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« Greenshirt thuggery condemned | Main | Greens blighting communities »
Wednesday
Feb102016

Tail wind

I once faced off against Paul Williams of Reading University in a radio debate. He came across as a pretty rational kind of guy and we had a nice exchange of emails afterwards. But I have to say that his most recent paper is one of those ones that make you despair with their sheer futility. Here's the BBC take on it.

Flights from the UK to the US could take longer due to the changes in the climate, according to a new study.

Global warming is likely to speed up the jet stream, say researchers, and slow down aeroplanes heading for the US.

While eastbound flights from the US will be quicker, roundtrip journeys will "significantly lengthen".

It's published in Environmental Research Letters, which is usually not a good sign. The authors apparently fed "synthetic atmospheric wind fields generated from climate model simulations into a routing algorithm of the type used operationally by flight planners" and deduced that westbound transatlantic flights were going to take longer while eastbound flights will be faster. But, almost inevitably, the losses are expected to outweight the gains.

I wonder what evidence there is that GCMs can predict, or even hindcast, changes in wind speeds in a warming world? 

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Reader Comments (109)

"Climate Models" enough said.

Feb 10, 2016 at 10:25 AM | Unregistered CommenterSean

Is global warming going to speed up the Jetstream? I dispute the proposition. As with extreme weather events (the incidence of which global warming is said to increase), the speed of the Jetstream is dependent upon the TEMPERATURE DIFFERNCE of adjoining air masses. Since global warming, by definition (it is “global”) increases the temperatures of air masses by the same amount, the temperature difference is unaffected by it. So, therefore, is the wind speed.

Feb 10, 2016 at 10:26 AM | Unregistered CommenterRichard Green

But, but, but, the NOAA said


Enhanced warming of the Arctic affects the jet stream by slowing its west-to-east winds and by promoting larger north-south meanders in the flow.

http://www.noaanews.noaa.gov/stories2012/20121010_arcticwinds.html

File under Settled Science.

Feb 10, 2016 at 10:49 AM | Unregistered CommenterCB

So disappointing that these serial fantasists keep dragging Reading's once respectable name through the ordure.

Haven't we all been told, ad nauseam proiectum that the *models* say the the poles warm differentially faster under AGW?

And don't we know that winds are in no small part generated by temperature differentials between tropical and polar regions?

So why would winds get stronger when there's less of an energy differential to redistribute?

Or did I miss something important here?

Feb 10, 2016 at 10:54 AM | Registered Commenterflaxdoctor

Er, sorry Richard, that was what you said...

Feb 10, 2016 at 10:56 AM | Registered Commenterflaxdoctor

Re: CB

Standard practise. If it speeds up then it was predicted, if it slows down then it was predicted. There is probably one tucked away somewhere that says there will be no change.

Feb 10, 2016 at 10:59 AM | Unregistered CommenterTerryS

For those wondering about projected temperature gradient changes: please appreciate that the surface T gradient changes are *opposite* to those at high altitudes. Airplanes cruise at around 250-300mb.

IPCC AR5 Fig. 12.12:

Ed.

Feb 10, 2016 at 11:13 AM | Unregistered CommenterEd Hawkins

Thanks for that Ed.

What's the answer to the question about climate models' skill in this area?

Feb 10, 2016 at 11:16 AM | Registered CommenterBishop Hill

Also, this is a classic in climate "science" in that it assumes that everybody will just stumble on doing exactly what they did before, when circumstances change. Do they not think there is any chance that airlines might alter the flightpaths in response to the strength, direction etc of the jetstream? Have they, in fact, ever noticed how flightpaths change today, all the time, in response to the jetstream?

Thought not.

Feb 10, 2016 at 11:20 AM | Unregistered Commenteragn

Perfect example of Poe's Law.

Feb 10, 2016 at 11:22 AM | Unregistered CommenterJonathan Abbott

Hi BH,

I don't know the answer to the question about climate model skill for jet stream wind speeds - perhaps someone else does? However, as some of your commenters have already said (Richard and flaxdoctor) - basic physics suggests that the T gradients are important here, and so an increase in T gradient (as projected) should increase wind speeds.

Ed.

Feb 10, 2016 at 11:23 AM | Unregistered CommenterEd Hawkins

The Met office only started talking about the Jet Stream fairly recently.
5 or 6 years ago there was no mention.

If it has now been included in global climate models I suspect this is a fairly recent development.

On the other hand the Jet Stream formed the cornerstone of the long standing climate model by Piers Corbyn the climate skeptic and brother of our next Prime Minister

Feb 10, 2016 at 11:27 AM | Unregistered CommenterBryan

"What's the answer to the question about climate models' skill in this area?"

The same as their skill wrt locationally specific forecasts.

BTW - Ed is that graphic really a forecast for the time period 2081 to 2100?

Feb 10, 2016 at 11:28 AM | Unregistered Commenternot banned yet

Why do people get grants to do this stuff?

Feb 10, 2016 at 11:32 AM | Unregistered CommenterSchrodinger's Cat

Piers Corbyn (www.weatheraction.com) has an alternative explanation to deadly CO2 causing the wild jet stream behaviour. He seems to think that the Sun has something to do with it.

It is standard meteorology that the recent wild weather extremes and contrasts follow from the wild Jet Stream (Mini-Ice-Age) behaviour...

‘Sudden’ winter warming of parts of the stratosphere are known to precede extra wild behaviour of the Jet stream...

The main periodical solar activity effect - the largest observed periodicity present in world temperature data - is the 22 year cycle (driven by sun-earth magnetic connectivity).

Feb 10, 2016 at 11:32 AM | Unregistered CommenterJack Dawkins

I love the concept of pre-industrial airliners but how about some experimental data?

In 1998, my last full year of flying the 747 Classic (widely derided as pre-industrial), I flew 98 Atlantic crossings including 12 flights from LHR to JFK and 12 from JFK to LHR. The typical cruising level was around 30,000 feet c 265 millibars.

My (unadjusted!) log book shows that the outbound (westbound) flights took [in hours and minutes]: 07.18; 07.29; 07.52; 08.08; 07.54; 07.33; 07.31; 07.35; 06.35; 07.20; 07.23 and 07.50.

The inbound (eastbound) flights took: 06.48; 06.46; 07.16; 06.41; 06.43; 06.52; 06.51; 07.05; 08.00; 06.48; 06.50 and 06.49.

Whilst these are flight times measured over the whole year rather than just in winter, they do seem to disagree radically with the modelled times in this, presumably taxpayer-funded, paper.

Feb 10, 2016 at 11:33 AM | Unregistered CommenterMike Post

"The wrong kind of jet stream."

Feb 10, 2016 at 11:35 AM | Unregistered Commentermichael hart


I wonder what evidence there is that GCMs can predict, or even hindcast, changes in wind speeds in a warming world?

Probably that they're based on some pretty fundamental laws of physics. What's your expectation? That we won't warm, or that we'll warm in some way that we won't see any changes to things like the jet stream, or you just don't know so assume that noone can know, or you're just asking questions?

Feb 10, 2016 at 11:41 AM | Unregistered Commenter...and Then There's Physics

...and Then There's Physics


"What's your expectation? That we won't warm"


Haven't we all agreed that temperatures haven't increased since 1998 ? Some call it a pause. I'm calling it a cessation. What about you ?

Feb 10, 2016 at 11:45 AM | Unregistered Commenteresmiff

From Matt McG's piece:

"Blowing hot and cold
While at present there is no firm observational evidence of changes in the jet stream, scientists point to the fact that the record time for a non-Concorde flight from New York to London is currently 5 hours and 16 minutes, set in January last year.
"We know what drives the jet stream, it's the temperature difference between the warm tropical regions and the cold polar regions at flight levels," said Dr Williams.
"We understand what that temperature difference is going to do in response to global warming, it's increasing, we are very confident that the jet stream is increasing as a consequence." "


If the air warms, it becomes less dense, and consequently offers less resistance. By how much would that counteract any increase in windspeed?

Feb 10, 2016 at 11:55 AM | Unregistered CommenterJoe Public

The CO2 Cult lives off bad-news headlines. They know they need them to keep the grants flowing in, and the preaching and prosyletising invitations as well. As someone noted on another thread a few days ago, it is so refreshing to read science papers and associated books from before this era of panic and hyperbole.

Feb 10, 2016 at 12:00 PM | Registered CommenterJohn Shade

I file this under: possible, but who cares, is it worth spending valuable research money on?

Feb 10, 2016 at 12:01 PM | Unregistered CommenterTheBigYinJames

The way these cons work is that the reader is sufficiently distracted by whatever impending catastrophe is being projected to forget that the assumption of a significantly warmer world is unsubstantiated.

There are an endless series of these scaremongering projections for which the magic words 'climate change' have opened a bottomless treasure chest of government funding.

Feb 10, 2016 at 12:05 PM | Unregistered Commenteresmiff

...and Then There's Physics

Probably that they're based on some pretty fundamental laws of physics.

Fundamental does not mean simple or even necessarily soluble. So why should we expect to be able to predict the Jet Stream? We can't even predict the rate of temperature rise.

Still, I am here to learn. So clarify for me please...
Please explain to me how the AGW caused by CO2 will affect the direction of the winds, the formation of the clouds and the movement of the humid air relative to dry air.
While you're at it, please explain the structure of the clouds - size of ice particles and water droplets.

Please explain the impact of AGW on the rotation of masses of air. After all, if AGW causes the Jet Stream to accelerate, will it accelerate rotationally instead - forming eddies?

Who knows?

It's a fundamental law of physics that chaotic systems are not easy to extrapolate when the parameters enter an unknown region. That's climate that is. You don't get to pick and choose your fundamental laws of physics.

Oh, and finally there is another factor to consider here - people react.
How will Airplane technology advance? And how will pilots react to that day's weather?

Is that also a fundamental law of physics?

Feb 10, 2016 at 12:06 PM | Registered CommenterM Courtney

The IPCC picture that Ed links to is the notorious missing tropical hotspot. Yet in the Guadian, Paul Williams is claiming that “This is good hard science that we understand very well”.

Feb 10, 2016 at 12:16 PM | Registered CommenterPaul Matthews


Is that also a fundamental law of physics?

No.

Feb 10, 2016 at 12:34 PM | Unregistered Commenter...and Then There's Physics

Paul Matthews,

Thanks for pointing that out. That's what I thought when I saw it, but wasn't sure. But then, I'm not a "climate scientist."

Feb 10, 2016 at 12:35 PM | Unregistered CommenterPhil R

Just another "Global Warming scare story of the day" surely ?
The idea of science papers is that they have new and original work ..or try to test others by replication.

Well funny that we have done this one* before with Paul Williams all over the BBC/Ususal-suspects in 2013
"It's certainly plausible that if flights get diverted more to fly around turbulence rather than through it then the amount of fuel that needs to be burnt will increase," he told BBC News.
paper PW with Dr Manoj Joshi of UEA published in Nature Climate Change, (just cos it's in Nature doesn't automatically mean its wrong!)
I quote from the abstract

Clear-air turbulence is linked to atmospheric jet streams6, 7, which are projected to be strengthened by anthropogenic climate change8. However, the response of clear-air turbulence to projected climate change has not previously been studied. Here we show using climate model simulations that clear-air turbulence changes significantly within the transatlantic flight corridor when the concentration of carbon dioxide in the atmosphere is doubled.
See it double dipping almost same paper from different grant money
But they get to have two propaganda scare stories
..GreenBlob speaks : More propaganda, than science.

* BTW "Authors" ,no it has one author

Feb 10, 2016 at 12:37 PM | Registered Commenterstewgreen

If I'm reading the picture correctly, I also not that there is no ocean warming at depth in any of the RCP scenarios. Where's the missing heat?

Feb 10, 2016 at 12:38 PM | Unregistered CommenterPhil R

Further to my comment at 11:55 relating to the warmer air the planes will be flying through, reduced air resistance is beneficial in both directions.

Another, probably greater benefit that also applies to flights in both directions, is is that warmer air aids combustion in that it needs less fuel to achieve combustion temperature.

Did the researchers factor that, too, into their calculations, I wonder.

Feb 10, 2016 at 12:46 PM | Unregistered CommenterJoe Public

Whilst these are flight times measured over the whole year rather than just in winter, they do seem to disagree radically with the modelled times in this, presumably taxpayer-funded, paper.
Feb 10, 2016 at 11:33 AM | Unregistered CommenterMike Post

According to my calculation from Mike's 1998 flight times:

Westbound flights
Total flights: 12
Average flight time: 7.32hr
coefficient of variation* of flight times: 5.1%

Eastbound flights
Total flights:; 12
Average flight time: 6.71hr
coefficient of variation of flight times: 6.8%

So Mike's westbound flights averaged ~37 minutes quicker than his eastbound flights.

____________________________________________________________________________________
* Standard deviation/mean

Feb 10, 2016 at 12:50 PM | Registered CommenterMartin A

But, almost inevitably, the losses are expected to outweight the gains.

Estimating small differences is difficult to do reliably even when when you have concrete data.

When you have the output of models (aircraft routing and performance) riding on the back of other models (climate predictions) estimates of small differences are, on any realistic assessment, going to be complete bollocks.

Feb 10, 2016 at 12:52 PM | Registered CommenterMartin A

Paul Williams is interviewed on BBC World and tells us the troposphere is warming and this is why the round trip to the US from Europe will take an extra two minutes. Possibly a naive question: looking at www.drroyspencer.com/latest-global-temperatures - I wonder if this warming is more significant than previous highs? Assuming I am not conflating data from different parts of the atmosphere, were flight times altered in 1998?

Feb 10, 2016 at 12:53 PM | Unregistered Commenteralleagra

Re: aTTP

> Probably that they're based on some pretty fundamental laws of physics.

Curious then that there are so many different models producing different results. After all, if all that mattered was a couple of basic physics equations then there would only be one model.

Could it be that the complex interactions between the many different systems, the feedbacks - positive and negative, known and unknown means the making predictions projections of this sort is little better than guesswork?

Run it on another model, or even this one with different starting conditions, and different results will emerge.

Feb 10, 2016 at 12:53 PM | Unregistered CommenterTerryS

On a fundamental level, I'm always amazed how (Tranatlantic) airline pilots always manage to find the clear-air turbulence just when you've been served your coffee....

Feb 10, 2016 at 12:58 PM | Unregistered Commentersherlock1

I really am starting to wonder why the type of people doing this "research" aren't bloggers like me aren't getting massively paid jobs in prestigious Universities.

Compare:
Paul Williams researching yet another simulation and "proving" that oh so evil global warming is going to make the flights of all those green hypocrites longer (German research showed green voters are far more likely to fly). So predominantly this is going to affect hypocritical greens more than others.

Mike Haseler (me) researching the potential impact of reduced atmospheric pressure during the ice-age cycle and how the increased average wind speeds in a low pressure atmosphere this might affect the Hadley cell structure tipping us between a 1/2 and 3/6 structure.
A complete explanation of the ice-age cycle..

PS, The article also outlines the model explaining how atmospheric pressure and greenhouses gas BOTH affect temperature, the importance of CO2 and plants in creating and modulating the H2O greenhouse effect. The role of clouds in creating the necessary negative feedback that dominates in inter-glacials and prevents further warming.

Feb 10, 2016 at 1:05 PM | Registered CommenterMikeHaseler

"a growing number of studies confirm this blah blah"
....As we can see often same old people, churning out the same old crap, self citing each other. All to generate more scare. Almost an IPCC MO.i

Feb 10, 2016 at 1:05 PM | Registered Commenterstewgreen

The sums apparently took a long time:
//
Our results provide further evidence of the two-way interaction between aviation and climate change. Future work is needed to apply our methodology to other flight routes globally, such as transpacific, transpolar, and cross-equatorial routes. Future work should also quantify the model-dependent uncertainties by using atmospheric wind fields from other climate models. A major limiting factor is likely to be computational resources, because calculating the minimum-time routes is computationally demanding. Indeed, previous studies have stated that calculating the minimum-time route for each daily weather pattern is not feasible (Irvine et al 2013). Although this feat has in fact been achieved in the present study, the calculations took several months of computational effort to complete. Finally, the route that minimises the journey time is generally not the route that minimises the turbulence potential or even the climate impact, because the latter depends on the radiative effects of contrails as well as emitted greenhouse gases. Future work should take these additional considerations into account.

Acknowledgments

The author is supported by a University Research Fellowship from the Royal Society (UF130571). The author acknowledges the modelling groups, the Program for Climate Model Diagnosis and Intercomparison, and the World Climate Research Programme's Working Group on Coupled Modelling for their roles in making available the CMIP3 multi-model data set. Support of this data set is provided by the Office of Science, US Department of Energy.
//

Feb 10, 2016 at 1:25 PM | Unregistered Commenternot banned yet

My thoughts here.

Among other things, the confident claims made by Williams to the media aren't supported by his paper or the papers he cites. And the effect, even if you believe the models, is tiny (1 minute on a 12 hour flight).

Feb 10, 2016 at 1:26 PM | Registered CommenterPaul Matthews

This is what Williams said, according to the BBC:

"We know what drives the jet stream, it’s the temperature difference between the warm tropical regions and the cold polar regions at flight levels," said Dr Williams.

"We understand what that temperature difference is going to do in response to global warming, it’s increasing, we are very confident that the jet stream is increasing as a consequence."


Well, they might have checked the tropospheric temperatures, which would have told them that the N Pole is warming up faster then mid latitudes!


https://notalotofpeopleknowthat.wordpress.com/2016/02/10/climate-change-to-make-transatlantic-flights-longer-or-not/


This has always been an integral part of global warming theory, so it should not really come as any surprise.

Feb 10, 2016 at 1:30 PM | Unregistered CommenterPaul Homewood

http://conservationmagazine.org/2014/09/the-forgotten-part-of-climate-change-slower-winds/
"Thanks to new research by Brandon Barton, a Univiersity of Wisconsin–Madison postdoctoral researcher in the Department of Zoology, wind may finally get its moment in the climate change spotlight.....Wind is created thanks to differences in temperature. And since the poles are warming faster than the equator, there is a smaller global temperature differential, reducing the speed of wind. In his paper, online this month in the journal Ecology, Barton points out that global wind speeds have decreased by some 5 to 15 percent over the last three decades, and are expected to decrease another 15 perfect in the coming century. You’ve heard of global warming? Get ready for “global stilling.”

Of course Lindzen always says that storms decrease in a warming world for the same reason - lower deltaT - according to standard textbook meteorology but hey Ed Hawkins surely must have read those textbooks too. Maybe we can be gentlemen and say it's a 50/50 shot? In any event the costs of flight depend a lot more on the fuel price so it's all academic as usual.

Feb 10, 2016 at 1:33 PM | Unregistered CommenterJamesG

Bishop, I like the choice of airline for the picture at the top of this article.

apparently fed "synthetic atmospheric wind fields generated from climate model simulations into a routing algorithm of the type used operationally by flight planners"

Surely any sensible airline will change their routing algorithm in the unlikely event of a permanent change in the Jet Stream. It's what businesses do to stay in business and to gain commercial advantage.

Feb 10, 2016 at 1:36 PM | Unregistered CommenterSandyS

From the paper: the estimated change in round-trip transatlantic time is 1 min 35 seconds. How does that compare with the expected increase in total aviation hours over the same period?

Typical climate change hype, dutifully reported by a compliant media.

Feb 10, 2016 at 1:36 PM | Unregistered CommenterMikky

Paul Matthews: "And the effect, even if you believe the models, is tiny (1 minute on a 12 hour flight)."

You have got to be kidding! Is that what counts as news in the BBC?

Feb 10, 2016 at 1:42 PM | Registered CommenterMikeHaseler

Key feature of this sort of stuff - if it's models all the way down, that means nothing is actually happening back in the real world for them to point to. Still rakes in the cash, though, for an easy job with no heavy lifting and no possibility of being fired for being wrong.

Feb 10, 2016 at 1:44 PM | Unregistered CommenterNW

Maybe one second doesn't mean much too you, Mike, but it is settled science that this is equivalent to 10^9 nanoseconds which is a really, really big, no amazingly massive number (550 times the population of Wales) and a loss of such a huge time cannot ever be made up with a paltry minute or two saving on the way back.

The BBC don't do swings and roundabouts or sciency stuff like 'rithmetic.

They do a great line in propaganda though!

Feb 10, 2016 at 2:02 PM | Unregistered CommenterRoyFOMR

Pure trivial speculation. And even if correct - so what? Is this what climate "research" is these days? Time to defund it.

Feb 10, 2016 at 2:04 PM | Unregistered Commenterchris moffatt

So agw will increase flight time by 0.13% some decades in the future.
But plane fuel efficiency has been improving by more than 0.3% per year.

Tempest, meet thimble.

Feb 10, 2016 at 2:08 PM | Unregistered CommenterChris y

This is very, very worrying news. Slower flights means more fuel consumption, means more fuel burnt at high altitude, means more catastrophic global warming, means slower flights.

We're doomed.

Feb 10, 2016 at 2:10 PM | Unregistered CommenterCapell

"We understand what [the temperature difference between the warm tropical regions and the cold polar regions] is going to do in response to global warming, it's increasing ...." Would somebody care to explain how this works?

Feb 10, 2016 at 2:12 PM | Unregistered CommenterRichard Green

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