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posted by martyb on Sunday January 25 2015, @09:39AM   Printer-friendly
from the there-are-no-birds-in-the-tropics dept.

No, I didn't get the headline wrong. While you surely have heard that aviation is bad for global warming, this is about the reverse: Climate change could make it harder for airplanes to get liftoff. From the article:

As air gets hotter, it gets less dense, and this can spell trouble for aircraft. Thin air can't generate enough lift and thrust to get a plane safely airborne within the fixed length of a runway. If it's too hot, airplanes will have to shed pounds, in the form of passengers and cargo, according to a study from Columbia University.

As the climate gets hotter, airports may have to adapt:

Airports might have to put in longer runways, or flights may have to be shifted to cooler parts of the day. The study, which was published in the journal Weather Climate Society and presented at the American Geophysical Union meeting this week, forces us to reckon with yet another niggling consequence of climate change.

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  • (Score: 0) by Anonymous Coward on Sunday January 25 2015, @12:11PM

    by Anonymous Coward on Sunday January 25 2015, @12:11PM (#137846)

    So how do planes manage to fly right now near the equator?

    • (Score: 5, Informative) by VLM on Sunday January 25 2015, @12:34PM

      by VLM (445) on Sunday January 25 2015, @12:34PM (#137850)

      So how do planes manage to fly right now near the equator?

      Basically a lack of habitation of whatever hot high altitude regions exist (if any, in the tropics). Think of Hawaii, there are hot areas at sea level, and there are cold areas up in the mountains, but there are no areas that are smoking hot AND very high altitude. On the other hand, as a counter example, think Denver in the summer, a mile up and 90 degrees, whoops. The Rocky mtns have aplenty of smaller airports at high altitudes for GA pilots. I would imagine you can get totally screwed in N.M., Nevada, Colorado in the summer.

      Imagine drawing a geographic cross section of altitude of an island, next to a graph of density altitude. The density altitude will be higher at the coasts and lower at the interior, its like turning the gain on an amplifier down. Most of the world is like that although there are some rare weird exceptions.

      Ask a pilot or at least someone who went thru ground school about pressure altitude vs density altitude or whatever. From decades old memory a cruddy inaccurate rule of thumb is something like 10C = 1Kft. Its quite non-linear over a very large range, yet for GA pilot work its close enough to linear that going all "fancy math" screws up more people than the extra decimal places fix.

      Most jetliners don't land/takeoff anywhere near their performance limits, at least not as risky as GA guys. Its WAY more exciting for general aviation pilots who have family members who want to pack "just one more suitcase" and stop over in Denver on a hot summer day, for example. For the jetliners its more of a "we're gonna burn 6% more fuel so you can expect ticket prices to go up about 2%" or whatever the exact ratio is. I suppose there's wear and tear issues on the engines, however small, one percent here, another percent there, pretty soon you're talking about real money.

      I know the GA situation and geography in the USA but being a typical American I'm not sure if there's anywhere else in the world as screwed as the USA WRT summertime density altitude. I bet Mexico City is interesting to fly out of in the summer. You need a strange geographic alignment to be toasty hot in the summer at a high altitude.

      • (Score: 2) by gman003 on Sunday January 25 2015, @02:58PM

        by gman003 (4155) on Sunday January 25 2015, @02:58PM (#137882)

        I know the GA situation and geography in the USA but being a typical American I'm not sure if there's anywhere else in the world as screwed as the USA WRT summertime density altitude. I bet Mexico City is interesting to fly out of in the summer. You need a strange geographic alignment to be toasty hot in the summer at a high altitude.

        Wikipedia has a helpful list of "hot and high" [wikipedia.org] airports and aircraft. Daulat Beg Oldi ALG (16,700ft and 35C summers) definitely sounds like a bad time to me, even with my limited experience.

    • (Score: 2) by JoeMerchant on Sunday January 25 2015, @01:19PM

      by JoeMerchant (3937) on Sunday January 25 2015, @01:19PM (#137863)

      Google JATO

      --
      🌻🌻 [google.com]
    • (Score: 3, Insightful) by sjames on Sunday January 25 2015, @08:59PM

      by sjames (2882) on Sunday January 25 2015, @08:59PM (#137987) Journal

      They fly just fine, but it's more expensive because they can't carry as much weight. That means less cargo/passengers or a shorter range since they can't carry as much fuel.

  • (Score: 2) by c0lo on Sunday January 25 2015, @12:36PM

    by c0lo (156) Subscriber Badge on Sunday January 25 2015, @12:36PM (#137851) Journal

    What about strap a hot air balloon to the plane.

    Or... how about increase the area of the wing by about as much as the density of the air decreases (maybe even variable geometry?). By the time the warming kicks-in full power, highly probable new planes will be built.

    --
    https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
    • (Score: 3, Informative) by maxwell demon on Sunday January 25 2015, @12:50PM

      by maxwell demon (1608) on Sunday January 25 2015, @12:50PM (#137853) Journal

      What about strap a hot air balloon to the plane.

      The drag from that balloon would certainly completely kill any chance to get lift (well, unless you give up normal flying and reduce the airplane to an airship passenger compartment).

      Or... how about increase the area of the wing by about as much as the density of the air decreases (maybe even variable geometry?). By the time the warming kicks-in full power, highly probable new planes will be built.

      FTFA:
      "Airplane wings are designed to be effective in cruise where it spends most of its time," says Coffel. That means the shape of a wing can only be changed so much to optimize it for takeoff.

      --
      The Tao of math: The numbers you can count are not the real numbers.
      • (Score: 2) by c0lo on Sunday January 25 2015, @01:09PM

        by c0lo (156) Subscriber Badge on Sunday January 25 2015, @01:09PM (#137860) Journal

        The drag from that balloon would certainly completely kill any chance to get lift

        My dear sir, would a whoosh be OK with you?

        That means the shape of a wing can only be changed so much to optimize it for takeoff.

        Variable geometry? Extensible flaps would qualify as well.

        --
        https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
        • (Score: 2) by maxwell demon on Sunday January 25 2015, @01:27PM

          by maxwell demon (1608) on Sunday January 25 2015, @01:27PM (#137867) Journal

          My dear sir, would a whoosh be OK with you?

          Only if it is fast enough to provide a lift. ;-)

          Variable geometry? Extensible flaps would qualify as well.

          Well, you'd probably want the plane still to be affordable. Otherwise, the cheaper solution would be to save weight by cramming less passengers into the cabin.

          --
          The Tao of math: The numbers you can count are not the real numbers.
          • (Score: 2) by Ryuugami on Sunday January 25 2015, @09:16PM

            by Ryuugami (2925) on Sunday January 25 2015, @09:16PM (#137993)

            Otherwise, the cheaper solution would be to save weight by cramming less passengers into the cabin.

            Hah! And I thought there was no positive side to global warming!

            --
            If a shit storm's on the horizon, it's good to know far enough ahead you can at least bring along an umbrella. - D.Weber
  • (Score: 2) by Gravis on Sunday January 25 2015, @12:48PM

    by Gravis (4596) on Sunday January 25 2015, @12:48PM (#137852)

    airplanes actually put out a LOT of CO2, so i have no sympathy for airports/pilots/passengers. time to start thinking about electric planes.

  • (Score: 0) by Anonymous Coward on Sunday January 25 2015, @03:14PM

    by Anonymous Coward on Sunday January 25 2015, @03:14PM (#137886)

    :)

  • (Score: 2) by Wootery on Monday January 26 2015, @04:52PM

    by Wootery (2341) on Monday January 26 2015, @04:52PM (#138215)

    If it's too hot, airplanes will have to shed pounds, in the form of passengers and cargo, according to a study from Columbia University.

    Don't we already have aircraft operating in a wide range of climates?

    If temperature really made a significant difference, wouldn't someone have noticed by now? Am I missing something?

  • (Score: 2) by Freeman on Monday January 26 2015, @04:57PM

    by Freeman (732) on Monday January 26 2015, @04:57PM (#138218) Journal

    I used to live in New Mexico and there were Gliders all over the place, because of the heat/updrafts caused by the heat. I am curious as to why heat would be a real problem for airplanes, if Gliders actually benefit from the heat. Or is this all due to the relative altitude of the flying contraptions?

    --
    Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
    • (Score: 1) by iWantToKeepAnon on Monday January 26 2015, @05:13PM

      by iWantToKeepAnon (686) on Monday January 26 2015, @05:13PM (#138227) Homepage Journal
      Well, gliders are INCREDIBLY light! And carry about ONE person. Also, most planes don't hover in order to get the benefit of an updraft. I know planes leave Arizona with empty seats in the summer because of weight restrictions (the hot air isn't dense enough to safely takeoff w/ a full load). It is a BAD THING(tm) to drag the tail of an aircraft on takeoff. :/
      --
      "Happy families are all alike; every unhappy family is unhappy in its own way." -- Anna Karenina by Leo Tolstoy