcing from a doubling of CO2. Now of course one can always say that it will be the 2 W/m^2 increase above the total cumulative average that will cause a much larger amount of warming by suddenly triggering very large positive feedbacks (that don't happen to exist or act on the original 99+%), but there really isn't any physical, logical, or empirical basis for that, especially given the total amount of radiative forcing is constantly changing spatially and in time...all the time (warming, cooling, etc). If the climate as a whole was a steady state and static system, it might be more plausible, but the climate system is incredibly dynamic instead. That the global climate doesn't even appear to be phased by a 14 W/m^2 increase in radiative forcing, suggests the net feedback operating on the system as a whole is strongly negative - not positive, and the tiny increase of only about 2 W/m^2 from a doubling of CO2 will be - if not infinitesimal, benignly small. -
RW1 at 11:15 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
Riccardo (RE: Post 12), All I did was apply the same gain factor for solar power to additional power from CO2. -
Riccardo at 11:05 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
RW1 you first calculated a sort of energy balance at the earth surface to calculate the "amplification factor"; then you took the (net) energy imbalance at TOA, the 4 W/m2 for doubling CO2, and used the same "amplification factor" to calculate the extra energy received by the surface and the increase in temperature. -
muoncounter at 11:03 AM on 19 December 2010Should The Earth Be Cooling?
#67: Apparently not. Look here and use that thread for further discussion if warranted. -
Henry justice at 10:50 AM on 19 December 2010Should The Earth Be Cooling?
Whenever a solar cycle stretches beyond 13 years as did SC23, then doesn't a grand minimum soon follows with global cooling. The role of water vapor, our major GHG, will then take on a devilish role. The air becomes colder, dryer, and the warming effect of our greatest GHG diminishes. Shouldn't this greatly overshadow the miniscule effects of CO2? Also, isn't airborne soot implicated in the melting of the glaciers, even when the air above them has not risen above freezing? -
Tom Curtis at 10:42 AM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Humanity Rules @5, your comment shows a misunderstanding of how the greenhouse effect works. It does not work by absorbing a certain amount of energy which is then distributed between troposphere, earth's surface and ocean. Rather, it reduces the amount of outgoing energy from the Earth's atmosphere. The temperature of the ocean, surface, and troposphere than adjust until the outgoing energy is restored to its previous value, in which it balanced with incoming energy. -
oamoe at 10:40 AM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Is it true that the troposphere absorbs almost all of the IR coming from the Earth's surface, reducing the amount of surface-originated IR that stratospheric CO2 absorbs? Does this help explain the cooler stratosphere? -
muoncounter at 10:25 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
#5: "from a doubling of CO2 ... an additional 3.2 W/m^2 will increase the surface temperature only about 0.6 degrees" We've already had more than 0.6C warming since ~1960, which only represents an increase of atmospheric CO2 from 317 to 388, nowhere near a doubling. So its clear your numbers are coming up short.
But at least you agree that it's warming and that CO2 is part of the GHE, so that's a start.
The general climate sensitivity question was dealt with on prior threads, notably here. You should check there for additional information.
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RW1 at 10:16 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
Riccardo (RE: Post 8), I'm not sure what you're trying to say either. Can you give me some specifics? -
AWoL at 10:11 AM on 19 December 2010The 2nd law of thermodynamics and the greenhouse effect
3 posts removed now , so obviously hit the spot. I would like to reply, scaddenp, but althought I feel free, I am not free.....if you see what I mean.Moderator Response: [muoncounter] No, no one sees what you mean. If you keep your posting to scientific questions and stop throwing around innuendo, suggestions of conspiracy, whining about moderation and such tripe, in keeping with the comment policy, you wouldn't have such problems. -
RW1 at 10:10 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
Very Tall Guy (Post # 7), You need to be more specific - I'm not sure what you're trying to say. The halving of the CO2 absorption is because the re-radiated energy goes out in all directions - meaning half is radiated upward in the same general direction it was already headed; thus it cannot contribute to additional warming. -
Chemware at 09:45 AM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
@ RSVP #5 "How does a packet of energy that raises the troposphere's temperature, also raise the temperature of the Earth's surface or ocean waters?" You're serious, aren't you ? Can't you see the connection between air getting hotter ergo surface (land or ocean) getting hotter ? -
Bob Guercio at 09:42 AM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
VeryTallGuy Thanks for the complement and I will start thinking about more blogs related to this. Let's not forgot that I got a tremendous amount of help and input from you guys. It's really a credit to the Skeptical Science website and forum members. Thanks, Bob -
Bob Guercio at 09:35 AM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Jeff T - 6 Thanks for the comment about linearity. It's fixed. I reread the post and I think the verbiage pretty much agrees with what you said. Bob -
Riccardo at 09:31 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
RW1 if you wish to (even roughly) calculate the result of an energy (im)balance you have to do it at the top of the atmosphere (TOA). You can not take two different pieces, at surface and at TOA, and mix them together. -
Phil at 09:28 AM on 19 December 2010The human fingerprint in the seasons
Argus @171 In addition to Daniel's comment, you might also google "Warm Arctic Cold Continent pattern" and look at some of the modeling. The high pressure over the arctic that we Europeans have had for the last 3 winter seems to be related to late freezing of the Arctic ice.Moderator Response: [Daniel Bailey] Article on that subject here. -
Daniel Bailey at 09:21 AM on 19 December 2010The human fingerprint in the seasons
Re: Argus (171) OK, I'll play. Let's take a look at the global temperature trend for the last 110 years or so:
Despite variability (noise in the dataset) overall temps are up. And up. And up. Despite predilections for cherry-picked short periods of declines, the overall trend is up.
OK, let's look at it a little differently. How about decadally? Here we go:
Hmm, 80s warmer than the 70s, 90s warmer than the 80s, the "aughts" warmer than the 90s, check. Getting warmer. Got it.
But when we speak about globally, surely it actually isn't warming everywhere? Aren't some places experiencing cold? Here's the 2000 - 2009 Temperature anomaly:
What about some of the temperature datasets, some of them have to show it's cooling!
Baseline-to-baseline, not really. Still up.
What about up north? Surely it's cold up there!
Sorry, Argus. Outside of recent, short-term weather events, looking at actual data says you're wrong. Well, maybe except where you live. But then that's not very global is it?
But do go ahead and watch that blue curve.
The Yooper
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VeryTallGuy at 09:02 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
RW1@3 "Then how do you explain the relatively large and fast seasonal temperature changes that occur in each hemisphere every year?" They are the ripples on the bathtub. Effects of external forcing are additive to them. @5 you are putting forward a logical fallacy. The greenhouse effect is made up of forcings (largely CO2) and feedback (largely H2O). The overall effect on the heat balance is the sum of both. Let's put a bizarre analogy together. Celebrities (CO2) are stalked by paparazzi photographers (H2O feedback). Each celebrity attracts 2 paparazzi. With one celeb, how many people are on the pavement - 3 Add one more celeb - by your calculation we only get 4 people, a 33% increase. In reality, of course, we get 6, a 100% increase. And your arbitrary halving of the CO2 effect from 4 to 2 W/m2 is also incorrect. -
Argus at 08:45 AM on 19 December 2010The human fingerprint in the seasons
"They found that winters have been warming faster than summers." Looking at the diagram in Figure 1 (top post), it certainly seems that way. At least as long as we limit ourselves to the period 1970-2000. But after 2000 the blue curve actually goes downwards! My prediction is that we will see a new trend with progressively colder winters, bringing the yearly average down. Watch that blue curve in the years to come! Just take a look at the winter 2010-2011 so far: record lows in the British Isles in November. The earliest winter for decades in many European countries. And it is not only western and northern Europe: in November, in Russia, Tver had -24 C, and all the way 6000 kilometers towards the east, Oymyakon had -50 C. I also read about severe problems with snow in Canada some of weeks ago. Right now British major airport are closed because of snow, and many motorists have to stay overnight in their cars on snowy roads. It is almost as bad in France. In Toscana traffic is severely hindered on the roads. Flights have been cancelled in France, Netherlands, Italy, and Germany because of snow. In Sweden the winter so far is the coldest for 100-150 years (depending on what city you are looking at). In Stockholm we have had snow cover for a month now (while the snow usually does not stay on the ground until after Christmas). -
RW1 at 07:57 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
muoncounter (RE: 4) "Are you suggesting that seasonal temperature changes are solely due to the difference in sun-earth distance at peri vs. api?" No, not at all. -
RW1 at 07:56 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
Here is a summary of where I'm getting my figures: The average incident solar energy is about 340 W/m^2. If you subtract the effect of the earth’s albedo (about 30% or 0.3 = 102 W/m^2), you get a net incident solar energy of about 238 W/m^2 (340 – 102 = 238). (*The albedo is the amount of incoming short wave radiation from the sun that gets reflected back out to space off of clouds, snow, ice, etc., and cannot be absorbed by GHGs or contribute to the greenhouse effect, which is why it’s subtracted out). From this you take the surface power at the current average global temperature of 288K, which is about 390 W/m^2 (from Stefan Boltzman), and with it you can calculate the gain or the amount of surface warming as a result of the greenhouse effect in the atmosphere. To get this you divide the current surface power by the net incident solar power, which comes to about 1.6 (390/238 = 1.6). What this means is that for each 1 W/m^2 of solar input, you get 1.6 W/m^2 of power at the surface due to the presence of GHGs and clouds in the atmosphere – a boost of about 60%. A doubling of CO2 alone absorbs only about 4 W/m^2 of additional power. About half this is directed upward out to space and the other half is directed downward toward the surface, resulting in a net of about 2 W/m^2. If you then multiply this additional 2 W/m^2 of power by the same gain calculated for solar power (as a result of the greenhouse effect), you get an increase in the surface power of about 3.2 W/m^2 from a doubling of CO2 (2 x 1.6 = 3.2). Using Stefan Boltzman, an additional 3.2 W/m^2 will increase the surface temperature only about 0.6 degrees C (390 + 3.2 = 393.2 W/m^2 = 288.6K). This is much less than the 3 degrees C predicted by the IPCC. Even if you assume all of the 4 W/m^2 from a doubling of CO2 goes to the surface, the temperature increase would still only be 1.2 degrees C – significantly less than the low end of the IPCC’s claimed range of 2 – 4.5 C. To get the 3 degrees C claimed by the IPCC, an additional 16 W/m^2 would be needed. This requires a gain of 8 rather than 1.6 (or at least a gain of 4 instead of 1.6 if we assume all of the absorbed power is directed back to the surface). The bottom line is the actual response of atmosphere (from GHGs and clouds) relative to net incident solar power, measured in W/m^2, is far less than the response claimed by the IPCC from a doubling of CO2, which is also measured in W/m^2. A watt/meter squared of heat and power is watt/meter squared of heat and power, independent of where it originates from – whether it’s the Sun, or redirected back to the surface as a result of more CO2 in the atmosphere (*If this was not true, then power from the Sun and additional power from CO2 cannot both be expressed in W/m^2 as they are). Ultimately, the total power flux at the surface is directly tied to temperature via Stefan-Boltzman - there is no escaping this. In short, the surface gain factor of about 1.6 supports an upper limit of only about 0.6 C from a doubling of CO2 because there is no physical or logical reason why a small increase of less than 2 W/m^2 will behave radically differently than the original 99+ percent - i.e. a gain of 8 or more needed for a 3 C rise is simply way outside the bounds of empirically derived observations of how the system responds to changes in radiative forcing. -
muoncounter at 07:41 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
#3: "difference in solar radiance between perihelion and aphelion" Are you suggesting that seasonal temperature changes are solely due to the difference in sun-earth distance at peri vs. api? -
RW1 at 07:28 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
Then how do you explain the relatively large and fast seasonal temperature changes that occur in each hemisphere every year? The seasonal hemispheric fluctuations in radiative forcing that occur are astronomically greater than the measly 1.85 W/m^2 that will come from a doubling of CO2. If what you’re saying is true, we wouldn’t see anywhere near the seasonal variability that occurs each year. (*The peak to peak difference in solar radiance between perihelion and aphelion is about 80 W/m^2. Divide by 4 to get the average of 20 W/m^2, then subtract out the albedo of about 0.3 and you get a net increase of about 14 W/m^2 at perihelion. -
VeryTallGuy at 07:28 AM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Bob, Great effort on a complex subject. I enjoyed the original thread, did a lot of thinking and learned a lot as a result. Putting the effects of UV heating of the stratosphere in a made it much easier for me to get my head around this - how about an intermediate version including temperature profiles & UV heating (greedy, I know). -
scaddenp at 07:11 AM on 19 December 2010The 2nd law of thermodynamics and the greenhouse effect
AwoL - before you think of new experiment, perhaps you might like to examine the many experiments already done. However, I am fully in agreement that nature is the arbiter. I have already suggested damorel provide an experiment which he/she thinks vindicates imaginary physics over textbook version. Certainly feel free to pose or demonstrate one also - though in this area I suspect the experiment is likely to have been already covered by painstakingly intricate work in the 1950s. -
Joe Blog at 07:00 AM on 19 December 2010Stratospheric Cooling and Tropospheric Warming - Revised
Good article Bob, as good as ive seen anywhere as far as this topic goes. -
VeryTallGuy at 06:57 AM on 19 December 2010Lindzen and Choi find low climate sensitivity
RW1 I've no idea if your figures are correct (reference please?). However the answer to your question is that CO2 adds the heat all the time, year after year (think of a bathtub filling), whereas changes during a year cancel out over longer timescales (think of waves in the bathtub).
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