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  2139  2140  2141  2142  2143  2144  2145  2146  2147  2148  2149  2150  2151  2152  2153  2154  Next

Comments 107301 to 107350:

  1. Berényi Péter at 08:44 AM on 11 October 2010
    Carbon Dioxide - Everyone's Favorite Pollutant
    If anyone is interested in how real pollution looks like, watch this: In an industrial disaster 700,000 m3 of highly alkaline (pH 13, powerful lye) heavy metal laden red mud (waste product of aluminum manufacturing) flooded several towns, rivers and the countryside, seven killed, hundreds injured with next to lethal burns. Takes a year to clean up, for plant life if ever, several decades to recover, townships destroyed can never be rebuilt at the same place. Liability insurance of the company responsible for it covers $50,000 in damages, its capital is also negligible compared to losses and expenses in life, health and property (up to a hundred million dollars). Therefore it will be payed for by taxpayers' money, what else? As soon as the stuff dries up, it turns into wind-blown fine powder, difficult not to inhale. The problem with calling CO2 a pollutant just like any immediately dangerous stuff is it makes impossible to enact compulsory liability insurance policies covering all possible damages for corporations trading in potential pollutants. This is why blurring the legal notion of "pollutant" by including harmless substances by sweeping generalizations is prime interest of corporate lobby groups. Here, in Hungary we have 50,000,000 tons more of this mud stored in aging repositories, declared safe for the time being, nevertheless property prices in those areas are plummeting like stone. Relief donations can be sent to: National Saving Bank, Budapest IBAN: HU7511702036-20707637-00000000 SWIFT: OTPVHUHB
  2. Climate Cherry Pickers: Falling sea levels in 2010
    So what I might do by way of attempting to demonstrate a change of the rate of change would be to do some multiple regression modeling until i got a reasonable and valid fit. Then I would start entering and removing variables from the model to see if the predictive power changes. Specifically I'd examine the residuals of the model and look for systematic changes in heteroskedascity at the end of the time-series when omitting key variables. A specific pattern of residuals will indicate an acceleration of the line of best fit gradient. Three problems here: Firstly the effect size may be too small over a short period of time relative to the other signal, and noise in the data for this approach to be worthwhile. Secondly this is a quantitative social scientist's approach to what is a physical problem, so there may be better approaches more well suited to this domain. Three, this would be a day or two's work at least, after curating the data (so give it a week) so it ain't going to happen in a science blog.
  3. Climate Cherry Pickers: Falling sea levels in 2010
    BP #97 "Departure from a linear trend may not be significant, but it is not accelerating either." Well strictly speaking you're making that conclusion due to a limitation in the methodology of regression (see this post which demonstrates the staggering lack of power in these univariate not-corrected for the limitations of time series procedures). In order to demonstrate a change to the rate of change you have to use more sophisticated methods than simple two variable regression.
  4. It's freaking cold!
    Tom Loeber, so some people made daft comments in the past (going back to Columbus's day), therefore you don't trust anyone ? How do you trust even your own conclusions ?
  5. How do we know CO2 is causing warming?
    @adelady My bad on understanding your analogy then. Having said that, the paper did get values for the skin temperature with varied downward LW radiation though. I offer the following chef analogy. A chef is asked whether he can cook for large groups and he says sure and cooks a single plate to "prove" it. The point of this is that he has shown he can cook the meal so its almost certain he could cook 50 of them...but can he do it fast enough to be successful?
  6. It's freaking cold!
    Tom Loeber wrote : "I find at times experts have been quite mistaken in a major way, a majority of them." Do you indeed ? Care to name a few of those times ? Tom Loeber wrote : "I think more important than depending on hear-say and the like, attempt to get a grasp of the data yourself and draw your own conclusions. Quite right, partly, I think. Don't rely on hear-say, definitely (and that includes media reports, etc.) - rather, rely on the experts, the expert studies and the science. Draw your own conclusions if you wish (and there are many so-called skeptics on here who certainly do !), but don't think that your conclusions are as valid as anyone elses, especially if your conclusions go against the conclusions of the science.
  7. Climate Cherry Pickers: Falling sea levels in 2010
    BP, Please respond to the questions that I posed to you at #89. Thanks. And your reference to Church is a red herring, and I would argue that you are misrepresenting their findings with the quote that you chose to produce here. How about we quote the relevant part of their abstract? "While sea levels have varied by over 120 m during glacial/interglacial cycles, there has been little net rise over the past several millennia until the 19th century and early 20th century, when geological and tide-gauge data indicate an increase in the rate of sealevel rise. Recent satellite-altimeter data and tide-gauge data have indicated that sea levels are now rising at over 3 mm year-1. The major contributions to 20th and 21st century sealevel rise are thought to be a result of ocean thermal expansion and the melting of glaciers and ice caps. Ice sheets are thought to have been a minor contributor to 20th century sea level rise, but are potentially the largest contributor in the longer term. Sea levels are currently rising at the upper limit of the projections of the Third Assessment Report of the Intergovernmental Panel on Climate Change (TAR IPCC), and there is increasing concern of potentially large ice-sheet contributions during the 21st century and beyond, particularly if greenhouse gas emissions continue unabated." Also, Church did not, as far as a can see, simply extrapolate a linear line to estimate sea levels circa 2100. The sea-levels circa 2100 were based on model projections with and without dynamic processes. Their Fig. 6 shows that sea levels are rising faster than predicted in TAR. Actually, it seems that each time the estimates are updated for sea levels they are higher , not lower, then previous projections. For example, the recent projections made by Vermeer and Rahmstorf (2009). Let me remind you BP, as far as changes in SL goes, it is still very early days, and the rise is not going to suddenly stop circa 2100.
  8. Climate Cherry Pickers: Falling sea levels in 2010
    kdkd@91, Sorry for the confusion. That is entirely my fault kdkd. I messed up when I was calculating the regression models and requested that the moderator remove the erroneous information. Time is an issue-- having to look after the little ones today. But I promise to get back to you ASAP. In the meantime, I have plotted the residuals and I cannot see anything that justifies using a quadratic model versus a linear model.
  9. We're heading into an ice age
    In the July 2003 pdf Doug Bostrom linked to, "Are Noctilucent Clouds Truly a 'Miner's Canary' for Global Change?"
    it is stated "Unambiguous observations of NLC go back to the summer of 1885,when NLC appeared above western Europe with a brightness and latitudinal extent which has never been reached again." As far as I can tell from the NASA graph I post above, their first siting was surpassed in the 1950s as well as the 1960s for the extent of that graph. Why does the pdf misrepresent the situation? How come it only considers its hypothesis that noctilucents play no role in climate change on less than a third of the time they have been observed? Isn't the fact that there is no record of them being observed prior to the industrial revolution of significance?
  10. Global warming is accelerating the global water cycle
    Syed et al. say that the trends of global mean discharge are statistically significant. It is surely true. But, the values they obtained for different periods vary wildly without understandable reason. As I look at their Fig. 2A, my impression is that there is no consistent trend. The part of year 1993-2005 of the figure which Charlie A quoted from Trehberth's paper is similar in a sense that there is no obvious trend, though its year-to-year peaks and valleys do not always match those of Syed et al. On the other hand, my impression of Syed et al.'s Fig. 2B is that the global mean evaporation from the oceans has a consistent positive trend in the 1993-2006 period, though I am not sure if the trend is attributed to enhanced greenhouse effect or multi-decadal variability. Evaporation from the ocean is a dominant part of the global total evaporation, which represents the largest scale of the global water cycle. On the other hand, the global total river runoff represents the partition between land and ocean -- one step smaller scale than the global mean. It seems (to me) that the trends in the actual water cycle is simpler in the global scale than in more detailed scales.
  11. It's freaking cold!
    I quite agree muoncounter. In considering climate, not just years or tens of years or even thousands of years, we should also consider hundreds of thousands of years as necessary because it shows a repeated oscillation that if not considered could lead to missing cues for worthwhile strategy determination. I find at times experts have been quite mistaken in a major way, a majority of them. I think more important than depending on hear-say and the like, attempt to get a grasp of the data yourself and draw your own conclusions. Always realize we can only hold onto an opinion. Socrates is quoted as having said "True knowledge exists in knowing you know nothing." Thank you for the reasonable comment moderator. I will attempt to post to that other thread again the egregious false claim made in the paper posted on down-playing noctilucents again.
  12. Skeptical Science housekeeping: Comments Gluttony
    I'd be interested in seeing a guest post by a skeptic only if it was rooted 100% in peer reviewed literature, assiduously written to claim nothing not found in conclusions directly traceable to peer reviewed work. That or if it was written by someone in a very narrow bracket probably best characterized by Dr. Roy Spencer. The last thing we need is to hear yet another bunch of disconnected opinion. Failing that, we'd be seeing a replication of ill-conceived fairness as practiced by newspapers and the like. Monckton redux.
  13. Climate Cherry Pickers: Falling sea levels in 2010
    Excellent, looks as though there's broad agreement that sea level is increasing. Except... BP, my point about tide gauges is rooted in the observation that the gauge network has been heavily skewed in density toward stations located in upper latitudes of the NH, for cultural reasons. Whatever conclusions may be drawn from tide gauges as a statistical population need to account for this. You say that sea level rise is not accelerating, but does your assertion take into account the density distribution of the gauge network? I think we can dismiss the "all continents are sinking" concept, unless we can posit some enormous addition of mass occurring simultaneously on all continents. Strictly speaking, as we're not speaking of falling sea level but rather accelerating increase of sea level, probably further exploration of this ought to take place at the conveniently named How much will sea levels rise in the 21st Century?
  14. Berényi Péter at 03:12 AM on 11 October 2010
    Climate Cherry Pickers: Falling sea levels in 2010
    #89 Albatross at 10:04 AM on 10 October, 2010 extrapolating that polynomial curve out to 2100 was a poor joke It was. But it's not a poorer joke in any way than the conclusion of Church 2008. "In situ and satellite data indicate an increase in the rate of rise since 1870 and that the sea level is currently rising at a faster rate than at any time during the last 130 years. The sea level is projected to continue to rise at an increasing rate during the 21st century." The reality is that although there is a considerable interdecadal variability in the rate of sea level change, it has not accelerated in any meaningful way during the last century. So even if sea level is projected to continue to rise at an increasing rate, this projection is not based on empirical evidence, but something else. Whatever this something else may be, it is surely incompatible with the time tested scientific method. And while we are at it, "projection" itself as it is used here is not a traditional concept of natural sciences and as such, has an ill-defined meaning. Therefore it should never be used in scientific papers. One is either able to predict what would happen or not. In the latter case it is a perfectly legitimate and acceptable scientific position to express it as we do not know. On century scale linearity and interdecadal variability of sea level change see: GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L01602, 2007 doi:10.1029/2006GL028492 On the decadal rates of sea level change during the twentieth century S. J. Holgate "Based on a selection of nine long, high quality tide gauge records, the mean rate of sea level rise over the period 1904-2003 was found to be 1.74 ± 0.16 mm/yr after correction for GIA using the ICE-4G model and for inverse barometer effects using HadSLP2. The mean rate of rise was greater in the first half of this period than the latter half, though the difference in rates was not found to be significant." "it is found that the high decadal rates of change in global mean sea level observed during the last 20 years of the record were not particularly unusual in the longer term context" "The highest decadal rate of rise occurred in the decade centred on 1980 (5.31 mm/yr) with the lowest rate of rise occurring in the decade centred on 1964 (-1.49 mm/yr)." Departure from a linear trend may not be significant, but it is not accelerating either.
  15. CO2 is not increasing
    Canadell et al. 2007 document the degrading of carbon sinks since 1960: We estimate that 35+/-16% of the increase in atmospheric CO2 growth rate between 1970–1999 and 2000–2006 was caused by the decrease in the efficiency of the land and ocean sinks in removing anthropogenic CO2 (18 +/- 15%) and by the increase in carbon intensity of the global economy (17 +/- 6%). The remaining 65 +/- 16% was due to the increase in the global economy.
  16. Global warming is accelerating the global water cycle
    #2 Spencer Weart at 02:49 AM on 8 October, 2010 says "Yes, too noisy to say anything very strong about a trend; the statistics must be marginal. Too soon to declare this another sign of AGW, it would be embarrassing if a couple years from now the trend turns down... " Au contraire, the paper claims the trend is very strongly supported by statistics, p<0.001. Actually they declare not one but THREE trends, all p<0.001. You don't have to wait a couple of years for a downtrend. The paper found a downtrend for the last 7 years of the study period, with significance p<0.001. "An increase in the ensemble mean of R is evident from 199412–199906 (2,904 km3∕y2; p < 0.001), followed by a decreasing trend (−756 km3∕y2; p < 0.001) through the end of the study period (199907–200611). The trend for the entire 199412–200611 study period is 540 km3∕y2 (p < 0.001)."
  17. Global warming is accelerating the global water cycle
    The water cycle is SLOWING, not accelerating according to NCAR: http://feww.wordpress.com/2009/04/22/surprise-worlds-largest-rivers-drying-up/ "Climate change drying up world’s 925 largest ocean-reaching rivers. About 72 percent of the world’s 925 largest ocean-reaching rivers are drying up, most of them because of the climate change, according to a report by National Center for Atmospheric Research, Boulder, Colorado." and "Annual freshwater discharge into the world’s oceans decreased during the 1948–2004 research period as follows" And here's a graph of global freshwater discharge from a 2010 study by Trenberth. It tells a rather different story than the Syad2010 that is the topic of this post. source: http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/ClimateChangeWaterCycle-rev.pdf
  18. It's the sun
    @Ken: "No, I hear what you say architeel - and it is wrong." You may hear what I say, but you clearly don't understand it. "So in fact for the AG forcings - the RELATIVE value IS the ABSOLUTE value because none supposedly existed in AD1750." The graph (assuming we're still talking about KR's graph at #623) doesn't show "AG forcings", it shows "well-mixed greenhouse gases" forcing. The fact that all forcings start at the same point should give you a hint that they are all relative values. Also, this tidbit after the graph is pretty clear: "This starts from a baseline of 1880 (where the "zero" is set), showing deltas (changes) from those values." What's the use of stating all kinds of numbers if you don't get simple logic?
  19. It's freaking cold!
    #20: "Should we expect a dynamic system to respond only linearly?" Who said anything about climate responding linearly? There are multiple inputs (solar variation, GHGs, aerosols, etc) and a complicated output. Hot years, cold years, differential heating from one part of the globe to another: Any understanding of that system requires two things: 1 - we must look at the long term trends, not the daily (or even annual) variation and 2 - we must base our understanding on the work of the scientists who are the experts in these things, not on the vaporings of those who cherry-pick data or see everything through their pre-conceived notions.
  20. It's the sun
    CBD #651 Yeah I had read the advanced version. Where did you get the TSI in AD1750 at 1365.5? The charts show it at or below 1365W/sq.m. Dr Trenberth calculates his climate response due to IR cooling at -2.8W/sq.m based on a surface warming of 0.75degC (close enough to 0.8). He equates this surface warming increase to the increase in the radiative equilibrium temperature of the planet. This figure is then used to subtract from the AG forcings from IPCC AR4 Fig2.4 which we know are referenced to AD1750. I have made the rash assmption that the surface warmng since AD1750 is 0.75degC (0.8degC for short), otherwise Dr Trenberth would not be adding or subtracting apples from apples, would he?
  21. It's freaking cold!
    Yes, for sure, I see that a vast majority of records are high. I just wonder. The climate is dynamic, not linear. We are changing more than one factor, the concentrations of more than just one greenhouse gas. Should we expect a dynamic system to respond only linearly? If the posts in the URL I just gave are records for locations then why did they miss the all time record low set at Los Angeles International airport this year or the ones in San Diego county or in other countries? In that other thread my messages never post to be deleted. You can see that has led others to cross post here too. If that is not being banned from that thread then I have to seriously consider that this whole endeavor is dysfunctional, it is not working as the moderator suggests.
    Moderator Response: Remember that moderation is dynamical, too. Overly-tight moderation constricts the mutual discussion of the science (and provokes questions as to motivations; a no-win scenario). Under-moderation results in chaos. We're human, and as such do the best we can, making allowances for the same by commenters. Keep your comments focused on the post topic and everything should be fine. Also realize that sometimes comments are deleted within seconds of being posted--perhaps before you have a chance to see them. And be sure that after you click the Preview button and verify that your comment appears as you intend, that you then click the Submit button to actually post it.
  22. Climate Change: The 40 Year Delay Between Cause and Effect
    Re: jonsblogger1980 (59) TSI is the measurement of solar activity, rising and falling with the 11-year solar (sunspot) cycle. For the 30 years or so of accurate measurements, TSI and sunspot activity are in good agreement. As such, sunspot activity is used a surrogate marker, or proxy, for TSI for periods predating the instrumental record. TSI has been static (actually, fitting a trend line to TSI levels show it declining slightly) while global temps go up. As you can see here: This has been thoroughly discussed by dana1981 here. As Ray Pierrehumbert said about solar warming,
    “That’s a coffin with so many nails in it already that the hard part is finding a place to hammer in a new one.”
    It's not the sun. Further discussions on TSI should probably be carried over to the It's The Sun page. The Yooper
  23. It's the sun
    Sorry for the double post at #664 My browser was showing nothing after page 13 - so I tried again. #665 Archisteel No, I hear what you say architeel - and it is wrong. There were none or negligible AG forcings BY DEFINITION in AD1750 because CO2 levels were steady at about 280ppmv and sulphate aersols, methane etc were not changed by large human release fossil fuel burning. This would be not much different in AD1850. So in fact for the AG forcings - the RELATIVE value IS the ABSOLUTE value because none supposedly existed in AD1750. Get it - anthropogenic forcing is supposed to be a human fossil fuel burning effect. So if you then use these AG forcings to illustrate the portions of warming contributed by each - you need to compare them with the ABSOLUTE value of Solar forcing to effectively compare apples with apples.
  24. How do we know CO2 is causing warming?
    OK TTTM. The analogy wasn't intended to demonstrate anything other than the problem of trying to get comparisons or measurements from a paper that intended to do neither. Sorry that wasn't clear.
  25. Climate Cherry Pickers: Falling sea levels in 2010
    Re: kdkd (94) See Albatross's comment currently at 93 above. The 2 comments were deleted by request. The 2 posts are still visible in the Deleted Comments bin. The Yooper
  26. It's El Niño
    #7: "I read a myriad of studies suggesting this." It would be helpful if you would provide some references, rather than just 'a myriad.' "But in recent years that trend seems to be dissipating or is too short of a time period to make any meaningful judgements?" Look at the graph in #6. What 'trend seems to be dissipating' are you referring to? Also note the 2nd and 3rd points from the Timmerman paper: - year-to-year variations may become more extreme and - with strong cold events (relative to the warmer mean state) becoming more frequent. Or to put it in terms of a 'forecast': Continued warming with a 30% chance of occasional heavy snow in some areas. 50% chance of record droughts and/or record flooding. 95% chance of skeptics refusing to look at the long term and seizing on minimal data to say 'No its not!' 100% chance of inaction on the part of the US government.
  27. It's freaking cold!
    17: "I wonder what is wrong with the data on this site that suggests all time record cold was recorded in the following countries during 2010:" Perhaps nothing is wrong with the data, but something is wrong with the approach you've taken. Refer to the key line at the top of this posting: A local cold day has nothing to do with the long-term trend of increasing global temperatures.
  28. Skeptical Science housekeeping: Comments Gluttony
    Any thoughts on having an Open Thread, where you can move comments that are off-topic and have no easily-identifiable thread to which they can be moved ? Or where general enquiries/legitimate moans can be posted ? By the way, I would be very surprised if any of the 'resident skeptics' ever managed to come up with a credible guest post...;-)
    Response: It would've been an interesting post and I was encouraging him to post it as it would've stimulated lots of interesting discussion. You never know, he still might, I expect he's reading this thread and knows what we're talking about :-)
  29. Skeptical Science housekeeping: Comments Gluttony
    The kink in the "hockey stick" graph appears to be at the end of 2009. Related to this perhaps ?
  30. How do we know CO2 is causing warming?
    johnd in practice they work much better at sea than in a millpond, given that oceans mix much more than millponds.
  31. It's freaking cold!
    Tom Loeber wrote : "I wonder what is wrong with the data on this site that suggests all time record cold was recorded in the following countries during 2010: Cuba, Philippines, Russia, Namibia, Antarctica, Australia, Bolivia from http://www.mherrera.org/temp.htm" You've virtually answered your own question there ! Those few countries had record lows in one, two or three locations (depending on which country you look at), to give a total of 13 minimum records - none of them all-time records. The rest of the list shown ('Records registered during 2010') are for maximum temperatures (I haven't counted them all but there has to be about 350 of them), and include (unlike the minimums) all-time records. Surely the difference is obvious ?
  32. The first global warming skeptic
    chriscanaris @15. You have the jist, but as The Ville suggests, some of the detail is a little awry. Firstly the Sun emits little or no IR radiation; photosynthesis absorbs a lot of visible light (not green, obviously!). Subsequent processes such as respiration convert that energy to vibrational (IR) radiation which the atmosphere can absorb. It is this asymmetry between incoming (visible) and outgoing(IR) radiation that allows the greenhouse effect to function. Burning fuel does not, of course, result exclusively in IR radiation; you may have noticed that gas burners produce blue visible light, log fires yellow and embers red as well as heat.
  33. How do we know CO2 is causing warming?
    The article "Does Back Radiation Heat the Ocean" referenced by Tom Dayton at 09:18 AM provides a couple of interesting charts. The first one shows the rate at which solar radiation is absorbed as it penetrates below the surface. About 13% of the total energy has been absorbed in the top 1mm, or nearly 25% by the 5cm depth at which the bulk temperature was measured in the experiment under discussion. The second one shows the absorption of the DLR which is totally absorbed in the first 10μm in the skin layer. The skin layer is also where the evaporation process takes place extracting heat in the process. One wonders whilst all theses measurements seem able to be clearly defined on paper just how well it works out in practice with a surface that is generally anything but a millpond. ....
  34. The first global warming skeptic
    chriscanaris, thank you for noticing the age of the paper quoted in my post. I could have found more recent and accurate papers, but I wanted to show that the basic physics is quite old and solid. In the seventies the post WWII huge increase in CO2 emissions had just started and the understanding of the impacts on climate was in its infancy. Honestly, it was too early to call for a radical change in the way we use energy and resources in general. Now we have no excuses. RSVP thank you. As for your question, had you read the paper you would have found the answer (pag. 239): "But such experiment have not been made as yet, and, as they would require very expensive apparatus beyond that at my disposal, I have not been in a position to execute them". Never think that scientists are not aware of the problems and limitations of their work.
  35. The first global warming skeptic
    Thanks Phil, that clarifies that issue for me.
  36. jonsblogger1980 at 21:56 PM on 10 October 2010
    Climate Change: The 40 Year Delay Between Cause and Effect
    Perseus asked: "Could this same 40 year lag in increased tempeatures be used as an 'explanation' by a sceptic for the Solar influence which peaked way back in the last century?" Response: "No, the way climate time lag works is when the planet is in energy imbalance (eg - more energy coming in than going out), the planet steadily accumulates heat and warms. As it warms, it radiates more heat out to space until eventually, the energy out equals the energy in and the planet is back in equilibrium. So the way climate time lag works is the planet gradually warms over decades and the energy imbalance gradually shrinks. That's not what we've seen over the last half century. After solar activity peaked in the mid-20th century, the planet's energy imbalance - rather than shrink - has actually increased as CO2 levels have increased." If you look at solar activity, to say it peaked in the mid-20th century you must be referring to sunspot activity. Whilst this is true in absolute terms, the average has continued to rise over the past 50 years, and would suggest the energy imbalance continues, as you have found. Average monthly sunspot activity from 2000-2010 is the highest seen since records began in the 1700s, and there was a rising trend since 1950, only starting to level off in the last few years since the Sun's activity has started to stall. So we could see another 40 years of warming due to the Sun.
  37. The first global warming skeptic
    The Ville @14 asks about emission. A CO2 molecule could "relax" from its excited state emitting a photon of IR, which would obviously be the correct frequency to be absorbed by another molecule: In more technical language: The rules that allow transitions between states in the molecule (known as "selection rules") apply to both absorption and emission. The molecule can also loose energy by collision with other molecules loosing its vibrational(IR) energy by dissipating it into smaller rotational and translational energy. As Riccardo states above, upward conversion of photons is unusual, so this pathway will not lead to photons that can be reabsorbed by CO2 vibrations.
  38. The first global warming skeptic
    I'm not sure you would call it IR energy chris. The plant would retain some of the energy from a visible light photon and re-emit at a less energetic frequency, retaining some of the energy for the processes that it requires to produce glucose etc.
  39. The first global warming skeptic
    Riccardo, Interesting article. Although it's hard to understand why Arrhenius himself did not take charge of experimentation and run these tests for himself.
  40. Carbon Dioxide - Everyone's Favorite Pollutant
    RSVP, while you're eating, try not to worry about any fillings you might have that are 'polluted' with mercury, or that any fish you might be eating might be 'polluted' by lead from fishing-tackle.
  41. The first global warming skeptic
    Thanks Riccardo - so absorption is the key variable. Clearly then, in burning fossil fuel or biomass, we release IR energy which has been 'absorbed' via photosynthesis (some also sequestered via conversion to fossil fuel) but much more importantly release CO2 which increases absorption of further incoming IR which in remaining IR will cause increased temperature. Interesting looking at Hulbert to see how 'old' the science is. I guess for many folk it's all Climate 101 but it's helpful to get one's mind around the concepts. What's even more interesting is how little of this was in public consciousness back in the seventies (which was when I had my last formal exposure to physics).
  42. How do we know CO2 is causing warming?
    @adelady, Actually your analogy is off. A soup on the stove heats by conduction and then convection whereas the ocean specifically doesn't heat by conduction/convection from the downward LW radiation. Thats why they did the experiment at all. There may be some amount of mixing down of the slightly warmer (but still colder than the bulk) skin due to the LW but according to the RC article, essentially the "warming effect" is one of reduced cooling rather than actual "warming".
  43. The first global warming skeptic
    I like Kooiti Masudas description but have some questions: If you had pure CO2, would photons be emitted and absorbed between the CO2 molecules until a path out of the gas was found? Or is the photon frequency degraded when emitted, to a point where it is no longer the correct frequency to be absorbed by another CO2 molecule?
  44. Skeptical Science housekeeping: Comments Gluttony
    Glenn #29 Yeah, I'd love to see a public sin-bin, but I suspect that would have counterproductive consequences.
  45. Carbon Dioxide - Everyone's Favorite Pollutant
    #136, #137 Words influence perception, and this ultimately affects social action. For this reason, terminology can make a difference. As I dine, I will henceforth muse how my soft drink is "polluted" with CO2.
  46. The first global warming skeptic
    chriscanaris, the conversion of UV or visible photons to IR is mediated by absorption and heating of something, earth surface or molecules in the atmosphere. You cannot have (to first order) the "upward" conversion, like from visible to UV or IR to visible. The light from the sun contains UV and visible frequencies; the former is absorbed in the stratosphere by ozone, the latter reaches the ground. Both results in warming where they're absorbed. (On passing, Hulburt 1931 pointed out the essential role of ozone in determining the structure of our atmosphere). In a few words, frequencies that are not absorbed retain their characteristics; if they are absorbed, they produce warming and then increase the IR emission.
  47. Global warming impact on tropical species greater than expected
    Probably safe to say Chris' immediately local population statistics were not influenced by global warming, more a case of natural variability. :-)
  48. Climate Cherry Pickers: Falling sea levels in 2010
    I'm surprised he used 12 data points when 2 would have been just as authoritative. Steve Goddard obviously has no pride; this is by no means his first foray into obviously bogus pseudo science.
  49. Skeptical Science housekeeping: Comments Gluttony
    kdkd @22 Perhaps, in an ideal blogosphere world, a deletions policy would show an 'audit trail' of what was deleted and why. However, see my comments to John about Functionality Creep.
  50. The first global warming skeptic
    I'm curious about one thing (evidence of my ignorance, no doubt). While energy is transmitted to the earth in a range of wavelengths, are we right to assume that the same energy retains the same wavelengths once in the troposphere? Presumably some UV energy may convert to IR energy and some visible light to UV. Does anyone have any idea of the extent radiation retains its wavelengths and how much if any impact this has on radiative transfer? For example, visible light becomes co-opted by photosynthesis into glucose which in turn powers the creation of complex carbohydrates, formation of proteins, etc, becoming dissipated through the biosphere. However, much of this would be potential energy which is presumably now in forms which would not affect our radiative budget greatly (or does it?). So what happens with visible light, UV light and other wavelengths?

Prev  2139  2140  2141  2142  2143  2144  2145  2146  2147  2148  2149  2150  2151  2152  2153  2154  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


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