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.
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Read more: https://www.reuters.com/article/us-airlines-climatechange-idUSKBN19Y0YD
The abstract of the study;
The impacts of rising temperatures on aircraft takeoff performance
Authors
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: https://link.springer.com/article/10.1007/s10584-017-2018-9
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.
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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. https://www.takeofflanding.com/ 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.
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.
Deep Thought knew the answer. 42.
Turtles ,,, turtles all the way down ,,,
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.
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.
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.
A negative feedback! Hurrah!
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.
Ironically aircraft may be the sole biggest contributor to global warming. That is by the effect of their contrails, not their CO2 emissions. As already shown, clouds (and science claims even more so the higher in the atmosphere they are, though I can not confirm that) have a massive heating effect on climate.
https://www.scribd.com/document/348761444/Its-the-Ocean-Stupid
Water vapor is present in greater quantity and distribution, and high density water populations (e.g. condensation trails) have an observable, reproducible effect.
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.
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.
Fly at night, recharge in sunlight. Or follow the prevailing winds.
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!
Well said.
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.
http://www.b737.org.uk/images/environmentalenvelope.gif
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.
https://www.faa.gov/air_traffic/by_the_numbers/
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.
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.
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
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.
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.
The sturdiest brick house built on a pile of crap is still going to collapse. And until it does, the stench is awful…..
the CMIP5 model suite under the RCP 4.5 and RCP 8.5 emissions scenarios, aka extrapolating the 80s and 90s warming to 2100?
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.
“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.
once fossil fuels are outlawed, electric engines are going to limit aircraft a whole lot more than a couple of degrees of warming.
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.
?w=720
http://jeremyshiers.com/blog/wp-content/uploads/2014/08/high-low-temps-download1-2014.png
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.
http://fs5.directupload.net/images/170304/2x7bkgok.jpg
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.
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.
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.
Ca. 1,5% of human co2 emissions.