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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.

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Comments 98901 to 98950:

  1. It's freaking cold!
    HH: a local account. If you live in the U.S. or Europe and find it's been a chilly winter, move north.
  2. Climate cherry pickers: Falling humidity
    Can the amounts of dust in different layers of an ice core be used as a proxy for humidity? I was reading in Mark Bowen's book Censoring Science about the Vostok ice core. It says, "Methane, like carbon dioxide, rose and fell with temperature, whereas dust tended to go the other way. This made sense, as methane and carbon dioxide levels fell and the air cooled, it would have lost water vapor through feedback and become drier and more dusty." Yet, I also recall reading in a US Army Southwest Asia (Middle East) manual that as the temperature increases in summer the soil dries. Without water to hold it down dust goes into the air. So in that case warmer air is dustier. How can we be sure that increased levels of dust in layers of an ice core indicate lower humidity?
  3. Could global warming be caused by natural cycles?
    Phila, but then a balloon filled with water will also drop to the floor. Therefore water and CO2 weigh the same. Yet I see water in the upper troposphere. This, then, can only be a proof of the existence of God: clouds are a miracle.
  4. Could global warming be caused by natural cycles?
    Oh, and yes, I am alarmed. But I am not an "alarmist." It is not my religion, it is not my ideology, it is not a matter of blind faith to me at all, and I am offended by the attempt to belittle the solid scientific arguments that describe what is happening in the world today. My alarm stems from daily observation of situations such as the rapidly declining Arctic sea ice over the past few years, careful reading of the arguments on both sides, and concern for my children and grandchildren.
  5. The Queensland floods
    #31: "extreme weather events to become more extreme and more frequent under global warming" Don't you just hate it when reality starts showing that you're right? See the extreme weather thread for additional examples. From Allan and Soden 2008 : Climate models suggest that extreme precipitation events will become more common in an anthropogenically warmed climate. ... the observed amplification of rainfall extremes is found to be larger than that predicted by models, implying that projections of future changes in rainfall extremes in response to anthropogenic global warming may be underestimated. -- emphasis added And now its personal: Global warming: the impact on global coffee --as temperatures rise, coffee will ripen more quickly, leading to a fall in quality. --as temperatures rise over the lower lying areas, coffee yields will be adversely affected.
  6. Could global warming be caused by natural cycles?
    @ apirate: I see no point to your exercise, we are where we are, and knowledgeable professional scientists in many different disciplines, conducting research along different lines, in competing institutions, in competing nations, agree on the cause. Your question is no doubt answered very well on other threads in this blog, it really is up to you to find it. I really mean that, I am tired of seeing the contributors to this site having to repeat the same things time after time after time, because people come here with a "prove it to me" attitude. No. You just be willing to put your position on record for your grandchildren, so they will know why no action was taken to prevent excessive warming when it might have been. And if you say, "I'm just trying to learn," then take the time to review this whole site for yourself. Further, your use of the term 'alarmist' reveals your point of view in an unpleasant manner.
  7. The Queensland floods
    I have said elsewhere, and been criticised for, the idea that intuitively you would expect these extreme weather events to become more extreme and more frequent under global warming. Observation seems to be bearing this out (with each new event met with a chorus by the deniers - ha, you can't say this was caused by global warming, a process which effectively removes all events from being recognised as symptoms). It seems to me that if you have more heat in air and ocean, you have more energy to drive weather events, including the SOI system. If you have more water vapour in one place you get more rain or snow, depending, and you get less moisture in another place. Also seems to me that as we watch the average temperature graph head steadily upwards, we are also seeing the variation around that mean head steadily upwards as well, that is "warm events" are getting warmer, "cold events" are getting warmer. So droughts get exacerbated, so do rain events, depending on the geography of where you are. Criticism anyone? Would be good to hear from those who know more about the climatology of this than I do. Perhaps a separate topic John?
  8. Could global warming be caused by natural cycles?
    This point is addressed in the intermediate section of argument #5 "Models are unreliable".
  9. Could global warming be caused by natural cycles?
    apiratelooksat50 - There's a good posting on that here, on Should The Earth Be Cooling. Short answer - somewhere around 0.6-0.8°C cooler than it is now.
  10. Could global warming be caused by natural cycles?
    About 0.8C cooler. Not quite sure what your point is here. All the natural cycles still operate but with a sharp GHG forcing imposed over the top.
  11. apiratelooksat50 at 07:16 AM on 13 January 2011
    Could global warming be caused by natural cycles?
    Let's propose for a moment that humans never evolved and never made the technological advancements that allowed them to use fossil fuels to power their society. We have a lot of data that is reasonable agreed upon by alarmists and deniers about historical climate and rises and fall in temperatures, ice, CO2, etc... Take away our 150 years of fossil fuel using, atmospheric CO2 injecting society, and where would the planet be?
  12. Could global warming be caused by natural cycles?
    And those claiming "more CO2 = more pressure" might want to check the change in oxygen. For every molecule of CO2 extra in the atmosphere, we are 'losing' three molecules of oxygen.
  13. The Physical Chemistry of Carbon Dioxide Absorption
    RW1 - the calcuations of radiative forcings at TOA (actually at tropopause if you look at precise definition in TAR) is so that you can do simple arithmetic on forcings like GHG, land use change, aerosols, solar etc to determine net forcing. So a 3.7W/m2 of forcing is calculated so it is equivalent to say 3.7W/m2 of solar forcing. To convert roughly to surface energy, then I believe you simply make geometric conversion for surface area of earth surface cf surface area of sphere at tropopause. (ie it will larger than 3.7 at surface).
  14. The science isn't settled
    I am not particularly interested in what the uninformed, incapable think and especially not interested in politically-motivated deception. That said, I figure that I would hear of any significant papers that challenge the consensus from Roy Spencer, and also take note of opinions of Peikle Snr (not Jr) though its debatable whether you would call him a skeptic. Lucia's "The Blackboard" is interesting also. You can safely assume commentary that is based on papers that are not published (or published in E&E) then I am not going to take much notice of.
  15. It's cooling
    #105: Cherry-picking again, Yooper? + Northern Hemisphere combined global land and ocean surface temperature was the warmest year on record, at 0.73°C + global land surface temperature for 2010 tied with 2005 as the second warmest on record, at 0.96°C + global ocean surface temperature for 2010 tied with 2005 as the third warmest on record, at 0.49°C --All anomalies quoted are above 20th century average. See how the full story is much cooler. Some will say: no warming since 2005! GW is so over.
  16. The Physical Chemistry of Carbon Dioxide Absorption
    The Ohio State university slide is black and white, so I cannot determine from it any overlap. H20 absorbs to some degree throughout the entire spectrum of the Planck distribution, and has very strong absorption in the main CO2 absorbing bands around 15u.
  17. The Physical Chemistry of Carbon Dioxide Absorption
    It's a simple question. How much total additional surface power is absorbed from a doubling of CO2?
  18. The Physical Chemistry of Carbon Dioxide Absorption
    Reponse to #50: I do not undertstand why our numbers differ so greatly- I calculate that the increase in temperature over 100 years for the Keeling curve ppm is 1.4 K and that this corresponds to an increased GHG effect of 7.4 w/sq.m. (this comes from taking the ratio of the fluxes to be the fourth power of the ratio of the temperatures). The number I get for a doubling of ppm CO2 is an increase of 9.5 W/sq. m. That is, using the 100 years hence number: (1+1.4/288) is 1.0049 and the fourth power of this is 1.02 i.e. the outgoing Planck flux when the temperature increases from 288 to 289.4 will increase by 2%.The current outgoing flux is 390 w/sq.m. and 2% of 390 is 7.4 w/sq.m. Do you see anything wrong with this? Why do our numbers differ so greatly?
  19. The Queensland floods
    The Toowoomba video has gotten wide coverage on US news reports. Seeing the longer version here, I was amazed to hear some of the folks wondering whether they should move their cars. Wasn't it obvious? Anyway, as to the attribution issue, the greater amount of moisture is not the only possible AGW impact. There is an hypothesis about AGW-caused pressure altitudes making blocking events stronger and longer-lasting, which could make some weather systems more intense. I don't know if this applies to your flooding season or not, and I've read that many climate scientists are skeptical of this hypothesis. But it is out there as a potential way to make actual cause-and-effect claims for intensification of individual weather events. Some details at http://www.weather.com/blog/weather/8_20427.html. The author is working on a submission to a peer review journal.
  20. Could global warming be caused by natural cycles?
    @13MPG: Why do you focus on the US and Europe? We are talking about *global* warming. Here in Montreal it's the second very mild winter in a row. If you look at global numbers, 2010 is among the hottest years on record. Stop cherry-picking, please. As for CO2 "sinking", that shows a profound misunderstanding of atmospheric dynamics. Even for an "amateur climatologist," that is pretty misinformed.
  21. It's cooling
    This just in: 2010 ties 2005 for coldest year on record! Brrr! Time to buy some coal for the furnace...preferably anthracite... ( -edit: NASA agrees end edit- ) The Poe-Yooper
  22. The Physical Chemistry of Carbon Dioxide Absorption
    Response to #49. With regard to the water vapor absorption, I am not trying to calculate the total effect - just that of the CO2. Therefore the only circumstance in which the result would be in error is when many water vapor absorption lines and CO2 absorption lines overlap. The slide in GWPPT6 that shows a detailed spectrum from Ohio State University with numerous single lines that do not overlap. The detailed calculations take account of any overlaps. So you might well ask, "why bother with GWPPT6?". First of all because the results of GWPPT6 agree with observation (see #25 above). Second of all because they also agree with the detailed calculations, and finally because the GWPPT6 calculation is readily accessible to anyone with a background in P. Chem and it shows the essence of what is occurring. In particular the often cited idea that comes from applying the linear Beer's Law for intensity, namely that more CO2 will not result in more GHG effect, is demolished. I have presented the details of a simple calculation that takes account of the absorption of radiation by CO2 and the geometry of the effect. The result agrees with observation and detaled calculation. You say, "you can't make these assumptions". You don't say to what assumtions you refer. I would say my only assumption is the the overlap of water vapor and CO2 lines is not sufficient to throw the calculation off. My basis for this assumption starts with the basic quantum mechanical result that the spectra are line spectra. If they had zero width overlap would be essentially impossible. If they have width it arises from life-time and/or pressure broadening effects. What about the assuption that you are making that these broadening effects are sufficient to cast doubt on the result of GWPPT6 (or I should say, "to cast doubt on the appilicability of the result to a system containg water vapor")? If you think the assumption that the result has applicability to the earth system is wrong show your reasoning quantitively, i.e. show some data or calculated effects that demonstrate that water vapor absorption interferes with that of CO2 substantially. That would be a great contribution! Because the calculation of GWPPT6 is for an earth-year average the issue of clouds is irrelevant to the calculation. I.e. a known average flux of energy is entering the aarth's surface. The earth's average surface temperature increases until the average flux radiated at the top of the atmosphere equals the average flux entering On the way out the flux has to interact with the CO2 in the atmosphere because the wave lengths are at the excitation for the rotational-vibrational transitions of CO2. This is all necessary and occurs whether there are clouds or no clouds.
  23. The Queensland floods
    Does this mean that global warming makes both El Nino and La Nina events more likely and stronger? Why? I would have thought that anything that makes El Nino more likely, makes La Nina less likely? There has already been quite a bit in the comments section stating why extreme events. i.e. both drought and flooding are more likely. Is this statement as robust as say global warming? I would have thought not, particularly as the predictions are regional and regional predictions have larger error margins. Is it possible to quantify how reliable these predictions are? Should Australia start building even bigger dams? Perhaps John or another expert could create a more comprehensive post regarding global warming and precipitation?
  24. It's the sun
    Nobody is arguing that variations in solar irradiance have no effect on the global temperature, rather that the effect from the enhanced greenhouse effect is larger.
  25. Could global warming be caused by natural cycles?
    DSL: This is the first time I've heard the argument that CO2 is too heavy to make it to the upper troposphere and stratosphere. Perhaps some of the more vocal "skeptics" could weigh in on this? GC, perhaps? Cruzn? KL? It's actually a pretty common argument in forums, newspaper comments etc. Apparently someone immediately noticed that CO2 is heavier than oxygen, and drew the commonsense conclusion. We've all blown up balloons and watched them fall to the floor. QED! This theory also helps to explain why smoke runs down chimneys like lava, and why we install furnaces in attics to ensure that they get an adequate supply of oxygen.
  26. It's the sun
    thepoodlebites - Certainly, if the sun goes into a less active phase there will be an influence on climate. However, given the low amount of such solar variation, the effects of such variation are going to be tiny compared to CO2. See What would happen if the sun fell to Maunder Minimum levels, and also the comparative values of forcings here - I find Figure 2a very clear. I believe you've been pointed to these items previously. Global cooling? No. Warming perhaps a little slower if solar variation reaches a low? Yes.
  27. thepoodlebites at 04:51 AM on 13 January 2011
    It's the sun
    #779: Please see Historical Total Solar Irradiance and type in 1900.5 to 2009.5. The historical TSI reconstruction shows five 11-year solar cycles between 1900-1950 and five between 1955-2005. Clearly, the five cycles after 1950 were more active than the five pre-1950 cycles. I agree that cycle 24 is unusually quiet and supports my thesis that the Sun does influence global surface temperatures. In this case, if cycle 24 is longer and weaker than previous (21-23), then we may see subsequent global cooling in response. It's interesting to note that the solar max in 1970 (cycle 20) was relatively weak. I remember the "Big Freeze" in 1977 when the Chesapeake Bay froze over.
  28. Could global warming be caused by natural cycles?
    BKSea, from a little while ago. Let me restate what I wrote earlier. I don't know that anyone is staking a claim that anthropogenic CO2 will cause an abrupt change at a certain level or point in time. However, there have been abrupt changes in the past, Dansgaard-Oeschger events and others, which should imply that there is good potential for them to happen this time around. Here are a couple of links: http://www.giss.nasa.gov/research/briefs/legrande_01/ http://www.ncdc.noaa.gov/paleo/abrupt/data3.html There are different signatures for climate forcings, but for gross effects, there probably isn't much difference between forcings of similar magnitudes, even if of different causes.
  29. The Queensland floods
    Regarding ocean temperatures around Australia (from this Australian Bureau of Meteorology report): "Based on preliminary data (to November 30), sea surface temperatures in the Australian region during 2010 were +0.54 °C above the 1961 to 1990 average. This is the warmest value on record for the Australian region. Individual high monthly sea surface temperature records were also set during 2010 in March, April, June, September, October and November. Along with favourable hemispheric circulation associated with the 2010 La Niña, very warm sea surface temperatures contributed to the record rainfall and very high humidity across eastern Australia during winter and spring"
  30. The Queensland floods
    MarR@13 and Mila @25, Thanks for linking those IPCC graphs. Fig. 11.17 summarizes things nicely.People are way too quick to make sweeping generalizations "I thought they said AGW was going to cause drought!"? Where, when....? The multi-model simulations show the eastern third of Australia typically receiving more rain circa 2100 in DJF, with drying over western third of Australia. If this forecast pans out Perth could be in real trouble. Also not that over the interior the models are showing marked warming but a mixed signal for precipitation-- this suggests an increase in ET and lower soil moisture. Perhaps it is best to show the Figure. Figure 11.17. Temperature and precipitation changes over Australia and New Zealand from the MMD-A1B simulations. Top row: Annual mean, DJF and JJA temperature change between 1980 to 1999 and 2080 to 2099, averaged over 21 models. Middle row: same as top, but for fractional change in precipitation. Bottom row: number of models out of 21 that project increases in precipitation. Source here.
  31. The Queensland floods
    #21: Regional precipitation projections are very hard, and papers studying them make this clear. The uncertainties are so large that it would be difficult to rule out AGW based on regional precipitation observations. However, net increase in atmospheric water vapour is a pretty solid prediction. If you could demonstrate this wasn't happening over a sufficiently long timescale then AGW theory would be in trouble.
  32. The Physical Chemistry of Carbon Dioxide Absorption
    RW1 - Looking through Myhre, I see that the total radiative change is really both the effects I mentioned here; band widening and the rise in effective emission of IR to higher (colder) altitudes. So some additional absorption, some less effective emission. The simplified formula Myhre comes up with for CO2 is: ΔF (W/m^2) = α * ln( C/C[initial] ); α = 5.35 For a doubling of CO2 from preindustrial 280 to 560, α * ln(2) = 3.708 W/m^2. Again, coming up with this equation is not a back-of-the-envelope calculation; I can't give you that, because it wouldn't be accurate.
  33. The Queensland floods
    #24 http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch11s11-7-3-2.html
  34. The Physical Chemistry of Carbon Dioxide Absorption
    KR, There is nothing in any of the sources you cite that answers the question.
  35. The Queensland floods
    Albatross Even before the present disasters much of this year has been wet in Eastern Australia. It had me looking at the BOM precipitation data a few weeks ago. You can have a look or download the full precipitation data for Eastern Australia here This years rainfall has managed to turn the trend for the full record around to a positive trend. I was looking at this because it struck me that even when somebody isn't cherrypicking and even when somebody is using long records it struck me that trend lines had the possibility of being very fickle things. Even playing with Hansen's time period if you start it in 1950 the trends negative, start it in 1951 then the trend is positive now that we have data running through to 2010. If you keep Hansen's end date the trend is negative if you start in 1950and it's flat if you start in 1951. I'm not favouring one start/end point or another I'm just trying to highlight the fickleness of some interpretations even when they're based on longish data set trends. From memory the IPPC estimate for change in precipitation for East Australia into later this century is between +50% and -50% (which obviously also allows the possibility of 0% change).
  36. Could global warming be caused by natural cycles?
    DSL take a look over at Deltoid and the post about Ken Ring (the magician and palmist). SUV/13MPG isn't the first.
  37. Could global warming be caused by natural cycles?
    #29: "Fine black dust from rubber and asphalt." Something as ubiquitous as this should have a well-established fingerprint of its own. We've discussed black carbon in the Arctic on prior threads; that particular soot serves as a marker for Asian-sourced CO2. If rubber and asphalt are to be taken seriously, they are not a natural cycle -- and hence are a component of AGW. Any data to substantiate this claim should go to the appropriate thread, which is probably one of the humans are too insignificant discussions.
  38. The Physical Chemistry of Carbon Dioxide Absorption
    I've added Myhre et al 1998 to the Links section under "CO2 is weak", "CO2 is saturated", and "CO2 is just a trace gas". That's a very important paper for baseline CO2 forcing calculations, and includes simplified formulas for CH4, H2O, and other greenhouse gases.
  39. The Queensland floods
    John, Good to hear you are managing, but my heart goes out to those stricken by this calamity. Here in Mid-Wales we have our first sou-westerly Warm Conveyor of 2011, with orographic enhancement leading to maybe 100mm of rain - but it's steady moderate stuff, not the convective deluges you guys have had. With regard to the AGW element of this, one way to look at it is to imagine the weather being the lump sum of money and AGW being the interest - as Kevin Trenberth noted, 4% per extra degree Fahrenheit (or ~6% per degree C if you like). Cheers - John
  40. The Queensland floods
    John, As one who lives in a hurricane-prone area, I feel your pain. Keeping up the good work in spite of natural disaster is the mark of a real trooper. I heard this morning that Australia's coking coal industry will suffer because of this flooding and that may increase the world steel price. No one can say that the increased risk of disasters of this magnitude won't affect the world's economy. Best of luck to you and yours!
  41. The Physical Chemistry of Carbon Dioxide Absorption
    RW1 - The link I gave you was behind a paywall; here's an accessible link to Myhre et al 1998. Long live Google Scholar!
  42. The Physical Chemistry of Carbon Dioxide Absorption
    RW1 - The most up to date calculations appear to be from Myhre et al (1998); these results are discussed a bit over at Real Climate - The CO2 problem in 6 easy steps. RC has some excellent references and links in that article. The total radiative forcing, the difference in energy leaving the atmosphere, per doubling of CO2 is about 3.7 W/m^2. Note that this is based on piece-by-piece integrations of atmospheric effects (it's more than a bit too complex to calculate by hand), and includes both CO2 absorption widening as well as the increasing altitude of final CO2 emission (where the atmosphere thins enough that the CO2/volume allows radiation to space); given the lapse rate, a rise in CO2 emission altitude means that the emitting CO2 will be colder, and hence emit less energy. If you disagree with these numbers, then do the work, and submit your results to Geophysical Research Letters as a reply to Myhre.
  43. The Queensland floods
    Good to here you're well John. No doubt within the AGW scenario harder punches are expected the question really is whether AGW theory is an accurate description of what's going on here. It's also worth considering that nature alone can pack a pretty hard punch. Even in the relatively short history of white settlement in the Brisbane area it's possible that the 1893 was harder although it probably didn't cause so much misery to so many souls. garythompson as the response suggests AGW allows for both drought and flood. The problem is that normal precipitation is also not inconsistent with AGW. Once you have all the bases covered it makes me wonder just what is the power of these sorts of statements. But this is a terrible tragedy, best of luck to all Queenslanders.
  44. Could global warming be caused by natural cycles?
    Or, Ville, we simply wouldn't be. I must congratulate SUV . . . errr 13MPG, though. This is the first time I've heard the argument that CO2 is too heavy to make it to the upper troposphere and stratosphere. Perhaps some of the more vocal "skeptics" could weigh in on this? GC, perhaps? Cruzn? KL?
  45. Understanding the CO2 lag in past climate change
    222, archisteel, I'm pretty sure a LIB is a Little Ice Blanket, a technique used by scientists to combat global cooling during the LIA. I read that on some really, really trustworthy and informative site, like WUWT, so it must be true. Don't ask what a LICk is, though... you don't want to know.
  46. Could global warming be caused by natural cycles?
    #50 - h Pierce You posted the same question on what looks like a denialist site and R. de Hann gave a reasoned response. There is so much dust in the atmosphere by natural causes that even the tons of rubber caused by tire wear simply disappear in the real big numbers. The hundreds of millions of tons of dust stirred up by the wind moving over the Gobi, Sahara and other deserts, the hundreds of millions of tons of dust and particles set free during natural forrest fires all over the world and hundreds of millions of tons of emissions from our volcano’s. You won’t see the effects from tire wear from space but you can certainly see the forrest fires, the volcanic eruptions and the dust storms. Yet again, it’s all a matter of common sense. The rubber dust, most of it sticks to the road and is washed into the sewer where it is mixed with dirt and sewage. Modern sewage plants contain trillions of bacteria that clean up the sewage and one of the products that comes is fresh earth for your garden or your balcony flowers. I noticed you did not respond.
  47. The Queensland floods
    adelady, the throw away comment you read may have been the one @5 above.
  48. gallopingcamel at 00:19 AM on 13 January 2011
    Graphs from the Zombie Wars
    Keith Pickering, Even Lubos Motl likes your post even though he has a quibble with the arithmetic. http://motls.blogspot.com/2011/01/climate-sensitivity-from-linear-fit.html Any comment?
  49. The Queensland floods
    I would echo the sentiments that others have so ably expressed about the safety and well-being of not only you and your family, John, but of that of all afflicted by the Queensland floods. May you continue to stay safe and dry! The Yooper
  50. The Queensland floods
    Thanks for mentioning cyclones Eric. I saw a throwaway comment somewhere that the previous best-known major SE Queensland floods were caused by rain events at the tail end /edge of cyclones. I've not checked it but it did ring a bell. Somebody's sure to put those stats together in the next few days.

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