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Another warming question

  1. May 2, 2008 #1

    fuzzyfelt

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    I am confused about much of the debates here about the earth getting warmer, but my daily experiences are that when it is an unusually hot or cold day people around me will joke about it being evidence for or against warming. A joke I think because the assumption is that a long term pattern of warming, despite particulars, is the evidence warming is based on. This was in the news yesterday, http://news.bbc.co.uk/1/hi/sci/tech/7376301.stm , that says things will cool for a couple of decades, but that that will change and meet up with warming predictions later. However, if things are not actually warming, how is this proof of warming?
     
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  3. May 2, 2008 #2
    There is enough proof!

    There is no reason to be confused, fuzzyfelt!

    Here are the proofs that I am aware of :-

    1)The average global temperature has been confirmed to rise by a degree at least every year.

    2)The Antarctic is melting drastically.

    3)Sea and Ocean levels are rising considerably every year.

    4) The Gangotri(the glacier that waters the Ganges) is melting down extremely fast.

    Moreover, logically why shouldn't the globe warm.The green house gases trap the heat and do not let out enough heat with proportion to how much it traps and this causes global warming.And these gases are none other than the familiarly emitted CO2, CO and methane. What about the ozone hole? This let's in infra - red rays which heat up the globe drastically. Isn't this proof enough?
     
  4. May 2, 2008 #3
    Well Ff, you raise a rather fundamental issue here. Can global warming still be true if it is actually cooling? Well, the warmers have the political power right now and if they decide so, what can we do?

    But to what extend will it be acceptable that they rewrite scientific philosophy, or philosophical science? In the old days we used to have a sort of scientific method. You'd observe some phenomena, you'd analyze those, formulating a possible explanation, a hypothesis, and using that explanation you would do predictions, what to expect if your hypothesis was to be right, in this case, an overwhelming effect of greenhouse gas forcing on global temperatures, as we read in the last two "summaries for policy makers" (2001, 2007). Then, if the prediction is right, the temperatue will increase as greenhouse gas concentration does. But if something else happens, like a dramatic cooling while the greenhouse gasses still rise, that would normally falsify this hypothesis.

    This used to be the main principle of classical science, falsification. But now we hear that, regardless if it is warming or cooling, the greenhouse global warming is true, no matter what, and no matter that the reality test failed. So it appears that we have to accept that the main classical scientific principle is no longer valid. The alternate, that the greenhouse theory is wrong, is absolutely unacceptable of course.

    Incidentely, the prolongued global cold spell does not only coincide with a reversal of the Atlantic Oscilation but also with a rather strong La Niña, an predicted reversal to the cold phase of the Pacific Decadal Oscilation and an equally predicted delay of solar sunspot cycle 24. The last prolongued minimum was the Dalton minimum of which Napoleon was very unhappy when his offense in Russia was smothered in an extreme cold winter. But this is all irrelevant of course if the global temperature is mainly dictated by greenhouse gasses, regardless if it warms or cools.
     
    Last edited: May 2, 2008
  5. May 2, 2008 #4
    But it has been noticed that the green house gases have not only caused warming but many other effects! I am not sure whether it is relevant, but it all seems to match perfectly.

    1) It has not snowed in many places in the USA this year.

    2)High levels of dust-storms in the whole of Gulf countries.

    3)Record temperatures of cold in many Northern cities in India.

    What do you say about that?
     
  6. May 2, 2008 #5

    russ_watters

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    Did you misstate that? It's waaaay off.
    This one too, though I guess "considerably" could be subjective enough to mean several milimeters a year.
     
  7. May 2, 2008 #6

    Gokul43201

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    And it's not just data over a long period of time, but also data from a large number of locations.

    The observation of a specific cooling behavior over the next few decades can only confirm that the model that predicts this is likely to be a good model. This model has been discussed in another thread here (titled "Peer Reviewed Global Cooling") and says that global temperatures can be well approximated by superposing a 60-70 year cycle on a linear warming trend. Unfortunately, we can only be confident that the science is good after we've observed a number of these cycles. So far, we have good enough climate data that only goes back long enough to cover 2 cycles. With every additional 70 years we wait and every additional cycle that passes by (if they do), the stronger becomes our confidence in the model.

    No, it's not. Besides, your point #1 is off by at least an order of magnitude.
     
  8. May 2, 2008 #7

    Dale

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    Global warming is like intelligent design, they are both politically driven and non-falsifiable. If it get's hot, it's global warming and the US needs to pay, if it gets cold, it's global warming and the US needs to pay. "My non-linear unstable differential equation predicts disaster, damn the US". "You need to pay billions of dollars to stop CO2 emissions despite the fact that it is one of the weaker greenhouse gases!"
     
  9. May 3, 2008 #8

    Gokul43201

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    Can we please keep the thread about the science and save the socio-political commentary for threads in the Lounge?
     
  10. May 3, 2008 #9
    Of course, now is the time to evaluate what has been predicted in the past about the climate now, rather than what is predicted now. None of the models evaluated in the several IPCC reports has seen the current cold spell coming, likely because they were parameterized (if that's a word) for greenhouse forcing dominance.

    Anyway, things started to change already after the hot January of last year, when a moderate force La Nina started to devellop but the real temperature drop started mid December 2007, coinciding with an unusually quiet sun, now also the Pacific Decadal Oscillation (PDO) reversed to the cold phase. Several scientific signers of the occasional anti-AGW petitions have repeatedly pointed out that the PDO-index corrolates closely with global temperature variation, unlike the variation in greenhouse gasses.

    Anyway, the point is that the modellers have had several months time to contemplate these changes and adapt model parameters. So the resultant cold prediction looks more like a damage control retrodiction.

    But the first signs of a El Nino are there, we may have a nice summer after all.
     
  11. May 3, 2008 #10
    Addition, the Last summary for policy makers predicts (pag 12):

    See that there is no mention that natural variation may modify the decadal warming trend. Yet had the authors looked at all the combined actual temperature series in 2006 when the summary was drafted, then they might have come up with something differently. Now it was refuted already while it was drafted.
     

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  12. May 6, 2008 #11

    Art

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    I'm amazed AGW is still even in the news. To summarise the faults found between the theory and observations we find,

    Prediction - Global temperature will continue to increase.
    Observation - No warming for the past 10 years and now even the proponents of AGW concede there will be no warming for at least the next 10 years and possibly even 20 - 30 years.

    Prediction - Massive sea level rise due to melting ice.
    Observation - The Antarctic ice pack which contains 90% of the world's ice is increasing in mass.

    Prediction - CO2 will create a positive feedback which will increase water vapor thus increasing GW.
    Observation - NASA's aqua satellite is showing there is actually a negative feedback with higher temperatures resulting in less water vapour creating cooling.

    It would seem scientists really need to go back to square 1 on all of this and start again from the beginning to build a theory which incorporates all of these new facts rather than desperately try to hang on to disproven hypothesis. They could call it anthropogenic global cooling; oh, but they've done that one already :)
     
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  13. May 6, 2008 #12

    vanesch

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    I think - and the current observations and "on the spot" explanations seem to indicate this, that as of now, nobody actually knows for sure what's going on. It is the IPCC's fault of being over-arrogant, of considering that they "own the scientific consensus" and all that. In other words, it sounds like bad science, or at least, over-sold science.

    However, this doesn't mean that the central hypothesis of AGW has been proven wrong either. The possibility exists, and observations over one decade doesn't mean much. We're still in the noise, and we will for several decades. The climate models are still very crude. But in as much as fear-mongering (and doing bad science for the "good purpose") was an extremely bad idea, we also have to suppress the urge in the other direction, namely comply with our "don't worry, be happy" human nature, and declare that we have now proven that AGW is impossible, or even, that it leads to AGC. The system is just very complex, and most is not completely understood yet. AGW remains a possibility, in spite of it being over-sold by cock-sure arrogant scientists.
     
  14. May 6, 2008 #13
    Why, if wrong ideas about greenhouse mechanism are being falsified both by revisiting theory and real world observations? I hear that the scholar interest in the ideas of Ferenc Miskolczi has intensified largely the last week.

    The resulting post global warming straying hang over btw, will be tremendous, limiting myself to Earth sciences, a major clean up is required, from the multi million years Ice house - hot house flips, the Paleocene Eocene Thermal Maximum, the Pleistocene ice ages, the last glacial transition, all scholar ideas are based on enhanced greenhouse gas effect.
     
  15. May 6, 2008 #14
    "Observation - The Antarctic ice pack which contains 90% of the world's ice is increasing in mass."


    can you show a pointer to the study about this 'increasing in mass' observation?
    You are the first time I have heard someone make a claim about increasing ice mass.


    I really enjoyed watching 'An inconvenient truth'. The studies and charts are quite convincing to me.
     
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  16. May 6, 2008 #15
  17. May 6, 2008 #16

    Art

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    There have been suspicions since at least 2002 (eg http://www.springerlink.com/content/x15642536779n353/) that the Antarctic ice mass is increasing not decreasing . Here is a quote from a recent study.
    http://climatesci.org/2008/04/07/recent-data-on-surface-snowmelt-in-antarctica/
     
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  18. May 6, 2008 #17

    wolram

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    What is the truth?

    http://oversight.house.gov/documents/20071210101633.pdf [Broken]
     
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  19. May 6, 2008 #18

    Gokul43201

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    Your "observation" is unrelated to your "prediction". Furthermore, it is flat out wrong. Warming over the last decade has been stronger than over the last 50 years. And your interpretation of the claims (though listed under "observation") is also at best, misleading.
     
  20. May 6, 2008 #19
    Perhaps not. Recheck this post
     
  21. May 6, 2008 #20

    Gokul43201

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    Andre you know that those linear trends are extremely sensitive to the '98 data point. What happens to the trend once you've established reasonable insensitivity to end-points? It is meaningless to speak of a trend otherwise.
     
  22. May 6, 2008 #21
    The trend is also extremely sensitive to removing the deep dip immediately following the spike of 1998. But perhaps we could conclude that it's not safe to say that warming over the last decade has been stronger than over the last 50 years
     
  23. May 6, 2008 #22

    Gokul43201

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    1. That's a spurious argument and you ought to know that a lot better than most of us here. There is no "deep dip" after 1998. The appearance of a deep dip is merely an artifact of clipping the dataset conveniently at 1998. Your own posts in other threads establish that there is no "deep dip" after 1998 compared to temperatures just before 1998.

    2. I've looked at the data with and without outliers of different strengths (2, 3, 4 standard deviations away from mean), and with each additional removal of outliers, the slope either increased significantly or changed very little. But even if you look at the 5 trend-lines as you have them in the linked post, with all outliers included, the average slope is 0.5K/cent, which is the same as the warming trend over the previous 50 or so years. Eliminating outliers or expanding the dataset and thus reducing the error bar on the trend to actually meaningful values gives a number that is roughly twice as big.

    I admit that I should have been a lot more careful with my statement about the recent warming data. While the trend is positive to a high degree of confidence, the confidence level is much poorer in the difference with the trend over the previous 50 years.
     
    Last edited: May 6, 2008
  24. May 6, 2008 #23

    Art

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    The IPCC predicted a temp rise that hasn't happened so what is your argument?? Even AGWs most ardent supporters now say it is likely we are in a 10 - 30 year cooling cycle. (which takes the heat off them for a few decades :biggrin: ) for eg
    http://www.theaustralian.news.com.au/story/0,25197,23411799-7583,00.html [Broken]

    It seems your argument is a statistical one based on if you squint your eyes a certain way whilst looking at gently massaged, cherry picked data you can at a stretch perhaps argue the temp hasn't actually fallen. That's what I meant about AGW proponents desperately clinging to a failed hypothesis.

    btw What did you do with the 'abnormal' global cooling figures of the 70's when creating your 50 year trend lines?
     
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  25. May 6, 2008 #24
    Perhaps have a look at the maximum extent of the data, the last 29 years, when in 1979 the satelites became operational.

    http://gallery.myff.org/gallery/245141/corrected-29y.PNG

    Some see a bit of a cycle emerging here, with lows in the late 1980s and highs in the early 2000's. of course in a cycle you can generate any trend.

    More interesting still is to figure out why GHCN and NOAA keep on warming while the other three clearly break with the trend.
     

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  26. May 6, 2008 #25

    Gokul43201

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    My argument is that your post was factually incorrect in addition to being scientifically meaningless.

    No, it is not, but I like how you walk into a science forum and argue that statistical analysis is the same as squinting and cherry picking, while your gross misrepresentation of the science is perfectly justified.

    Sounds almost like you are addressing me.


    I didn't fit trend lines for 50 year data, only for the last decade or so. For the long term trend, I used the most often cited number (it was also used in one of the anti-warming blogs that was cited recently in one of these threads). What I did use long term data for was evaluating the distribution of noise in the data.
     
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