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Philippe Chantreau at 01:44 AM on 27 April 2011Cosmic ray contribution to global warming negligible
Common sense says that there is not that much of a debate if there is no physical mechanism. There is none so far by which cosmic rays can directly influence cloud formation, because it has not been shown that any kind of CCN can actually be generated by CRs. On the other hand, CO2's radiative properties are well understood, so is their physical mechanism, with empirical measurements that agree with the theoretical calculations. It does not prevent "skeptics" to apply all sorts of doubts, even some that indicate complete diregard or lack of understanding of physics. Cloud formation is subject to the kind of variables that "skeptics" take as an excuse all the time to claim that nothing can be asserted with any level of certainty. The lack of physical mechanism prevents any kind of theoretical prediction. The correlation claimed by Svensmark has been examined and not reproduced by other teams. Common sense says there is even less debate there than meets the eye. Papers published that did not confirm Svensmark's hypothesis will cite him as well. I'm not so sure that 462 citations in 14 years is that remarkable. Common sense dictates to go to the physics. If there isn't any for particle growth, this hypothesis should be given low consideration. -
damorbel at 00:43 AM on 27 April 20112nd law of thermodynamics contradicts greenhouse theory
Re #1015 Fred Staples you wrote:- "The theory suggests that doubling the CO2 in the atmosphere moves the boundary between the optically thick region below, and the optically thin region above, where radiation to space is relatively unimpeded. Since this region is colder, outgoing radiation falls, and the sun warms the entire system, shifting the lapse rate to the right." This hypothesis has many weaknesses. One of Tyndall's most important discoveries was that GHGs were the perfect absorbers of their own emissions. This has the important consequence that, if two samples are irradiating each other, heat energy only goes to the cooler from the hotter, (tending to raise it temperature) thoroughly in accord with the 2nd law. The same is true for density, the denser emits more radiation than the less dense, assuming the two samples have the same temperature. Of course in the atmosphere both effects (density and temperature difference) are to be observed, so there is considerable energy transfer, but only upwards. Without energy transfer 'downwards' there will be no heating of the surface by adding GHGs.Moderator Response: [muoncounter] This is not a forum for endless repetition of your prior comments (see #143 on this thread and its rebuttal here). If you can only recycle your prior words, perhaps you really have nothing further to contribute. -
HumanityRules at 23:39 PM on 26 April 2011Cosmic ray contribution to global warming negligible
3 arch stanton I really should have directed you to his 1997 paper "Variation of cosmic ray flux and global cloud coverage - A missing link in solar-climate relationships" which has 462 references on Web of Science and is still being actively referenced this year. I'm not sure it makes any sense to think the peer-review process would allow "this guy is wrong" to be published 462 times, or that Svensmark would be still getting grants or publishing on this work if that was the case. Common sense says the debate is still alive. -
HumanityRules at 23:31 PM on 26 April 2011Cosmic ray contribution to global warming negligible
Ari you wrote "This distribution of correlation results a possible effect to global cloud cover which is smaller than 1%." and "Assuming 1% effect of the cosmic rays to cloud cover, this would cause a warming of 0.002°C in global surface temperature." Can you just confirm what you meant here? My reading is CGR may have been responsible for ~1% change in cloud cover. And this 1% change causes 0.002oC rise in temperature? That doesn't sound right, a 1% change in clouds seems like a lot and would have a significant affect on albedo. Are you sure you got your numbers correct (I can't access the paper unfortunately). This abstract from a presentation by the authors in 2010 suggests a 0.2% CGR flux in the past 50years and a 0.01% change in clouds.Moderator Response: [DB] Fixed missing URL. -
Bob Lacatena at 23:28 PM on 26 April 2011CO2 effect is saturated
131, RW1,which means 1/3rd of the surface is clear sky. 396 W/m^2 x 0.33 = 131 W/m^2 emitted from the surface to the clear sky.
I won't get into Trenberth's diagram with you again (entirely). I'll repeat that you don't understand it, you are making invalid assumptions, you don't understand enough of the underlying physics of atmospheric heat transfer, and this is all leading to gross misinterpretations. However, concerning this particular statement of yours about "1/3rd ... clear sky"... First, you can't just assume that because 1/3 of the sky is clear then that the clear sky absorbs 1/3 of the radiation. The ability to absorb long wave radiation is dramatically different between clear sky and clouds (clouds probably absorb substantially more, being made up of a powerful greenhouse gas, but I've never really seen any numbers on this). Clouds and the radiative properties of the surface are also not evenly distributed over the globe, either in space or in time. Everything else is not homogeneous. Second, you cannot ignore the non-radiative components (thermals and the release of latent heat). Third, and most importantly, you cannot ignore a major element which is not included in the diagram, which is the transfer of heat between "clear sky" and clouds. What happens when a cloud dissipates? Does the heat vanish? Is it forced to instantly radiate up to space? Does it fall to the ground with the rain? Hint: When a cloud absorbs LW radiation, it is capable of transferring that heat to the surrounding and pervading atmosphere (remember, a cloud isn't a solid object, it coexists in space with the O2/N2 of the atmosphere). So it doesn't really matter which absorbs the radiation. The atmosphere (consisting of "clear sky" and clouds) absorbs the radiation, and the two cannot be separated into distinct components re this diagram. This diagram is not a GCM. It's just a diagram intended to help communicate the earth's energy budget to the casual viewer, and nothing more. You cannot read as much into it as you are attempting. So, again: 1) You need to study more before you can comment on or interpret Trenberth's diagram. 2) Trenberth's diagram is not the topic of this thread. [This will be my last post on the subject (here), so please don't come back with an angry list of "but what about this?" questions. I'm not biting.] -
HumanityRules at 22:56 PM on 26 April 2011Cosmic ray contribution to global warming negligible
3 arch stanton I just checked Web of Science and there are 167 papers referencing Svenmark's early 2000 paper. I haven't checked all of them and I'm guessing you haven't but if "Little in the scientific literature supported it then and even less does now." was true then almost all would have to have come down against Svenmark's work. If that was true it would be fair to say we wouldn't still have a debate in the science. Just a quick check at 2010 papers finds this paper. The scientific debate seems to be more alive than you present it. -
CO2 effect is saturated
Berényi - The infrared atmospheric window was derived in 1918 from the H2O spectra, first estimated (by hand) in 1928. Now the value of transmitted energy is determined as a side product of the line-by-line radiation models, to distinguish between surface radiation actually transmitting directly to space and atmospheric radiation on the edges of the window also radiating to space. Trenberth may have thought that it wasn't necessary to to spend much time on a value that has been known for >80 years. A value you could have determined with a few moments of web search, I'll note. In my opinion, your language here is skating the thin edges of the Comments Policy regarding accusations of deception.Response:[DB] Sometimes, in the course of human events, it's necessary to reinvent the wheel.
As you note, the fact that some then find it necessary to reinvent the flat tire is revealing.
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Fred Staples at 22:41 PM on 26 April 20112nd law of thermodynamics contradicts greenhouse theory
In order to discuss the “higher is colder” theory, which most contributors to this thread endorse as the only plausible explanation of AGW, we have to leave the comfortable certainties of thermodynamics, (and G and T) and move on to the more controversial arguments of climate science. A good debate on the basic Physics can be found at “Climateclash.com”, which includes the basic spectroscopy as well as “higher is colder”, presented in a long paper by Ray Pierrehumbert (Infrared radiation and planetary temperature) and numerous posts from Leonard Weinstein. The theory suggests that doubling the CO2 in the atmosphere moves the boundary between the optically thick region below, and the optically thin region above, where radiation to space is relatively unimpeded. Since this region is colder, outgoing radiation falls, and the sun warms the entire system, shifting the lapse rate to the right. To some extent this must be true, but it is reasonable to ask if effect is detectable. It is almost never quantified (an obscure calculation at P 113 of Taylor gives an elevation of 3kms, and a temperature increase of 18 degrees C). With a lapse rate of 6.5 degrees C per 1000 meters, we are looking for an elevation of the effective radiation level of just 154 meters for an increase in temperature everywhere of 1 degree C. Since the transition from thick to thin must be gradual, and different for different frequencies of radiation, there is no possibility of detecting such a change directly. Then there is the role of water vapour. At sea level, the H2O concentration about 12000 ppm, or more than 30 times CO2. Over the troposphere as a whole it is 20 times CO2, and at 5 kms (the region of effective radiation) it is still 4 times greater. Doubling CO2 to 600 ppm will still leave H2O as the dominant greenhouse gas. Thereafter, it falls away rapidly, to create the optically thin region, but it is will still mask the effect of any increase in CO2 absorption at the effective emission point. The only mechanism by which doubling the CO2 concentration can elevate the emission level is absorption, with atmospheric warming (via kinetic energy) and subsequent emission (and consequential cooling). To measure that effect we would expect to find experiments. The usual suspects (Woods and Angstrom) are a century old, and hotly disputed (usually without the tedium of repetition). One experiment reported on the net is at espere.net/united kingdom/water/uk_overview.htm. It is an attempt to demonstrate the greenhouse effect, they pass short wave radiation through gas-filled containers, with long wave radiation filtered out. Back-warming of the gasses is from black cardboard (which absorbed the incoming radiation)in the base of the containers. They compare air (at atmospheric pressure) with 100% CO2, a greater concentration than on Venus. Anyone expecting a dramatic difference will be disappointed. Initially, the CO2 warms rather faster. After 5 minutes the increases are : 100% Co2 15 degrees C Air 10 degrees C In the next 15 minutes additional warming was as follows: 100% Co2 13 degrees C Air 12 degrees C Sadly, the experiment stopped (before equilibrium) just when it was becoming interesting. For those with long lives ahead, the earth’s AGW experiment will go on long enough to resolve doubts and errors, and reach a conclusion. -
Bernard J. at 22:40 PM on 26 April 2011Lindzen Illusion #1: We Should Have Seen More Warming
Chris G at #69 and LazyTeenager at #87. 'H Pierce' appears to be one Harold Pierce Jnr, a recalcitrant, statistically-inept AGW denialist who has a long track record at Deltoid of inappropriate use of statistical tests. For example, HPJ used many dozens (at least) of t-tests to compare various weather station temperatures over time, even after the issue of repeated measures was pointed out to him. Further, I suspect that I have previously pointed out to HPJ the very fact of the accuracy of averages of large datasets being greater than the accuracy of any random individual datapoint in the set. Cherry picking and misrepresentation, such as demonstrated by Lindzen in the top of this thread, are prime devices for denying the existence of climate change. Deliberate and incompetent misuses of statistics and analysis are some of the favoured tools to achieve this denial, as tens of thousands of denialist comments on hundreds of blogs and in hundreds of newspapers will attest. Sadly, it is unlikely that objective science can ever really decapitate this beast of ignorance. In this regard, I feel Sphaerica's pain at #62. Perhaps one partial solution would be to have a list of basic statistical rebuttals here similar to the ever-growing list of conceptual rebuttals on Skeptical Science - then all one would need to do is to provide a link, and leave alone the painful repetition of basic explanations that have been covered many times previously. -
JMurphy at 19:17 PM on 26 April 2011A Convention for Persons Displaced by Climate Change
I have added a comment on the Texas situation on the Extreme Weather thread. -
JMurphy at 19:16 PM on 26 April 2011Extreme weather isn't caused by global warming
This report provides further information to a discussion going on over on the A Convention for Persons Displaced by Climate Change thread : Interior Releases Report Highlighting Impacts of Climate Change to Western Water Resources. Specific projections include: •a temperature increase of 5-7 degrees Fahrenheit; •a precipitation increase over the northwestern and north-central portions of the western United States and a decrease over the southwestern and south-central areas; •a decrease for almost all of the April 1st snowpack, a standard benchmark measurement used to project river basin runoff; and •an 8 to 20 percent decrease in average annual stream flow in several river basins, including the Colorado, the Rio Grande, and the San Joaquin. Report available here : Reclamation : Managing water in the West -
Berényi Péter at 19:14 PM on 26 April 2011CO2 effect is saturated
#130 Tom Curtis at 11:21 AM on 26 April, 2011 Trenberth 09 shows a 40 Watt/m^2 atmospheric window That 40 W/m2 is not substantiated anywhere in the paper. It was just pulled into Fig. 1. out of thin air.Response:[DB] "It was just pulled into Fig. 1. out of thin air."
Please substantiate, or withdraw, this allegation.
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RSVP at 19:04 PM on 26 April 2011Waste heat vs greenhouse warming
KR #398 "there's no effect on climate until it ("buried energy") surfaces" I can only assume you deny the effects of convective heat transfer because your models do not include them. Likewise, if you deny the existence of heat conduction in materials, in preference to science fiction, I suppose we are speaking in different languages. -
Forced Migration Review at 18:53 PM on 26 April 2011A Convention for Persons Displaced by Climate Change
Coming to this late. You might be interested in articles in Oct 2008 issue of Forced Migration Review focusing on climate change. For example, 'The numbers game' by Oli Brown - online at OliBrown-article Full pdf and contents listing online at FMR31-climate-change best wishes Marion (co-editor, Forced Migration Review) -
damorbel at 18:09 PM on 26 April 20112nd law of thermodynamics contradicts greenhouse theory
Re #1012 Tom Curtis you wrote:- "Consequently if you are not explicitly discussing 2nd law issues, may I suggest you take your discussion elsewhere." The argument I put is that adding gases that radiate (and absorb) are to the mixture comprising the atmosphere in the zone known as the troposphere, cannot change the equilibrium temperature of the surface because this region is almost always colder than the surface. The argument is based on the 2nd Law of thermodynamics which is that energy transfer (which is required for temperature change) cannot result in an increase (i.e. net increase) of the surface energy which would be required for a rise in surface temperature, because the temperature of the troposphere is, in general, lower than the surface. This fact is known because with a few exceptions known as inversions, the gradient of temperature against altitude is negative, meaning that the troposphere is almost always colder than the surface. It may be thought relevant why the Troposphere is always colder than the surface, I suggest this is a relevant matter. -
michael sweet at 16:53 PM on 26 April 2011Extreme weather isn't caused by global warming
Johnd, The climate changes caused the Anasazi civilization to collapse. Is that what you want to happen to our civilization? Jahred Diamond used this as one of the examples in his book Collapse about how previous civilizations found changes in their environment too much to survive. Current changes are greater than the Anasazi had to deal with. -
Ken Lambert at 14:14 PM on 26 April 2011A Flanner in the Works for Snow and Ice
Daniel Bailey #130 Quite a bard Daniel. We can do science in rhyming couplets if you like - the numbers will still end up the same. I have already calculated the heat gain from the loss of sea ice mass at #66. Using the trend off the PIOMAS chart of -3.5E3 km3/decade, the number comes to 1.17E20 Joules/year. I used 1000kG/m3 for the density of ice, and Tom Curtis 'corrected' my hasty calc by pointing out that the density of Sea Ice is 917 kG/m3. Tom helpfully said: "You forgot to compensate for the lower density of ice, which is 917 kg/m^3 which reduces your figure to 1.07*10^20 Joules per year" Since this reduces my number by a massive 9% to be closer to Dr Trenberth's number of 0.9E20 Joules/year, his pedantry just does not transpose to his own calculations which at various times have be out by factors of 15 times, 2 times (was it 149 times way back in the beginning?)etc etc. Such bizarrity has even extended to Tom quoting temperatures to about 8 places behind the decimal point, for what purpose I cannot fathom. Even if we accept Flanner's number for NET Arctic sea ice melt due to reduced albedo of the missing sea ice, the number is still 5/145ths or 3.45% of the Earth's net imbalance from the Arctic - 4.4% of the planet's surface area. At the beginning of this thread - the theme was the supersized contribution of the Arctic to global warming. Anyway Daniel - what is your point? -
adelady at 13:33 PM on 26 April 2011A Flanner in the Works for Snow and Ice
db, I think I'd re-do that graphic without the links from year to year. Just a couple of simple dotted lines. One across at 8000 cubic km, one vertically at 4 million sqkm. Doesn't matter what we think about comparing trends, years, decades. We really are in new territory.Moderator Response: [DB] Thanks for the suggestion; that one was not mine, though. The looming Zero point on the graph is compelling in itself. "We really are in new territory." Sadly, yes. And it happens on our watch. -
muoncounter at 13:31 PM on 26 April 2011Extreme weather isn't caused by global warming
johnd#20: "cause and effect are confused ... evidence found by Dr. Jeffrey Dean of a historical major disruption in the area's typical rainfall " Confused? Hardly. No dispute that there was a disruption in typical rainfall. But from your link, Recent climatological studies by other scientists suggest that rainfall patterns were disrupted in a way that might have made the Anasazi disillusioned with their old religion. ... Suddenly, the customary pattern of heavy snows in the winter followed by summer monsoons had become unpredictable. Even if there was not a great drought, moisture may have been coming at the wrong times. The summer rains, so necessary to keep the spring crops from dying, were no longer reliable. The rain dances were not working anymore. Apples: the rain dances weren't working as they had. Oranges: heat waves, drought and wildfire; monsoons; cold winter with deep snow, meltwater floods. Tornadoes. Thundersnow. But maybe it was just like that back in Anasazi days. And so the rain dance of today, 'don't worry, nothing unusual is going on,' isn't working either. -
RW1 at 13:16 PM on 26 April 2011CO2 effect is saturated
muoncounter, OK. Maybe KR is right and there should be a dedicated thread to the Trenberth diagram and energy budget. -
johnd at 13:07 PM on 26 April 2011Extreme weather isn't caused by global warming
muoncounter at 11:28 AM, it will obviously seem an apples and oranges comparison if cause and effect are confused as you have done so. However the evidence found by Dr. Jeffrey Dean of a historical major disruption in the area's typical rainfall that I referenced, is a valid apple on apple comparison to your comments regarding present day emerging patterns, and thus also relevant to this thread. -
Daniel Bailey at 12:58 PM on 26 April 2011A Flanner in the Works for Snow and Ice
Continuing in the vein of offering mute testimony to the growing dominion of the summer sun in the Arctic:
[Courtesy L. Hamilton]
"No icecube is an iceberg, entire of itself;
every icecube is a piece of the iceberg,
a part of the Arctic Sea Ice cap.
If an icecube be melted away by the sun, the Arctic Sea Ice cap is the less,
as well as if a promontory were, as well as if a manor of thy friend's or of thine own were:
Any icecube's demise diminishes me, because I am involved in the Arctic Sea Ice cap,
and therefore never send to know for whom the bell tolls; it tolls for thee."
Apologies to both Hemingway and Donne.
The Yooper
Moderator Response:[DB] Forgot to post the linear relationship details on the chart: R = .94
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Ken Lambert at 12:14 PM on 26 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
mclamb6 #158 I did not mean to ignore your contribution. It is just that the Moderators are zealously snipping me. "The theory is sound as are the observations supporting the theory. Nonetheless, you cherry pick ARGO measurements (which apparently is the new gold standard despite the fact that the ARGO measurements are being refined and there isn't even close to a statistically significant period of observation) and attach your cherry picked measurements to your skewed interpretation of Trenberth's email." I have not spent the best part of 2 years reading everything about AGW to make a trite comment about Argo. Anyone who understands the first law can also make the leap to the critical point that any warming imbalance must show up somewhere in the Earth system as heat energy - over 90% stored in the oceans. OHC increase is a direct measure of TOA imbalance. Accurate measurement of OHC will make or break the AGW case. -
LazyTeenager at 12:00 PM on 26 April 2011Lindzen Illusion #1: We Should Have Seen More Warming
h pierce at 05:46 AM on 23 April, 2011 Don't get carried away with these kind of graphs because temperature mesurements used for calibration aren't that accurate. In the US temps at weather stations are measured to +/-1 deg F. In Canada temperature data is reported to nearest +/- 0.5 deg C. Where are the error bars for plots in the graph? You need at least ca. 1 deg C difference between means of two sets of temperature data for stat significance at p < 0.05. ---------------------------- Err no. This is a very common misconception in climate skeptic land. I have explained why it is wrong before without success. It's amazing the number of people with technical backgrounds don't/won't understand how averaging of data produces a higher resolution result than the input data. -
RW1 at 11:57 AM on 26 April 2011CO2 effect is saturated
Tom Curtis (RE: 130), I might also add that Trenberth's "window" of 70 W/m^2 is not referenced in the paper. It appears to just be a rough estimate or guess. He also has greater than half of the surface power absorbed by the atmosphere being emitted up out to space, which is inaccurate. To get half up and half down requires a "window" of 82 W/m^2 with his numbers (396 - 82 = 314; 314/2 = 157; 239 + 157 = 396 at the surface). Even this site's hfranzen from first the link I posted in #124 has diagram on page 19 of his paper showing a "window" of 88 W/m^2. Take a look: "Flux balance on the Earth"Moderator Response: [muoncounter] We've been through the half up/half down bit before. By assuming that model, your argument is turning circular. You're also veering off topic (and it's hard to do both at the same time). This thread is on CO2 absorption band saturation. -
Ken Lambert at 11:56 AM on 26 April 2011A Flanner in the Works for Snow and Ice
Daniel Bailey #130 I assume by your entry to the thread Daniel that you are informing Tom Curtis' rather than me. " Melting ice cares not for sophistry. Or is it that Arctic Sea Ice declines from it's current winter maximum of about 13.5 million square mile area to it's melt season low of about 4.2 million square miles out of sheer habit...:" I assume you mean sq.km not sq.miles Daniel. And what is 'sophistry' about my sound calculation which points out the trail of basic errors in Tom's elongated journey.Moderator Response: [DB] "I assume you mean sq.km not sq.miles Daniel." Thanks for the heads-up on the slip-up. And sadly, no: 'Tis not Tom engaging in sophistry. -
CO2 effect is saturated
John Cook, Moderators - Might I suggest a thread on the Trenberth diagram and energy budget? This has been repeatedly misunderstood, misquoted, and misused for more instances of mathturbation than just about any graphic I can think of. - It's not a model, contains no information whatsoever about interdependent changes of climate elements upon perturbation. - It's a four layer accounting of energy interchanges between these layers (Sun, surface, atmosphere, space). Some of these exchanges (161 insolation, the 40 W/m^2 "window" from surface to space) skip a layer, most do not. - Energy entering a level of this accounting does not retain identity/sourcing with what goes out; it's all joules, all the way down, which for example is why the atmosphere can radiate 169 W/m^2. - If somebody disagrees with a number in the Trenberth budget, they should take it up with Trenberth, who has done a clearly sourced and researched work with plenty of references to look at for each individual number. "I don't see how this is possible" is not a valid objection; it's certainly not science. -
LazyTeenager at 11:50 AM on 26 April 2011Lindzen Illusion #1: We Should Have Seen More Warming
I find this Lindzen thing getting a bit confusing. In the first place he doesn't say what models he is referring to. As far as I am aware the most sophisticated models do in fact take into account the oceans and so thermal inertia should be part of the model and be reflected in the model output. The article seems to be arguing that we have the ?some? unspecified model which we have to apply thermal inertia corrections to. This looks kind of wrong. I think it would be more to the point to show a specific model's predictions and mark on it what Lindzen says the model prediction is and what the actual temperature is. That way we have an instant conclusion: Lindzen is right or wrong!!! -
Ken Lambert at 11:44 AM on 26 April 2011A Flanner in the Works for Snow and Ice
Tom Curtis #131 I hung in there Tom, because I could not let you get away with the litany of error and denegration of both my calculations and 'principles'. Your final paragraph tells the story of this bizarre exchange. Quote: "More importantly for this thread, Flanner estimates that the increased net energy absorption (additional energy absorbed - additional energy lost) due to arctic sea ice melt is around 5*10^20 Joules, or approximately 42% of the conservative estimate of additional incoming energy flux. As Ken would say, this is quite close to Trenberth's figure of 3.4*10^20 Joules needed to explain melting and warming of Arctic ice." So Flanner's actual number for NET energy absorbed is around 5E20 Joules (presumably per season or per year). Is not what global warming is all about - the NET increase in heat gained by the Earth?? So where did you get the number "2004-2008: 6.97E+021 Joules" which is 69.7E20 Joules over 4 years or 17.4E20 Joules per year? -
RW1 at 11:33 AM on 26 April 2011CO2 effect is saturated
Tom Curtis (RE: 130), "RW1 @127, I don't want to buy into another fruitless conversation but, Trenberth 09 shows a 40 Watt/m^2 atmospheric window, and also shows 30 W/m^2 emitted to space from cloud surfaces, with another 169 W/m^2 emitted from the atmosphere other than from clouds. These three combine to make up the OLR." I don't see how this is possible. Think about it. How can the clear sky atmosphere emit 169 W/m^2 to space when surface only emits about 131 W/m^2 to the clear sky in the first place? We know this because the ISCCP data says clouds cover 2/3rds of the surface, which means 1/3rd of the surface is clear sky. 396 W/m^2 x 0.33 = 131 W/m^2 emitted from the surface to the clear sky. -
muoncounter at 11:28 AM on 26 April 2011Extreme weather isn't caused by global warming
johnd#18: "compare what changes may be appearing now with those that confronted the Ancient Pueblo People" An apples and oranges comparison. We have no idea how sensitive their civilization was to climate change; however, we may surmise that without air conditioning and turbo-diesel backup generators, they were more sensitive than we are. However, anthropology is hardly the topic of this thread; the pace and intensity of current climate change's impact on weather is. -
Tom Curtis at 11:21 AM on 26 April 2011CO2 effect is saturated
RW1 @127, I don't want to buy into another fruitless conversation but, Trenberth 09 shows a 40 Watt/m^2 atmospheric window, and also shows 30 W/m^2 emitted to space from cloud surfaces, with another 169 W/m^2 emitted from the atmosphere other than from clouds. These three combine to make up the OLR.
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RW1 at 11:21 AM on 26 April 2011CO2 effect is saturated
KR (RE: 128), I'm not disregarding any spectra. I'm also well aware there are bands that are saturated. I also agree that the CO2 absorbing bands are not saturated - there is room on the wings to expand and capture a little more outgoing surface power. This is where the additional 3.7 W/m^2 from 2xCO2 is coming from. -
CO2 effect is saturated
RW1 - Got it, you are going to continue to disregard the spectra between 600-750 microns, let alone around 450 microns, where IR from the surface cannot reach space unintercepted, and where increasing CO2 concentrations raise the effective emission to space to higher/colder altitudes. Quite frankly, I cannot take your discussion of the greenhouse effect seriously when you ignore major components like this. -
RW1 at 10:32 AM on 26 April 2011CO2 effect is saturated
KR (RE: 125), Trenberth et al 2009 has a transmittance or "window" of 70 W/m^2 (40 through the clear sky and 30 through the clouds). If when CO2 is doubled, the "window" decreases by 3.7 W/m^2 (or 7.4 W/m^2) and 1.85 goes up out to space and 1.85 goes down to the surface (or 3.7 goes up and 3.7 goes down) (*Trenberth actually has it being 52% up and 48% down). -
RW1 at 10:25 AM on 26 April 2011CO2 effect is saturated
KR (RE: 125), "As has been said to you before, the windowing effect (where IR goes straight from the surface to space) is only part of the reduction in IR. The rest occurs in the full absorption bands (where IR from the surface makes it only 10's or 100's of meters before absorption)" When I refer to the "window", I mean transmittance - the amount of the whole spectrum of emitted surface power that passes through to space without being absorbed by the atmosphere (not just one particular band). This is the amount that should reduce by 7.4 W/m^2 if the referenced 3.7 W/m^2 is all incident on the surface as claimed when CO2 is doubled. There appears to be some confusion in regards to the definition or use of the term "window". Some refer to this as the mostly transparent region between about 8u and 13u, but this is not how I use the term. Nor do I believe this is how 'novandilcosid' is using the term either. You don't seem to understand that there are other parts of the spectrum besides the CO2 absorbing bands that are not completely saturated and a portion of surface emitted energy passes through them unabsorbed out to space. The aggregate amount that passes through the whole spectrum of emitted surface energy is the "window" or transmittance. -
Tom Curtis at 10:18 AM on 26 April 2011A Flanner in the Works for Snow and Ice
Ken Lambert @128 and further to my 129, when going over the figures I noticed that the historical sea ice extent data defines summer as July, August and September, while I have been using solar altitude data for May, June and July. This means that I am over estimating sea ice area for the relevant period (although the large underestimates I use on other factors still mean I am underestimating additional incoming energy flux). Never-the-less, the name of this game is give Ken every bias in the data he could ask for, and I have a personal preference for greater accuracy. Therefore I corrected by calculated values as follows: 1) For each of May, June and July, I determined the 1979 and 2010 values of sea ice area from the following chart:The chart tracks the trends in median monthly Arctic sea ice area. I used the trend chart to avoid distortions from start point or end point effects. 2) I then determined the mean of the three monthly values, and the May and July values. For both of these, I determined the difference between 1979 and 2010 values, and took the lowest value (May, July as it turns out). 3) I then used this value to calculate the additional energy absorbed by the ocean over the summer months in the Arctic in 2010 relative to 1979 on the trend due to the shrinking of Arctic sea ice. As previously noted, this is the gross energy absorbed over the summer, and does not factor in any increased energy losses over that period. The final value thus determined is 1.21*10^21 Joules. That is 13% less than my previous best conservative estimate @84. It is no where near the 75% reduction Ken thinks he has found in the data. In other words, even allowing every possible bias in his favour, and taking into account all the factors he considers relevant, there is still more than three times additional energy coming in than he thinks there should be. More importantly for this thread, Flanner estimates that the increased net energy absorption (additional energy absorbed - additional energy lost) due to arctic sea ice melt is around 5*10^20 Joules, or approximately 42% of the conservative estimate of additional incoming energy flux. As Ken would say, this is quite close to Trenberth's figure of 3.4*10^20 Joules needed to explain melting and warming of Arctic ice. But though he might say that, 1.6*10^20 Joules is a lot of additional heat left over after that process. Regardless of that, the conservative calculation of additional incoming energy shows (unsurprisingly) that low arctic insolation due to low solar altitude in the Arctic does not provide a principled basis to reject Flanner's results.
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CO2 effect is saturated
RW1 - As has been said to you before, the windowing effect (where IR goes straight from the surface to space) is only part of the reduction in IR. The rest occurs in the full absorption bands (where IR from the surface makes it only 10's or 100's of meters before absorption), as increased CO2 concentrations raise the level of effective tropospheric radiation to colder altitudes. Why are you disregarding that very significant effect? Why are you claiming that all of the IR decrease occurs by a reduction of the 40 W/m^2 window, when that is clearly not the case? -
nigelj at 09:48 AM on 26 April 2011Cosmic ray contribution to global warming negligible
The atmosphere of Venus is mostly CO2 and full of dense clouds of sulphuric acid. Its surface is far hotter than Mercury which is closer to the Sun, and is due to a runaway global warming. The sceptics can choose which element is predominant in its high tempertures CO2 or cloud cover. -
RW1 at 09:47 AM on 26 April 2011CO2 effect is saturated
novandilcosid, I don't want to rehash this debate here. See the posts by 'co2isnotevil' and myself in the following threads: Here and Here Also, this paper by co2isnotevil: "Proof that only half of absorption affects the surface" -
RW1 at 09:23 AM on 26 April 2011CO2 effect is saturated
KR (RE: 121), You even stated the following here: "As has been said here, repeatedly, the 3.7 TOA number means that 7.4 W/m^2 is being absorbed and radiated isotropically from CO2." There is definitely a halving effect. The fundamental question is if the 3.7 W/m^2 represents the post or pre halving effect. If it represents the post halving effect, as claimed here, then the "window" or transmittance (i.e. the amount of surface emitted that passes straight through the atmosphere unabsorbed and goes out to space) should reduce by 7.4 W/m^2. -
RW1 at 09:12 AM on 26 April 2011CO2 effect is saturated
RE: DB and KR, I haven't ignored or disregarded anything. Just because I was given an answer doesn't mean it is the correct answer. I'm still working on the issue and hope to eventually resolve it once and for all. -
CO2 effect is saturated
Re: my past post - CO2 effects are on topic. However, George White/co2isnotevil's incorrect assumptions about 'halving' really are not. 3.7 W/m^2 is the decrease in IR leaving the atmosphere for a CO2 doubling, as per line-by-line multi-level atmospheric modeling, CO2 spectra and physics, and confirmed by top of atmosphere satellite measurements. No 'halving' occurs. -
CO2 effect is saturated
RW1 - Your erroneous "halving" has been addressed repeatedly, you have simply chosen to disregard the answers you have received. 3.7 W/m^2 is the drop in IR emitted to space for a doubling of CO2. This is due both to the rise in tropopause and effective emission altitude from increased CO2 concentration (and hence lower CO2 emitting temperature) and absorption band expansion. The window decreases slightly, but the predominant change is decreased emissions across the CO2 absorption bands. Hence "If the net effect at the surface is 3.7 W/m^2, then the "window" should close by 7.4 W/m^2 when CO2 is doubled" is simply wrong. There are two effects, not one, and your insistence on assigning all change to one effect has been corrected over and over again. Anyone interested in that discussion should look at the Lindzen and Choi thread, where RW1 and others were informed of the details over 448 postings. Please do not rehash that here. This thread is about CO2 saturation, and it is hence off-topic. -
Berényi Péter at 08:17 AM on 26 April 2011It's not bad
#117 Albatross at 07:12 AM on 26 April, 2011 of course, not linked Here is the full exchange (open access). -
RW1 at 08:14 AM on 26 April 2011CO2 effect is saturated
I should say the "window" should decrease by 7.4 W/m^2 when CO2 is doubled (not close). Trenberth et al 2009 has the window being 70 W/m^2 with the atmosphere emitting 157 W/m^2 down and 169 W/m^2 up (48% down and 52% up), if your interested in running some numbers. -
RW1 at 08:06 AM on 26 April 2011CO2 effect is saturated
novandilcosid (RE: 110), If the net effect at the surface is 3.7 W/m^2, then the "window" should close by 7.4 W/m^2 when CO2 is doubled. -
RW1 at 08:04 AM on 26 April 2011CO2 effect is saturated
novandilcosid (RE: 110), "I note in passing that increased Radiative Forcing (=energy inbalance at the Tropopause) is entirely different to increased absorption of Surface Energy, so that Tom's entire post is a confusing non-response to the question. Does anyone have a figure for the decrease in Surface Energy passing through the window due to a doubling of CO2 and assuming no temperature change at the surface?" The figure is 3.7 W/m^2. When CO2 is doubled, the window (i.e. transmittance) reduces by 3.7 W/m^2 and the atmosphere absorbs an additional 3.7 W/m^2 of surface emitted radiation, half of which goes down to the surface and half of which goes up out to space (1.85 W/m^2 up and down). It has been claimed here and elsewhere that the halving effect is already accounted for in the 3.7 W/m^2 figure; however, I have not been able to verify this through numerous inquiries to the climate science community. No one can give me a straight answer, but I'm still working on it.Moderator Response: (DB) In reality, you were given an answer, which you have chosen to ignore. -
johnd at 07:27 AM on 26 April 2011Extreme weather isn't caused by global warming
Again it would be prudent to compare what changes may be appearing now with those that confronted the Ancient Pueblo People that led to their displacement. This an excerpt from an article examining the Anasazi Collapse "Studying tree rings from 27 sites across the Southwest, Dr. Jeffrey Dean of the University of the Arizona tree-ring laboratory has found evidence of a major disruption in the area's typical rainfall. Suddenly, the customary pattern of heavy snows in the winter followed by summer monsoons had become unpredictable. Even if there was not a great drought, moisture may have been coming at the wrong times. The summer rains, so necessary to keep the spring crops from dying, were no longer reliable." -
Albatross at 07:12 AM on 26 April 2011It's not bad
Please note, re the critique of the phytoplankton paper by Boyce et al. (2010) cited @116: Boyce et al's response to the critique was, of course, not linked.
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