Guest essay by Eric Worrall
Climate Scientists predict Global Warming will be bad for air travel – but their claims ignore human adaption.
Climate change means longer take-offs and fewer passengers per aeroplane – new study
February 14, 2020 2.23am AEDT
Guy Gratton Associate Professor of Aviation and the Environment, Cranfield University
Paul D Williams Professor of Atmospheric Science, University of Reading
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As the local climates at airports around the world have changed in the past few decades, the conditions that pilots have relied on in order to take off safely have changed too. Our new research suggests that higher temperatures and weaker winds are making take-off more difficult. In the long run, this means that airlines are delivering fewer passengers and cargo for the same amount of fuel.
“Climate” essentially means the average weather conditions at any given place. Scientists know this is changing, but not uniformly. While global temperatures have risen by about 1°C on average, some places have warmed by much more already – and others may be getting cooler.
But climate change isn’t just about temperature – winds are slowing down and changing direction around the world too. This is a problem for airport runways that were built many years ago to align with the prevailing winds at the time.
Research has predicted that take-off distances will get longer as the climate warms. This is because higher temperatures reduce air density, which the wings and engines need to get airborne. With reduced headwinds, aeroplanes also need to generate more groundspeed just to get into the air. Once they’re up there, they’re subject to in-flight turbulence, which is getting worse due to climate change increasing the energy in jet stream winds.
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That could mean that airlines must reduce the numbers of passengers they carry on flights, or search for ways to lengthen their runways. In some extreme cases, it could become impossible for some aeroplanes to use some airports altogether. This is another reminder of how rapidly and extensively human actions are transforming the world around us, and how ill equipped we are to deal with the consequences.
Read more: https://theconversation.com/climate-change-means-longer-take-offs-and-fewer-passengers-per-aeroplane-new-study-131613
The abstract of the author’s study;
The impacts of climate change on Greek airports
Guy Gratton, Anil Padhra, Spyridon Rapsomanikis, Paul D. Williams
First Online: 13 February 2020Time series of meteorological parameters at ten Greek airports since 1955 indicated the level of climate change in the Eastern Mediterranean area. Using this data, take-off performance was analysed for the DHC-8-400—a typical short range turboprop airliner, and the A320, a typical medium scale turbofan airliner. For airports with longer runways, a steady but unimportant increase in take-off distances was found. For airports with shorter runways, the results indicate a steady reduction in available payload. At the most extreme case, results show that for an Airbus A320, operating from the, relatively short, 1511m runway at Chios Airport, the required reduction in payload would be equivalent to 38 passengers with their luggage, or fuel for 700 nautical miles (1300 km) per flight, for the period between the A320’s entry to service in 1988 and 2017. These results indicate that for airports where aeroplane maximum take-off mass is a performance limited function of runway length, and where minimum temperatures have increased and/or mean headwind components decreased, climate change has already had a marked impact on the economic activity in the airline industry. Similar analyses could be usefully carried out for other runway-length–limited airports, which may often include island airports. It is also noted that previous research has only considered temperature effects, and not wind effects. Wind effects in this study are less significant than temperature, but nonetheless have an effect on both field performance noise and pollution nuisance around airports.
Read more: https://link.springer.com/article/10.1007%2Fs10584-019-02634-z
Why am I disputing the predictions of a professor of aviation?
For starters, the body of their study expresses a lot less certainty that anthropogenic climate change is responsible for the observed changes than is suggested by the press release. From body of the main study;
In Greece, in particular, the wind speed at 20 measurement sites at a height of 2 m has decreased over the period 1959–2001, consistent with our findings at airports. A possible explanation for these wind trends is that anthropogenic climate change is warming the poles faster than the tropics in the lower atmosphere, weakening the mid-latitude north-south temperature difference and consequently reducing the thermal wind at low altitudes (Lee et al. 2019). Another possible explanation is that anthropogenic climate change is expanding the Hadley cells, pushing the fast winds associated with the storm tracks towards the poles and away from the midlatitude regions. A final possible explanation is an increase in surface roughness, caused by an increase in vegetation or (in our case) development around the airports.
Read more: Same link as above
I have personal experience flying an aircraft. “Surface roughness” has a huge impact on low altitude wind speed. “Surface roughness” should have been their first theory, not wild speculation about Hadley Cells or reduced latitudinal temperature differences, especially given recent observational evidence that away from “surface roughness”, global windspeed is actually increasing.
Urban heat island from all that development might also explain much of the observed rise in temperature at the airports in the study.
What about the other points the professors make? Their calculation of the impact of wind speed and temperature on aircraft performance look reasonable, temperature and wind speed do have a significant effect on aircraft.
But the authors of the press release did not explain that their study ignores human adaption to changed circumstances.
If local warming at the airports and reduced wind speed does start to have a significant impact on the ability of aircraft to operate in some regions, aviation companies will not simply abandon profitable routes whose airfields which are causing them operational difficulties. Aircraft manufacturers will respond to new requirements by upgrading the aircraft; by modifying the engines to deliver more thrust on takeoff, or by adjusting aircraft wings to provide greater lift for difficult takeoffs.
And yet …
RECORD BREAKER Qantas breaks world record for longest ever continuous flight flying for 19 hours and 16 minutes from New York to Sydney
A HISTORIC test flight by a commercial airliner arrived in Sydney today after completing a non-stop 10,000 mile journey from New York in a whopping 19 hours.
https://www.thesun.co.uk/travel/10174750/worlds-longest-flight-record-qantas/
We humans sure are clever creatures. Higher, faster, farther, safer, cheaper.
Gosh, full planeloads take off from Montreal in -10C and land safely in Dominican Republic at +30C. Then they return to Montreal with another full planeload. They already seem to be robustly designed for this. The same aircraft types have been doing this routinely from Vancouver to Sydney. From Heathrow to Dar Es Salaam…. Remember, the tropics temperatures are basically unchanged, the Arctic would, according to the science, increase 4 to 6 degrees C and the major ‘take-off ‘ cities in the temporate zone may be about a degree. Hey, we’ve already got you covered to 2100 at least
Gee, I have no trouble arguing with a professor of aviation either. To be an alarmist you seem to have to check your brains at the door when you go ti work.
“Winds are slowing…” Maybe a few more windmills removing energy from the wind… nevermind.
I always wondered why ?aeroplanes? fell out of the sky over the tropics, now, I know why.
Super silliness. What about seasons? What about daily temperature variation? The density altitude problem is bad only on the hottest days and with high humidity. Only a few days and then only for some period of time on those days will there be a problem. Not much different from bad weather passing through. We can keep track of how often density altitude impacts flights. I’m betting if it does, it won’t change by much over a decade or so.
Author can’t stop promoting his paper on twitter.
Not surprisingly…
“…AeroEng, researcher, writer, pilot. VisProf & Aviation Skills Cons. @CranfieldUni, VisSrRschFellow @Bruneluni. Climate, safety, electric a/c, FltTest. He/him…”
Oh gosh, who knew?
Anyone who knows much about aviation knows that higher temperatures reduce performance-limited takeoff weights thus potentially reduce payload or range. Reductions could be runway length required or second-segment climb with an engine out. (I don’t remember if brake-energy or tire speed limits – which may be encountered if overspeed takeoff is used to increase climb performance at the expense of using more runway – change much with temperature. I’ve encountered cases where the aircraft is at all four limits.)
One reason newer designs may have better takeoff performance may be that higher bypass ration engines used for fuel economy lose more thrust with altitude thus higher thrust engines are needed to reach efficient cruise altitude. But manufacturers keep stretching designs which increases weigh unless engines are also upgraded.
The question here seems to be the cause of higher airport temperatures.
Also note IMO it is better for airport measturements to error on the high side,
Flying out of McCarran Intl in Las Vegas last July 5th mid afternoon, it wasn’t the speed or runway length that had me worried, it was the very bumpy ride due to all the up/down drafts we encountered over the local mountains that scared the bejesus out of me. But, I figured that was the way it always was so not to worry.
“operating from the, relatively short, 1511m runway at Chios Airport”
relatively?!!!
In my book, that’s ridiculously short for an airport designed medium range planes.
Electromagnetic catapult for every runway. Just shift the bulk of flight movements to night.
As a child in the 80s, the scream of the old jets still operating was barely tolerable while walking from parking to the main terminals of Hartsfield.
As the eyes upgraded to more fuel efficient and powerful high-bypass turbofans I noticed it getting distinctly quieter.
And this guy’s worried about a few tenths of a degree Celsius? Some professor, bowing at the alter of the new global religion, just to keep his job.
Pathetic.
“As a child in the 80s, the scream of the old jets still operating was barely tolerable … As the eyes upgraded to more fuel efficient and powerful high-bypass turbofans I noticed it getting distinctly quieter…”
Either that or your ears wore out.
Has anyone told the navies of the world? You know the ones that operate floating steel airports called aircraft carriers. These things operate from the tropics to the arctic. Or could it be even remotely possible that the designers of these things are aware of the effects of temp variations on the performance of their craft?
Over the water the temperatures do not get as hot as over land.
Note: this is OLD news.
“The version of the Joint Strike Fighter (JSF) that has been bought for the £5.5bn carriers is still in development but currently cannot land vertically – as its predecessor the Harrier jump jet could – in warm climates without jettisoning heavy payloads, the National Audit Office says.”
https://www.theguardian.com/uk/2013/may/10/navy-jets-cant-land-hot-weather
I believe airport weather is biased hot to ensure pilots are on the safe side of the density altitude formula.
Some helicopters such as the jet ranger are susceptible to low air density.
At a training base they essentially were grounded with a density altitude above 3500.
The runway length / payload equation is not at all linear – a small change in temperature and or wind will have a large impact off of a short runway, whereas the same changes will have a negligible impact on a much longer runway. These guys are just engaging in masturbatory scaremongering. Shameless! Only an Idiot would publish such drivel – picking flyscat out of the coffee grounds.
Airliners are designed to get the most out of the runways most available and intended to be used – not out of some backwater flyspeck strip of asphalt laid down in the 1930’s.
Forget climate change. Passenger weight is a more widespread problem!
https://www.orlandosentinel.com/news/os-xpm-2005-08-11-vbigair11-story.html
Not available in UK or Europe
FAA raises weight calculation for fliers
Jon Hilkevitch Chicago Tribune
THE ORLANDO SENTINEL
August 11, 2005
Reflecting society at large, the average air traveler and carry-on items now tip the scales at almost 200 pounds, according to new data the Federal Aviation Administration is requiring the airlines to use starting today to calculate the weight and center of gravity of aircraft before flight.
The new statistics also reveal that more women are having as much trouble as some men in squeezing into tightly packed airline seats.
The more than 10 pounds in added payload many passengers are carrying, along with the record fuel prices causing a financial drag, are the primary reasons airlines have gone on crash diets that include shedding magazines, seat phones, extra cans of beverages and even life vests from some planes. Heavy cabin dividers have also been replaced with curtains on some aircraft.
Passenger bulge and the belongings people drag on trips have become such a weighty problem that some airlines cut out a row of seats on smaller commuter aircraft, and they often load less cargo into the belly of the planes, eating away at revenue in an industry struggling to survive.
“Maybe instead of just using those [metal boxes] at the gates to limit carry-on bags to certain sizes, the airlines need to have a people-sizer with a sign asking, ‘Do you fit into this?’ ” said Dave Grotto, a registered dietitian with the American Dietetic Association in Chicago.
Obesity among adults has risen significantly in the United States during the past 20 years. Thirty percent of adults 20 years of age and older — more than 60 million people — are obese, according to the National Center for Health Statistics. The percentage of overweight children and teens has tripled since 1980.
In response to the super-sizing of the American lifestyle and government surveys showing that airline passengers — women especially — are getting fatter, the FAA has updated weight-and-balance guidelines used by the airlines to calculate the total load aboard aircraft. The measurements are essential to determine a plane’s center of gravity, takeoff speed, how much fuel to carry and other flight characteristics.
Today is the deadline for the airlines to factor in the new passenger-weight standards, although virtually every carrier has already done so.
The airlines have also gone leaner by jettisoning nonessential cabin items because of the high fuel prices — heavier planes burn more fuel — and due to recent accidents involving small commuter planes that were overloaded.
Excessive weight in the back of a US Airways Express plane, along with maintenance issues, were blamed for the crash of the commuter jet shortly after takeoff Jan. 8, 2003, in Charlotte, N.C., the National Transportation Safety Board concluded. All 21 people aboard the Beech 1900D died.
Still, the new FAA weight standards don’t mean passengers will be asked to hoist themselves aboard baggage scales at airline ticket counters. Nor will they be subjected to embarrassing comments about their waistlines from airport security screeners asking whether a stranger had packed their bags.
But two years after Southwest Airlines started enforcing an existing rule of charging extra-large passengers for two seats, now other airlines are increasingly focusing on bottoms and bottom lines.
The new FAA standards increase the average adult passenger and carry-on bag weight to 190 pounds in the summer and 195 pounds in the winter — up from 170 pounds and 175 pounds, respectively. The numbers include an extra 10 pounds for heavier clothing in winter and 5 pounds for clothing in summer. Both scenarios include a 16-pound allowance for personal items and carry-on bags, up from 10 pounds previously.
Female passengers in particular are flying heavier since the last revisions were made in the mid-1990s.
The FAA told the airlines to increase the allowance for the average weight of female passengers and their carry-ons from 145 pounds to 179 pounds in the summer, and from 150 pounds to 184 pounds in the winter.
The average weights for male passengers with carry-ons were increased from 185 pounds in the summer to 200 pounds, and from 190 pounds to 205 pounds in winter.
For children ages 2 to 12, the weight estimates were raised slightly, from 80 pounds for both summer and winter to 82 pounds in summer and 87 pounds in winter.
Most of the weight on an aircraft does not come from the passengers or cargo, but from fuel. In some cases, planes carry only as much fuel as is needed to reach a destination, plus a reserve in case the flight must be diverted to another airport. But airline economics often dictate that jetliners carry excess fuel to avoid filling up at airports where the prices and taxes are higher.
If troubled by density altitude, go for night time departures when it is cooler as ain Nairobi. Doh
The history of aviation in the Climate Alarmist Era since 1980 has been one of steady advance with safer planes, shorter take-off distances and steadily increasing average passenger loads. Yet another Warmista Fable fails.
Thanks to ‘Moderately Cross of East Anglia’ for the funniest posting of the year depicting Electric Planes on the M25 with passenger assisted take-off viewing rusting abandoned electric cars as entertainment.
The POH and amendments for each aircraft type include tables for calculating both takeoff and landing runway length required. This has been a thing since aircraft operating manuals were a thing.
Inputs to these tables are the density altitude of the runway, and aircraft takeoff weight, generally. There may be other inputs, like the condition of the ground for non-paved runways. Wet grass or mud can definitely affect performance.
Density altitude is nothing more than taking atmospheric pressure and temperature into account to normalize the effective (to the aircraft) runway height (in terms of air density) to the ISA normal atmospheric properties of 1013.25hPa and 15′ C such that the air density “felt” by the aircraft and engines (the performance) can be determined safely for the situation at hand.
Student pilots generally work out the density altitude with a circular slide-rule. More advanced pilots tend to use flight-planning apps. Sometimes the aircraft’s inbuilt Flight Management System can handle these planning functions as well in commercial aircraft.
In a nutshell, temperature and pressure at the runway are already part of the planning process for any given flight, and people have been taking off in scorching-hot deserts since people have been taking off. You just need to allow for the conditions (or wait for them to improve) so as not to kill anybody.
Your average furry house pet will have 500 less hairs
As usual it pays to read the paper before commenting. It does appear that this is just another academic computer study designed to show whatever those that paid for the study wanted.
Using two aircraft models and 10 airports, they tried to show that “climate change” was going to have disastrous effects on commercial aviation. BUT nowhere in the study did they actually ask the airlines that flew into these airports (1) if they actually flew that aircraft into those airports, and (2) if they ever had any problems taking off with a full load with those aircraft. Never let reality get in the way of a good computer study.
And actually it wasn’t that good a study. While all airports show an increase in the minimum night time temperature (UHI anyone?), three of the airports showed no change in wind speed and one airport actually showed and increase in wind speed over time. So 40% of the airports chosen did not fit their assertion that wind speed decreased over time.
A “full load” is max gross takeoff weight, which can be limited by environmental conditions (temperature, wind speed and direction which can vary temporally – as in “wind shear”, precipitation, runway contamination, and airframe icing); runway elevation, slope, length, and obstacles; aircraft equipment and actual performance of both airframe and engines; load distribution (the “and balance” part of “weight and balance”; and pilot skill.
In other words, the known variables in expected aircraft takeoff performance are many and of very large magnitude. Air temperature, as it affects “density altitude” is certainly significant but there are many other variables that usually control whether a takeoff may be performed safely. The net effect of a 1 or 2 degree warmup is penny ante and negligible.
As for the temperature they could just take off a bit earlier on the day, or wait for the evening.
I really wonder how planes could ever take off from Denver in 1500 meters hight. Denver airport must be filled with planes that landed and could not take off again.
This assistant deputy associate professor and his side kick may have a point.
After all, back in 1850 when this evil Glowballs Warming kicked off, the climate was almost 1⁰ colder than now.
Little known records demonstrate that the A320s of that period only took half a furlong to get airborne.
Climate alarmists / future World Communist apparatchiks have a simple solution for this imaginary problem. There won’t be any civilian air travel. Our elite rulers will have private jets just as they do today. As for you, take the train, “flyover peasant.”
This is yet another typical stupid argument.
Nearly all of the world’s scheduled commercial transport runways have significant excess runway lengths to accommodate transport aircraft fully loaded with passengers and cargo with sufficient fuel onboard to safely conduct their scheduled missions with plenty of fuel reserve. In most instances transport aircraft carry less than maximum fuel, because the more fuel carried the lower the fuel efficiency.
In only a very tiny percentage of scheduled transport flights is max range a limiting consideration for fuel loading … i.e., transoceanic flights.
The tiny amount of warming projected by even the most grossly exaggerated warming scenarios would only have a very small effect on a tiny minuscule percentage of scheduled flights … tiny enough to not matter at all.
This is just climate alarmist masturbatory fantasy.
btw – I have been a licensed airman (pilot) for 44 years
Hey, I like that–‘masturbatory fantasy’. The professor is another Climax Alarmist. Self motivated.
I too have been a private pilot for over 40 years, and often calculated density altitude because with the little planes I fly it is REALLY important–but no big deal. Those of us that have know that 1ºC of temperature change occurs just about every morning between, say, 0800 and 0830. That much average temperature rise indeed will theoretically affect take-off distance–just like peeing the ocean will theoretically increase sea level. I was thinking of more comparisons, but on thoughtful review I concluded that peeing into the wind affects only the peer (get it?–this statement was peer reviewed).
Also–most of the average temperature rise from my plotting of GISS data indicates that it is due to less extreme lows, not higher highs. Temps at 4 am affect no flight during the heat of the day.
And–it is still not a problem at Fort Yukon in Alaska- the temperature was -46C there again this morning. Flight would be difficult, but not from density altitude–from not being able to get the thing started.
Yes – Density altitude is a big deal for light aircraft that tend to be underpowered and overloaded compared to turbine powered multi engined commercial transport aircraft. Not so much for operations from low elevation airports (under 2,000 ft msl), but definitely so from higher elevation airports such as in the Rocky Mountain region of the US.
But remember that we’ve had but one deg C warming in 160 years with zero acceleration in that rate. Commercial aviation, as a practical business enterprise using large transport aircraft, has only existed for the last half of that period – 80 years – so about 0.5 deg C warming since the beginning of commercial transport service.
In that same timeframe we went from Ford Tri-motor aircraft carrying about a dozen passengers cruising at about 110 mph for short hops of but a few hundred miles, to B787s and A380s carrying up to 500 pax at Mach 0.85 non-stop across entire oceans.
Think we might be able to cope with another 0.5 deg C of warming over the course of the next 80 years of aeronautical technology development?
Fort Yukon is hoping; it’s -51F/-46C there again this morning. Another day closer to spring, and not another degree warmer. If this trend continues…
The biggest alignment problem airports face in this century is renumbering the named (magnetic orientation) runway designations due to the fast moving magnetic North pole.
The prevailing wind direction change for runways thing is total bunk. Just one more junk climate science claim in long list of junk climate change claims.
The temperature change is also just more junk science claims. If Seattle temps become like San Francisco, or London’s like Madrid, do they really think the airline and the pilots can’t adjust over those 70 years of slow rising temperatures?