Climate Prediction: “Take-off distances will get longer as the climate warms”

British Airways Aircraft at Heathrow Airport
British Airways Aircraft at Heathrow Airport. By, CC BY-SA 3.0, Link

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

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. 

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:

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 2020

Time 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:

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.

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February 15, 2020 10:10 am

And yet aviation advances steadily, with shorter take offs and increased passengers. Funny how that works!

Charles Higley
Reply to  2hotel9
February 15, 2020 10:34 am

As the planet is not warming and likely actively cooling, take off distances are not an issue. Their point is that warmer air is thinner air. However, it is known that the atmosphere is contracting so much that the drag of the upper atmosphere on the International Space Station has been decreasing, which indicated a contracting and cooler atmosphere. This is another piece of propaganda based on the assumption that the average reader assumes that the climate is warming, which it is not.

Reply to  Charles Higley
February 15, 2020 12:19 pm

The outer atmosphere is contracting because the sun is in the quite phase of this cycle. It has nothing to do with the temperature of the planet.

Komrade Kuma
Reply to  2hotel9
February 15, 2020 12:58 pm

And simultaneously aviation related climate research goes backwards as desperate wannabee academics publish increasingly shallow and speculatice ‘research’ that is essentially a vehicle or the term ‘climate change’ and a general narrative that articulates the doom and gloom attributed thereto.

Woke world expands its frontiers.

Methinks the local development affecting surface ‘roughness’ and ‘heat island’ would be the primary drivers to consider regarding any material effect on aircraft take off performance. The latter seems to have a significant effect on the brains of certain academics causing memory loss in some instances and event full blown dementia in others not to mention delusions.

Reply to  Komrade Kuma
February 15, 2020 3:19 pm

It’s time for another government grant. That new Porsche looks awfully good!

Ivar Ivarson
Reply to  mikee
February 15, 2020 4:31 pm

The pity is that practitioners of “Science!™” won’t be able to market their results to the People’s Liberation Army since the Chi-Comm spymasters won’t buy fictional studies.

Reply to  Ivar Ivarson
February 19, 2020 4:50 pm

Bugger! Those damn Chi-Comms.

Reply to  Komrade Kuma
February 16, 2020 8:29 am

Get woke, go broke. The only way woke-ism can continue is by stealing tax dollars.

Joe Crawford
Reply to  2hotel9
February 16, 2020 9:42 am

In other words, become a Climate Science academic?

Reply to  Joe Crawford
February 16, 2020 10:57 am

Or politician, both simply exist to lie and steal.

Greg Woods
Reply to  2hotel9
February 15, 2020 1:58 pm

The answer is quite simple: Manufacturers need to develop aircraft that can flap their wings, for that added boost at takeoff….

Leo Smith
Reply to  Greg Woods
February 15, 2020 2:47 pm

aircraft wings are already flapped.

Reply to  Greg Woods
February 19, 2020 8:03 am

The latest iteration of aircraft carriers are using electro-magnetic catapults. We should expect that, maybe as soon as the next 10-20 years, these systems will begin to be used at commercial air fields.

A catapult on a carrier brings a fighter jet up to takeoff speed using only about 300 feet of runway. A jumbo jet, weighting roughly 7 times as much as a fighter jet, would have maybe 3000 feet of runway for the catapult and engines to get the plane up to takeoff speed. Plus, the electro-magnetic catapult would reduce the on board fuel needed during takeoff, saving money and increasing the paid payload capability.

D. Boss
Reply to  2hotel9
February 16, 2020 6:42 am

Gibberish by idiots who know a little about aviation. What is that axiom? “A little knowledge is a dangerous thing”. Indeed.

I am a pilot and an essential element of pre-flight rigor – whether a Cessna 150 or a 747 is the weight and balance determination. Which factors in density altitude, wind speed and direction vs active runway heading, empty weight, fuel and passenger and baggage weight, and where the actual CG of the aircraft is. (or rather if the CG is first within the safe operating envelope, and second what it’s position dictates regards trims and critical speeds and flap settings etc) Maximum takeoff and landing weight, and most critical takeoff distance required at the anticipated flight conditions. V1, Vr and V2 etc….

This has been the norm for a long time. Reduced operational parameters are nothing knew to anyone who has “real” aviation knowledge. But pinheads like the authors of this study are either clueless or deliberately lying to scare people.

Aircraft already operate in a hugely wider envelope of atmospheric conditions than any minuscule “global warming” temperature increase would present. The argument is essentially “lies, damned lies and statistics”.

There are charts, calculators (used to be rotary slide rules, but now there are apps) for pilots of any [aircraft] type to render these essential determinations before takeoff – from way back when CO2 was 350 ppm or less.

As an example, I was on a charter with ~250 other idiots going to India back in 1977 – we were in Srinigar – and only 737’s could use the runway as it was some 5,200 feet ASL, and it is HOT there. (so we needed 2 flights to carry all of us back to Delhi)

As we boarded and awaited leaving the gate in Srinigar on a 737, it was 110 F at 09:00 and it was rising at 1 degree every 2 minutes. My fellow idiots were then complaining as cabin crew started removing passengers – a dozen in fact.

I commented to the whiners – shut up! As the reason for the removal was the plane could not fly with the weight at these high temps and thin air!

Sure enough the takeoff roll was scary as hell – to me anyway… The 737 did a short field run up (hold brakes and bring thrust to 100% before brake release) – and it lumbered along – and along and holy crap batman this is an Extremely long take off roll, I said to myself…. Then just as the plane rotated, the frigging runway end passed under us and plane dropped 50 feet at the cliff edge before it started gaining altitude!

This issue (take off distance vs wind, and density altitude) is part of normal operations and has been for as long as big planes have been around. (well the unprofessional Air India pilot’s behavior is not good – they cut it way too close on their calculations)

My point is, this diatribe on takeoff distance is misinformed, or misleading to say the least.

Crispin in Waterloo
Reply to  D. Boss
February 16, 2020 8:14 pm

D Boss

Good story!

The reason all long distance flights out of Johannesburg take off after sunset is rather obvious: it is Denver high and pretty darned warm on the runway.

There used to be a Montreal-Moscow Aeroflot direct flight that had to take off about 7:30 AM because after that it couldn’t get into the air, it was so loaded with fuel. And that is at sea level.

A contact of mine who flew short hops from Lubumbashi to Kolwezi said the standard safety limits meant the takeoff weight was less than half what was technically possible. As the Russian planes piloted by Ukrainians in the Congo fall out of the sky far too frequently, he was worried. He was asked to take mining drills and heavy items in the aisle – running about 150% above the safe takeoff payload. He complained because hanging in the props just after takeoff was very risky. One misfiring cylinder and the plane would fall. Simply ridiculous. They fired him and hired someone who wouldn’t complain.

My point is that any prof who thinks the safety margin is zero now needs his head read. If the temperature rises 2 C the effect on air viscosity is what, exactly?? Is he aware that the viscosity of air increases with temperature? Yeah, little subtle things like that are sometimes important when setting limits. The density goes down but the viscosity goes up. Did he know that or is the all-knowing prof factoring in everything relevant, like the great advances in wing design and power to thrust efficiency?

Colour me unimpressed. Flying is amazingly efficient and moreso all the time.

February 15, 2020 10:13 am

The most drastic changes from these things might be a reduction of 5% at most in the efficiency of takeoff. So only the most marginal of locations is going to be effected and that is simply until the Aircraft mature to be more efficient, as they always do.
As in most safety issues, there is usually a built in safety factor of at least 50%, usually 1 times to 2 times is normal.

Leo Smith
Reply to  astonerii
February 15, 2020 2:48 pm

Aircraft already do not take off from Johannesburg in the heat of the day.

Robert B
Reply to  Leo Smith
February 15, 2020 5:40 pm

That’s the other issue. A lot of airports are high and hot already. They have restrictions in the heat of the day on very hot days. It’s as easy to overcome as changing flight times to avoid the hottest part of the day.

Russ Wood
Reply to  Leo Smith
February 16, 2020 6:08 am

The Concord did it’s “hot and high” trials at Johannesburg in 1976. And, as an aviation apprentice in the UK, I copied out altitude/temperature/runway length/takeoff weight tables from graphs. Aviation has ALWAYS had a ‘hot and high’ problem.

Reply to  astonerii
February 15, 2020 9:41 pm

In CAGW land (all model-driven), the only thing that may be “warming alarmingly” is AVERAGE daily temperatures.

But airplanes don’t take off and land in AVERAGE conditions, they operate in ACTUAL temperatures, wind speeds, altitudes, and loads.

The ACTUAL data show that the only things warming slightly are overnight lows, winter temperatures, and locations surrounded by human construction and activity. The aviation industry has already adapted to all of those minor changes.

They might as well have written that butterflies will evolve larger wings to compensate for thinner air.
Sheesh – Stupid is as Stupid Does.

February 15, 2020 10:21 am

Unless I’m mistaken airlines and their pilots already know how to fly in and out of Qatar, Abu Dhabi, and all those other hot and humid annexes of Hell when it’s up to 130 Fahrenheit. Also, engineers know how to put larger and more efficient lifting surfaces on aircraft….so even if manmade global warming were happening, (and as an engineer I say it’s entirely unproven at best) it’s effects on aviation are easily overcome.

Bryan A
Reply to  Kalashnikat
February 15, 2020 10:33 am

Slats and Flaps?!!!

Reply to  Kalashnikat
February 15, 2020 11:38 am

Taking off from Joburg in a 747-400, the limitation was often the maximum tyre speed, not runway length.

Gerald Machnee
Reply to  Kalashnikat
February 15, 2020 1:17 pm

The occasional problem exists is when locations experience a heat wave and did not account for it. It happened for a few days in the SW USA when loads had to be decreased.
Most aircraft have accounted for this after an aircraft (4 engine) crashed into a cabbage patch near Toronto in the 1950’s or 1960’s. I think it was determined that it lost lift due to density loss in the heat.
As far as “global warming” causing a problem – not likely. There is more seasonal variation in temperatures.

February 15, 2020 10:22 am

They have to add 6 inches to the length of a runway. So what?

Reply to  MarkW
February 15, 2020 10:47 am

Or just lower the fence and not worry about it!

Moderately Cross of East Anglia
February 15, 2020 10:26 am

Perhaps the study is a premonition of the future fictional electric airplanes. Presumably these will need runways longer than most motorways in the UK. Future Heathrow passengers will be sitting in their electric jumbos going round and round the M25 with their arms out of the windows flapping hard in the hope that a sudden gust of wind will finally enable them to take off after a day or so while viewing the vast numbers of abandoned and rusting electric cards along the hard shoulders.

Reply to  Moderately Cross of East Anglia
February 15, 2020 10:36 am

@ MCEA you daft bugger,
You owe me a new keyboard

Moderately Cross of East Anglia
Reply to  saveenergy
February 15, 2020 11:29 am

Sorry, but why?
I just find it increasingly impossible to take any of the eco conjured-up claims and hysterical drivel at face value or worth serious comment anymore.

Reply to  Moderately Cross of East Anglia
February 15, 2020 11:53 am

Probably spilt his coffee laughing at your funny comment. This assumes the M25 carpark is empty of course.

Reply to  saveenergy
February 15, 2020 12:46 pm

Yes, it was the mental picture you conjured up made me snort

saveenergy, aka…. Angry of Anglesey.

Reply to  Moderately Cross of East Anglia
February 15, 2020 10:52 am

I imagine that an electric airplane with high torque motors would have a shorter runway. However, as batteries are low-density energy storage units, the plane would not fly, but rather progress in a leapfrog fashion with periods of rest and renewal. Think layovers with a Green blight distribution.

Leo Smith
Reply to  Moderately Cross of East Anglia
February 15, 2020 2:54 pm

Amusing as your post is, in fact electric aircraft do not suffer from lack of power.
It is lack of duration.

It’s perfectly possible to flatten a lithium battery in less than 5 minutes to give massive peak power.

Vertical take-off is no problem.

It is flying to London afterwards that is the problem

Reply to  Leo Smith
February 15, 2020 4:31 pm

Much like the cars, fun to dice with a lecky car. Then I drove home and he had to go recharge…..

In the Real World
Reply to  Moderately Cross of East Anglia
February 17, 2020 6:35 am

Did a back of an envelope calculation for electric aircraft .
A 737 is a lot more fuel efficient than earlier types , but uses an average of 750 gals an hour for a transatlantic flight & will carry fuel for 10 hrs .
7500 gals equals about 300,000 KWh of energy .
Ignoring the fact that it would have to be propeller of fan , & therefore a lot less efficient than jet , an electric aircraft would need 3000 100 KW batteries which weight over half a ton each .

So can anybody help with the calculation on how long a runway would be needed when there is 1500 tons of batteries on board

Walter Sobchak
February 15, 2020 10:34 am

I guess extending the runways is completely out of the question. N’est-ce pas?

Bryan A
February 15, 2020 10:34 am

Of course they could adapt passenger aircraft to VTOL

Bruce Hall
February 15, 2020 10:38 am

Good for my golf game, however.

Reply to  Bruce Hall
February 15, 2020 11:55 am

There’s your headline. Global warming lowering golf scores.

Michael Jankowski
February 15, 2020 10:40 am

“…A final possible explanation is an increase in surface roughness, caused by an increase in vegetation or (in our case) development around the airports…”

So development and the lack of development cause the same issue. All bases are covered.

“…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…”

Reduced winds and increased winds. All bases are covered.

Reply to  Michael Jankowski
February 15, 2020 10:45 am

Cooling… warming… change. Undeniable. Unfalsifiable.

Gerald Machnee
Reply to  Michael Jankowski
February 15, 2020 1:21 pm

Jet streams – another false claim.
If the poles are warming the jet stream will decrease. However some Brits wrote a model speculation a few years ago claiming the jets will increase and cause more turbulence. So the media ate it up as usual.

Steve Reddish
Reply to  Michael Jankowski
February 15, 2020 7:07 pm

Question about slower headwinds extending takeoff distance – Aren’t runways designed with the worst case scenario in mind – no wind at all? Any headwind would would cancel out a slight increase in temperature.

February 15, 2020 10:40 am

Note that the DHC-8 and A320 were both introduced in 1984, and that the -400 version of the dash 8 was brought out in the 1990s. The meterological data was selected from 1955 for one region. Not mentioned were the many and various business, economic, technological, and social-political factors that changed over the same periods (either 36 or 65 years, depending on which baseline is used). At minimum, such a study should at least also normalize for passenger air/distance, payload air/distance, and costs of fuel before development of an hypothesis for future research. A simpler explanation could easily be established by review of the need to carry less fuel, the means of expanding aircraft life and maintenance cycles, the increase in cargo transport, and the improvements in weather prediction and communications. In this case, it is difficult for me to imagine how the conclusion was not determined before the data was gathered. Beyond the idea of cherry-picking, this study seems to be yet another justification for an update of the GIGO law for Green ideologues: Climate change in -> climate change out.

Robert of Texas
February 15, 2020 10:41 am

It’s all good, AOC is canceling all forms of transportation anyway in her Green New Dumb.

Modern aircraft have better flight controls, better engines, and are more efficient. I can’t imagine that the next generation same-size aircraft are going to have ANY trouble taking off from existing runways – likely able to carry heavier cargo at the same time.

And since when were the Greenies claiming that Global Warming causes less wind? How does this tie into their narrative of all storms, tornadoes, hurricanes and cyclones are becoming worse?

Reply to  Robert of Texas
February 15, 2020 1:13 pm

The windmills ate up all their wind…

Reply to  meiggs
February 16, 2020 12:33 pm

And their minds.

Reply to  Robert of Texas
February 15, 2020 1:25 pm

Robert, it will get so hot that rain will become drier. Oh sure, flooding will increase, but they will be drier floods.

Reply to  Robert of Texas
February 15, 2020 1:28 pm

More storms, tornadoes, hurricanes and cyclones, and worse still air.

More of everything worse and less of everything else.

February 15, 2020 10:44 am

Local, perhaps regional, transitory (“weather”) effects.

Farmer Ch E retired
February 15, 2020 10:48 am

“. . . weaker winds are making take-off more difficult”
I wonder if the author has taken off or landed in a gusty crosswind? Most would welcome weaker winds. A 1C temp increase would be equivalent to adding about 500 feet to the airport elevation. Each new aircraft seems to be more powerful, lighter (graphite composite), and more fuel efficient.

Here are some big jets landing at Heathrow on February 9th. These pilots could definitely use weaker winds.–kauZE8

Ivar Ivarson
Reply to  Farmer Ch E retired
February 15, 2020 4:57 pm

Not so. Global Whamming theory teaches that the winds will be weaker unless they are stronger. That too, however, is an effect of Aggravated Klimate Change propaganda.

Farmer Ch E retired
Reply to  Farmer Ch E retired
February 16, 2020 8:55 am

“A 1C temp increase would be equivalent to adding about 500 feet to the airport elevation.”

I took another look and used the ideal gas law to calculate the air density change resulting from a 1C temp increase. The 1C temp increase at sea level, 1 atm, and 273 K would be equivalent to adding about 30m or <100ft to the airport elevation. Pretty insignificant. You are welcome to check my math.

February 15, 2020 10:49 am

An Airbus A320 couldn’t come even close to legally or safely operating on a 1300 meter runway. (LGHI airport in Greece). A320 balanced field length is about 2100 meters. It’s somewhat silly to talk about future limitations on something not done currently. A professor of aviation? Good grief.
Ongoing increases in aircraft power to weight ratios are far exceeding even the worst of the alarmist projections.

Reply to  CGTG
February 15, 2020 12:49 pm

Not quite a professor of aviation. “Associate Professor of Aviation and the Environment” So, almost guaranteed, incapable of actually designing an aircraft.

February 15, 2020 10:51 am

A bit OT I know, but in his autobiography ( A hostage to fortune ? ) Ernest K Gann describes his time flying “The Hump” from India in a DC3, and the problems of having to take off in the early morning before the air became warmer and thinner. He also describes how he almost wrote off the Taj Mahal. Well worth readibg if you can find a copy.

Reply to  Oldseadog
February 15, 2020 10:53 am

…. reading …
Stupid computer still can’t spell.

Reply to  Oldseadog
February 15, 2020 1:19 pm

We knew whatcha meant.

Reply to  Oldseadog
February 15, 2020 10:59 am

I think you are referring to “Fate is the Hunter”. Still easily available. A must read for any budding pilot.

Dave Ward
Reply to  Oldseadog
February 16, 2020 10:24 am

Somewhere in my old VHS collection is one entitled “The Last African Flying Boat” – documentary about one man’s attempt to recreate the Imperial Airways route from the UK to Africa. He was using a PBY Catalina which was, admittedly, not in the best of condition. After landing on a lake at some 5000ft altitude they then had considerable difficulty getting out. Numerous take-off runs during the heat of the day failed to gain sufficient speed, and eventually they gave up, waiting till dawn the next day. Even then, and having left all the passengers behind, the old girl only just made it into the air.

My own experiences of operating an ultralight aren’t quite so bad, but I do remember the difference in rate of climb: On a hot, muggy summers afternoon I used to get 600ft per minute, but on a crisp winters morning this could be nearly 900ft per minute.

February 15, 2020 10:51 am

Given the Prof seems unaware of the invention of the Turbine Engine, and the massive increase in power they offer over IC aero engines, students studying under him have my commiserations. 🙂

More seriously, is there any subject that cannot claim to be negatively affected by CC ? Apart from Climate Studies, obviously. 🙂

Reply to  Fanakapan
February 15, 2020 2:40 pm

“Is there any subject that cannot claim to be negatively affected by climate change?”

I was going to say Betelgeuse goes supernova, but I now realize it too will be blamed on climate change.

February 15, 2020 10:54 am

I’ve been flying for over 40 years. Density altitude is what you have to know to figure out your aircraft performance on takeoff. It is the altitude the aircraft actually feels as to compared to the altitude it feels on a normal day (standard pressure and temperature). For a non turbocharged aircraft (like a Cessna 172) typically the takeoff roll goes up about 25% for every 1000′ of altitude due to less engine power and lower propeller efficiency. Piston aircraft with turbochargers don’t lose the engine power so much so they have less of a performance loss. Jets and turboprops also are less effected than the little old Cessnas.

All aircraft have charts in their operating handbooks that give take off rolls based on weight, density altitude and runway conditions. Airports like Salt Lake City and Phoenix have extra long runways to compensate for their base altitudes and the density altitudes of very hot days. Phoenix actually shuts down when the temperature reaches a certain threshold. But today’s aircraft engines are very powerful and the aircraft they go on typically don’t have an issue with density altitude.

I can only remember two times I had to wait on the temperature to drop to depart, and even then I was legal to depart but didn’t want to chance an engine failure at marginal conditions. I really find it hard to believe aircraft will have to restrict operations on what is stated in the article. I wonder if any of the authors even looked at how much margin is built into the aircraft. I can remember leaving SLC on a fully loaded L-1011 in July on a really hot day and getting out. (The L-1011 was notoriously underpowered compared to today’s aircraft). It took all 12,000′ and we circled the airport 3 times to get enough altitude to clear Park City to head east, but if we made it with the L-1011, today’s aircraft will easily make it.

Reply to  rbabcock
February 15, 2020 11:27 am

In the past, if there was a commercial advantage, the authorities would just extend the runway. I can’t see that reasoning changing, unless there are planning consideration (aren’t there always of course).

I think the only time I have had to wait for the temperature to drop, was due to brake temperatures which were over the limit, due to the couple of short hops we did in Africa. That was a DC10. From a performance point of view the worst occasions I have come across are when there was snow & icing conditions. That really knocks the performance.

At our local airport there is a move afoot to ensure aircraft take off and land in each direction 50% of the time, to share the noise around, despite the fact that the prevailing wind is westerly. Taking off in a tailwind has a tendency to reduce performance!

With that sort of thinking who needs global warming.

Reply to  JBW
February 15, 2020 11:37 am

Taking off in a tailwind has a tendency to reduce performance!

Well, according to the article, winds are slowing down and changing direction, so you have that going for you!

My suggestion is putting some the more vocal proponents of the asinine suggestion in your right seat on a very windy day, taxi out to the runway with the tailwind and tell them there is a 30-70 chance you will get off the ground before the end of the runway due to the tailwind so buckle up tight.

Reply to  rbabcock
February 15, 2020 11:48 am

Splendid Idea.

Dave Ward
Reply to  rbabcock
February 16, 2020 10:34 am

“The L-1011 was notoriously underpowered compared to today’s aircraft”

But probably still better than the B707:
And this (now legendary) clip from DownUnder: “The Vodka Burner is Rolling”

Tom Abbott
February 15, 2020 10:57 am

From the article: “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.”

Well, there’s no evidence for this. These scientists just pulled this claim out of thin air.

Reply to  Tom Abbott
February 15, 2020 11:06 am

Turbulence in jet streams is mainly due to the shear caused by the rapid change of windspeed within the core of the jet. Generally, if it was severe, we would just change altitude by 2000 ft or so. Negotiating a change of altitude mid Atlantic could be a slow process though, especially when the only method of communication was HF radio!

Gerald Machnee
Reply to  Tom Abbott
February 15, 2020 1:25 pm


Reply to  Tom Abbott
February 15, 2020 4:44 pm

Is that why on feb. 8 a flight New York – London finished after 4:56 h instead of somewhat over 6 hs ?

Nick Schroeder
February 15, 2020 11:14 am

Not a problem for DIA or Aspen even on hot days

Mike From Au
February 15, 2020 11:23 am

Bees are also subjected to reduced air densities.
Honey production may also slow if bees are subjected to reduced air densities. It would then be blindingly clear that therefore the added ‘in-flight turbulence’ would also contribute to slowing honey production.

From the article……”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.”

February 15, 2020 11:28 am

If you are from Alabama you could face more cuts than just your air miles.

Flight Level
February 15, 2020 11:29 am

(2x palmface)
Penny pinching and noise abatement keep us on ground further than climate few degrees shift ever could for whatever ground temperatures accuracy means to airports. Which in practice for summer operations resumes punching 25C for the southbound and 30C for the northbound legs while trying to figure how understated the “cabin weight” will be.

A piece of cake when compared to winter icing voodoo algebra.

Earlier companies school was to get up like homesick angels. Never mind old Capt’s grunting, evil fuel flows and EGT’s, quicker up, quicker in thin air savings, faster at destination, more speed, more prestige, more better.

Then the word was to keep noise down and guess, less revs mean less noise as long as there’s runway to spare.

Some noise abatement gurus even tried to outlaw flaps but I guess were quickly brought to more appropriate for their mental state medications.

High and higher bypass super fuel saving turbofans brought asymmetric take-off thrust anxiety to new levels.

Finally alien civilizations were hired to establish flight crew operating manuals and implement the corresponding algorithms in the thrust management computers.

Surprise, take-off’s turned longer when all was taken into account, fuel saving, noise abatment, engine and airframe wear and tear, safety and somewhere deep sown the list, passenger comfort.

Which is BTW what old grumpy steam-gauges Capts (with a capital “C” please) used to yell, as long as there’s runway, use it !

So yes, globally we take our time at take-off and our distances have comparatively increased with respect to the golden age.

However this has nothing to do with global warming, so, for cryin out loud Mr. Professor, mind your own business, whatever this might be and stay clear from serious topics.

Reply to  Flight Level
February 15, 2020 11:43 am

Funny, but so true!

Carl Friis-Hansen
Reply to  Flight Level
February 15, 2020 4:05 pm

After reading the article I thought: What have the professors been smoking.

I remember a flight with a 747 from Copenhagen to New York, where the captain said we were a bit late. I have flown a few times with 747, but this time it felt like he was only using a few hundred meter of the runway. I must note that it were some decades ago.

So from above mentioned acceleration, I assume the professors were fantasizing.
For confirmation I searched the page for Flight Level and got my suspicion confirmed.

I think it is tragic that CC politics and Green money spinning has sunken to a level where professors writes stories so stupid and ignorant, that it could have been a dictate from a Swedish teen.

Flight Level
Reply to  Carl Friis-Hansen
February 15, 2020 7:11 pm

CFH, reputable companies would (should ?) consider the cost of missed connections with respect to extra fuel and according to the weather (not climate !) mood and “uh-uh” fuel reserve of the day, dictate us to punch a higher cost index.

Which, because in such case, cost of time massively prevails cost of fuel, results in guzzling take-off, gunned initial then slower climb and overall a greater average ground speed profile.

Affordable mass travel is a very complex system of equations, far above the comprehension altitude of politicians and wannabe green economy experts, let alone indoctrinated brainwashed voters.

Reply to  Flight Level
February 15, 2020 4:27 pm

How do new reactor designs make the asymmetric power risk more serious?

Flight Level
Reply to  niceguy
February 15, 2020 5:43 pm

NiceGuy, officially, on all jet engines, particularly on high bypass burners, the acceleration profile is not linear. Control law is defined to optimize the acceleration in a way that the risk of engine stall is reduced.

The more airfoils become fuel-optimal, the less tolerant they are to stall. Compressor & hot section blades inclusive. Mixed with unavoidable tolerance discrepancies and wear & tear, thrust management becomes quite a deal.

Specifically when only 2 engines with huge rotational inertia are in charge of the operation.

Single engine taxiing, late starts, cross-gusts add their cumulative effects to the mix.

Once well primed, veering oscillations on acceleration roll will increase unless split second take-off reject.

It feels like if you’re gunning a Winnebago uphill on an iced road.

February 15, 2020 11:31 am

Maybe a good idea anyhow to reduce the seating. Would give everyone a little extra room. And this shows there are benefits to climate change

February 15, 2020 11:34 am
Ivar Ivarson
Reply to  MrGrimNasty
February 15, 2020 4:50 pm

Not to worry, the UK will get more and more of its energy needs from the wind. Wonder what the overall engineering assumptions are for wind turbines? Declining? Sure hope those don’t contradict the cited aviation study.

February 15, 2020 11:36 am


Thanks, rbabcock.

Many posts by many with little actual knowledge of the problem, much less experience. But I can forgive a certain amount of ignorance.

With about 4,000 hours of fighter time that included several hundred operating at max gross weight and in a hot, humid climate to go blow up things and hurt people, I feel qualified in this matter and agree with rbabcock. A few degrees is like a thousand feet of altitude, and the turbine engines feel it as much as the motors with propellors, maybe a bit more.

While the alarmists have a sliver of real science and engineering to support their conclusions/findings, or whatnot, it is like the model predictions they disagree with – all the emission reduction possible might only lower temp by a fraction of one steenkeeng degree, and result in 8 inches of seal level rise in 100 years or longer from now. Our roll might be another few hundred feet, maybe a thousand feet longer at higher temperatures, so big deal.

Make no mistake, however, about the proven facts and performance of aircraft and engines. Density altitude and gross weight are huge players for we pilots trying to get off the ground in the available runway. And basic weight still obeys one of Newton’s laws concerning foce and mass and acceleration. That means you better check the charts at high altitude, high temperature with a very heavy plane.

Gums sends….

Reply to  Gums
February 15, 2020 12:12 pm

Assumption here,

If the Prof is waving the scare flag in relation to Civil Aviation, then over the time frame of change (not 12 years), aircraft designs would evolve to have larger wing area or diminished carrying capacity, or even bigger engines ? Its not inconceivable that the time could come when the A380 is shown to have been ahead of its time, rather than being a disappointing speculation.

Airport expansion is something of a hot topic here in the UK at this time, so whilst the facts concerning air density and lift potential are very real, I’d have to think that the Prof is trying to get on the bandwagon that portrays peasants houses being demolished to extend runways and thus pander to those who are supposedly destroying Mother Gaia.

As ever the advice regarding Bandwagons applies, to wit, once you can see it, its too late to jump on. 🙂

Reply to  Gums
February 15, 2020 1:47 pm

Was the goal to hurt some people, blow up their things, or to defend other people, and conserve their things?

James the Elder
Reply to  n.n
February 15, 2020 5:37 pm

All of the above.

Reply to  Gums
February 16, 2020 9:40 am

Density altitude problems were a part of basic flight instruction when I took it in the Sixties .

Density altutude is just one of msny factors that have to be kept in mind when flying. It is hardly a novel issue. You adjust to changing conditions. If you land a light plane at a short, high altitude airport on a day that gets hot you are wise to wait for late afternoon cooling before trying to take off. Been true forever.

Meanwhile, places like Phoenix and Tucson fly regularly with temperaturrs well over 100 degrees though at aroud 120 they check their air density tables more carefully I suspect.

Reply to  Young
February 16, 2020 11:12 am

As a young troop, US Army, I was taught methods and necessity for gauging atmospheric conditions for calling in helicopters for resupply, extractions, insertions, dustoffs and close air support. Almost as if these sorts of conditions and issues were already well known to the aviation industry and those who utilize its components! Guess the schmucks pushing this “study” could use some remedial training under the harsh and unrelenting direction of some senior NCOs.

Johann Wundersamer
Reply to  Gums
February 26, 2020 6:59 pm

Gums, “Many posts by many with little actual knowledge of the problem, much less experience.”

You assume world population doesn’t consist solely of Airline- and Bush Pilots.

There still must be Resistance Nests of pedestrians.

February 15, 2020 11:41 am

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.

We humans sure are clever creatures. Higher, faster, farther, safer, cheaper.

Gary Pearse
February 15, 2020 11:44 am

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.

Sal Minella
February 15, 2020 11:49 am

“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.

February 15, 2020 11:50 am

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.

Michael Jankowski
February 15, 2020 12:02 pm

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…”

February 15, 2020 12:13 pm

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,

Tom in Florida
February 15, 2020 12:15 pm

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.

February 15, 2020 12:19 pm

“operating from the, relatively short, 1511m runway at Chios Airport”


In my book, that’s ridiculously short for an airport designed medium range planes.

February 15, 2020 12:43 pm

Electromagnetic catapult for every runway. Just shift the bulk of flight movements to night.

Peter Morris
February 15, 2020 12:56 pm

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.


Reply to  Peter Morris
February 15, 2020 1:28 pm

“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.

Clarky of Oz
February 15, 2020 1:11 pm

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?

Gerald Machnee
Reply to  Clarky of Oz
February 15, 2020 1:27 pm

Over the water the temperatures do not get as hot as over land.

Reply to  Clarky of Oz
February 15, 2020 3:27 pm

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.”

Jean Parisot
February 15, 2020 1:15 pm

I believe airport weather is biased hot to ensure pilots are on the safe side of the density altitude formula.

Gerald Machnee
February 15, 2020 1:29 pm

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.

February 15, 2020 1:42 pm

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.

David Dibbell
February 15, 2020 1:43 pm

Forget climate change. Passenger weight is a more widespread problem!

Reply to  David Dibbell
February 15, 2020 1:53 pm

Not available in UK or Europe

David Dibbell
Reply to  saveenergy
February 15, 2020 2:53 pm

FAA raises weight calculation for fliers
Jon Hilkevitch Chicago Tribune
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.

John Hardy
February 15, 2020 1:50 pm

If troubled by density altitude, go for night time departures when it is cooler as ain Nairobi. Doh

February 15, 2020 1:52 pm

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.

February 15, 2020 2:00 pm

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.

Hocus Locus
February 15, 2020 3:14 pm

Your average furry house pet will have 500 less hairs

old engineer
February 15, 2020 3:34 pm

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.

Reply to  old engineer
February 15, 2020 6:00 pm

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.

Svend Ferdinandsen
February 15, 2020 3:56 pm

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.

Martin Howard Keith Brumby
February 15, 2020 3:57 pm

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.

Ivar Ivarson
February 15, 2020 4:37 pm

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.”

February 15, 2020 5:47 pm

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

Len Werner
Reply to  Duane
February 15, 2020 7:02 pm

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.

Reply to  Len Werner
February 16, 2020 5:27 am

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?

Len Werner
Reply to  Duane
February 16, 2020 7:35 am

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…

Joel O'Bryan
February 15, 2020 5:52 pm

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?

February 15, 2020 6:23 pm

No problem at all .
Greta is arranging a fleet of ocean going sail boats .
Locals can sit on the floor in a train .

Robert of Ottawa
Reply to  george1st:)
February 15, 2020 8:22 pm

Passengers on the ocean liners can row.

Robert of Ottawa
February 15, 2020 8:21 pm

Global warming will make airports bigger! Is there anything that isn’t made bigger, smaller or dangerously similar by global warming.

James A. Schrumpf
February 15, 2020 8:33 pm

The stupid truly burns with this one. Planes fly in Greece winter and summer, the the temps vary by 17.7 C between the seasons,; yet another bit of fractional warming will wreak havoc?

Truly, ivory tower thinking at its finest.

Reply to  James A. Schrumpf
February 16, 2020 8:22 am

Forget Greece, just look to North/South Dakota airports if you want a massive variation in temps and winds.

February 16, 2020 1:05 am

The vital thing about all research is that it must identify areas of future research to keep and enhance the findong stream and the soze of the professor’s department. So expect new grant applications for research into the effect of increased surface roughness around airports on aircraft take-off performance resulting from enhanced vegetation growth due to climate change.

February 16, 2020 1:49 am

…. to keep and enhance the funding stream and the size of the professor’s department

February 16, 2020 2:29 am

“There are some ideas so absurd that only an intellectual could believe them”- George Orwell.

Reply to  Herbert
February 16, 2020 5:22 am

The surplus value to afford ever more marginal dilettanti is the major downside of the Industrial Revolution and the use of fossil fuel energy. Some days you get the feeling a good sharp dose of Pol Pottyism mightn’t go astray.

February 16, 2020 5:13 am

Will the batteries be able to cope getting the EPs off the ground before we can manage to cool the runways? I feel a grant application coming on.

February 16, 2020 5:17 am

Why should we worry about a 2 degree C increase at airports in 2050 (or whatever year in the future), if temperature this afternoon is going to be 10C higher?

February 16, 2020 6:30 am

FADEC systems often don’t run at fullest fwd fan speeds as not usually needed. there is leeway.
oh noes….the hot sky is falling cats and dogs are copulating etc etc….

Ian W
February 16, 2020 8:14 am

For commercial aircraft on a particular runway the aircraft is intended to achieve weight off wheels at close to the same point on a particular runway regardless of temperature or wind. The climb out should follow almost the same profile each time as that is often a noise abatement requirement.

What everyone seems to forget is that the air carrier dispatcher’s task is to ensure that each flight is safe, efficient and as much high value freight can be added if there is spare weight/volume for more cargo.
The dispatcher has:
> The passenger and passenger baggage load which can be guessed/assumed but is a little more certain after the bags have been checked in. This leads to recalculation of all values after check in has closed and within an hour of Target Takeoff Time – more freight could be added.
> The fuel load required, the aircraft must land at destination with a set endurance to allow diversion if required to a defined diversion airport. The fuel calculation is based on winds and temperature over the entire route and the crew spend a lot of time during the flight confirming that the actual fuel burn is what was forecast
> Takeoff performance of that particular aircraft (engine age can affect performance) – the aim is to use the minimum power necessary to be safely airborne before there is insufficient runway left to stop safely (see ) The days of firewalling the throttles for takeoff have long gone, too much noise, fuel burn and engine wear.
> If at the particular performance index the dispatcher wants the aircraft to use for the flight, the aircraft takeoff distance is not correct then the performance index can be increased/decreased OR the amount of high value cargo can be increased/decreased.

Modern aircraft have so much surplus power that even ‘hot and high’ airports are not usually a problem unless the dispatcher has made a mistake in calculations and loaded too much weight; and the flight crew who [should] cross-check those calculations do not pick up the error. In most cases both dispatcher and flight crew have computer decision support tools to do these calculations.

The very small changes in temperature, claimed to be due to ‘global warming’ are well within the performance capabilities of modern aircraft. If the runways are too short for safe operations then air carriers stop operating affected aircraft to the airport, the airport starts losing business until it extends the runway. It is a self correcting safe system.

No need for white knuckles on takeoff.

Jean Parisot
February 16, 2020 8:28 am

I wonder what the effect of today’s passenger routing algorithms that keep flights full are on takeoff rolls?

Kelvin Vaughan
February 16, 2020 8:56 am

The people who make these stupid claims always forget the variation in temperature across the planet. They are stuck in an average box.

Reply to  Kelvin Vaughan
February 16, 2020 10:51 am

+ 10. Should be obvious that the delta to the peaks are ten to twenty times the change to the average that would be caused by even worst case Global Hysteria temperature change.

February 16, 2020 10:43 am

I would surmise that aircraft have a much larger problem with the ever continual “Urban Spread: and the ensuing “Noise Control” rule changes about takeoff/landing flight paths and permissible power levels to meet these rules.

February 16, 2020 11:42 am

“Global Warming” is small compared to the “Airport Heat Island” warming that has occurred in the past few decades.
In UK, the paved area at LHR has doubled with the addition of ‘Terminal 5’ and the new and now much larger ‘Terminal 1’.
In Australia, BOM had to make a 2 Celsius temperature adjustment at RAAF Amberley to cover the years from 1940 to 1980 – when the weather station was located within a growing Airport Heat Island. (Since 1980 Amberley RAAF weather station has been well-sited outside of the AHI.)

michael hart
February 16, 2020 11:54 am

Climate Prediction: “Take-off distances will get longer as the climate warms”

Maybe. But passengers will also need to wear less clothing in warmer climates, thus reducing baggage weight carried by aircraft and shortening take-off distances.

I could think of other arguments like this all day long if somebody paid me to do it. Is it a facetious argument? Yes. But it is little different from, and no worse than, that which is engaged in by the climate alarm industry.

There aren’t many thing in the universe that are NOT affected by temperature changes. So it’s just a short step to claim that temperature changes from global warming might adversely affect pretty much any variable under the sun. Of course, sensible people know that the changes will likely be trivially small or beneficial but the alarmists then just claim that it’s “uncertain”, and more money is still needed to study it. How did we arrive at this insane state of affairs?

February 16, 2020 12:57 pm

Won’t the air be heavier and more buoyant with all that co2.

February 16, 2020 3:00 pm

I’m in turbine repair. Around 2008-2009 we lost an airfoil contract (for one of the ‘Big 3″ american airlines) to a repair house in Mexico for 1/2 the price we were charging. We said “whatever” and moved on to more profitable parts.

About 6 months later, planes were parked all over the US because the Mexican repair shop didn’t understand that LPT airfoils need to machined to close tolerance at repair, or they can fracture…and they did. Turbines with broken airfoils can’t fly.

The Airline came crawling back and told us they would pay what they had been paying us + a premium until there fleet was back up. We initially told them no, but they threw money at us.

The Airline’s excuse to the media for all of the parked planes? It was summer, so… Global Warming. I am not kidding.

John Culhane
February 16, 2020 3:49 pm

It’s always fun looking back at these predictions. This one was commissioned for the world wide fund and written by David Viner then of the University of East Anglia about the impact of climate on tourism in 2020

Climate Change and Its Impacts on Tourism
Report Prepared for WWF-UK
David Viner and Maureen Agnew
Climatic Research Unit
University of East Anglia
Norwich, UK NR4 7TJ
July 1999

Had to go to the wayback machine for it. Enjoy.

Cold Guy
February 16, 2020 7:29 pm

This is nothing more than just another alarmist piece designed to pepper the ignorant public into taking action for no good reason. As a pilot of heavy aircraft with nearly 5,000 hours, I can absolutely tell you it is just spin with little to no real impact.

Even if the temp were to rise 2-3 degrees on average (stupid concept), it is no different than taking off at 9 AM versus 7 AM, and you know, in that time, that big thing in the sky warms it up maybe 5 degrees anyway. Hmm. Temperature is a big deal when computing performance and it definitely affects performance, but the variation in any given day has waaaay more affect on ops and it doesn’t seem to make an impact now, except for aircraft operating on the ragged edge of performance in the first place. And that is not normally a common occurrence. Sure, it happens, but out of my thousand or so flights, I had to seriously crunch numbers and was on the ragged edge maybe a couple dozen times due to mission requirements, runway length, temps, weight, pressure altitude, etc. And when we were a No-Go, we simply burned some fuel, waited for a headwind call (something I normal didn’t use, its gravy), or some other factor that increased takeoff performance. I never cancelled or was seriously impacted due to temps. And I have flown a huge amount in very hot climates.

The sad part is some yahoo alarmist will cite this as a serious issue….it isn’t.

February 17, 2020 4:26 am

lol … increase the engine thrust or carry less weight boneheads!

Johann Wundersamer
February 26, 2020 5:48 pm

Eric Worrall,

We keep in mind that

Guy Gatton, Associate Professor of Aviation and the Environment, Cranfield University


Paul D Williams, Professor of Atmospheric Science, University of Reading

Declare: higher temperatures are associated with weaker winds.

“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

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.”

Johann Wundersamer
February 26, 2020 6:05 pm

The link

“subject to in-flight turbulence, which is getting worse”

gives: 404: Page not found –

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Johann Wundersamer
February 26, 2020 6:41 pm

“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.”


There’s Airports south of Greece, near the sea, e.g. Abu Dhabi, with warmer environment than Athens.

And where Airbus A320′ easy arrive at and depart.

– what for “studies” – Profs. Guy Gatton & Paul D Williams could ring Abu Dhabi. Or any charter line.

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