Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  2192  2193  2194  2195  2196  2197  2198  2199  2200  2201  2202  2203  2204  2205  2206  2207  Next

Comments 109951 to 110000:

  1. How much did aerosols contribute to mid-20th century cooling?
    That was an interesting point in the section "Days cooled, but nights warmed". Can anyone point to a global anomaly graph that tracks the night time temperature minimums and C02 since the industrial revolution? It would make an excellent centrepiece for debunking CO2 scepticism.
  2. It's El Niño
    Erl - for a warming trend, you have to increase the net energy on the planet. Where is the evidence of this in ANY ocean cycle. While the initiation point of an ENSO event remains tricky, (is it wholly a dynamical phenomena?), I would say that other aspects are now pretty well understood. I also note that "ENSO" emerges in climate models, and yet these models do not create temperature trends unless there is a forcing (like CO2 or solar) applied.
  3. How much did aerosols contribute to mid-20th century cooling?
    #10: "during the mid-century cooling period, PDO was negative essentially the whole time" So I looked at a PDO data file and graphed it with global LOTI for the same period (1900-current). The mid-century negative certainly looks like the mid-century cooling, but the PDO seems to be touching negative territory since the late '90s: with no sign of any cooling. PDO: Pink is summer 3 month average; light blue is winter. LOTI (dark blue) on the right-hand scale. You can't have it both ways. Perhaps there is no real coupling between PDO and temp and the mid-century was mere correlation without you-know-what? Or perhaps any such coupling was faint and is now swamped by CO2? In either case, its now PDO 0, aerosols 1.
    Response: Note: added "width=450" to your image. I get a little grumpy when people break my web design. Just letting you know for future reference :-)
  4. How we know the sun isn't causing global warming
    Moved discussion to there...
  5. How much did aerosols contribute to mid-20th century cooling?
    Daniel #6 (in reply to Rab #5 Thanks for the coherent explanation of that particular piece of erroneous thinking. You made me realise that this was another example of so-called climate sceptics (sub-consciously?) using the often uninformative technique of philosophical solipsism in an attempt to maximise perceived uncertainty.
  6. The contradictory nature of global warming skepticism
    Stop the presses, this just in: NOAA reports 2010 hottest year on record so far. And the warming continues, anon. The Yooper
  7. The Pacific Decadal Oscillation and global warming
    The point still stands that PDO physically cannot cause a long-term global temperature trend, certainly not in both surface air and ocean temperatures.
  8. How much did aerosols contribute to mid-20th century cooling?
    It's valid to point out that during the mid-century cooling period, PDO was negative essentially the whole time (though still a relatively small impact on average global temperature). But PDO does not cause long-term temperature trends, as discussed in the rebuttal linked by muoncounter in #9. Nor can negative PDO explain the nighttime warming trend discussed above.
  9. How we know the sun isn't causing global warming
    Ken, If we are to be sure that the sun is not responsible for recent climate change we that we fully comprehend all the possible linkages. Therefore, with all due respect to a man who is obviously very sophisticated, I urge you to consider the atmospheric dynamics described at http://climatechange1.wordpress.com/2010/08/17/is-enso-rather-than-a-%E2%80%98greenhouse-effect%E2%80%99-the-origin-of-%E2%80%98climate-change%E2%80%99-by-erl-happ/ It is generally acknowledged that the ENSO phenomenon is not understood. It is my belief that when it is understood, we will understand the the nature of the sun-climate link.
    Response: I suggest moving any discussion of ENSO to the "It's El Nino" page
  10. How much did aerosols contribute to mid-20th century cooling?
    And here's someone answering my question on a related thread. Gotta love skepticalscience!
  11. How much did aerosols contribute to mid-20th century cooling?
    #1: "Aerosols 0. PDO 2. " I'm mystified why so many people throw around these ocean cycles as an explanation for just about everything. Clearly I do not understand enough about ocean dynamics. But it is apparent just by inspection that there is no long term trend to these cycles: From The PDO From The AO and the NAO So I have to ask: How can cycles with no long term coherency be the causes for an effect (increasing global temperatures) that has a long term trend? Wouldn't those cycles more likely be the causes of the short-term low-amplitude variations?
  12. Positive feedback means runaway warming
    5, John Brookes: The carbon-cycle aspect has a positive feedback, because the increase in T => increase in CO2 => increase in greenhouse effect => increase in T. The T^4 radiated power has a kind of negative feedback, because the increase in T => increase in cooling => reduction of the increase in T. (But actually, T^4 behavior is not really the way the system works: If it did, we wouldn't be talking about the greenhouse effect.)
  13. Positive feedback means runaway warming
    4, Lazy Teenager: - I don't quite get your point: The solubility of CO2 in water declines with increasing temperature. Last I heard, the uptake of CO2 has dropped in recent years, although up til now it has absorbed about half the CO2 produced by fossil fuels. - I don't understand the issue regarding equilibrium.
  14. How much did aerosols contribute to mid-20th century cooling?
    #! Thingadonta Aerosols are currently increasing in SE Asia significantly, but this doesnt correspond to any cooling (?). Please stop indulging in argument by assertion, and start providing credible evidence for your claims. Thanks!
  15. How much did aerosols contribute to mid-20th century cooling?
    Re: Rab (5)
    "Drawing the blue lines in the top curve is not helpful. I realize this is often done to "guide the eye", but I think especially to non-scientists, it looks like you are trying to make more of the data than is there: nothing happened up to 1920, then something happened, linearly, changed completely all at once in 1940, and again in 1975."
    Are you referring to Figure 1? If so, this is from a post by Tamino over at Open Mind. Tamino is a professional time-series analyst. He used this figure to illustrate how a time-series dataset can show natural "break points" in the data where a "tipping point" can be demonstrated to have occurred. The purpose of the blue line is not to "guide the eye". The red line is a loewess smooth to show the trend with less noise. I recommend following the link to Open Mind for further detail. The Yooper
  16. Climate change: Water vapor makes for a wet argument
    Just read your post more carefully... In ground thermometer, the measuring device equilibrates to surroundings by conduction and so is measurement the temperature of the immediate surroundings. With thermopile. BOTH ends of the thermopile equilibrate to surrounding by conduction, but only one end of the thermopile is heated by IR. This makes the device directional. If you turned it face the ground rather than the sky, then you measure the outgoing LR. Point it at the sky and you measure DLR (backradiation). If you measure both (and the short wave as well), then you can see the individual heat balance like the Trenberth diagram but on an hour by hour basis. And by the way, while I think Spencer is wrong on many things, he does science the right way - publishing his ideas in reputable journals.
  17. How much did aerosols contribute to mid-20th century cooling?
    This is a good post except for one thing. Drawing the blue lines in the top curve is not helpful. I realize this is often done to "guide the eye", but I think especially to non-scientists, it looks like you are trying to make more of the data than is there: nothing happened up to 1920, then something happened, linearly, changed completely all at once in 1940, and again in 1975. I know you don't claim to say this, but to the non-scientist it seems like you are trying to prejudice the reader into seeing lines when in fact there is only noisy data. Leave the data alone and readers can see the trends for themselves.
  18. Positive feedback means runaway warming
    3, Josie: I see it as runaway if the system goes to an extreme that is stopped only by a lack of resources of some sort: in the case of the amplifier, limits to power; in the case of the Venusian atmosphere, exhaustion of water. In this model, the feedback is positive but decreasing, so it just stops adding up. I consider it self-limiting, as opposed to runaway.
  19. Video update on Arctic sea ice in 2010
    7.CBDunkerson I did better and read the published paper that presented this work. It contained nothing about previous years. If there were important multiyear observations he should have put them in the paper. Although it did have 14 uses of teh exciting "rotten ice" term. The real scientific content of that paper is that direct observations show that there are problems with the interpretation of the satellite data, as pointed out by Rob Honeycutt. Something I don't have a problem with. What's making the headlines, and what makes this a standout for warmists, is the lurid use of "rotten ice". Unfortunately Barber seems well aware this is the newsworthy content in his paper and is pushing that point. I have problems with that and with regard to any comments about long term ice thickness trends based on this work. I stick to my point this is one data point with no attempt at historical context. If Barber hadn't used "rotten ice" would this study represent anything new with regard post-2007 arctic ice? Apart from the satellite data insight. The fact that 2007 represented a clearing out of MYI is well known and ignored by Barber here. There are better post-2007 direct observations which suggest little has changed in the quality of the arctic sea ice and that the Barber (and POIMAS) predictions of it "continuing to disappear at an alarming rate" are exaggerations. The paper below suggests little has changed since 2007 which is remarkable given that this work was done in April 2007, before the huge clear out of MYI. The problem with Haas is he hasn't realised that sticking to the facts doesn't get you the headlines. You need plenty of fluff, something Barber seems to excel in. http://epic.awi.de/Publications/Haa2010b.pdf On PIOMAS I agree that the warmist blogosphere is in love with the PIOMAS model, I was asking whether the arctic science community felt the same way. I don't see it's widespread uptake as represented by published work. Show me the papers and I'm happy to concede the point.
  20. How much did aerosols contribute to mid-20th century cooling?
    Hmm. Globally, I thought aerosols were flat or declining Asia emitting more as industry moves there while reducing in the west? Anyway, remember that climate is not single-factor. The overall effect is sum of all forcings, positive and negative. Claiming PDO as cause may be mixing cause and effect. The PDO argument is somewhat moot anyway because there is no trend.
  21. How much did aerosols contribute to mid-20th century cooling?
    thingadonta - yes, PDO was another small contributor to the cooling during this period. And so were volcanoes, and black carbon caused some warming, etc. etc. I can't address every single global temperature influence in one post, so I covered the big ones. Your claim that aerosols are not causing any cooling in SE Asia is incorrect. Their local cooling effect is overwhelmed by anthropogenic warming, but that doesn't mean it doesn't exist. That's like saying 2 + (-1) = 1, therefore -1 isn't negative.
  22. How much did aerosols contribute to mid-20th century cooling?
    thingadonta. The chindian aerosols are one of the nasty effects in the wings. Anyone who says that CO2 emissions aren't lining up with the observed temperature increases should look at what could happen as aerosols reduce in the same way as those in advanced economies.
  23. How much did aerosols contribute to mid-20th century cooling?
    None of the your figures show the obvious correlation with mid 20th century cooling and the PDO cool phase of the mid 20th century. Aerosols are currently increasing in SE Asia significantly, but this doesnt correspond to any cooling (?). Aerosols 0. PDO 2.
  24. The contradictory nature of global warming skepticism
    @Eric: "If you look at my first post on the topic (102) I said since hunting was the main factor for the decline it should be addressed in the thread. You answer to that is now a straw man: "over-hunting"." That is *not* a strawman - if hunting is the main reason for the decline (which means that more bears die than what is required to sustain the population), then by definition it *is* over-hunting (or over-harvesting, etc.). As it is, nowhere in the link is anyone arguing that over-hunting is currently responsible for declining bear populations *overall*, therefore there is little evidence to support your claim. "Bottom line is I can't say that hunting deaths are greater than climate change deaths without a lot of missing information which I need to research." That's the most sensible thing you've said so far in this thread. Thank you.
  25. Climate change: Water vapor makes for a wet argument
    John - you are again making wrong assumptions. I really wish you would read the science of doom article I pointed to long ago. What you are describing is the laws of CONDUCTION. back radiation is not conduction. What you say makes no sense because of this fundamental difference. If you had no greenhouse gases, the warm ground would warm the atmosphere by conduction - just not very much. Spenser's experiment was aimed at reducing conduction effects and concentrating on the radiative energy transfers.
  26. The contradictory nature of global warming skepticism
    @Baz: "Ask yourself why I'm answering EVERYONE else but not you. Is it because your points are more clever than theirs, and that I have no counter-arguments to your points? Is it, mate? Really?" Yes, it is. (There can't be any other explanation, since I wasn't impolite to you.) Case in point: looking at the last three years (instead of five, or ten) shows dramatic warming. Why not see this as a sign the warming has resumed?
  27. The contradictory nature of global warming skepticism
    Baz... To follow up on the Yooper and your comment at 204, "I feel there are far too many closed minds in both camps." I think minds are less closed on the AGW side of the fence than you might be lead to believe. Yes, there are some aspects that climate scientists will battle to their dying breath over, but what they're battling over is not a matter of opinion. They're defending the basic scientific facts, as Daniel listed above. As a layman I've come to side with the AGW camp because I see them stating both the very clear science and presenting the aspects that are uncertain. Whereas on the other side I keep seeing isolated and contradictory arguments (the point of this blog post). The late Dr Stephen Schneider put it very well in this fairly recent TV discussion where he says, "If you see one side, either side, saying they KNOW the answer, they're wrong. Science doesn't do absolutes. But when you see someone saying, 'Here is what were sure of, here's what fairly certain of and here are the uncertainties' that is who you should be listening to." The basic science of AGW is, as so many say, done. Man made CO2 is warming the atmosphere. There are just no two ways about that. But there are uncertainties with feedbacks and climate sensitivity. Is it going to be 1.5C or 6.2C for doubling CO2? We simply do not yet know. But we do know enough to act to make sure that we do not expose the planet and human civilization to the potential catastrophe of, as Dr Richard Alley puts it, "the long tail of the distribution." (i.e., the possibility that things are going to be worse than we think).
  28. What about that skeptic argument that Jupiter is warming?
    You might want to add Uranus to the list. Apparently it's been cooling. (Link is to 2001 study - PDF)
  29. Climate change: Water vapor makes for a wet argument
    scaddenp at 07:35 AM, the point I was making is that what Spencer is tracking with his crude IR thermometer supposedly reading back radiation from the sky, is the same as that what a simple thermometer lying on the ground would track. The problem perhaps is the term back-radiation itself. I think everybody accepts that any body or matter that contains heat will exhibit such energy and allow the transfer of such heat through all mediums. Obviously any medium that has a higher heat content than those adjacent will transfer such energy at a rate relative to the heat differential that exists between them until such time equilibrium is reached. What is the situation then? No nett transfer of heat energy as outgoing and incoming are equal. In the physical world it is the nett results that are relevant, and back-radiation only affects the rate of the nett transfer of heat, not the direction. In the environment that Spencer conducted his experiment, and BOM record their terrestrial minimum, convection is the major form of heat transfer as it is in all the atmosphere, and it too responds accordingly to the magnitude of the heat differential. So it comes back to the original question, what was Spencer's experiment tracking that a thermometer lying on the ground wasn't?
  30. How we know the sun isn't causing global warming
    KL #53 Two obvious problems with your post: 1. An incorrect assumption about TSI (see dana1981's response at #58) which means that the logic of your post is not sound. 2. You're still assuming that the OHC estimates are good enough to be able to draw strong conclusion from them.
  31. The contradictory nature of global warming skepticism
    There was only one question mark in your 177, and I responded. I was not asking questions, I was responding to your questions… e.g. "there is no correlation though, is there?", "What's happened to the heat?" "what would it take for man-made global warming to be falsified?" If you accept those answers, I'd be interested to know that. If you reject them, I'd be curious about the basis of your disagreement. I've engaged your questions with respect and courtesy, as has Daniel Bailey, who has done so with much more detail and substance. Do you have any response at all to the answers he gave to your questions?
  32. Why positive feedback doesn't necessarily lead to runaway warming
    Chris: Also, I saw some place some folks talking about detecting water vapor at 11+ km recently. Have you heard anything about this? Obviously, if that's a significant amount, it would screw up the picture.
  33. Why positive feedback doesn't necessarily lead to runaway warming
    61, Chris: - Your first paragraph confirms the conclusion I had come to about why CO2 is so important despite being only about 4% of greenhouse gases. The height of the 15-micron photosphere is most significant from this perspective, since CO2 and H20 share this band: It would make most sense if the 15-micron photosphere would be well above the point at which there is significant H20 vapor: Otherwise, the abundance of H20 (on average) is 25X that of CO2; and the absorption coefficient looks to be only about a factor of 2 smaller. So if H20 and CO2 were competing at the same altitude, H20 would have an advantage of a factor of about 13, and indeed it would be hard to credit a major role for CO2. - I guess 6.5-degK/km is the lapse rate assumed, for "typical" humidity? The figure I'm used to is 10-degK/km (for dry air). - You refer to the scale height for H20. How useful is an exponential model, given that temperature is dropping with altitude? I would have thought that an adiabatic model would be more appropriate.
  34. How we know the sun isn't causing global warming
    Ken Lambert - the radiative forcing calculated in the IPCC report is the *change* since 1750. That's what causes a radiative forcing - a change in the associated causal factor (greenhouse gas concentrations, solar output, etc.).
  35. Human CO2 is a tiny % of CO2 emissions
    You are asking questions that are well answered on this site. Go to the "arguments" and check them out. However please bother to read the counter-argument before just repeating the assertion. muoncounter's argument is that if 380ppm seems too small to have any effect consider what would happen if you replaced each molecule of CO2 with a molecule of say H2S or HCN. (To save you looking it up, it would annihilate mammalian life on earth at least with a couple of hours). 380ppm does not mean insignificant.
  36. The contradictory nature of global warming skepticism
    archiesteel (#197) says: "So, again, you have utterly failed to indicate that over-harvesting is the main factor responsible for the decline in polar bear number" If you look at my first post on the topic (102) I said since hunting was the main factor for the decline it should be addressed in the thread. You answer to that is now a straw man: "over-hunting". The three causes of polar bear deaths can be categorized as (1) hunting, (2) natural, not climate-related and (3) natural and climate-related. The reproduction rate is about 0.5 cubs per female per year. That means births of 500 in SHB and WHB and deaths a bit higher than that and about 5000 deaths worldwide annually. The hunt worldwide is about 700 http://www.solcomhouse.com/polarbears.htm The mortality dynamics are heavily dependent on cub survival which will indirectly affected by climate change, other natural factors, plus hunting to a smaller extent. Life expectancy improves after that so cub deaths are probably what matters. Also some studies suggest climate stress affects the birth rate so I would need to factor that in as well for SHB and WHB in particular. Bottom line is I can't say that hunting deaths are greater than climate change deaths without a lot of missing information which I need to research.
  37. Climate change: Water vapor makes for a wet argument
    The point of looking at Spenser article was to show that even skeptics accept the backradiation is a reality and can be demostrated with back yard equipment. However, the real stations that actually measure all the radiation elements do so with sophisticated instruments, quantify it and then use it for calculating the global radiation balance.
  38. The contradictory nature of global warming skepticism
    Baz - this "GISS using proxies" for arctic smacks of some disinformation from a denialist site. How about a closer look at how the two different data sets estimate the arctic? Hadcrut doesnt - or more to the point their global estimate effectively assumes that the arctic anomaly is same as the global average. A built-in assumption that arctic warms or cools at same rate as global average. GISS instead interpolates the missing grid squares from the nearby northernmost stations. This is what I assume what you mean by "proxies". Given that what evidence we do have (satellite, the northern stations etc) suggest that the arctic is warming faster than the rest of the globe, which measurement technique do you think is likely to result in the best estimate of temperature? Also, I would take another approach to falsification. Climate theory (of which AGW is merely a result) makes a large no. of predictions, not just about the temperature trend but also things like the temperature distribution (eg arctic amplification, land/sea anomaly differences), OHC, stratospheric temperature profile, seasonal shift, day/night anomaly differences etc. The scientific approach is to compare the predictions with observations (taking into account the error estimates in both the observations AND the predictions). An unaccounted difference would require at very least modification of the theory. So far our theory of climate is doing well.
  39. Why positive feedback doesn't necessarily lead to runaway warming
    The scale height for water vapor is quite small, about 2 km so abundance-wise you are correct. This is one reason why water vapor doesn't overwhelm the CO2 greenhouse effect, as water vapor is relatively leaky high up. CO2 has a very little effect in an atmosphere that is really wet up into the stratosphere, as you might get prior to a runaway scenario, but Earth is quite far from this regime. CO2 is pretty well-mixed until the stratosphere or so; I'm not sure how the CO2 mixing ratio changes once you get above the stratosphere (clearly water vapor is not really existent here) but for radiative transfer purposes there isn't really much greenhouse influence this high anyway because the air is so thin. One you get above the so-called "photosphere" at a given wavelength you become pretty optically thin, and below it pretty absorbing. If you use David Archer's model (which I plotted a few example diagrams in my link in the last comment) you can convince yourself that right at 15 microns the CO2 emission comes from the stratosphere (and in the wings, closer to the surface), since there appears to be an upwards blip inside the ditch in the spectrum itself (this becomes really obvious if you put like 100,000 ppm of CO2 into the model). The reason for this is that the temperature of the stratopsphere becomes isothermal or increases with height. Numbers of a spectrally averaged "photosphere" is about 5 km, since 288 ~ 255 K +(5 km)(6.5 K/km) Hope that helps
  40. Skepticalenergyguy at 07:20 AM on 16 September 2010
    Human CO2 is a tiny % of CO2 emissions
    muoncounter, with H2S being around .0000002% of our atmosphere, I'm not too worried about your 380ppm. The real question is, Is CO2 really causing global warming? Or is it the scapegoat for earth's natural cycle of weather change?
  41. Climate change: Water vapor makes for a wet argument
    michael sweet at 07:18 AM, I'm not sure whether you were claiming expertise as a psychic or as a comedian, but your claim regarding the Spencer's articles left me ROTFLMAO. On the contrary I have read about Spencer's experiment and it should have been obvious that this discussion was leading towards it being introduced, and I thank you for doing so. I was reluctant to introduce it myself as invariably, as often witnessed on this site, whenever Spencer is referenced to support an argument, Spencer's credibility is questioned and thus by association, used to question the credibility of the argument being put. With the Spencer experiment having now been introduced, it allows what he measured to be compared to what BOM measure and record as the terrestrial minimum temperature. The obvious difference is that BOM only record the minimum whilst Spencer tracked it continuously. However Spencer claims that his insulated box is a crude IR thermometer and that he is measuring infrared radiation of heat energy resident in the sky, whilst BOM are measuring ambient temperatures at ground level with a simple thermometer totally exposed on all sides. The first question is really whether or not Spencer is measuring anything different then what a simple thermometer lying on the ground measures? The second question relates to the principle of back radiation which has it that the heat contained within any body also radiates outgoing energy even though it is receiving incoming energy. If the temperature on the ground falls below the temperature of the air just 1.2m above it, why then is not the outgoing, or back radiation of that body of air received by the air just immediately below it? The theory of the transfer of thermal energy by radiation does not explain it, however the principle of convection does. The other point that Spencer's experiment is relevant to relates to earlier points made about how the high temperatures that the direct solar radiation produces at the surface are a greater force driving evaporation than back radiation. In his experiment he found that during the day the solar radiation caused temperatures that flat-lined for about an hour at the limit of the instrument, that being 158F. He expressed surprise at seeing temperatures so high, which in turn really surprised me. I would have thought that EVERYBODY knew just how hot anything receiving direct solar radiation can get. This is really school-kid stuff with most people learning early by burning their hand picking something up off the ground. This perhaps relates to another of my concerns, that being that despite all the claimed knowledge of the physics and theories, a large number of people have little or no knowledge of how it all manifests itself in the real world on a daily basis.
  42. It's not bad
    Re: Johngee (39) Welcome aboard. There's room for all here. At Real Climate, Climate Progress, Deep Climate, Rabett Run, Open Mind, Only In It For The Gold (the list of quality science blogs is very long). I lurked for about 18 months before I started chiming in. There's a ton of basal and ancillary background material to digest. If you're interested, go to Real Climate to the Start Here tab & find your comfort level. Any questions I can help with, just post. Welcome aboard. The Yooper
  43. The contradictory nature of global warming skepticism
    @Baz >Would you be choosing it too, if it was saying what you want to hear? I'm not "choosing" anything, I'm looking at all the data as a whole, including the HadCRUT and the ECMWF data. You on the other hand are choosing one particular time frame of one particular dataset on which to base your entire position. The best "rational" justification you can provide for this logic is because it is from "where you live". Sorry, but that's pathetic. Either you are a troll, or you lack a basic understanding of how scientific reasoning works.
  44. European reanalysis of temperature confirms record warmth in 2010
    Global Temperature Anomaly Map - August 2010 http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2010&month_last=8&sat=4&sst=1&type=anoms&mean_gen=08&year1=2010&year2=2010&base1=1951&base2=1980&radius=1200&pol=reg
  45. The contradictory nature of global warming skepticism
    Re: Baz (204) Thank you for re-centering and distilling your position. If I understand you correctly, you wish to know from the readership here:
    1. How the "AGW hypothesis" may be proven false. 2. What length of time is needed in time series data involving temperatures to be statistically significant?
    Am I reasonably close? I will assume I am, at least for now. Question 1. Reasonable question. Let me first offer up a clarification: it is something of a misnomer to refer to it as the "AGW Hypothesis" when in reality we are discussing the greenhouse gas effects of CO2, whether naturally-occurring or produced by man via the combustion of fossil fuels. Let's break it down, a step at a time:
    1. The greenhouse effect of certain gases was discovered by Joseph Fourier in 1824. Without the effects of greenhouse gases raising the Earth's temperature, the average surface temperature would be about -18 degrees C (i.e., no liquid water and thus no life). Based on that effect, increasing the level of a greenhouse gas in a planet’s atmosphere, all else being equal, will raise that planet’s surface temperature. 2. CO2 is a greenhouse gas (first reliably experimented with by Tyndall 1858 and first quantitatively reported by Svante Arrhenius in 1896) . Arrhenius, BTW, predicted a temperature response (sensitivity) due to a doubling of CO2 to be about 3 degrees C (the mid-point of the accepted range of 2.0 - 4.2 degrees C currently accepted). He was right in the magnitude, but had some details wrong (but in his defense, the sum errors mostly cancel out. Translation: he got it right because he was lucky). 3. CO2 is rising (Keeling et al. 1958, 1960, etc). Well established. Being a well-mixed gas, stable global concentrations are reached quickly. Monitored for over 50 years, seasonal variations and all. 4. Therefore (given 1-3 above) the Earth should be warming. Multiple, independent lines of evidence shows that this is the case. Listed in next line item. 5. From multiple converging lines of evidence, we know the Earth is warming (NASA GISS, Hadley Centre CRU, UAH MSU, RSS TLT, borehole results, melting glaciers and ice caps, etc., etc., etc). Looking at all of the data we have, over time, we know the Earth is warming. 6. The warming is moving in close correlation with the carbon dioxide (r = 0.874 for ln CO2 and dT 1880-2008). Based on the known physics of greenhouse gases, all computable by hand (i.e., no computer needed) the amount of warming predicted by the radiative physics of GHG's and the physical relationships of solids, liquids and gases, very closely matches observed increases. I cannot emphasize this point enough: this is basic physics, not some fancy GCM. 7. The new CO2 (as shown by its isotopic signature) is mainly from burning fossil fuels (Suess 1955, Revelle and Suess, 1958). We can reliably differentiate between naturally-occurring CO2 present in the carbon cycle and that produced by the burning of fossil fuels. And that produced by volcanoes (fossil fuel emissions of CO2 are 100 times greater every year than that produced by all the volcanoes in the world). 8. Therefore the global warming currently occurring is anthropogenic (caused by mankind).
    So, in order to disprove the "AGW Hypothesis" one merely needs to provide a physical basis for why the fossil fuel CO2 concentrations chemically don't interact with our physical world like CO2 that is already a part of the natural carbon cycle. Looking back into the paleo record, we see a tight relationship between temperatures and CO2 concentrations. The only thing different today is that fossil fuel CO2 contributions have raised CO2 concentrations 40% above the highest levels occurring during the interglacials of the past several hundred thousand years. And the world is warming. And it continues to this day. And will continue to do so (with normal seasonal variability/noise), as long as man continues to raise CO2 concentration levels. Question 2. 30 years. Here's one source for that. If you want something a little less "math-ey", look up the World Meteorological Organization (WMO) definition of climate. 30 years: anything less is weather. So there you have it. Quibbles about atmospheric temp increases (warming) vs ocean (warming) vs North America (warming) vs the Arctic (warming vs the Antarctic (warming) are just that: quibbles. If you have a physics-based alternative to the observed & predicted effects of CO2 and GHG's that explains what we can see and measure that ALSO explains why CO2 derived from fossil fuels DOESN'T act as a GHG, then I'm all ears. And I also expect a formal submission of that alternative to a reputable, peer-reviewed (which eliminates E&E) publication for scientific review. Exxon Mobil will pay you billions, if you can do so. If, at this point, you have genuine concerns that you wish my help on, I'm here. Otherwise, all we have left is debate. And we both agree on the pointlessness of that. I look forward to our next chat. And if we don't, have a good life. The Yooper
  46. Why positive feedback doesn't necessarily lead to runaway warming
    ClimateWatcher: I'm not really following the discussion on Dessler & Davis, but I did notice your following remark: "4. The statement: 'And finally, we point out that there exists no theoretical support for having a positive short-term water vapor feedback and a negative long-term one.' "I take this as saying: The observations must be wrong because they don't match the theory." I think it's perfectly reasonable for a paper to point out that a certain set of observations doesn't make any sense within current theory. First, it raises the stakes for the cited paper - which is not a bad thing for the authors, provided they're professional enough to know that their results were going to raise some eyelids. Other readers will focus a little more attention on it, see if it's compatible with their own experience. This is good. Second, it not infrequently happens that the experimental data ARE wrong. The UAH measurements on tropospheric warming/cooling were discrepant with ground-level temperature measurements for over 10 years, and all the climate community could say for sure was that it didn't make any sense - until the UAH team finally figured out their data analysis was in error. Likewise, I remember talking to Richard Feynman about evidence for solar neutrino oscillations, and he pointed out that the question of whether there was a real question had to do with the size of the error bars on some optical solar measurement, and if the uncertainties were just a bit more than the experimenters thought, the whole thing would be a non-issue. He said that part of the game of theoretical physics was knowing whose error estimates you could rely on.
  47. Human CO2 is a tiny % of CO2 emissions
    #60: " whatever we do to reduce the CO2 in the atmosphere is so negligible that it won't be seen. " How do you know that? Please cite such a claim with a reputable source. If you can find any to back it up. Consider the flip side: We've done plenty to increase atmospheric CO2 that is not negligible and can easily be observed. So your argument makes no sense. Please look more carefully at the plentiful information on this subject: Fossil fuel burning now emits CO2 on the order of 30 Gigatonnes each year, whereas the number you quote for volcanoes is in Megatonnes. Fossil fuel burning produces about twice the annual rate of atmospheric increase (after converting metric tons to ppm by volume). The remainder is stored in the oceans and/or biosphere. As far as "low" concentrations necessarily not having an effect, try hanging around an environment of 380 ppm H2S for a while.
  48. The contradictory nature of global warming skepticism
    Dear Baz; If you don't want to be accused of making "strawman" arguments, don't make them ("Scientists claim to KNOW the future"). If you don't want to be accused of cherrypicking, don't do it (the last 10 years support my argument but the last 15 don't, so I'll stick with 10). Also, if you don't want to be accused of "argument from authority", don't base your claims on being a self-proclaimed expert ("I work with acids, so you're wrong"). And if you don't want to be accused of "appeal to the people", don't pretend that the "man-on-the-street" is more knowledgeable than the experts - especially when you have no evidence that popular opinion agrees with you anyway. The reason these are all termed logical fallacies is that they represent faulty reasoning. You don't impress anyone here by saying "I work with acids", and it doesn't convince anyone when that's the basis for your argument.
  49. Why positive feedback doesn't necessarily lead to runaway warming
    Chris, - I used the 4-micron band for illustration, because CO2 doesn't share it with H20, unlike the 15-micron band. So it's a conceptually clearer example to discuss. - I started to use the term photosphere to describe the (radial) altitude level at the "atmospheric edge" for a specific frequency, because of seeing solar-physics photos. I'm not against using standard terminology; but I don't particularly care for "height level" because it sounds so "flat-Earthish", whereas I want to convey the mental image of a photon doing a random walk through a spherical space (well, a spherical space with a big rock in the middle! 3-dimensional equivalent of an annulus). - Yes, when I write something up, I may run it past you. In the meantime, maybe you would know the answer to this question: It's my impression that CO2 is quite significant up to 100 km, whereas H20 vapor quits at around 10 km. Is this true? And at about what altitude does the optical path length = 1 for the 15-micron band? (Where is the 15-micron "photosphere"?)
  50. The contradictory nature of global warming skepticism
    e @217, Maybe I can help. Someone seems to be under the impression that GISS uses "proxies" for their Arctic temperature data-- what they mean by that they have not said. For someone accusing others of being close-minded I find it ironic that the person in question refuses to consider other datasets. Anyhow, the HadCRUT data show statistically significant long-term warming, as do the other data.

Prev  2192  2193  2194  2195  2196  2197  2198  2199  2200  2201  2202  2203  2204  2205  2206  2207  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us