The Sky is Falling Friday Part 1: Study: Aircraft Will Have More Difficulty Flying Because Climate

Guest essay by Eric Worrall

A study published by Columbia University has suggested climate will disrupt future flight operations because it will be more difficult for aircraft to take off.

Climate change may hinder aircraft takeoffs in years ahead: study

Alana Wise

NEW YORK (Reuters) – Extreme heat over the next several decades will make it more difficult for full planes to get off the ground, requiring airlines to offload fuel, cargo and at times even passengers to manage smooth takeoffs, according to a study by a research unit of Columbia University released on Thursday.

If severe heat waves related to climate change become more common in the coming years, researchers at the Lamont-Doherty Earth Observatory have concluded that 10 percent to 30 percent of fully loaded planes may have to shed payload during the hottest parts of the day or delay flight until cooler hours.

“Our results suggest that weight restrictions may impose a non-trivial cost on airlines and impact aviation operations around the world,” said Ethan Coffel, lead author of the study and a doctoral student at Columbia.

Read more:

The abstract of the study;

The impacts of rising temperatures on aircraft takeoff performance

Ethan D. Coffel, Terence R. Thompson, Radley M. Horton

Steadily rising mean and extreme temperatures as a result of climate change will likely impact the air transportation system over the coming decades. As air temperatures rise at constant pressure, air density declines, resulting in less lift generation by an aircraft wing at a given airspeed and potentially imposing a weight restriction on departing aircraft. This study presents a general model to project future weight restrictions across a fleet of aircraft with different takeoff weights operating at a variety of airports. We construct performance models for five common commercial aircraft and 19 major airports around the world and use projections of daily temperatures from the CMIP5 model suite under the RCP 4.5 and RCP 8.5 emissions scenarios to calculate required hourly weight restriction. We find that on average, 10–30% of annual flights departing at the time of daily maximum temperature may require some weight restriction below their maximum takeoff weights, with mean restrictions ranging from 0.5 to 4% of total aircraft payload and fuel capacity by mid- to late century. Both mid-sized and large aircraft are affected, and airports with short runways and high temperatures, or those at high elevations, will see the largest impacts. Our results suggest that weight restriction may impose a non-trivial cost on airlines and impact aviation operations around the world and that adaptation may be required in aircraft design, airline schedules, and/or runway lengths.

Read more:

All this ignores likely advances in aircraft construction, the complete inability of climate models to forecast global temperatures, let alone regional temperatures, and the growing likelihood that climate models have grossly overestimated climate sensitivity to CO2 emissions.

But lets assume the authors of the study are right. There is an obvious solution; if aircraft are likely to be adversely affected by midday heat, avoid scheduling takeoffs for midday.


199 thoughts on “The Sky is Falling Friday Part 1: Study: Aircraft Will Have More Difficulty Flying Because Climate

      • Quote from the article – not particularly OT:

        “News has now come that Michael Mann, a “world leading climate change scientist” to the AGW zealots, has refused to submit the data behind his infamous “hockey stick” graph in a defamation lawsuit against a Canadian scholar and another one against noted conservative writer Mark Steyn. He may now be in contempt of court in Canada and the United States both. For those who have not followed the arcana of the AGW debate, Mann’s “hockey stick” graph is nothing if not the proof positive of global warming for his acolytes. By putting together two different graphs, Mann makes 400 years (900-1300) of medieval global warming, when temperatures were much higher than today, disappear. Some call that fraud, others, like Mann’s friend, Phil Jones, of the East Anglia Climate Research Unit, “Mike’s nature trick to hide the decline.” Whatever the case, Mann’s fraudulent stick is a key piece of evidence in the IPCC 2001 assessment and has been cited hundreds of times in the AGW literature. Without it, there is not much left to global warming.”

        I can just see judges citing Distinguished Professor Michael Mann for contempt of court.

    • Take a silly topic, create a model, feed it garbage in, review the garbage out and write it up. Result = LPU (least publishable unit), kaching goes the cash register and academic life goes on.

      • All they would probably need to do is redesign new planes and retrofit existing planes with extending slats in the wing trailing edge. The slats are extended doring takeoff and landings to reduce the speed necessary to induce lift. Greater wing area is more lift. Simply increase the length of the slats to counter for the less dence hot air

      • On the plus side, doesn’t warmer air have a lower density and offer less drag, thereby reducing fuel costs? Isn’t that one of the reasons why jets are flown at high altitudes? Just asking.

      • Did they also consider the gains that would be enjoyed by warmer winters and fewer icing problems?

      • Trebla,
        Warmer air Does have a lower density. This density difference has little effect on the aircraft that is traveling at 620mph though other than increased efficiency through less drag. Problem is, they can’t take off at 620mph to negate the effect of less dence air. Take off speed is around 180 – 200mph and air density makes a huge difference at that speed

      • There is another -real- problem with too high temperatures: the motor power drops with lower air density:

        Less air is compressed and thus less fuel can be burned and the motor runs at lower compression, thus losing a lot of power.
        At the factory where I was working, we had a 24 MW generator powered by a fixed airplane motor. On hot days the maximum yield was 22 MW, due to the compression loss, thus some 10% power loss on (for here normally 30-35°C) hot days.

        Recently they had to stop air flight take offs at Phoenix, Arizona, because of that problem, when temperatures reached 48°C, even too hot for Phoenix…

        But indeed the basic questions remain: why should that increase further, what is the human part in it and what if airplane motor manufacturers find a solution in some technique to temporarily boost power…

      • I hadn’t read a lot of other comments, but indeed airports at higher altitudes have the same – or – worse problem, they only need longer runways and the problem is solved…
        Further, the problems at Phoenix were mostly for smaller aircraft, all other flights were at schedule…

      • Did a transfer one summer in the Madrid airport.
        The plane we were on was delayed because of temperature, they needed to wait until the longest runway was open as the temperature had gotten to hot for the plane to take off from any of the shorter runways. (The delay was long enough that we lost our transAtlantic slot and had to wait almost an hour before the next slot was available.

      • But, doesn’t the modeling predict that most of the world’s airports will be underwater by 2080?
        And, who will need airliners when the world’s economy has been destroyed by CAGW?

        Just be afraid – fear is the only persuasion the socialists have.

      • The Goons had this sorted back in the 1950’s all you do is call up the “air ministry” pay the money and they will have the air you need to fly your aeroplane in place when you need to fly,,,,,,SIMPLES

        What you do have to be careful of is not running out of fuel as you might get stuck and not be able to land!!!

        James Bull

      • “Greater wing area is more lift.”

        It’s not that simple. Wings create lift by deflecting the airstream downwards. Flaps (slats) increase lift by increasing this deflection. However this has a price in increased induced drag, so acceleration will be slower. Stronger engines and/or longer runways will be needed.

      • tty: “Wings create lift by deflecting the airstream downwards.”
        Wings create lift by making the air flow over the top of the wing have a higher velocity than the airflow under the wing. The faster airflow reduces the air pressure on the top of the wing creating lift.

      • >>

        Not exactly. Wings create lift in two ways. One is through differential pressure and the other is angle-of-attack. Angle-of-attack is how kites fly. Basically the wing creates lift by differential airflow. But as you fly slower, to maintain altitude you must increase angle-of-attack. There’s a limit to how slow you can go, because a too high an angle-of-attack will cause the wing to stall. Flaps do several things: they increase wing area, they increase wing camber, and they increase drag. All these allow you to fly slower.

        The wing root usually has a higher angle-of-attack than the rest of the wing. As you approach stall speed, the root stalls first. This creates eddies that travel along the fuselage and shake the elevators. This warns the pilot that he is about to stall. Some airplanes can’t use this feature, so they add an electrical stick shaker that senses stall and warns the pilot.


      • >>
        There is a reason you don’t see wings attached to the body of the airplane at a 45 degree angle.

        That’s exactly how a kite flies. For a given camber, the faster the airspeed, the greater the pressure difference. I’m not sure about your “decrease pressure” statement WRT angle-of-attack. Are you an aeronautical engineer?


      • General Atomics in San Diego makes a catapult for carriers using electro magnetic acceleration (like a rail gun). I expect that to be scaled up within 10-20 years to help launch jumbo jets at US airpots, so there’s no need to worry about difficulty taking off.

    • Actually it’s “over” or “out”. Using the two together, as my drill sgt used to say, means “talk to me, shut up.”

      • I though “over” meant “your turn to talk” while “out” meant, “conversation over”.

      • “Over” means: “I’m done talking and I expect a reply,” while “Out” means: “I’m done talking and I don’t expect a reply.” “Over and Out” is nonsense.

        Jim (retired Naval aviator)

  1. Who new planes are effected by heat and weight!!!
    This is so new it must be worth an award /s

    • So now these so-called *climate scientists* are suddenly become aeronautical engineering experts. Sure, sure, we’ll buy that bridge you’re selling too…

      • Couldn’t help but notice, that nowhere in their doomsday speculations did they include the words; “And there won’t be any engineers”!

    • Okay, I’ve looked through the comments and haven’t found anyone coming up with the real reason warmer air is detrimental to takeoff performance. Nothing to do with less lift or bigger flaps or redesigning airplanes.

      The real reason:


      It’s that simple. Less power – lower performance. Clueless “researchers” who apparently haven’t discovered that fact aren’t worth listening to.

      • It also reduces lift since the weight of the air deflected by the wing at a given speed decreases.

      • @tty,
        you seem to be fixated on only one aspect of lift, momentum lift. There are two forces acting on a “wing” moving through the air, momentum lift and dynamic lift. Momentum lift works much as you say, like a vane deflecting the flow. This is how most house fans work. This is sometimes referred to as “flat plate lift”. It works for house fans because mostly they are turning rather slowly (compared to aircraft flight) but are very inefficient when they speed up. That is mostly why you hear a lot of “noise” from the fan. The noise is “stalled” air on the back side of the turning blades and circulation losses from the tips.
        The other component is dynamic lift, that caused by making the air on the “lifting” side move faster by making it travel farther. This is often referred to as “Bernoulli” lift. Slats and flaps mostly effect this sort of lift by making the wing appear more curved on the upper surface.
        For landings these devices allow the wing to perform at much lower speeds so the plane doesn’t’ need to land “hot”. These devices are not used much during take-offs.
        So much for the lecture on lift.
        The primary reason planes don’t like hot temperatures at air ports is due to loss of thrust generated by the engines needed for take-off due to the higher temperatures, as has been stated in previous comments. In order to get moving fast enough for take-off the runway needs to be longer. The planes could take off on the existing runways, but there may not enough length IF the take-off needs to be aborted and the plane stopped. The FAA has good rules for good reasons.

        BTW, I am an aerospace engineer (MIT) who designs aircraft and rockets for NASA and the military.

    • Any of these “Chicken Little” studies are merely variations on the same theme… imagine anything, doesn’t matter if it is supported by empirical evidence or even by the maths behind the theory, that sounds like it MIGHT could be brought about by the Monster-Under-The-Bed I mean Climate Change, and run some computer games I mean simulations I mean models, that show how bad it could be when this imaginary effect happens, and there you have it, It’s Worse Than We Thought™!!! I don’t understand why every academic sweats bullets over their next paper and getting it published, obviously it’s as easy as falling off a log.

  2. I would expect there will be more problems with global cooling than warming (I’m talking a long time in the future). Just saying.

    • Even longer term in the future, on the order of a billion years, we’ll have more trouble with global warming. The sun’s luminosity will have increased enough to destroy our oceans, and ultimately all metazoan life on earth.

      • Alan,
        Noted, and broadly agreed, although I have a feeling I have read that it is likely to be ‘five billion years’ from now . . . . .
        A distinction without a difference, though, as I, and I suspect you, too, will not be here in even a significant fraction of a billion years.
        Whoever is quoting better – it doesn’t matter – at all.

        Have a great weekend.


  3. We have to eliminate air travel to save the planet anyway, so this sounds like win-win to me.

  4. So it will be impossible for aircraft to get airborne in New York because they already can’t get off the ground in Dubai.


    • There was a day recently when some Canadair regional jets were grounded in AZ. Their top operating temperature was 118, and temps at the airport hit 120. This didn’t affect Boeing and Airbus planes.
      In general, warmer air does affect takeoff roll and climb, as the air is less dense – both in warm weather, and in humid – rainy weather. Something every pilot has to take into account. My old club lost our insurance when our most experienced pilot forgot to take the temperature – especially at a high altitude airport (Mexico City) into account. Put our biggest aircraft into the woods.
      The rest of us learned a valuable lesson.

      • Yes. But as my business partner and pilot informed me, the density altitude in Phoenix at 118F is more advantageous for takeoff and landing than is the density altitude on a warm day in Denver, CO. The recent issue in Phoenix was mostly about published and tested specifications, not actual airplane capabilities.

        One simple way to compensate is to have longer runways. Also, some Boeing jets offer enhanced take-off and landing packages.(slightly more powerful engines and larger flaps I think) that can be ordered for planes that must operate out of short runways, high altitudes, and other disadvantaged situations.

      • Neither Boeing nor Airbus is going to offer a larger flap package on one of their aircraft. That would require a complete recertification of the design.

        If anything, they would offer flat rated engines, one with higher thrust that is limited to the lower thrust the plane was certified with. Such engines can maintain the certified thrust to hotter temperatures and higher takeoff and climb altitudes.

      • Mike,

        Boeing currently produces ten models of the 737 and several military variants. What makes you think they wouldn’t make an eleventh with different slat/flap configuration?

        Also, i agree that changing the wing design would require recertification but it is not clearl to me why changing the engines would not require the same. Can you elaborate?

    • Crispin…not really related, but I kinda feel like congratulations are in order that you, apparently, are back home…in Waterloo, and not “really” elsewhere… :)


      • ripshin

        Correctamundo. I survived another go-round. 84k air miles this year already. I am really in Waterloo where the conversation is: “I wonder when May will end and summer begin.”

      • I’ve had some moments of fun, speculating about the nature of Crispin’s business travels.
        I hope some day, it becomes possible for him to tell us.
        He’s posted here at times from such exotic places as Ulaanbaatar and Beijing, on the same day!

        And the stories he could tell…
        Think about what he’s seen and heard during his far- flung adventures and his insights gained from diverse human contact, the likes of which, only the smallest, tiniest fraction of mankind has ever experienced.

        Crispin, you could even take a page from our friend Willis’s book and serialize stories here, while writing your book!

        Think how much fun it would be, (when time comes to tell us,) to run a quick contest here at WUWT… kinda like a Carmen San Diego thing, only “Why in the world, is Crispin in Kuala Lumpur?”

    • Have you ever seen Dubai airport in action around lunchtime in high summer. There’s plenty going on!

    • Plus longer runways. Density altitude is a well and long known law of mother nature. Nothing new at all.

      • You are correct. I guess “reporters” who know little if any thing about basic physical properties of gasses and temperature suddenly came across this and….. !OMG were all gona die!

      • Mike McMillan

        Whether or not people on this blog actually understand how an aeroplane flies makes no difference to the idiotic nature of the study in question.

    • There will be Boeing engineers rolling on the floor clutching their sided in mirth at this latest nonsense.

      On the other hand they might feel quite insulted that this moron imagine they can’t design a plane to cope with high temperatures, I mean they’re only looking at scram jets to put a plane into low orbit making a New York to London flight one hour long.

      But I bet they’re still howling with laughter, shaking their heads with tears rolling down their faces.

      • They’re probably laughing at many of the comments here by people guessing how airplanes fly.

      • Mike McMillan

        Whether or not people on this blog actually understand how an aeroplane flies makes no difference to the idiotic nature of the study in question.

        (Sorry, posted under the wrong comment earlier.)

  5. Have you noticed a sudden spate of really off-the-wall and over the top ALARMIST!! articles two weeks after we bowed out of Paris? Methinks they’re on the ropes, which is making them scream louder and dumber to practically no one.

    Reply: This is only Part 1~ctm

  6. That’s why they moved the meteorological weather stations from far away to near airport runways, so pilots can calculate load factors before take-off or landing. The weather stations then show the micro-climate of the runway. This data is then processed to prove global warming.

    • And unadjusted load calculations, based on 1930’s average body weight, lead to an air crash in the 80’s or 90’s, I don’t recall which. But it was the figures fed in to that formula that spat out inadequate figures for fuel and thrust. Thankfully that “issue” has been addressed.

  7. Geez, technically it is correct, a warmer temp does result in less lift so temperature is a calculation in plane load.

    However its almost like saying, when you drive in the rain you should slow down, it might rain more, and people dont normally slow down and there are more accidents with more people being killed, so Global Warming will kill more people in car accidents.
    I could also argue that Global Warming with potentially warmer temps, there would be less ice in the winter which causes accidents and less people will be killed..

    Its fear mongering at its finest..

    • Intercontinental jumbos always wait for the evening to take off from Johannesburg, when its 40 degrees and you are already 5000 feet up.

      A fully loaded jumbo waddles into the air using the whole runway….

      • Yeah and on the flight to NY you had to land on a Cape Verde island in the Atlantic to refuel because you couldn’t take off with a fuel tank from Jo’burg. From NY it’s a non stop flight.

      • Indeed we do. I seem to recall the limiting factor was the maximum tyre speed. So its not all lift and drag. (747-400)

      • Leo,
        It is also about arrival times.
        Folks round Heathrow get no jet landing until [Not sure, but something like] 0530 local time.
        Joburg is ~11 hours away. So take-off needs to be by noon – hot air problem, but gets in before nighttime closure – or after about 1900 Local time, to get a straight-in slot at LHR. No-one wants to stooge about over southern England for an hour until LHR and LGW are allowed to open for business . . . .

        I have seen a dozen airliners in sight when walking to the station at about 0615 Local time – more than once.

      • Leo S

        The airport in JHB was built on some of the lowest land around in order to get the thickest air available. All the long hauls are indeed after sunset or thereabouts because of the lift issue. It is 5500 ft above sea level. It is typically in the 20’s C by evening. For ‘time to roll’ it is the longest I have experienced. One runway is 14,000 ft long and they use most of it.

        It is one of only three airports that serve all 6 continents with non-stop flights.

    • If it rains more, people will get more used to driving in the rain, resulting in fewer accidents while it’s raining.

  8. Of course, they ignore the times airports are currently shut down due to cold and/or ice which should be reduced in a warming climate. How about fog? It often forms when warm air moves over cold ground. If we have less cold ground there should be less fog.

  9. I guess that is way better than spending hours lined up to get deiced. I learned to fly where the runway temperature was over a 130+F the entire time but we never canceled a day’s flying and we always got off the ground within the normal take off run up range distance. We didn’t reduce fuel or load. The “chicken littles” of the world, especially those who claim to be scientists, are getting very, very tedious. A year ago I would laugh and see them as sadly humorous but their recent reactions to Trump’s withdrawal from the Paris Climate Agreement indicate to me that they truly are dumber than posts.

    • Ed I July 14, 2017 at 8:28 am
      I guess that is way better than spending hours lined up to get deiced. I learned to fly where the runway temperature was over a 130+F the entire time but we never canceled a day’s flying and we always got off the ground within the normal take off run up range distance. We didn’t reduce fuel or load. The “chicken littles” of the world, especially those who claim to be scientists, are getting very, very tedious.

      What were you flying, 737, 757 and 767 wouldn’t make that.
      The max temperature shown in the plane manual that I learned on was 40ºC, but you were flying at 55ºC.

  10. You think planes have it hard now, wait until they replace fuel tanks with batteries and wings with solar panels. Everyone knows solar powered jets will work better at midday.

  11. [blockquote] If severe heat waves related to climate change become more common in the coming years…..[/blockquote]
    ..and “if” I win the Lottery, I can buy that 500SL Mercedes coupe.

    Folks have already identified the “endangerment finding” as a foundation block for a lot of regulatory nonsense and thus something worth challenging.

    Similarly a worthwhile red team-blue team exercise would be a data driven analysis of RCP 8.5 which seems to be underpinning of so many absurd studies.

  12. This is the imagined extreme heat resulting from AGW is it? Or is there new information from naturally evolving climate change?

  13. So, right now every single flight out of every airport is maxed out on fuel, cargo, and passengers? Somehow, I’m thinking…no.

    • The airlines do everything they can to make sure each plane is maxed out in regard to passengers.

  14. Firstly, they need to explain how adjusting data sets not showing warming affect anything in reality, never-mind aircraft.
    Secondly, then need to demonstrate that climate has any affect on aircraft over recent decades.
    Thirdly, it is a model with no confirmation it agreed to any timeline.
    Fourthly, the regional variations in climate between destinations are far bigger than any future change.

    This is just the continued repetitive pattern of trying to do any research and trying to link it to climate. They won’t go into any of these points because it would mean doing some science without assumptions.

  15. Even if this study is correct, it claims an RCP8.5 warming would require weight restrictions “ranging from 0.5 to 4% of total aircraft payload and fuel capacity by mid- to late century.” That’s not a whole lot, especially at the low end of the range, and it’s with today’s technology. Do these savants really believe they can forecast aircraft performance and technology in mid- to late century?

  16. The study assumed temps 3 degrees (Celsius ) greater. Not likely, and any estimates that assume CO2 levels much about our current level are just stupid – they assume no advances in cars (gee, you’d think they would know about electrics by now, especially since Tesla has a 600,000 waiting list for their lower priced model) , no advances in power technology (ignorant of the dozen countries, and companies moving very close to commercialization of molten salt nuclear reactors, which will be popular irrespective of any carbon issues.). These estimates display a great deal of ignorance, and not just about climate.

    • This is a science of projections. Closely related to astral projections and witchcraft.

    • Apologies. The falling sky credits belong to authors Ethan D. Coffel, Terence R. Thompson, Radley M. Horton. Alana Wise gets a special mention for calibrating Reuters against bird brains.

  17. This is predicting a 0.5% – 4% effect on airliners 100 YEARS FROM NOW!

    100 years ago there WERE no airliners. Who knows what there will be in 100 years time? I can only be sure of one thing – we won’t be flying current Airbuses using current engines out of airports which are the same size and place as they are today….

      • The Americans like to claim that the first airliner was the Curtiss JN 4, used for passenger service in 1915 – but that could only carry one passenger. The Russians had a 14-passenger Sikorsky Ilya Muromet designed and flying in 1914, but it never went into commercial service due to WW1.

        The first aircraft you would recognise as airliners were probably the converted bombers which were used on the first scheduled air routes in Europe – aircraft like the Handley Page Type W. They made their debut in 1919…

    • I certainly won’t be there to see it, but I’d hope there is matter-energy-transportation a century from now. Of course, I’m still waiting for that Jetson’s style flying car that folds into a briefcase…

  18. “”

    Lookss like US flights will be OK???

  19. Just thought I’d point out that the problem is with the chart that at least some airlines use. Namely it only goes to 120f. So airlines cancel flights if runway temp is above that. If, and that is a pretty big if, temps above 120 become common they will need to pay someone to create new charts.

  20. Here we have computer model projections based on other computer model projects based on … ad naseum. Our simulated future will be so dystopic that no computer model will be able to project how it all will end.

  21. As a certified, bone fide aircraft pilot (from the United States of America government nonetheless!) I will say there is a modicum of truth to their hypothesis. There is such a thing as density altitude. If your aircraft takes a certain amount of runway to lift off and you increase the air temperature, the air becomes less dense and 1. the engine puts out a little less power and 2. the wings develop a little less lift.

    The powers that be express this as if you are taking off the same runway only at a higher altitude, hence density altitude. So the higher the air temperature, the higher the apparent altitude of the airport and the longer the roll and higher the speed needed to rotate.

    Most jets have the spare power to handle this. However there are times when the margins get so slim they shut down operations (Phoenix for example) above a certain temperature. But if the airport is high to start with, it can come into play at lower temps. Non turbocharged piston singles have more issues with this, especially the older planes with the smaller engines.

    When it is hot, you really need to look at the charts in your POH to make sure the runway is long enough to get off the ground and you can climb fast enough to miss that big tower, especially if you are heavily loaded.

    • Tell me if I’ve got this right:

      Aircraft fly at high altitudes to take advantage of the less dense atmosphere. link In that light, shouldn’t higher temperatures, with their resultant decrease in density, be an advantage for commercial traffic?

      • But by the time they reach that altitude they are moving at 600mph. Still can’t go 0 – 600 over the course of an airport runway (yet)
        Perhaps if they had the same set-up that is utilized on aircraft carriers they could reach 600mph within a mile

      • The problem is this, is the runway long enough for your engines to get you up to take off speed before you run out of asphalt?
        Less dense air means you have less thrust and you need more speed in order to take off.

      • An Aircraft Carrier style catapult system could get them to speed in far shorter distances and would enhance the flight experience

      • Sorry, but, no, that isn’t right. Aircraft turbine engine thrust is related to the difference between inlet and exhaust temperature. Maximum exhaust temperature is determined by maximum turbine* inlet temperature, which is determined by the materials used for the turbine blades. So, going to higher altitudes provides for a lower engine inlet temperature, thereby increasing the difference between engine inlet temperature and engine exhaust temperature, thereby increasing the thrust. However, as this effect is really useful, one also has to deal with air density lowering with altitude. So, there is a tradeoff between the coldest engine inlet temperature and the air density. Of course, there are other considerations as well.

        * Note that the engine is called a gas turbine engine, and the section of the engine aft of the burner cans is called the turbine. A bit confusing. Ultimately, one is trying to maximize T(engine exhaust) – T(engine inlet).

        This has very little to do with takeoff performance, as the plane’s altitude is determined by the concrete, not be the thermodynamics. However, the hotter the runway temperature, the lower the engine thrust (for a given throttle setting) and the lower the lift (for a given airspeed). Can always go back to the good old days of water injection.

      • Aircraft at high altitude fly fast. Thin air is then an advantage because of lower drag. And engine efficiency improves with lower temperature in the intake air (typicaly c. -55 C at the tropopause).

        Even so the speed range between high speed stall and low speed stall can be fairly small at maximum certified altitude. Violent maneuvers are definitely not recommended.

    • The article was about aircraft takeoffs where you want enough lift to get you off the ground before you run out of runway.

      You are correct you go faster the higher you go due to less drag. But it isn’t all that simple. Piston engines lose power the higher they go unless they have a turbocharger (and they also have their limits), so you are playing improvements to airspeed vs power available to drive you through the air, so depending on your aircraft you have optimal altitudes and speeds you want to hit to get best economy or fastest cruise, etc. All tradeoffs.

      Jets have ample power and want to get high as fast as they can to take advantage of thin air and less drag. They also have issues with compressibility which is why they use mach numbers, have to worry about transonic induced drag (why they have swept wings) and the stall speeds are much higher at altitude. All in all a very fascinating subject.

  22. Simple test, ask airlines that fly non-stop from New York to the Middle East whether they have different load factors depending on the direction they are headed — higher load factors going from New York to the Middle East than in the opposite direction.

    • Load factor is the percentage of actual payload to max permitted. What you are thinking of is fuel load and that is a question of strength and dirction of winds at altitude. West to east goes with the flow (generally) whereas east to west goes against the flow. The easy way to find the answer is to look at the airline timetable, and compare the inbound and outbound flight times.

  23. If there are times at which flights have to be restricted, that will reduce the efficiency of the airlines, which will make travel more expensive.
    It’s a lot more complicated than just declaring, don’t try to take off at that time.

  24. This must mean that planes can’t currently fly into and out of Las Vegas in the summer when temperatures reach over 115 degrees F. Someone tell all of the casinos.

    • Water vapor is present in greater quantity and distribution, and high density water populations (e.g. condensation trails) have an observable, reproducible effect.

  25. I noticed they refer to RCP4.5 (could be) and RCP8.5 (bogus) in the abstract, but they dont make clear the difference in outcomes between the two cases. Rcp8.5 is bogus, therefore if the load factor change is mostly due to temperatures derived from RCP8.5 inputs, the work and the paper are a wasted effort.

  26. Planes of the future will just be designed with large wings for more lift, or larger engines with more thrust. What the airlines could do now is limit the passenger load, if they really needed to fly at that time.

  27. What a load of crap. None of the 757 or 737 flights were canceled in Phoenix when it was 120 f out. Only smaller less efficient commuter jet planes were affected, and only a few of those. Solution even if this did happen? Longer runway and a better plane!

    Wake me up when we have consistent 120 registering in Chicago, New York, or even Atlanta. We also need to start fining authors of garbage like this for excessive embellishment BS!

    • ossqss July 14, 2017 at 9:59 am
      What a load of crap. None of the 757 or 737 flights were canceled in Phoenix when it was 120 f out. Only smaller less efficient commuter jet planes were affected, and only a few of those. Solution even if this did happen? Longer runway and a better plane!

      Looks like they came rather close.

      • I just read a pilots’ forum where they discussed this and there was no consensus on why an absolute upper limit. Bambadier, a Canadian company, have a 118 dF limit, Boeing 126 and Airbus 127.
        If it were an air density thing then it would be a matter of a chart such as you show. If it is performance of laminates then Airbus has more of them than anyone else.
        The conclusion drawn was simply that the airline didn’t pay for the extended operating temperature range chart or the manufacturer didn’t publish the data.
        What value is a “scientific” paper where the reason for the limit wasn’t explored?

      • Solution, don’t fly in a desert environment if you don’t have proper equipment in the summertime? Find a good weather forecaster to boot, and adjust accordingly.

        Just sayin, lets have a look at some actual numbers and qualify/quantify a few commuter heat cancellations from the FAA as an example….. Now consider the hype in the paper.

  28. I always love it when they use the words “may”, “could’, “possible”. Means they don’t know but let’s scare the masses anyway because the press will report it as fact.

    • The media relies almost 100% for “fright” stories, in addition to the disgusting or salacious or tear-jerking, for the all-important clicks that feed the ad revenue. Anyone who thinks this is “information” is uninformed.

  29. Your suggestions of how to deal with the problem are ridiculous and take away any credibility you may have on climate temp sensitivity to CO2. Don’t be a Contard.

  30. If severe heat waves related to climate change become more common in the coming years, researchers at the Lamont-Doherty Earth Observatory have concluded that 10 percent to 30 percent of fully loaded planes may have to shed payload during the hottest parts of the day or delay flight until cooler hours.

    The hottest parts of the day, Maximum temperatures, have been on the decline – at least in the United States for nearly 100 years

  31. The Los Angeles Times pulled this out of the study:

    “The study said average global temperatures have increased nearly 1.8 degrees Fahrenheit since about 1980 . .”

    And then added:

    ” . . average global temperatures . . will rise by as much as 5.4 degrees by 2100.”

    Note – ‘will rise,’ not even, ‘are predicted to rise.’

    So – it’s a fact. Let’s go camp out on our new iceberg continent – down under.

  32. I looked up the highest temps in the 150 years or so of data from Central Park. The all time hottest day was 106F/41.1C July 9, 1936 — 80 years ago. Second place — 104F/40C in 1918, 1977 and 2011, That would seem to support the well known thesis that CO2 induced warming will primarily affect winter and nighttime temperatures and won’t affect Summer highs much at all. Which then leads to the question of whether these folks have even the slightest notion of what they are talking about.

    • In response to a recent LAT’s article about our heat wave, I look up and found that for the summer months of June – Aug in Los Angeles, there were still 24 record high temps standing from before 1900.

      This would have been long before any possible urban heat island effect in the downtown part of this metropolitan area. To actually tie, or break, any of those records today, the target should be raised 4-6 degrees F.

  33. The sturdiest brick house built on a pile of crap is still going to collapse. And until it does, the stench is awful…..

  34. the CMIP5 model suite under the RCP 4.5 and RCP 8.5 emissions scenarios, aka extrapolating the 80s and 90s warming to 2100?

  35. What’s with steadily rising mean as well as extreme temperatures hindering takeoffs? It’s only the extreme highs that do that. And how many have noticed what years the record highs for each of the 50 states have been set in? Mostly 1936 or before.

  36. “But lets assume the authors of the study are right. There is an obvious solution; if aircraft are likely to be adversely affected by midday heat, avoid scheduling takeoffs for midday.”

    it’s clear Eric Worrall has never run a business before. Aircraft fly 12-14 hours per day. So let’s just cut out 3 hours per day, or 20-25% of their flying time, and have them sit on the ground, incurring gate fees and/or parking fees.

    • It’s called route planning. You build your operating schedules around known problems. Back in the 1980s in the days when 747s didn’t have the legs they have now, London to Asia flights had to stage through a Middle East airport to refuel. During the day it was known to be hotter in the ME so flights were sceduled for refuelling stops during the night when it was a bit cooler. So Eric Worrall is exactly right and you, Chris, who does not know how airlines operate.

      • That’s a re-fueling stop for a single route.
        Now try shutting down major airports in the middle of the day for all flights.

      • Not all flights Mark. Just the extreme long haul flights. Short haul have no trouble 12:00-15:00.

      • Mark W, do you actually understand the concept of scheduling and route planning? Yes, my example was a single case for a single route but as an illustration of how airlines in their planning deal with known problems. The case of hot/hot and high has been known since the early days of aviation, though mistakes were made, and airlines, believe it or not, PLAN to get around this, and other restrictions, without having to shut down an airport and lose more money than usual.

  37. Even the data from warmest folks shows that there are a lot less heat waves than in the past by a large margin. Look at the data.

    Also data shows that the summer highs in the US are lower than the past:

    This data shows that the warming is predominately in the Arctic where there is little plane traffic and the temperature never reaches the highs they talk about. Warming in the latitudes where people live is actually modest. Of course on can cherrypick isolated locations to fool the public, but the overall data does not jive with their claims.

    Finally as a taxpayer I am tired of seeing and paying for these fake claims, wasting $$$, Trump needs to defund all these useless projects and use the money to build a wall.

  38. The morons at Colombia University think they can get away with half truths and lies to support their “global warming agenda” Density altitude, the effect that temperature has on air is dealt with on a daily basis by pilots. Long before passengers embark calculations are done to ensure aircraft can take off successfully. Even if the temperatures forecast by the IPCC and their dodgy computer models were to come true – their 1.5 degrees C would make little difference to aircraft safety. As someone who regularly flies out of Dubai where temperatures are often above 40C modern jets have no problems. The Colombia morons further demonstrate their ignorance by referring to “fully loaded planes.” In the real world there is no such thing. Planes today are never, “fully loaded” – instead they have always been loaded with fuel, passengers and freight according to the distance to be travelled, the fuel requirements for this and the density altitude of the the airfield in question. To try to link all this to notional and unproven “global warming” is merely the dodgy work of charlatans. No wonder more and more reasonable people question both the media for promoting such garbage and so called “scientists” for trying to promote their own political agenda.

    • Good point. The plane flying out of Phoenix AZ probably isn’t fuelled for a 17hr flight. It’s probably fuelled for 3hr or less.

      The only planes flying full range out of ultra hot places would be the Emirates / Qatar / Etihad type carriers out of MENA and a single Air India flight that set a world record out of DEL.

      This study is pure FakeNews.

  39. If global warming is a real catastrophic threat, why is commercial aviation allowed at all?
    It should have been banned decades ago. It is a large avoidable source of emissions.

  40. Air transport creates global warming.
    Global warming hinders airplanes from taking off.
    Thus, man-made global warming reduces air traffic.
    Problem solved!

  41. Over the years airlines have been making their seats smaller and smaller. They also place them closer together reducing leg room. All this of course is to squeeze more people in to the aircraft so they can make more money. If we are lucky they will have to reverse some of that. I say bring on the heat.

  42. Al Gore and DiCaprio will have more trouble jetting around the world to save us from ourselves?
    Pour on the Coal!!

  43. They’re talking about high temps proportional to air pressure; the higher the temp the lower the pressure.

    Well co2 is 60% heavier than ambient air, so for every co2 molecule added to the ambient, the air pressure should rise, lowering the temperature.

  44. By “19 major airport around the world” I gather we are talking about SIN, BKK, Dubai, Phoenix, Jakarta, Delhi, etc? Randomly selected hottest cities pretending to be representative?

  45. Or given 80 years to plan, AUH and DXB could build 500m longer runways at a distant future resurfacing.

  46. The abstract claimed, “Steadily rising mean … temperatures as a result of climate change will likely impact the air transportation system over the coming decades.” It is only the extreme temperatures that have an impact. One or two degrees in the mean temperature will be inconsequential. Another example demonstrating that the alarmists have not thought this issue through!

    As others above have commented, there are engineering solutions to this supposed problem. By the time this presumably becomes a problem, all of the current air fleet (except the venerable B-52s) will be retired and replaced with aircraft capable of handling the alleged future problem.

  47. If you have read all the parts of this series of posts, and you want some more amusing, but really inane climate hysteria, try this:

    “The Uninhabitable Earth, Annotated Edition: The facts, research, and science behind the climate-change article that explored our planet’s worst-case scenarios.” By David Wallace-Wells on July 14, 2017.

    “I also believe very firmly in the set of propositions that animated the project from the start: that the public does not appreciate the scale of climate risk; that this is in part because we have not spent enough time contemplating the scarier half of the distribution curve of possibilities, especially its brutal long tail, or the risks beyond sea-level rise; that there is journalistic and public-interest value in spreading the news from the scientific community, no matter how unnerving it may be; and that, when it comes to the challenge of climate change, public complacency is a far, far bigger problem than widespread fatalism — that many, many more people are not scared enough than are already “too scared.” In fact, I don’t even understand what “too scared” would mean. The science says climate change threatens nearly every aspect of human life on this planet, and that inaction will hasten the problems. In that context, I don’t think it’s a slur to call an article, or its writer, alarmist. I’ll accept that characterization. We should be alarmed.”

  48. Hon Kong — recently a study presented a steady increase in temperature due to urban heat-island effect. This increase in temperature has not resulted any disruption of aircraft take-off or landing processes.

    Dr. S. Jeevananda Reddy

    • I’d be interested to see that study. HK Observatory (whose personnel are rabid climate change fatalists) does tend to report only what happens at the observatory site itself which is in an urban heat island. They disregard the temperature variations, both temporal and geographic, throughout the territory. As for the airport, it is a massive concrete platform but (a) the runways are long enough to cope and (b) the temperature does not get above about 36/37C even in summer.


        Sveral of such studies are available on net.

        Hong Kong Runway is built in water. In India large airports changed the location. In Hyderabad from Begumpet [heart of the city] to Shamshabad a rural area close to Himayatsagar Lake. Now surrounded by new constructions. New Delhi changed the Airport [international]. Mumbai changed the international terminal [when I was undergoing Met training, for practical experience, Mumbai [Santacruz] Airport was allotted. I was there for a month].

        Dr. S. Jeevananda Reddy

  49. I wonder if their model included the offsetting increase in air density due the increase in CO2. Although this wouldn’t balance several degrees temperature, it would make a small a measureable effect. Not withstanding all of the above operational changes that could be applied to adapt.

    • If it did not need air then why is there an air intake feeding fuel and air into a turbocharger?

      • It’s not a turbocharger, it’s a supercharger. It will burn with or without air. The supercharger compresses the air to increase density before the fuel burns giving more power. More expanding gas than without air

      • “Dr. Strangelove July 15, 2017 at 1:40 am

        It’s not a turbocharger, it’s a supercharger.”

        The difference is what drives that induction system. Superchargers are driven by the pulleys off of the engine. Turbochargers are driven by the burnt fuel via the exhaust. Either system is a forced induction system, forcing air into the system. That is why they are sometimes called “blowers”…all that AIR! Petrol, diesel, nitromethane all need air to burn. You will notice in your pic two “dizzies”…so they also need spark plugs too…

      • It has spark plugs because it’s a car engine. It uses air to increase power output. Nope nitromethane doesn’t need oxygen to burn. It’s a monopropellant – it has it’s own oxygen unlike hydrocarbons (gasoline, diesel, methane, propane, kerosene) The combustion reaction of nitromethane:

        CH3NO2 = CO + H2O + H2 + N2

      • Nitromethane is a fuel that needs a heat source to get going. In a small engine in a model aircraft, the glow plug is heated externally, until the engine runs. Then the platinum in the plug “reacts” with the nitro fuel and heat to “keep the platinum coil hot” thus acting as “spark plug”. It’s just hot all the time. Still needs air. These top fuel engines need an air source too, spark and valve timing, otherwise they simply won’t run. Why would they need valves and valve timing?

  50. The extreme temperatures will also make the passengers more fractious, and perhaps drunk, so the airline will have to hire more, bigger, stronger staff to throw the difficult ones off the plane. I wonder if their model includes that?

  51. This reminds me of analog gauges in Star Trek. The authors take todays technology and project it into the future. With the possible exception of JetBlue, all of the planes currently in service will be retired by the end of the century. They fail to take into account changes in technology. If we look back 80 years there were no commercial jetliners.
    Also, the aircraft industry tests and designs using wind tunnels and not broken computer models.

  52. Modern aircraft are “turbo-fans” rather than pure jets of the early years. That is why we see more two engined craft as apposed to four.

  53. Since planes fly on fossil fuels, making them unable to fly ought to be considered a good thing by greens. Maybe they think it’s a problem cause they fear not being able to go to their annual or semi-annual climate conferences – always in someplace like Durban, Rio, Marrakesh, Bali, Tahiti ….

  54. Given that, as a commercial pilot, most of my take-offs use less than max thrust, a couple of degrees of warming will make no difference whatsoever. A lot of the time, we don’t use full runway length.

    Maybe a teeny bit more thrust will be needed. Certainly not a cancelled flight.

    A non-story if ever there was one

  55. Fake news: A story about a junk study of the hypothetical consequences of hypothetical climate change.

    Aim: Keep the climate alarm bells ringing.

  56. Has no one noticed the late evening/night time departures in the Middle East ? Not exactly a “new” issue. Even in southern Canada 50 years ago. Sheesh!

  57. My brother was a pilot of small commercial aircraft. He told me of an experience at Nairobi, both hot and high, and in reference to clipped hedges, he said that when taking off there with a heavily loaded plane – right up to the allowable limits, after actually taking off the procedure was to fly level and straight for the first 7 miles or so, with an altitude of no more than about 15 ft. At this altitude, Wing In Ground effect kept the plane flying although it could not climb. After that 7 miles or so, sufficient fuel had been burnt off that the plane could rise. Same WIG effect as that used by Ekranoplanes – remember the Black Sea Monster?

  58. BTW he was also a test pilot for the RN, and for a commercial aviation outfit, and flew helicopters – including cold weather trials from Fort Churchill of further north. Bit of a change from Nairobi. Was once in the control tower when a plane was arriving from somewhere like San Diego, and the pilot asked if the runway was cleared of snow. All in the control tower fell about laughing – the runway was made of snow!

  59. Bring back the VC-10 ….. It was specifically designed with “hot and high” airports in minf (BOAC flew them to South Africa). It had clean, high lift wings to generate the lift required lifting off from J’burg even with the much less powerful engines of the time.

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