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jryan

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Posts posted by jryan

  1. Opinions don't belong here; this is a thread for discussing science. If you have opinions to share, open a thread in politics or general discussion.

     

    Well, I will reword my statement and say that those are my own observations based on the science posted by other people. "Opinion" was the wrong word. Should I also hold off on personal observation? Are we left to simply parrot studies?

  2. UHI cannot explain low latitude-high altitude or high latitude glacier retreat/ ice loss. It cannot explain increased ocean heat content. I found the blog to be really lacking in information. Really, there is little difference between the rural and full series data station over the long-term trend, and there is a rather clear "external" signal in the climate system. A few worthwhile papers are Parker (2004,2006), Li et al. (2004), and Peterson (2003)

     

    Absolutely true... but again, observational melt and CO2 concentrations can not be directly corelated. They can both be corelated totemperature independantly, but you can't then simply jump to a Ice melt - CO2 corelation as CO2 doesn't directly melt glaciers. So again we are back to whether or not current models are accurate enough to project out into the future with regard to temperature and CO2 forcings. If they are then we can take those predicted temperatures and THEN estimate melt.

     

    And again, the Schwartz study already admits to the 0.7 degree warming that we are associating with both AGW and glacier melt.... so current melt and Schwartz can't be put at odds, they agree. Where they diverge is in predictions of future temperatures, and future melts... which also can't be determined from current observed melt.

  3. Chris C

     

    Here is another interesting evaluation of the Schwartz model

     

    http://rankexploits.com/musings/2007/time-constant-for-climate-greater-than-schwartz-suggests/

     

    Though I can see from the outset that she does not well document her recalculation of the time scale (why is it that they all seem to fail on this critical piece of their evaluation?? Schwartz primary assertion is on the simplified time scale... and everyone changes it and doesn't really say why)

     

    Anyway, Lucia determined that the problem with Schwartz appears not to be a matter of autocorrelation, but of data inaccuracy.

     

    More fuel to the fire (pun intended) I suppose.

     

    Also, back to UHI.. here is another interesting article:

     

    http://bishophill.squarespace.com/blog/2007/7/22/its-all-in-the-adjustments.html

  4. I'll keep looking. I have found numerous links to other news sources like:

     

    http://query.nytimes.com/gst/fullpage.html?res=990CE3D91530F935A1575AC0A963958260&sec=&spon=&pagewanted=3

     

    Though the explantion of what is happening is different.

     

    This is rather new, so I would guess that there are studies still in the works. Even though the primordial-vs-fossil fuel debate was hot back in the late 1800s and early 1900s. The fossil folks won out... of course they hadn't exhuasted any wells back then either, and were ill equiped in time and resources to observe wells refilling.

  5.  

     

    I removed most of the quote for simplicity. Thanks for the link... but I am not sure I entirely agree with that comment by Foster et al either. As was said earlier, Schwartz admits that he is using a simplified model, and that further study is called for, but in reading that comment, I can't agree with the method used.

     

    Essentially the study comment appears to not disagree with Schwartz on his assumtion that a simplified time scaling model is potentially useful.

     

    What he DOES do is completely alter the model as presented by Schwartz, inserts his on time scales, selects one he thinks would be most advantageous to Schwartz, and reruns the model. Is it just me that finds this approach strange? Further he dismisses the 5+/-1 y Time scale, and then runs a model designed to treat incidental measures as trending on monthly data. This also seems strange.

     

    Am I reading this wrong or has Foster et al simply said: "We can't dismiss his assertion of a single time scale out of hand.. so here is his model with a bunch of changes we made and it doesn't work."

     

    According to the data presented on this page, the correlation between CO2 levels and temperature is quite straightforward. For some reason, I have never seen it displayed like this. I wonder if there is something questionable about the data. Notice how, on the second chart at the end, CO2 levels are rising above 375 currently. Doesn't CO2 start getting toxic for humans around 380?

     

    http://www.freewebs.com/fyiglobalwarming/

     

    No, it would need to be significantly higher. We are current at about 383ppm, I believe the toxicity begins at a few thousand ppm, but you will get a better answe here I am sure.

     

    I ask you again... specifically which models do you challenge and where?

     

    THis again? I have already pointed to the models posted in response to my comment on Mann, if you want to know, go back the response, and my response to it. Note that those models listed only correlate well when the temperature is already known.

     

    I commented on your own cited studies:

     

    last2000.jpg

     

    So to answer your question: Briffa, Esper, Mann, Jones and Mann, and Jones. If you want to know what issue I have with them based on your citation, go read what I wrote.

     

    My comment implied that you did not fully understand the double-blind methodology, and you haven't addressed my question which pertained to how this methodology can be applied to climate research.

     

    Well, first of all, it can be applied to the gathering and vetting of proxy data. If the theory of correlation between ice cores, tree rings, et al are accurate and reliable, then a double blind study could and should be used to correlate that data, but at the moment it isn't. The same people that collect the data do the correlations.

     

    Secondly, it is entirely possible to model temperature without actually knowing that you are modeling "temperature". If you have established sound proxy data, sound direct observation, and you submit that data for analysys, it wouldn't matter if you called a given variable "anthropogenic CO2" or "potato", technically the statistical model would be the same.

     

    Are you assuming that the modelers, and statisticians MUST know the data is for temperature forcings, and global temperature before they can do analysis? Numbers are numbers, are they not? Or are you suggesting that the site studies that gather ice cores MUST know that they are collecting data for a GW study, and that "oh yeah, most people think you should find *this*" and shown then the projections from a model?

     

     

     

    They do agree. Did you miss my previous post on this?

     

    To your comments on the charts I shared, they were in response to your argument that we cannot model climate. I ask you where precisely you challenge them or their accuracy.

     

    They only really agree duiring the period where the outcome was already measured. Pardon me for not being wowed by a models that get it mostly right when we know what right is, but diverge when they all try to model a period where the outcome is not known.

     

    So, I challenge their accuracy for the periods prior to the 1900s, because the further back in time you go from that point, the less they agree on the Y axis.

     

    Again, I did not share those charts as proof of anthropogenic global climate change. That issue is well argued and agreed upon elsewhere. I shared the charts in response to your broad sweeping generalizations regarding our understanding of past climate and our modelling ability.

     

    And again, how can the point be so well agreed upon (are you saying it isn't open for debate???) when your very own models don't agree? I would have to assume that the models are pretty accturate when they knew what accruate was... so they will become accurate in the future? I'm not buying it.

     

     

    Here's a different one, then:

     

    As you can plainly see, the slope on the trend line is clearly positive.

     

    And as you can plainly see, you are arguing against a point that NOBODY HERE IS ARGUING. I am not saying that the data does not show a warming trend. Can you get that, please? Reread that last statement as many times as it takes to sink in.

     

    No I ask you, how much of that is AGW? Obviously some. But how much? And more to the point, how abnormal is this 150 year trend compared to previous periods? The trouble is that we don't actually know the answer to that question, yet we want to make decisions on the future as if we do. And those furture decisions revolve around models that we can't even get to agree on historical projections..

     

     

    To your comments that you don't need to share data to support your claims, I advise you start. This is, after all, a science forum.

     

     

    So what, I am not allowed to question your sources based on my own observation? What you propose is not "science" as much as it is rival fans arguing the merrits of their favorite teams. If I have a question about a source of yours, I will ask you.... and I don't need a source to verify that I have a question. That is as much science (or moreso) as just wrote linking to skepticalscience.org.

  6. Thanks for the link, but in that paper he expressly states that his analysis rests on a simple single-compartment energy balance model and it is not representative of the overall climate system since it is an analysis based on a simplified model.

     

    He isn't dismissing his own study by admitting that. He is taking a new angle at determining global temperature and tolerances and he is concluding that more studies should be done using a more elaborate form of his method. His findings diverge drastically from current models, while at the same time supporting the findings of studies such as Lyman who observed rapid heat loss in the oceans between 2001 and 2005, which would not be supported by current models.

     

    I'm fairly certain he didn't do all that work just to say "Here is what I found, but my study is unimportant because the others are more complex". :)

     

    Many claims, and not a single citation. Learn from the examples of others here: make a claim, back it up.

     

    I tend to save citations for things that I figure others here may not be aware of. I assumed you would know about "urbanization" or "urban heat island" or "UHI".

     

    But if you don't know about UHI you can read a study that uses it here.

     

    You can also do a search on Realclimate to obtain several discussions about is usage.

     

    As for the rest of it, it is my opinion. I could link you back to the post if you like.. but I fail to see the point in that. :P

  7. While the methods of the 1998 Mann et al. paper have been challenged, the results align quite well with other studies. These other studies did not suffer the problem in methods that the 1998 Mann et al. paper did, and they remain accurate and unchallenged. In other words, if we ONLY had the 1998 Mann et al. data on which to rely, and that data was flawed, THEN your comments would have greater merit, but since we don't, they don't.

     

    And again I have to question a these models as they only seem to correlate when the temperature was fairly well known. It appears more that the measured temperature is informing their model soley... but when left to the proxy data, they begin to vary.

     

    The issue is not that these models can't model a period of time where the data is already fairly well known... it is that we are supposed to be using the current trend and measuring it against a historical period in which anthropogenic CO2 was NOT a forcing medium. It is in THIS stage of the evaluation that the models fail. We don't really know from these models whether the current anthropogenic assited GW is even abnormal, as we can't really determine what "normal" is.

     

    We then want to take these same models and project them into the furture and pretend that their seeming agreement for a scant 100 years or so out of their full 1200 years qualifies them as a good predictor. And at least on of those studies varies greatly from Mann.. and it happened to be the study done as a contemporary to the Mann study.... so I am left wonder how it could be that the later studies agree with the Mann study that was critically flawed, and so divergent from the Jones study.

     

    Again, it would seem that expectation may be driving the modeling, and the expectations, until recently, were weighted heavily on the Mann study.

     

     

    Now this is actually quite humorous. How do you suppose we prevent the climate from knowing whether or not it was in the control group? :doh:

     

    You are correct that double-blind studies are generally viewed as more stringent and less prone to bias, but can you explain how this approach could be applied to climate research?

     

    You don't need to use the "weather" as the control group. You might as well ask "how can you tell the illness that it is a control group?". We are talking about correlations of proxy data and temperature, and of modeled temperature -vs- actual measured data. In a way, you can see the effect of the double blind study in that Mann comparison chart above. For the most part, the various studies agree when they knew what the outcome actually was, but disagree when nobody is certain. Were these studies done completely through double blind methodology, you would more likely see just as much divergence in results even during the periods where the "answer" was already known.

     

    But again, we want models that can project into the unknown... right now they can't agree on that historically, so why trust them on future data?

     

     

     

     

     

    Have you seen the historical trends? The scale is abundantly clear. What is it that is preventing you from being convinced?

     

    Again, what are you claiming with that graph? That the Earth is warming? No convincing needed.... now show me where that graph is supposed to convince me that that trend is something out of the ordinary.

     

    petit150.jpg

     

    Ok, now look at that graph for a second and tell me what I am supposed to be seeing.

     

    What I am seeing is that based on this particular study, the entire mid-holocene period is completely unlike the previous interglacial. It seems to cap lower in "degrees change", and plateau, rather that drop "abruptly" (in terms of a graph that measures in 10,000 year incriments). But this anomoly, if you can call it that, is something that is shown as being the case for over 10,000 years... and not unique to our minute period of industrialization. So I don't see what that chart really does to prove or disprove anthropogenic global warming (AGW).

     

     

    Precisely with which data do you challenge the accuracy?

     

    See: Everything you have posted. It doesn't meet the criteria for proving AGW... or at the very least, AGW as an impending global catastrophe that requires trillions of dollars spent.

     

     

     

     

    Fairly stable in it's increase, perhaps.

     

     

     

    global-blended-temp-pg.gif

     

    Actually, no. Look at the chart again. The last 5 years, given the (well, what I assume to be) standard error from the black brackets shows no statisticaly discernable variance in that time.

     

    That isn't a chart of the average increase for each year, rather the variance from the norm. So they may have been hotter than previous years on that chart, but that doesn't show continued warming.

     

    Why is it that doubters never seem to have specifics or data to support their claims, just a bunch of hand-waving? :rolleyes:

     

    The kinds of data that you are tossing out is really all I need to make my point.

     

     

    Have you noticed a lack of data and evidence, or is it just me? :)

     

    All I really need to do is wait for data to be posted, and ask questions. That is the beauty of being a skeptic. I am not here to prove that global warming doesn't exist. That is a scientific impossibility even if it actually doesn't exist. Where it is needed, I will provide studies and evidence to support my claim, but when my job is to disecting global warming studies, you can just provide them for me. :cool:

  8. I also would like to insert the following study into the debate:

     

    http://www.ecd.bnl.gov/steve/pubs/HeatCapacity.pdf

     

    I found his conclusion rather interesting, as it appears to be rather moderate in it's estimates.... not coming off as a full fledged skeptic, nor one that you could include in the AGW camp.

     

    In this study Wilson found that the total final warming due to anthropogenic doubling of CO2 (currently expected around 2100 AD) to be roughly 1.1 degrees K, 0.7 of which has already occurred.

  9. The Mann model of 1998 comes to mind as a model that is poorly designed (the famous "hockey stick"). It has been shown that his normalization methods are such that his model will return a hockey stick graph even with random data.

     

    It is also troubling to me to see an overlay of "proxy data" models that only seem to coincide when the average global temperature is fairly well determined, but vary dramatically when projected into the past.

     

    Furthermore, as I read these studies on current and furture warming, the often used "urbanization" adjustment also is fairly troubling. I wish that I could find the studies that I used in a previous debate, but in one study there was a calculation for "urbanization" with regard to global temperature, and a second follow-up study that barrowed the urbanization calculation, but had to adjust it because the barrowed calculation would have resulted in "cooler than expected" measurements. So in essence they changed the calculation to produce warmer readings. That just struck me as odd at the very least.

     

    Finally, for now, it bothers me that from theory to collection to evaluation many studies seem to be done "in house" rather than using a double blind methodology to evaluate data correlations. There was a study done some time ago where it was shown that even absent direct manipulation of data, statisticians have a 75% chance of supporting a correlation when they know the expected result, whereas it is fairly even when the expected result is unknown. This is why the medical field requires double blind studies when producing medication. It would seem even more important to conduct double blind studies in a field where their is a "consensus" in the exptected outcome.

     

    I have little doubt that the Earth has gone through a warming trend, I am less convinced of the scale, and even less convinced of the abnormality of the current increase in forcings, or the warming trend for that matter.

     

    We can take politics out of the discussion all we want, but the simple fact remains that a huge amount money and political capital has been and will be spent on what is currently seen as an oncoming anthropogenic catastrophe. In that light, I would like the information to at least be accurate.

     

    Also, a warming trend of the last 30 years in not entirely accurate, as for the last 6 years the temperature has remained fairly stable. Claiming thirty years of warming is like me claiming that the Washington Redskins have been a Superbowl calibre football team for the last 30 years... even though that stopped being the case in 1991. :)

  10. Not sure which topic to throw this under, but I thought this may turn out to be an interesting piece of the global warming puzzle...

     

     

    Oil: A renewable resource?

     

    It is an interesting theory... what I find most interesting in the theory is the three potentials for CH4 in the Earth's crust. I have to wonder whether draws on one carbon reservoir affects the availability (or production) of the other? It would seem that given the three potentials (CO2+steam, Natural Gas, Crude Oil) are produced under great pressure that a draw down of one would affect the production of the other two. This could be why we see huge influxes of oil in tapped reserves, but we never see a explosion of oil due to built up pressure.... once the reserve is full, and pressure stabilized, the oil is no longer produced in that region, but rather forced down one of the two other avenues.

     

    I would think that a study of the CO2 concentration in volcanic eruptions would show whether a draw down of gas and oil reservoirs affects the CO2 concentration in magma. Although... I don't think that could be tested with any great accuracy. THough I suppose an ongoing study of CO2 concentrations could be done (probably already is)..

     

    Actually, an interesting study.... the volcano in Antarctica is unique in that it is furthest from human contamination (and far from oil drilling), and has the highest CO2 emission level on record.

  11. Consider the distance equation for planetary heating, which I have seen requiring the earth to rise anywhere from 86 degs to 3,100 deg. Celsius to account for solar heating of Jupiter and Pluto (another claim apparently). Somehow I doubt this theory.;)

     

    So it is a coincidence thatwe see heating on all of these planets and moons at the same time? Is there a theory for why the melting is happening otherwise? Or is this one of those points of interest we are just not supposed to ask about?

  12. Websites and blogs geared toward debunking bad and/or politicized science abound. Creationism/ID, "alternative" medicine (e.g. homeopathy), other topics within medicine (e.g. HIV/AIDS and mercury-autism), various flavors of non-mainstream physics (e.g. anti-relativity, anti-QM), etc. Some people are bothered by seeing fallacious or otherwise unsound arguments go unchallenged.

     

    Aint that the truth... of course which side is voicing "fallacious or otherwise unsound arguments" is not always so certain.

     

    I hope you can see that mean level and equilibrium are two very different concepts. Anthropogenic means it was made by humans, usually in the context of being made in ways that other animals don't produce, e.g. burning fossil fuels.

     

    Yes, I know that. The fossile fuels were also part of the above ground environment at one point as well. The simple notion of "fossile fuel" means that it has been part of the environment at one point or another.

     

    Life on earth may deal just fine with varying conditions, but that does not mean that human life will. Conditions present millions of years ago have no bearing on what present life is well-adapted to.

     

    That doesn't mean it won't either. Nobody seems to consider that the converse of the argument may also be true. To maintain the human footprint of today and protect the human species (ie. stable coastlines) would require that we would shepard the Earth in stasis in a manner that it will be unwilling to accept quietly, and we may very well be unable to manage sanely. Too often the cure proves worse than the disease.

     

    Of course, then there is the strange collision between two camps, both wanting to reduce the use of fossile fuel... one saying that at the current rate of use we will expend the fuel in 50-80 years... the other saying that at the current output we will burn the planet in 150 years.... it seems to me that we can kill two birds with one stone focusing on fossile fuel as a limited resource, and let the climate sort itself out.

  13. In order...

     

     

    #2 - I have seen this graph numerous times (though I have noticed that many studies and reports no longer overlay the graphs). The thing about that evidence that is always a sticking point for me is that CO2 doesn't appear to be a driver of temperature any more than temperature is a driver of CO2 (since warming oceans release more CO2). I know this is usually explained as a feedback loop... but it seems that more often than not the temperature plumets before the CO2.... which cools the ocean and allows it to reabsorb the CO2. IT just seems odd that CO2 can be such a driver of global temperature rise while CO2 decreases are then dependant on global cooling.

     

    On the ice age... the skepticalscience.com article is not particularly convincing. Or at least it doesn't explain it's conclusion all that well. The linked abstract says that the conclusion of the volcanic study was that the activity of the 1925-1960 may have introduced a 70 year "ocillation" in global surface temperatures.... has that word changed meaning since I last used it?

     

    Also note the drastic split in the global temperature graph right at around year 2000.... what is that about? I would assume that the range in modeled global temperature would narrow as we reach the modern era.... but we have the introduction of a wide split (solid red drops precipitously, while red dotted line keeps climbing)... are they just not explaining that chart well?

     

    #3 - I have a problem with this graph too.... how is it that supposed consistent proxy data can be so varied for historic data modeling, but so much more correlated in the period when temperature is being directly measured? My understanding is that tree rings, ice cores, and other proxy data is supposed to remain fairly constant over time, and is therefor fairly reliable.... but from that chart they only seem to agree when the actual primary measure is already known... this too fails to make me flush with confidence.

     

    #5 - They were.. but that was also the period of the greatest expansion of life on Earth... so ecologically speaking, I still fail to see the oncoming disaster. It may mean that humans need to move further inland.... but apparently life on Earth deals just fine with CO2 concentrations five times the current level... possibly better. It is certainly a spark for the growth of flora.

     

    #6 - Well, if it isn;t a proper concept, then what exactly are we discussing here? How can there be an improper increase in CO2 without there being an alternative proper amount? When I say equilibrium, I guess I am talking more about a mean level. Obviously variation happens (the temperature has gone up 5 degrees since I got up this morning... that doesn't mean I will be cooked well done by midnight :)) but we are talking about abnormalities when we talk about anthropogenic CO2 and global warming.... what is normal? I haven't seen anything to actually say convincingly what normal WOULD be.

     

    Al Gore said we should reduce CO2 to 150ppm.... this is what really scares me right now... the notion that we may actually attempt something that foolhardy.

     

    #7 - I remember it beinga bigger deal than that site claims... but my laymans interest and study in climate predates any episode of 24 by a decade and a half. :)

     

    And finally... I find the existence of a website geared specifically to targeting skeptics to be rather odd.

     

    His layman view is obviously geared specifically at debunking the skeptics... and in my estimation, from the links, he doesn't to a terribly great job of it.

  14. I am going to jump in here with some questions that still remain unanswered for me, the layman. Hopefully someone can answer my questions without disparaging me for asking them.

     

    1) How are historical temperature measurements accurate enough that they are used in direct correlation to current satellite data? I ask this because I often hear claims of "greatest heating trend in X thousand years".... how are we this accurate? I have seen studies of just the last 150 years with standard errors too high to make that claim.

     

    2) About half of the last 1000 years has been spent falling into, and then pulling out of a little ice age. Shouldn't we expect there to be a warming trend? Why is this one different? Or, I guess the better question is: How do we know this one is different?

     

    3) I am aware that the recent poor reviews of the Mann "Hockey Stick" study, and the correction of NASA climate data were both admitted to, and who's importance was diminished, by the climatology community as a whole... but the issue that I wonder about is what changes do these discoveries make in tandem? And are we supposed to just assume that these are the only faulty studies?

     

    4) It was reported recently that ice cores were pulled up in Greenland that date back about 200,000 years that contain a layer of 200,000 year old ferns, butterflies and pollen, a time period that current models say was about 5 degrees C warmer than today. If the current estimate is 3 degrees C in 150 years.. then why am I hearing reports from people like Al Gore that the Greenland glaciers will melt away completely in 50 years? They were apparently there 200,000 years ago when the Earth was warmer than even current models are predicting. Why is it different today?

     

    5) I have been checking historic CO2 level charts for a while now and see that at the beginning of the Tertiary period the CO2 levels were 2000ppm. Why didn't that lead to catastrophic global warming?

     

    6) Life on Earth depends on CO2 as much as it does oxygen. The trouble is we have seen a drop in CO2 levels on Earth over the last 65 million years (as stated before: from 2000ppm to 280ppm pre-industry). Are we assuming that the 280ppm of preindustrial modern Earth is the equilibrium level? If so, why?

     

    7) My understanding from the Early 1980s science (yeah, I was reading about climate then too :D ) was that we were due for another ice age... and that the precursor of that was going to be a warming trend (as shown in the geologic record), though at the time the exact reason why warming leads to cooling was unknown. Research today believes that warming leads to a flood of fresh water into the North Atlantic, which breaks the Atlantic conveyor of warm water from the south up to the North Atlantic. I like this hypothesis because it also explains why at equal latitudes, land is still colder the further you get from the ocean (central Siberia, the Upper mid-west Americas). So can I still assume that the final effect of anthropogenic global warming would be the hastening of an ice age? Or would it be the prevention of one?

     

    Those are my questions for now... I was always taught by my professors that science is harnessed skepticism, so I prefer to ask questions rather than assume someone else knows better. >:D

  15. I'm not talking about an explosion in terms of energy, but instead the spread of physical law.

     

    Also, for the universe we see today to exist energy would have had to be non-uniformly dispersed. If it were uniformly dispersed at the time of creation then there would be no known force that would cause it to "congeal" non-uniformly.

  16. This will be very quick, but I would be interested to see what those here can come up with... it is more of a brain game for the cosmologically inclined (ie. how could you test this crackpot theory? :D):

     

    What if the Brane and Big Bang theories actually can coexist?

     

    If for instance the "big bang" was less about matter, and more of an explosion of physical law?

     

    In this thought of mine, energy+law= a universe. I would therefor not define the result of the big bang as a "universe", but more of an instantaneous definition of the laws under which this universe exists. A tabula rasa onto which the matter has yet to be "written". I will call this portion of the universe the "Construct"

     

    Now lets assume that there is a resulting force from this "explosion" into which sporadic brane collisions insert energy. A sort of "momentum of law" which pushes away from the central point of creation. This energy would not be inserted uniformally, and would allow the creation of matter. As dictated by the laws of The Construct, as we know it.

     

    So my question would be, how would you test for this "momentum of law" which favors motion away from the point of Construct creation, but may or may not exceed the inward pull of gravity? May we just be mistaken this force for something more mechanical?

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