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Climate change sceptics 'wrong'

  1. Nov 18, 2004 #1
    I guess I just beat Ivan by posting this.

    The abstract is here.

    Sounds like water is boiling at o degrees Celsius.
    Some background on
    urban heat island effect. (All not true anymore?!).

    Anyone want to comment?
     
  2. jcsd
  3. Nov 18, 2004 #2
    Very interesting. I've thought a lot about how good an argument I think this is. I find it odd that windy nights showed no significant change at all. The correlations are very close to perfect. I wonder what affect suburban sprawl has on this.

    In any case, this paper is enough to make me uncomfortable with the "urban heat not global warming" argument personally.
     
  4. Nov 18, 2004 #3
    Heh, by the way, the next article in the journal:

    "Early peak in Antarctic oscillation index" by Julie M. Jones,Martin Widmann

    So many things to consider :/
     
  5. Nov 18, 2004 #4
  6. Nov 18, 2004 #5
    I don't understand that figure well.

    But the population would have been changing. California grew by an awful lot between 1940 and 1996. What population did they use? The final one? Why would a high population lead to a higher rate of temperature increase (which is what is plotted)? Why not simply a higher temperature and hold?

    My training as a physicist has equiped me with some problem solving skills (or so I'd like to think!) but in much of this debate I find there is a great deal of information I need to understand what is being discussed.
     
  7. Nov 19, 2004 #6
    That's exactly the point. And the idea of the Urban Heat Island effect is that the temperature rising trend measured at a certain station is actually caused by the growth of the city, increasing the urban heat island effect.

    The graph is not documented very well so we have to guess it would be logical to put in the current population.
     
  8. Nov 19, 2004 #7
    Take for instance these plots. Source here. The upper blue one is the average yearly temperature of Louisville Kentucky, presently at close to one million inhabitants. So the trend is a cooling of 0.7 mK/year or 0,07 degrees per century.

    Now the second pink plot below is the average temp of Shelbyville, a rural station only a distance of 46 kilometer (30 miles) away from Louisville with a cooling trend of 0,6 degrees per century. We see a absolute difference close to two degrees, that could be explained at least partly with the urban heat island effect, whilst the growing trend of Louisville would explain why the trends diverge and why Sherbyville cools quicker than Louisville.

    Cooling? Certainly. There are several places in the world where nobody believes in global warming, because it's getting so cold. This will show up quickly if you play with that station link.

    The world champion urban heat effect is likely to be Tokyo as can be seen by it's closest rural neighbors
     
    Last edited: Nov 19, 2004
  9. Nov 19, 2004 #8
    Actually we could also make a plot of warming trend against population of a city. Of course we cannot pick a random spot on the globe. We need lots of long active weather stations in a confined area with a common climate and with cities with populations in several orders of magnitude like a few million, few hunderd thousend, few ten thousend and rural stations. I think only the USA would qualify. I'm looking around a bit to see which areas would be suitable.

    Those look good as data sources:

    Dallas
    St Louis
    Washington DC
    Toronto - Niagara falls
    Atlanta
    Kansas City
    Chicago

    I'll let the list grow and then somebody could randomly pick one and see if we can find the same relationship between population and warming trend as fig 13 halfway down
     
    Last edited: Nov 19, 2004
  10. Nov 19, 2004 #9
    I think Atlanta would be interesting (I only live a couple of hours from there). I used the link you provided and have started making excell graphs but haven't had time to finish.
     
  11. Nov 19, 2004 #10
    I did Atlanta and Newnan. Between 1920 and present Atlanta plainly increases in average temperature until it obviously surpases newnan.

    So this paper in nature seems to refute something that is plainly obvious. I'm not sure what to think about that.
     
  12. Nov 19, 2004 #11
    Okay I'll compose a population - trend comparison for the nearest stations, the 3 rural, 4 medium sized and two large cities, Birmingham and Atlanta. Coming up soon.

    Actually for the same period of interest 1950 - present
     
    Last edited: Nov 19, 2004
  13. Nov 19, 2004 #12
    Now, that didn't take too long. Did it.

    Here is the warming trend versus the population for the Atlanta area.

    http://home.wanadoo.nl/bijkerk/Atlanta-trend.JPG

    Data and spreadshead available for cross check.
    Using a logaritmic scale I had to give the rural stations an arbitrary population of 1000.

    And the result is pretty much as expected.

    Edit

    This version shows the station name, the population in thousends (rural arbitrary: 1) and the warming trend in degrees K per year.
     
    Last edited: Nov 19, 2004
  14. Nov 19, 2004 #13
    Exactly, And I find that very scary.

    Remember Mann et al (MBH1999) did the same with the Little Ice Age and the Medieval Warming Period, by creating the hockeystick. And a fierce battle followed to protect the myth of anthropogenic global warming. It's finally broken now (well I think it is - there are still people believing that the world is flat).

    But what is happening to mankind? One tends to philosophize about an obvious need to invent less sound scientific methods, just to serve an idiology?
     
  15. Nov 19, 2004 #14
    As we infer from the graph here, there are two stations not behaving according the assumed trend. Gainsville is too hot for it's modest size and Birmingham is too cool for it's considerable size. I have no idea of the reality living in Germany/Holland but a few reasons could be thought of. Gainsville could have emerged out of nothing in a few decades, having a much stronger growth as normal, alternately the weather station could have been smothered by new close by buildings and fences etc, increasing direct warming factors.

    As for the too cool Birmingham. Did the city not expand that much the last few decades? or is the met station in or close to a big park, acting as a pseudo rural environment?

    There must be people around who could tell.
     
  16. Nov 19, 2004 #15
    I'm not sure where the met station is, or I'd drive over there myself and see :D

    Birmingham experienced white flight in the '60s through 80's unheard of in most other places. The greater birmingham area has been growing by leaps and bounds over the past 40 years. Downtown has been stagnant for decades. If the met station is downtown there is no reason to expect urban heating to have increased the temperature there for decades. If the met station is in Hoover then something odd is going on.

    It's also worth keeping in mind that birmingham is a series of hills that each traps heat. We've had a lot of problems with ozone and other pollutants that may skew the data.

    How should I find out where the met station is here?
     
  17. Nov 19, 2004 #16
    Try the telephone directory?

    Shall we do another city this weekend and which one?
     
  18. Nov 20, 2004 #17
    This is the kind of thread I like.

    Those are nice plots you put together, but I have to say that atlanta trend-line looks to be pretty statistically unconvincing. And the three to the far left are all that's tilting it. All having remained the same population they could all be related in another way (similar area, geography, topography, ruralness, etc) that could also result in a group like that. Gainesville and Birmingham are outliers compared to the expected result, but with so little data and so much variance those two could be the only ones displaying the true result, one that was unexpected. Theres just not enough data, too much variance, and too little knowledge of other factors (like the smog, or geographic differences). But i'm very interested in the idea of doing these plots. Though I can't help but feel like this must have been done and published somewhere before. right?

    anyway, if you do another one, i'd suggest somewhere where there is minimal geographic/topographic diffferences among the data collection sites. maybe oklahoma, nebraska, or somewhere nice and flat like those would be good.
     
  19. Nov 20, 2004 #18
    Of course essence is that those three are rural, devoid of any direct Urban Heat Effect, as long as it's not too close to a city.

    And yes of course, there is so much clutter in inhomogenous areas. Nevertheless it would be interesting to see if my speculations could be retrodictions of abnormal factors around those weather stations of Gainesville and Birmingham.

    Oklahoma next then, although I have no idea yet about enough variation in the urbanisation.
     
  20. Nov 20, 2004 #19
    Okay here is the same story for Oklahoma city. I guess it's the same definite maybe.

    I used only the four closest rural station (Pauls valley, Geary, Meeker and Kingfisher) for oklahoma city and all the towns on the page.
    It occurs to me that I compare apples with oranges. What should be compared is the trend in temperature rise versus the trend in population growth. A city that doesn't grow should not have a different trend. A city that shrinks should be losing urban heat effect. So if anybody has historical data about town sizes in those areas as of 1950 then we would be in business.

    Nevertheless, that highest warmer, Ponca city, (+0.0153 degK/year) bugged me, so I compared it with the closest rural stations, Perry (+0,0008 degK/year) and Newkirk (minus 0.0192 degK/year) and indeed it's weird. The area is not warming, but Ponca city certainly is, much more than you would expect. It appears that the last hotter spike years (1998-2001) make the difference. Compare the spikes against 1954-1956 when all three were about identical. Now is that Urban heat effect?
     
    Last edited: Nov 20, 2004
  21. Nov 22, 2004 #20
    I have the same feeling I used to get when I'd skip class :redface:
     
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