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Philippe Chantreau at 02:53 AM on 1 July 2010Ocean acidification
CO2 bubbling? A piece of ocean acting like a soda pop? Sorry but that looks like total nonsense at first glance. -
Philippe Chantreau at 02:46 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
"intensely forced convection that is not found anywhere in nature." What a convoluted way to make a false assertion for the sake of argument. Check out these pictures, the convection in them dwarfs any engine cooling system. They routinely contain vertical wind shear in excess of 60 mph. http://www.mesoscale.ws/pictures/structure/ -
KR at 02:45 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Absolutely right, Chris - the distance varies with the number of GHG molecules per unit volume. I was typing quickly (carelessly) there about the lower atmosphere; mean free path length increases as pressure drops. -
barry1487 at 02:43 AM on 1 July 2010Perth forum on climate change: all the gory details
Scott Mandia, thanks for the reply. I was under the impression that glaciation took the longer time, and that deglaciation, accompanied by rising CO2 levels, took ~5000 years in late Quaternary ice age cycles*. I'm sure the skeptics I face would soon point this out and the main point would be derailed. * (Again, please correct any misapprehension on my part) -
KR at 02:40 AM on 1 July 2010Hockey stick is broken
marty - an excellent question. Kudos to you for checking additional data sources; many people don't bother. As Tom pointed out, there are a number of different temperature measurements (proxies) listed at the top of the page. I believe the Mann 'hockey stick' is composed of data from ~100 different temperature estimates, including some tree ring data. Mann felt (with some reason) that the later part of the tree ring data set was distorted, possibly due to other influences (drought) on tree growth for those proxies. It doesn't really matter, though, as including/excluding the later period tree ring data doesn't really change the graph by more than a couple percent either way. This is a popular 'skeptic' tactic, marty, which you might see elsewhere - picking a tiny piece of evidence, pointing out issues (correct or not) with it, and using that to claim that a conclusion based on many, independent lines of evidence is therefore invalidated by that tiny piece. -
Chris G at 02:33 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
#37, Umm, no, I don't see a connection between what I said and what you said. Regarding #39, Nothing in nature burns? Nothing in nature gets hot? If greater than zero things get hot in nature, what would be the accumulated heat over, say, 4.5 billion years? #40, Gases absorb and emit at the same wavelengths, specific to each gas. If 97% of the air does not emit IR, it doesn't absorb it either; it passes through unaffected. KR, thanks for the detail. I think got the gist of correcting myself at #34. I'm confident you know this, but I'd think the distance traveled would be dependent on the density of the gas. The density of air diminishes rapidly with altitude; so, I suspect it is a mistake to use a fixed value for distance traveled. -
Tom Dayton at 02:29 AM on 1 July 2010Hockey stick is broken
Marty, read the post at the top of this page. See all the graphs of temperature data from sources that do not include bristlecone pines? -
Peter Hogarth at 02:25 AM on 1 July 2010Sea level rise is exaggerated
daniel at 10:49 AM on 30 June, 2010 Much of this debate is focusing heavily on one Donnelly paper based on data from one area (Southern New England). Let me take a different tack. If we accept that the temporal sampling in Donnelly 2004 on historical sea level is sparse, we have two options. 1) We look for more data to fill in the gaps from other sources, and build up a higher resolution composite. Though there are difficulties with different rates of rise in different regions this process is ongoing and 6 years is a long time in climate research. From what I have read and am aware of in a professional capacity the evidence suggests relatively small changes in sea level over this period consistent with Donnelly (allowing for occasional dramatic localized crustal movements). 2) We also look at the physical effects which cause sea level rise and see if these have changed over the period in question. This might be viewed as “modeling”. Any dramatic sea level variability between or over the temporal range of uncertainty of the samples (as you suggest could hypothetically be present) would be driven by dramatic variability in temperature, land ice volume or hydrological cycle, or some combination. The evidence on past variability in temperature is far denser temporally and spatially and better researched, and is consistent with the published estimates of past changes in sea level (for example see Grinsted on Medieval Warm period). The ice core data which can give not only regional (North and South) temperature proxies but estimates of deposition/loss rates is consistent with this also. Then we must apply this same logic to what is happening now, and look at recent research in other areas of climate related science. Temperature is rising, global ice mass is diminishing and sea levels are rising with both thermal and ice melt contributions. For some more recent overviews and a few more clues on extra data see Church 2008, and Milne 2009 as well as Grinsted linked previously. -
KR at 02:22 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Very true, RSVP - and that 3% is the 'antenna' that the energy of the entire mass of air can radiate IR from. Or receive upon, for that matter. And as the CO2 and water vapor lose/gain energy from IR, thermal collisions with the rest of the air mass spread those effects throughout, lowering or raising the temperature of the entire air mass. -
marty at 02:20 AM on 1 July 2010Hockey stick is broken
I just read an article saying that it was responsible for the hockey stick appearence and wondered if it was true that it makes temperature records have a hockey stick shape. Obviously if there are hockey stick shaped graphs that don't include the tree ring records of bristlecone pine then the article is clearly wrong. The article is on a site called spiked and I was rather hoping that someone knowledgeable about this issue might like to clarify things either here or in a posting to the letters page on spiked. http://www.spiked-online.com/index.php/debates/copenhagen_article/9056/ Since I haven't made up my mind about the science I obvioously flit between sites like spiked and this one. I'll have a look at the NOAA site and if it's not too technical I'll see if I can figure it out myself seeing as no one here can just give me a straight answer to what seemed to me a straight question. cheers -
KR at 02:17 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Chris G - latent heat is estimated at ~76-78 W/m^2 (can't remember exact number off the top of my head) from liquid to vapor form; evaporated from surface water and ground moisture. This gets deposited primarily at the condensation point in the lapse rate where clouds form - no energy is deposited by condensation until the bottom of the cloud, when the temperature has dropped enough. Thunderstorms and major convective events (hurricanes) can draw water vapor high into the troposphere and even in extreme cases the lower stratosphere, but generally the energy movement is to the middle troposphere. I wrote something quite wordy about thunderstorms, lapse rates, and the like, in a previous topic, and now I can't find it! Oh well... Given that the IR pathlength is on the order of 10's of meters before absorption/emission events, this certainly moves the heat into the atmosphere, warming it. IR radiation to space occurs when CO2 density and total water vapor (along with total pressure) drops low enough to permit it, in the stratosphere, hence the GW phenomena of a warmer troposphere and colder stratosphere. -
Alexandre at 02:16 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Very nice text. The radio analogy is definetely one I will use when explaining the frequency spectrum to other lay people. -
RSVP at 02:09 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
KR <> As was sited way above, water vapor and CO2 only make up about 3% of the atmosphere. AGW rests on the asumption that the other 97% does not emit IR very well. That is what our engines are warming. -
RSVP at 02:03 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Chris G The engine cools through intensely forced convection that is not found anywhere in nature. -
daniel at 02:03 AM on 1 July 2010Sea level rise is exaggerated
Further quotes from #33 "if I get you right and correct me if I'm misunderstanding you, you're suggesting that it's equally reasonable to pick and draw a series of lines perhaps pointing up and perhaps pointing down between any chronologically linear pair of samples." Well almost, what I'm really saying is that the paper hasn't got a hope of determining the short term sea level trends during 1300-1850 AD. This ties in with what you say next: "That's not as conservative as doing what Donnelly did." You like to regurgitate that word but I wonder if you know why Donnely et.al. used it? It's because they are trying to claim that the centres of their 95% confidence boxes are of a higher likelihood of being where the true paleo record lies. I cautiously agree with them on that, but I can't see how it legitimises their final comparison. If the centres of the boxes were the true paleo sea levels then in an attempt to obtain short term trends from the data (which is tje only valid comparison to make when trying to detect unusual recent uptrends in the last 150 years) you could in principle draw lines between each pair or in other words connect the dots. But then you would have to explain the jump back in time between samples 10 and 9 or explain why the rapid rise in sea level between samples 7 and 8 is not as, or even more alarming, then the recent rise over 150 years. No I won't let them have it both ways. If thier long term trend line doesn't need to cut right through the centre of the boxes then neither do my short term trends. You continue: "As well, doing such a series of arbitrary choices leaves the issue that the entire series must begin somewhere within the region circumscribed by the sample 4 and 11 confidence boxes, meaning that the overall conclusion of the series of choices made to connect individual samples ends up being nearly the same, confined by the beginning and ending samples." Sigh. When will you understand that the important point here is that a lack of certainty in short term trends invalidates any claim that recent rises are alarming. "Meanwhile, it appears that the slope described by the direct recent tidal measurements is inevitably going to be steeper than the sum linear product of whatever combination of ups and downs you might choose to impose on the paleo series..." Same as above "sum linear product" is irrelevant, short term uptrends of similar rate and range are. They cannot be detected by a study of this type. "...and as well covers a disproportionate vertical range compared compared to the paleo series. This suggests to me that attempting to create and insert arbitrary additional information into the series is pointless." No the paleo data covers something like 60-70cm and the recent data covers 30-40cm. Plenty of slack for a similar uptrend and a plateau. " The suite of dating refinements employed by Donnelly I refer to are an example our ignorance, as I mentioned before." You make it sound complicated but as I've outlined before, people who are educated in distant fields to climate science can easily understand a climate science paper. The principle of superposition is simply applying the logic of higher stratum are younger than lower stratum. Using known historical markers from the introduction of different plant species as added refining tools for dating is not complicated. Just becausr you don't understand it doug doesn't mean that I don't. -
KR at 02:02 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
RSVP - Duh, when your radiator heats the air it cools by conduction, convection, and (via heating ALL of the air in that space) heating CO2 and water vapor, which can indeed emit their energy as IR. Come on, RSVP - I've read your posts, you know this stuff! And you know (or should by now) that total waste heat from industrial (and automotive) processes represents 1/10,000 the energy of the CO2 driven radiative imbalance. It has no significant impact on global warming. -
RSVP at 01:59 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Chris G at 00:51 AM on 1 July, 2010 #32 That is a good question, but it sounds like you are implying that hydroelectric power is trapping heat, since you cant get something for nothing. If the net effect is zero, where is the energy from a dam coming from? Are you now saying that dams are causing global warming as well? -
Chris G at 01:57 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Regarding #33, OK, I wondered if you were talking about condensation of water vapor, but I still think you are not considering the wavelengths outside of what the human eye can detect. 'White' just means that all 3 flavors of our cones are highly stimulated, but each flavor of cone is optimally responsive on a fairly narrow band. The human eye is actually pretty limited; we can't even tell the difference between a red-green brown and a blue-orange brown. But, I digress. Clouds don't treat all wavelengths the same; as evidenced by people getting sunburned by UV on a cool and cloudy day. How does the air warmed by your engine cool? Same as warm air has always cooled since the earth was formed; but ultimately, energy only leaves the earth, atmosphere included, through radiative processes. -
KR at 01:53 AM on 1 July 2010Sea level rise is exaggerated
daniel - while the tone on this thread has become quite heated, you have made some extremely strong statements (utter joke) regarding the Donnelly paper. Looking at your initial comments, are you indeed saying that the current rise in sea levels could drop in between the samples Donnelley collected? And that therefore their data is not strong enough? Keep in mind that while there _may_ be space between samples for a steep rise, it would have to be accompanied by an equally steep decline or halting trend to match later samples. And that the samples are independently dated except for elimination of carbon date repeats by physical position ordering - an excellent technique for disambiguation, I would add. Between the multiple species examined, carbon dating, choice of uncompacted site, etc., this is an excellent paper. And hence, it shouldn't be a surprise that some people have reacted strongly to your harsh dismissal of it. As to sample 11 (representing ~8% of the data) - you may have a point there, it looks like they left the younger (eliminated) date box for #11 on the chart. But their fitting appears to use the information from Table 1, and while this looks to be an editing issue, that doesn't seem IMO to affect their calculations or their conclusions. They certainly seem to have used the #11 older date for the curve fitting. And as to how such an error might occur? While editors appear to be inhuman in nature (grrr) they are actually fallible in reality. I'd suggest dropping a note to Donnelly et al and asking whether this is the correct chart. It might be interesting to ask if these samples could be used as date tags, and examine intermediate samples (in some number) to see if there were fossil variances indicating different levels of sea rise (short term variations) - but as it stands, with the data they extracted, the linear mapping with a curve at the beginning of the industrial era is perfectly justified by the data used to generate the trend lines. -
Icarus at 01:44 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Karl_from_Wylie wrote:========================================= "..The message for today, however, is that anyone who tells you that carbon dioxide does not cause global warming, either does not understand the basic science, or is being deliberately misleading." Bias. Increase in Carbon dioxide does not assure Global Warming. There are more variables to the equation. =========================================
Carbon dioxide certainly does cause global warming because if atmospheric carbon dioxide increases then the world will become warmer than it would otherwise be, and this can't not happen (not without changing the laws of physics). It's certainly possible for another forcing to have a cooling influence which counteracts the warming from increased carbon dioxide, such that there is no net warming, but the warming influence of increased carbon dioxide is still there (if it wasn't, then in that situation there would be global cooling). So, there is no valid sense in which increasing atmospheric carbon dioxide doesn't cause global warming. It does, and it has to, regardless of what other forcings and feedbacks are in play. -
Chris G at 01:39 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
I have a tendency to be exacting; so, I've been mulling over the words I used in #32, and I think they are not quite right. I'd think that would be some energy left behind in the air media, and would begin a journey at the point of condensation. If that condensation occurs at 500 feet, then it probably makes little difference whether it started there or at the surface; if it begins at the top of a thunderhead, say near 40,000 feet, then it probably does. Regardless, the amount of water vapor in the air, over the ocean, is largely dependent on temperature (and altitude). The overall effect of clouds, considering high and low altitude, day and night, is still in contention, but water vapor is always a GHG. So, I wouldn't look to a cooling effect of clouds, which require water vapor to form, as a cooling effect greater than the warming effect of CO2 and water vapor combined. -
RSVP at 01:36 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
<> Addressing your comment... The nonlinearity I was talking about has to do with how water vapor "turns opaque" (i.e. reflects white light) on the turn of a dime as per triple state diagram. As far as what I was talking about in terms of waste heat... I am saying that a thermal radiator such as that of my car's engine heats up air. AGW rests on the assumption that 97% of "air" is transparent to IR. This means that it is just as bad a emitter of IR as absorber. So please explain how this warmed up air is suppose to cool? -
VoxRat at 01:35 AM on 1 July 2010Ocean acidification
JC #70 "At a talk last night David Archibald finished by showing a picture of some coral and CO2 bubbling past. " CO2 bubbling past!? That would indicate that the water is saturated with CO2. "What do you make of his claim that coral is resililent to acidification? " It looks to me it's worth the paper it's printed on. Assuming it's not printed. -
daniel at 01:04 AM on 1 July 2010Sea level rise is exaggerated
No I don't have a degree in advanced Geology or a shining track record in paleochronology, but people like yourself just don't seem to understand how irrelevant that is. The debate on these issues is debased by this kind of ad hominem garbage. The details of what the researchers did is all laid out in the paper. Scientists from multiple fields need only read, perhaps suppliment that reading with some supporting material and they can have a thorough and detailed understanding of what has been done. It is a fantasy for you to think that you yourself cannot research the methods of the scientists and critique their papers just because you have not studied it or worked in the field. It is patronising nonsense. You put these people on a pedestal of heavenly heights and praise them as infallible heroes who shall not be questioned..... but that is just not realistic in the slightest. I did not say "pure junk" but "utter joke" and you felt you needed to leap to the aid of researchers who may actually be embarassed by your amateur attempts to dress them up as god like figures. How do you know that they might not agree with me in retrospect? How many times do I need to explain that I was never disputing the quality of the data but referring to the validity of the final comparison of two very different data sets? You have done it again in comment #33 Lets go through that one with some quotes. You said: "I see your point about samples 7 & 8, I'm sure Donnelly would have been happier if they'd resolved better but because they're embedded in the middle of the series their effect is not very drastic; interpretation of those is constrained by the surrounding boxes." Does Donnely et. al. actually say that? At what level of confidence can we say that the true paleo sea level is in the middle of or at the extremes of the boxes? If you want to say that it is closer to the middle you will lose statistical confidence to less than 95% At 95% you can speculate that the paleo sea level may have been at one or the other extremes. This reality is part and parcel of scientific data doug you can't wish it away regurgitating the word "conservative" from the paper. Here's where again you (after having plenty of time to just read what I say and not imagine it) seem to be putting words in my mouth: "As to your problems with multiple date ranges for samples, if you read the text carefully you'll see how Donnelly eliminated date ranges by using methods beyond C14" I'm not disputing the eliminations for samples 1 - 10. But..... look carefully at the graph like I asked you to and you will see that sample 11 has two date ranges assigned. Two boxes, not greyed out lines, but boxes at the same height labelled 11. This is actually in conflict with table 1 which seems to suggest the younger range is rejected. But the researchers can't use the principle of superposition adequately here to dismiss the younger age range for sample 11 because it is still slightly younger than or equal in age to samples 9 and or 10. Either the box assigned to the younger age range is a printing error or the authors neglected to discuss this inconvenient data point in detail. How did such an error occur in the indestructable field of climate science? -
Chris G at 00:51 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Regarding #27(2), When a water molecule evaporates from, say, the ocean, energy is transferred from the ocean to the atmosphere. When the molecule condenses back into rain, and precipitates, energy is transferred back. The net effect is zero. How does this contribute to global cooling? (At what altitude (range) does most precipitation form and is that high enough to significantly affect how readily it is radiated out?) -
Ned at 00:45 AM on 1 July 2010Perth forum on climate change: all the gory details
chriscanaris, the report is thoroughly German in other ways, too. The table of contents lists sections hierarchically up to four layers deep. The table of contents & list of figures etc. runs on for 35 pages! -
JMurphy at 00:39 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
NickD wrote : "As a member of the general public, I can assure you I come to this site often, refer other members of the general public to this site as a great resource for laypersons to understand scientific concepts, and I appreciate the explanations provided by John Cook, Kevin Judd, Doug Bostrom, and many others." Hear, hear and seconded. I would also like to add mention in the dispatches to Marcus, Ned, David Grocott and ChrisG, who always have detailed and referenced answers to all the strange theories and assertions that some people post on this site, especially recently. I admire the forbearance of you all... -
Ken Lambert at 00:37 AM on 1 July 2010Astronomical cycles
Peter Hogarth #111 I used this chart: http://sealevel.colorado.edu/current/sl_ib_ns_global.jpg which is IPB corrected and seasonal signals removed. Running a linear fit between 2003 and 2009 gives about 2.1mm/year and 2002 to 2010 gives about 2.4mm/yr. It is clear that the 3.0 +/- 0.4mm/year linear trendline is not a good match for the 2002 - 2009 period of Jason 1. The 60 day smoothed line is above the trend for the 2002-2007 period and crosses below it for 2007-2010, with an uptick in the last year or so apparently due to Jason 2. This is clearly a flatter trend for the Jason 1 perod than the 17 year trend line. It sounds like splitting hairs, but according to Dr Trenberth's Table 1 (Aug09 paper 'Tracking Earth's global energy') the total land ice loss accounts for about 2.0mm/year of SLR but only 2-3E20 Joules of heat is required to melt it, while every 0.4 - 1.2mm of thermosteric rise equals about 20-95E20 Joules of increased OHC. So finding more steric rise is the only way to get closer to an energy balance; and more ice melt rise rapidly worsens this energy budget shortfall. Problem is you can't have increased glacier melts and a flattening SLR without reducing the steric component consistent with a flat OHC in the top 700m; and have a TOA energy imbalance of 145E20 Joules/year at the same time. It is indeed a travesty of conflicting data. -
RickG at 00:37 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
RSVP, I assume your water molecules get replaced by other water molecules such that the overall amount of water vapor remains relatively constant (on the average). So water vapor remains relatively constant and global temperature keeps rising? Seems to me you just ruled out water vapor as a cause for GW. -
Chris G at 00:36 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Hopscotching comments here. Regarding #25, OK, so waste heat has to "...go through the CO2 gauntlet..." the same as the energy from the sun after the earth has, in effect, converted SW to LW. The amount of energy in has to be on long-term balance with energy out; so, how much energy does the earth receive from the sun compared to how much industry puts out? The sun's energy is orders of magnitude larger. Yet, somehow waste heat has a larger impact? -
KR at 00:29 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
RSVP - while all sources of heat do feed into the equation, a simple order of magnitude calculation indicates that waste industrial heat accounts for one part in 10,000 of global warming compared to radiative imbalances. So yes, industrial heat does add to global heating, but not enough to matter - not even enough to show up over noise/chaotic daily weather/measurement error/phase of the moon (Joking on that last one, joking! Although I believe lunar irradiance does have some effect...). -
RSVP at 00:24 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Marcus "This potency is further amplified by the fact that the resident lifetime of a single CO2 molecule-in the atmosphere-is much, much longer than that of a single molecule of water. " Two things. 1) I think it was Shrek, not the donkey. So I will admit making a mistake on that count. 2) I assume your water molecules get replaced by other water molecules such that the overall amount of water vapor remains relatively constant (on the average). If so, not sure why this matters? Not only that, it just happens to take energy for this to happen, which is a plus for global cooling. -
chris1204 at 00:21 AM on 1 July 2010Perth forum on climate change: all the gory details
I've just opened the previous post tonight and was very pleasantly surprised to find Volker's study which I've just downloaded. Now that's just so thoroughly German (in the best sense of the word) to address the very question I thought nobody seemed to be asking (the carbon cost of making a transition to renewables). I'll be reading it with great interest. Thank you John and Volker :-) -
Chris G at 00:21 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Not to make it 'pick on RSVP' day. But... "...any "transparent" gas..." "...water vapor is transparent and reflects light depending on temperature and pressure..." OK, I might not be getting what you are meaning here, but 'transparent' is a poor term for gasses. Mainly because their transparency is function of the wavelength of the light, not temperature and pressure, btw. Water vapor and CO2 are transparent at some wavelengths and not at others. That's kind of the whole reason why there is a greenhouse effect. "...and non linear. " Right, we know that; it is a log function. (Unless you are talking about how water vapor condenses and precipitates, but that is the part that isn't clear.) "...waste heat is accumulating." Hmm, if the absorption and emission of IR (heat), and hence retention, is negligibly affected by an increase in an IR absorbing gas, like H2O and CO2, what keeps the waste heat from radiating off into space? The only thing that would prevent that would be a greenhouse effect stronger than AGW needs, yet you are arguing that there isn't a greenhouse effect strong enough to let AGW happen. -
RSVP at 00:16 AM on 1 July 2010What is Global Warming and the Greenhouse Effect?
Marcus "your "it's waste heat" hypothesis falls flat on its face-" Not so fast... One thing you can be sure of is that waste heat is entering the atmosphere. (If this were not true, my car's engine would overheat.) And its not just heating the CO2. Its heating all gasses, even those that do not emit IR so well (as per AGW). Similar problems exist for thermal pollution entering our rivers and the ocean. After that, this same heat has to go through the CO2 gauntlet upward, which you adamantly profess has made heat escaping more difficult. Just as can happen with commuter traffic, when the throughput increases, you get a traffic jam. This happens even when the same number of lanes are free. Just imagine if a lane gets closed (this would be the CO2 factor). So, it may be a combination of both effects. -
Arkadiusz Semczyszak at 23:52 PM on 30 June 2010Perth forum on climate change: all the gory details
@Marcus 280 ppmv. Easily accessible (due to warming) and natural sources, eg : detritus of soil - estimated age: at least 1000 - a maximum of 10,000 years (the majority in the polar area, which is the fastest warm feeling) is still currently available quantity is estimated at 600 - 800 Gt C. -
Marcus at 23:16 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
Oh, & "imagining" CO2 has no impact is very different from it actually *having* no impact. We know-& can directly measure-the impact CO2 has on outgoing long-wave radiation, & even its natural (non-enhanced) effects totally dwarf any known impacts of thermal pollution by several orders of magnitude. -
Ned at 23:15 PM on 30 June 2010Temp record is unreliable
It seems to me that a lot of the questions people ask about the surface temperature data have been answered, at least in part, by the various "independent" (i.e., non-official) reconstruction tools that have been developed over the past six months. For example, all of the following questions have been addressed: (1) Can the "official" temperature records (GISSTEMP, HADCRU, NCDC) be replicated? [Yes] (2) Does the GHCN adjustment process have a large effect on the surface temperature trend? [Generally no] (3) Does the decrease in high latitude (or high altitude, or rural) stations have a large effect on the temperature trend? [No] (4) Does the location of stations at airports have a large effect on the the temperature trend? [No] (5) Does the overall decline in station numbers have an effect? Don't you need thousands or tens of thousands of stations to compute an accurate global temperature trend? [No, it can actually be done with fewer than 100 stations] There are probably other questions that I'm forgetting. Anyway, here are some handy links to tools that people have put together for do-it-yourself global temperature reconstruction. Many (but not all) of these are open-source, and many are very flexible, so that you can create reconstructions using different combinations of stations to test particular hypotheses. * Clear Climate Code (exact replication of GISSTEMP using Python). * Ron Broberg's blog "The Whiteboard" (replication of GISSTEMP and CRUTEMP) * Nick Stokes's GHCN processor * GHCN Processor by Joseph at Residual Analysis * Zeke Hausfather's temperature reconstructions (no single link, but see here and here) * Tamino * RomanM and Jeff Id * Chad at "Trees for the Forest" If there are others that I'm missing, maybe someone could add links in this thread. -
Marcus at 23:14 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
OK RSVP, on point (1)-have a look at the above posts-aside from you & Karl, everything here *does* agree with me-so its a pretty fair assumption. This has nothing to do with belonging to a "club", but everything to do with having more than a basic grasp of scientific concepts. (2) if recent warming were the result of accumulating waste heat then (a) there would be some correlation between rising industrialization & rising temperatures (we don't, btw); (b) we'd expect to see the most rapid warming in industrial sites, with non-industrial sites warming less rapidly, if at all (in fact, many wilderness sites-like the Arctic & Antarctic-are warming at a significantly faster rate than urban & industrial sites) & (c) we'd be able to account for every Joule of that energy to *prove* that it was accumulated waste heat. As I've said before, waste heat accounts for as little as 0.01% of all the energy the planet receives (about 13 Terra-watts), as compared to the roughly 180 Peta-watts worth of solar radiation that enters the system from the sun. So, on all 3 of these counts, your "it's waste heat" hypothesis falls flat on its face-& no amount of repeating a dud hypothesis will suddenly make it good. -
RickG at 23:08 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
RSVP, You seem to be ignoring that water vapor is a feedback, not a forcing, as well as the well known and understood physics of CO2. -
RSVP at 22:57 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
Marcus "What I love is how RSVP can claim that CO2 is too "small" to have an impact on the climate, yet he still holds to the notion that industrial heat-which accounts for less than 0.1%..." Two things (as the donkey on Shrek said...) 1) It appears you are directing your comment to readers that you assume agree with you. Are these club members? 2) Just imagine if CO2 was having zero impact. That then would be saying a lot about how much waste heat is accumulating. Remember integration from college? -
Marcus at 22:44 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
What I love is how RSVP can claim that CO2 is too "small" to have an impact on the climate, yet he still holds to the notion that industrial heat-which accounts for less than 0.1% of all the energy this planet receives-is to blame. Talk about holding two contradictory views at the exact same time. A good analogy for CO2 might be a biological toxin like Pertussis or Botulinus. An average human being weighs more than 50kg, yet doses measured in milligrams could prove potentially fatal. There are other toxins which are even more deadly, in smaller doses. Its not the quantity that matters, but the ability to effect the system that matters. CO2, NO2 & CH4 are all *trace* elements, yet they're all exceptionally good at absorbing outgoing IR radiation. This means that you don't need much of them for them to start having a malign impact-just as you don't need much of a compound that blocks neurotransmitter function to kill a person! -
NickD at 22:34 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
RSVP at 17:17 PM on 30 June, 2010 says: "And I doubt that the "general public" you are referring to come to this site, or even have much interest in global warming theories." As a member of the general public, I can assure you I come to this site often, refer other members of the general public to this site as a great resource for laypersons to understand scientific concepts, and I appreciate the explanations provided by John Cook, Kevin Judd, Doug Bostrom, and many others. -
Marcus at 22:32 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
I really think that people like John D & RSVP need a sense of perspective. On the one hand you have water vapor, making up 3% of the Earth's atmosphere & accounting for, on average, roughly 65% of the *natural* Greenhouse Effect. Then you have CO2, making up less than 0.03% of the Earth's atmosphere (pre-industrial), yet accounting for almost 20%-on average-of the *natural* Greenhouse Effect. This suggests that, on a parts per million basis, CO2 is about a 20 times more potent greenhouse gas than water vapor. This potency is further amplified by the fact that the resident lifetime of a single CO2 molecule-in the atmosphere-is much, much longer than that of a single molecule of water. Yet we're to believe that artificially ramping up the levels of CO2 in our atmosphere will have only a negligible impact on our climate-in spite of the fact that we've had a greater than 0.6 degree warming in the space of only 60 years-which just happens to coincide with a significant rise in anthropogenic CO2 emissions & a decline in solar activity. Some people appear to believe that we're a bunch of mugs! -
Ned at 22:29 PM on 30 June 2010Temp record is unreliable
Berényi Péter, you're part way there. Handling the US and the rest of the world separately is a good start, and for a simple order-of-magnitude guesstimate it might be enough. But as with everything in statistics you need to understand your assumptions. Treating the rest of the world as homogeneous will not yield an unbiased estimate of the global mean adjustment unless either (a) the stations are distributed approximately uniformly in space or time, or else (b) the expected value of the adjustment for station X in year Y is independent of that station's location. (For that matter, this also applies to treating the US as homogeneous). We know that (a) is untrue. So the question is whether (b) is true, or close enough to true that you can live with the resulting bias. (As an aside, the existence of nonstationarity in the expected value of the adjustment is not evidence of "tampering" ... there are many valid reasons why stations in country 1 or state 1 would require different types of adjustments than stations in country 2 or state 2). Again, you can just assume that the impact of any spatial heterogeneity will be small, and ignore the bias in your calculations. That's essentially what you did above. Alternatively, you can weight the data spatially, e.g. by gridding, and remove the problem. Does this help? -
David Grocott at 22:22 PM on 30 June 2010What causes the tropospheric hot spot?
Baa Humbug, You've made a few misleading statements there.Regarding the hot spot being a "signature" of GHG warming, I must respectfully disagree. It's not just the IPCC presenting a chart which clearly shows the distinctive signature of GHG warming...
...as modelled from 1890 to 1999. That's a rather important caveat. It is not a 'distinctive signature' of AGW at all. Please see my previous postings on this, at is a very important point. If it were a unique 'signature' of AGW, and you chose to believe it was absent, then it would be plausible to say that current warming is not being caused by human activity. But as it is not a unique signature, if you choose to believe it is absent, then that leads to the obvious conclusion that warming is not occuring, period. This is a much more difficult argument to make. This is the last time I will outline this distinction, as I'm starting to get bored of the sound of my own voice. The four images which you have provided reflect the same reality as the image I provided at #48, labelled 'For 2xCO2'. They demonstrate that a doubling of CO2 creates a tropospheric hotspot. As my other image at #48 shows, a 2% increase in solar activity (a forcing in the same order of magnitude as a doubling of ACO2) creates a similiar tropospheric hot spot. The comparison is the important bit, not the accepted fact that a doubling of CO2 should cause a tropospheric hot spot, as your images show.The IPCC quote you provided is unequivocal IMHO, where it states, "The combination of a warming troposphere and a cooling stratosphere has likely led to an increase in the height of the tropopause and model-data comparisons show that greenhouse gases and stratospheric ozone changes are likely largely responsible". So if GHG's are largely responsible, then GHG's are the main cause of the distinct hot spot, which as the 6 graph chart shows in C and F, is much more powerful than other forcings, man made or natural (a,b,d,e)
As 'e' pointed out at #57:the tropospheric hotspot is a distinct concept from stratospheric cooling + tropospheric warming. The tropospheric hotspot is a greater warming of the troposphere in lower latitudes relative to higher latitudes. This is a prediction that follows from any warming, not just from CO2. Stratospheric cooling is the cooling of the stratosphere while the troposphere warms across all latitudes. This prediction is unique to warming from GHG's.
I've also pointed out a number of times that a warming troposphere (distinct from a specific hot spot) and a cooling stratosphere, is a unique signature of AGW. The existence of both of these phenomena are supported by observational data. Although your logic breaks down, you are right in saying that (assuming we accept the IPCC's assertion that human activity is causing the majority of observed global warming) "GHG's are [or rather 'should be'] the main cause of the [current] distinct hot spot". As I've pointed out,if (big if) you conclude that the tropospheric hot spot does not exist, then you must argue against the observation of global warming from any source, as opposed to just AGW. There's actually very little in the IPCC document about the tropospheric hot spot - presumably as a result of the fact that it proves very little beyond the fact that the models are accurate (or not) in their predictions of atmospheric zonal temperature responses to warming (of any kind). The small, oft-quoted section that there is, is fairly misleading. Much greater 'air-time' is given to the warming troposphere/cooling stratosphere phenomonen, which is undeniably being observed, and is a signature unique to AGW. The brief section of the IPCC document which concerns us...The simulated responses to natural forcing are distinct from those due to the anthropogenic forcings described above. Solar forcing results in a general warming of the atmosphere (Figure 9.1a) with a pattern of surface warming that is similar to that expected from greenhouse gas warming, but in contrast to the response to greenhouse warming, the simulated solar-forced warming extends throughout the atmosphere.
...doesn't refer to the tropospheric hot spot at all, but rather to the fact that solar forcing results in a warming of the whole atmosphere, where as AGW forcing results in a warming of the troposphere and a cooling of the startosphere. The fact that it links to a picture of a number of charts showing zonal mean atmospheric temperature change from 1890 to 1999 (which happen to show the hot spot created by greenhouse gases during that period) is neither here nor there. This is a matter which has been mistakenly leapt on by 'sceptics', not least Jo Nova, who appear to consider it the lynch pin of AGW theory. Like you I look forward to some more definitive papers on the matter. -
Marcus at 22:17 PM on 30 June 2010Perth forum on climate change: all the gory details
Maybe John, its because you were trying to drag the topic back to CO2 as a plant food again- & again without a skerrick of proof to back you up. This comment will probably be deleted, but I hope you see it before it does, so you understand why your post was OFF-TOPIC, wheras mine at 16:11 continues the already existing theme for this thread-namely how to respond to denialists like yourself. -
sleepership at 21:57 PM on 30 June 2010What is Global Warming and the Greenhouse Effect?
The Science of Global warming---the Greenhouse condition is over 100 years old- and is not 'exotic' but basic science. The science is solid and basic physics. The doubt comes from what some believe is the human imprint to warming- which actually has been very strong- increased industrialization shows the burning of fossil fuels to have increased CO2 levels to nearly 400ppm. -
Berényi Péter at 21:55 PM on 30 June 2010Temp record is unreliable
#78 Ned at 01:39 AM on 30 June, 2010 Contrary to what BP claims, it's really important to use some form of spatial weighting (e.g., gridding) when doing this, because the stations are not uniformly distributed. OK, I have understood what's going on. In a sense you are right, but for a different reason what you think you are right for. You do not have to do any gridwork, just treat the US and the rest of the world separately. 1. Until about 2005 the USHCN used to be heavily overrepresented in GHCN (since then it is getting underrepresented, 4.16% in 2010). 2. Between about 1992 and 2005 up to 90% of GHCN readings came from USHCN, before that time it was 20-40%. 3. Since 2006 there is no adjustment in USHCN and since 1989 for the rest of the world. 4. Adjustments for USHCN are much bigger than for the rest of the world. They also follow a different pattern. It looks like two different adjustment procedures were applied to the US data and the rest of the world and the results were only put together after that. US land area is 9,158,960 km2, world is 148,940,000 km2, therefore the US has 6.1% of land. If the world is divided into two "regions": the US and the rest and area weighted average is calculated, trend in global adjustment is 0.1°C/century for 1900-2010 (the same figure is 0.39°C/century for USHCN). Unfortunately this peculiar feature of GHCN is undocumented. -
Riccardo at 21:40 PM on 30 June 2010What causes the tropospheric hot spot?
The quoted paragraph from the IPCC refers to troposphere warming AND stratosphere cooling and of GHG AND ozone. The graph you show are for doubling CO2 not for what we should currently observe.
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