Real Exhaust Emissions

[angelorange]

There is much debate in the media, between green activists, amongst scientists and even aerospace engineers about the amount of global warming caused by aviation.

But what are the facts?

Clearly every industry pollutes but aviation is an easy and highly visible target.

It is all very well saying our aeroplanes are responsible for just 3% of EU CO2 per annum but how much CO2 does a 737-800 emit compared with a 737-200? Are all the green party figures based on early 1970s B747 technology?

If the media focused on say energy inefficient house construction in the UK compared to Germany or targeted our lack of a national transport system then we might see a more level playing field for aerospace in striving for cleaner technology.

Every UK MP on our TV screens seems to be in complete agreement over more taxes - only call them green ones!

Where are the real incentives (ie: carrots not just sticks!) to help the public reduce CO2 ? "Powershift" grants seem to have long gone.

Denmark and Germany offer free road tax for 5 years for the least polluting cars such as the 100 mpg Audi A2 1.2 TDI and Lupo 3L.

Vehicles like the well marketed Toyota Prius are all well and good (but watch out for replacement battery costs and lower mpg out of town) but even Clarkson agrees he'd rather have a standard diesel car that out performs it, uses less fuel and emits less CO2.

In Europe there is no tax on Bio Fuels like Bio Diesel that can run in almost any Diesel car. But in the UK you have to pay duty on free to collect used Chip Fat that hasn't even been filtered!

At least Richard Branson and Co are spending some serious research money on alternatives. Even the USAF is converting coal into Jet fuel for their smokey B52s.

Let's hope a solution/compromise is found before the Govt taxes us out of our jobs!

Does anyone have specific information on current airline fleets? Q400 is supposed to be low noise, low emissions but I've never seen any figures for CO2 g/km per pax.

[Slavedriver]

Fuel extracted from coal isn't green by any description! Bio-Fuel is the way to go for aviation, it just requires some foresight like Branson's to make it happen (oh and a bit of loot)

The Q400 and the ATR72 seem to be heralded by many as the ideal low polluting eco-friendly green machine but as you hinted at they burn more fuel per seat than a reasonably high density 737/738/319/320 e.t.c and as CO2 production is in direct proportion to fuel burn erm, well umm so much for Flybe's new "Carbon grading" system where they are going to give a grade to each aircraft like you get on a dishwasher. I'm sure they'll figure it out somehow to make the E195 and Q400 "A+++". :}

[JackOffallTrades]

I wonder how these greenies travel when they go on holiday? :yuk:

[angelorange]

The Independent ran a front page article yesterday (2 Nov 2006) which was very negative towards aviation - page one said UK aerospace put out 3% of all UK CO2 turn over the page and the next article said it was a tad under 6%! Consistent journalism then!

[High Wing Drifter]

Just had a look at the IPCC Special Report. Here is a bitesize summary:

* The data is from 1992

* Aviation emissions in 1992 were 2% of total anthropogenic emissions in 1992

* Aviation CO2 emissions in 1992 were 13% of all transportation related emissions in 1992.

* However, the CO2 atmospheric concentration attributable to aviation in 1992 is 1% of the total!

Some other snippets wot I noticed:

* Emissions of CO in the upper trop create more GH ozone than at the surface.

* However, aircraft sulpher and water emissions deplete trop ozone offsetting the effects to an unknown degree (more work needed).

* CO emissions deplete methane (a GH gas), estimated at 2% less than would exist without aircraft now and 5% reduction due to aircraft in 2050.

* Upper trop lower strat ozone create a local effect. Methane depletion creates a global effect, therefore predictions unreliable as to net effect despite possible global numerical cancellation.

Clearly the story is not as black and white as some believe and that this data is at odds with that reported.

[skiingman]

I think this is a very interesting subject where far too little good research has been done. Consider the vast reductions in non CO2 emissions from automobiles in the last thirty years and compare that to the relatively incremental improvements in aviation.

Anecdote: I live about three miles from the ramp at KABQ. On a fairly calm night full of cargo aircraft, I can clearly smell the distinctive aroma of Jet A emissions on my front porch. A single grossly polluting automobile passing a hundred feet from my door is rarely bad enough for me to get a whiff of hydrocarbons.

So while I think the global warming/greenhouse gas emissions aspect needs lots more good research, I think it is fairly obvious that aircraft operations dump loads of smog forming pollutants into the areas surrounding airports. That opinion is of course based on anecdote and could be completely wrong.

[angelorange]

From Ryan Air site: "These aircraft (737-800) are equipped with all of the latest technological advances in engine type, aerodynamics and blended winglets which ensure maximum fuel efficiency and have allowed Ryanair to reduce fuel burn by 45% and cut CO2 emissions by 50% per seat (cf 737-200)."


The ELFAA (Mar 2006) state: "Within the sector, airlines have been heavily incentivised for years to operate more efficiently – through the high price of kerosene. Over the past 30 years, airline emissions have fallen by 64% and continue to reduce as new technology and more fuel efficient aircraft come on stream. Opportunities for further abatement within aviation are therefore limited. The report’s authors have identified opportunities for abatement in EU aviation of the order of 17 million tonnes of CO2. This forms some 8% of all emissions generated by EU flights. However, about 50% of this improvement would come from improvements in Europe’s famously inefficient air traffic management system and its patchwork of control centres – so efforts to improve air traffic management services must be prioritised."

So improvements are up their with automobile engines.

[angelorange]

http://www.ryanair.com/site/EN/about.php?page=About&sec=environment

states that fuel burn is down from around 7.9 ltr/pkm 1998 (35mpg per pax) to 3.8 ltr/pkm 2006 (74 mpg per pax) which shows how much the 737 has improved but still not as good as EU Combined 2.88ltr/100km of the 2000 Audi A2 1.2 TDI which can carry 4 pax.

[NutLoose]

One thing that struck me of interest was a while ago I attended a Shell seminar on their products.... they i am sure said that because of the PC'ness against leaded fuels they had been trying various cocktails to try to produce a lead free Avgas but they were not getting anywhere close to the power output, even though they had calculated the amount of lead released into the atmosphere per year for the total world piston fleet was about 4 tonnes.......... now that is a block about the size of a coffee table.

Odd thing was, when we had unleaded car fuel any Avgas that failed to meet the Octane rating would be blended with motor fuel and sold that way....... Now because they do not have leaded car fuel they have to pay a company to come and burn the stuff for them preventing the lead from entering the atmosphere......go figure.

And as for electric cars, the "greener cleaner approach", you still have somewhere down the line a coal powered power station or such like chucking out pollution to produce your "cleaner greener electricity" for your car........

[skiingman]

One thing that struck me of interest was a while ago I attended a Shell seminar on their products.... they i am sure said that because of the PC'ness against leaded fuels they had been trying various cocktails to try to produce a lead free Avgas but they were not getting anywhere close to the power output,
Having much experience with dime a dozen auto engines that run on 87AKI fuel at 10:1 compression ratios with zero knock via modern combustion chamber design and ignition control, I'm absolutely floored by how ridiculously bad a motor as agrarian as an aircraft motor has to be to not run well on this fuel. Lots of aircraft engines can't even run at rated power on 100LL without using excess fuel for cooling/detonation margin. The dual plugs aren't just for redundancy, the mag check demonstrates that these motors actually need two plugs to burn most of the mixture.

IMO the problem is not the availability of suitable alternative fuels, its the availability of the capital needed to certify modern sensible alternative powerplants. It looks like the industry is going to skip right over the modern gasoline powerplant it should have been using for the last twenty (or forty) years and go straight to oil burners.

[N1 Vibes]

An airline of fleet size 100 a/c can consume about 3,000,000 tonnes of fuel a year. Imagine how much American Airlines uses with 736 a/c? Last year Airbus produced 378 a/c, 56% of the world airliner production. So about 700 a/c a year worldwide. So that's 2,100,000,000 tonnes potential fuel consumers added every year.

Big numbers. Hmmm...:confused:

[Kiwiguy]

Having seen Al Gore's movie " An Inconvenient Truth" last week I have turned from a sceptic into a grudging believer, however for the same reasons why aviation was left out of the kyoto accords I do not believe aviation is the place to start cutting CO2 emissions.

Aviation was left out of Kyoto for the very reason that it is the one form of transport which has no immediate and practicable alternative to hydrocarbon emission. What I mean is if we as a society converted just 10% of car emissions and 10% of truck emissions, whether by electric, hydrogen fuel cells, or even biofuels, it would more than offset global aviation emissions.

I would be happy to drive a biofuel powered car. Somebody offer me a fuel pump at my local gas station and I'd do it gladly.

I did hear a scary statistic. When USA's aviation fleet was grounded on Sept 11th there was a perceptable 2% drop in CO2 emissions.

There have been attempts to develop soya oil for gas turbine engines with a Rolls Royce Dart. The engine functioned well. the problem was that the fuel gelled above the -40 Celsius minimum required for FAA certification.

Branson's idea to tow aircraft to the start of a runway seems silly to me for various reasons, but towing an aircraft after a landing to the gate might not be so stupid.

CFM-56 engines have acheived extra fuel efficiency by creating two concentric rings of burner cans. At take off, all the cans are used. In cruise and descent only the inner ring is used. That avoids unnecessary fuel burn and inefficient burning.

Next idea coming is Pratt and Whitney's PW6000 & PW8000 geared fans. These are large LP fans driven by a small core always operating at the same power setting. The shaft will have an equivalent of an automatic gearbox shifting gear to change the LP fan speed.

This will be the jet engine equivalent of a constant speed propellor. Then I guess we could always go back to airships using biofule diesels ?:ok:

[angelorange]

Interesting read about the CFM56 Kiwiguy. Read in the RAeS aerospace magazine recently that oil-less bearings are being looked at to improve spool performance and remove the need to burn off spent oil.

[haughtney1]

Having seen Al Gore's movie " An Inconvenient Truth" last week I have turned from a sceptic into a grudging believer

Sorry Kiwi Guy, I took the time to look up a little of big "Al's" research notes regarding what was stated in his campaign for relection movie....:ok: And a large portion of his "facts" are pure fantasy:ok:

I did hear a scary statistic. When USA's aviation fleet was grounded on Sept 11th there was a perceptable 2% drop in CO2 emissions

Nobody mentioned I'm sure that motor vehicle traffic for the same period was around 12% less :ok:

[Rainboe]

Listen everybody- stop believing all these statistics being thrown at us about how we are polluting the planet and killing ourselves, and it's all our fault because we want to fly on holiday! It's garbage. The world warms up and the world cools down- it does not stay static. So it's warming up. It will cool down again. It will not runaway- it's managed to remain in fairly balmy conditions for hundreds of millions of years to allow life to develop, and so it shall restore itself. But now we are undergoing a propaganda blitz to get us to accept somehow we will solve the problem and make it better if we all pay Robber Brown extra taxes to fly in aeroplanes and drive our cars. Punishing ourselves for daring to produce 2% of world pollution in the UK when India and China are going crazy seems a little bit weird!

[High Wing Drifter]

I did hear a scary statistic. When USA's aviation fleet was grounded on Sept 11th there was a perceptable 2% drop in CO2 emissions.
Interesting how the number "2" keeps popping up. I believe that 2% of CO2 is related to aircraft, how this 2% can suddenly dissapear overnight reinforces either how confused people can be, how many lies are promulgated or how unreliable the data is in the first place.

However, the Global Dimmers claimed that Calafornia for 2deg warmer because there weren't any contrails...go figure.

[cwatters]

I would be happy to drive a biofuel powered car. Somebody offer me a fuel pump at my local gas station and I'd do it gladly.


I can only assume that governments don't want us to switch to biodiesel in our cars and lorries for some reason. It would seem to have quite a few advantages. Perhaps there simply isn't enough production to meet the demand that could be created by a change in government tax policy?

http://www.biofuels.fsnet.co.uk/basics.htm

Tailpipe Emissions

The tailpipe emissions from biodiesel are far more people-friendly than those from petrodiesel. They are neither carcinogenic nor mutagenic and cause far less bronchial irritation. EPA confirms that -

Carbon monoxide is reduced by 47%.

Because biodiesel is an oxygenated fuel, much of the harmful carbon monoxide is converted to the dioxide.

Carbon dioxide is increased by 2%.

This doesn’t matter – the plants from which the oil came absorbed the carbon dioxide from the atmosphere when growing. This is carbon recycling.

Particulates are reduced by 48%. Total unburned hydrocarbons by 67%

This figure may be improved even further by the use of particulate traps. A reduction of 41% was achieved in Belfast during trials with a 22 year old Translink passenger bus after less than 50 miles travelled.

NOx emissions may be increased by up to 10%.

This is using 100% biodiesel in a standard diesel engine without a catalytic converter fitted. A reduction of 4% may be achieved when a catalytic converter is fitted and by retarding the fuel injection timing by 2 or 3 degrees. Using a mix of biodiesel and petrodiesel results in proportionately decreased NOx emissions.

SOx emissions are reduced 100%.

Biodiesel does not contain sulphur other than by trace contamination,.

Lifecycle Emissions


The main reason why the UK is so far behind other EU member states is an incorrect report published in 1995 which stated that the use of biodiesel would save only 60% of carbon dioxide greenhouse gas emissions. This was contrary to all other reports published world-wide, but it has taken many years to overcome government resistance.

No two lifecycle studies have produced the same results, due to the fact that there are so many variables in the crop production equation.

The US Environmental Protection Agency conclusion was that a 78% carbon emissions reduction, versus petrodiesel, is achievable.

[angelorange]

It's no good sticking our heads in the sand Rainboe. The fact is our industry is under attack from the green lobby and we need to fight back with facts not hearsay. It is powerstations, houses, businesses and cars that produce more emissions than aviation worldwide. Newsnight researchers believe UK households can reduce their carbon footprint by 20% without too many changes. That's a lot more than stopping aeroplanes flying around Europe.

Man does contribute to global warming - it is not just volcanoes. How much is debatable. Certain farming methods and timber harvesting has removed much of the natural worlds CO2 absorbers. The BBC's Blue Planet programme ran an interesting post programme show about the changes in the past 5 years let alone millions.

The sahara desert is expanding south at a rate of 1km a year. If we can make a meaningful reduction in man made CO2 emissions and offset the planet's "self made" ones by not chopping down all the forrests, life on earth benefit in the longer term. But to do this means the developed world will have to foot most of the bill. We are the biggest consumers afterall.

By using India and China's growing economy as an excuse for inaction means at the very least, we will not reap the benefits of selling eco technologies to those countries. If we don't care why should they?

[angelorange]

WILBUR & ORVILLE WRIGHT LECTURE

Aviation & the Environment
Dr John Green, Chief Scientist, Aircraft Research Association Ltd

Thursday 14 December 2006
No.4 Hamilton Place, London W1J 7BQ

[angelorange]

Lecture notes now available as a pdf from the RAeS Website at www.aerosociety.com/conference.

If you click on the lecture icon to the right of the screen you will go through to a list of lectures and a link to the presentations.

Interesting P&W geared turbofan version of Airbus A320 for 2010/11 here: http://www.freerepublic.com/focus/f-news/1748918/posts
should reduce fuel consumption by 6 to 12% over existing model.

[angelorange]

Here we go again - http://news.bbc.co.uk/1/hi/uk_politics/6233019.stm

and the arguement is only going to get more intense so we need to know what we are talking about when people suggest aviation is the chief of emission sinners!

[N1 Vibes]

Does it really matter who is the worst offender, as long as somebody is making significant steps to improve things?
And if the airline industry is perceived to be the worst offender, yet not actually the worst, if they make the first 'big step' then perhaps the real worst offender will follow suit?
Rather than sitting around doing the blame game bit, should we not get off our widening backsides and do something......

[JenCluse]

[quote=Kiwiguy;2977669]
I did hear a scary statistic. When USA's aviation fleet was grounded on Sept 11th there was a perceptable 2% drop in CO2 emissions.

My son was in LON when 'it' happened.

Shortly afterwards he e-reported clear skies for the first time since he had arrived there, and that the temperatures plunged in the 4-5 days that Atlantic traffic was halted. No readings to support the assessments.

Three of my years, while flying in the Middle East downstream of Europe, when I did not <i>once</i> observe the sun rising from, or sinking behind, the horizon, has convinced me to remain in Oz, to enjoy the clear skies while they still exist here, and to try to work out how this solitary mote can effect the atmosphere of the world - for the better.

I'm sure I can. I'm sure I can. I hope to sh*t WE can.

Jen of YBBN

(p.s.
Can anyone point me to where I can arm the html editor on this site? Ta! [In early poster mode.])

[barit1]

What's missing from the 9/11 "CO2 drop" data is - what is the statistical day-to-day variation in CO2 level?

We know that temperature, pressure, water vapor, etc. all vary from time to time and place to place. Do we really think that CO2 is a constant? Is the "2% drop" statistically significant?

Maybe the answer really exists, but it hasn't yet come to the surface.

[angelorange]

Some more confusion here:

http://www.bbc.co.uk/dna/actionnetwork/A18167727

[cfwake]

JenCluse

I don't mean to sound smart-arsey or anything, but the fact that the temperature dropped and the skies cleared several days after the grounding of air traffic means absolutely nothing, at least in the UK! Whether the traffic was in the air or not, i can almost guarantee that the weather would have changed anyway!!!

As an aside, as a youngun, as many of us are, it isn't for me really a case of whether the environment is changing with or without input from human sources, I personally feel that people should do as much as they REASONABLY can to reduce this whole carbon footprint - use a bicycle where realistic, walk, etc when it isn't necessary to travel by any other method.

And while I'm not sure whether global warming is that heavily affected by humans, what I am sure of is that the things we do put into the atmosphere make the air we breathe less pleasant and more unhealthy with who knows what toxins. Up in the north west, the ICI paint plant produces an extremely unpleasant smell when you go past it and you know that the poor people that live around it have to breathe that air.

But then again, why am I on this forum? Because I'm just about to start training to fly airliners and burn masses of fuel over my (hopefully) 35 year career so who are we to give advice - no matter how little they contribute?!

cf

[lomapaseo]

The scientific mind in me desires relative data before supporting opinions.

From a relative standpoint I would be interested in variations by yearly decades not by days. I expect large amounts of daily hash in the data but some trending up and down as well.

We can then postulate all we want on the reason for the trending variations.

From a relative standpoint, can we see variations driven by volcanic eruptions (pretty common stuff). Major wars with oil fires? deforestation by burning?

I suspect that air travel emissions are minor compared to the above.

[N1 Vibes]

Lomapaseo

refer to my previous post. Why does somebody have to be 'the worst offender' before they actually have to do something?

Sorry for the analogy - are today's terrorists 'better' than a certain notorious German who died in '45? They have all killed.

Are airlines better than power generators? They are all polluting.

Best Regards,

N1 Vibes

[lomapaseo]

Lomapaseo

refer to my previous post. Why does somebody have to be 'the worst offender' before they actually have to do something?

Sorry for the analogy - are today's terrorists 'better' than a certain notorious German who died in '45? They have all killed.

Are airlines better than power generators? They are all polluting.

Best Regards,

N1 Vibes

I believe that we have not yet agreed on the usage of the word offender in your context.

There is nothing offensive in living our lives in the world that we live in. Nature is a series of balances and we are only a tiny bit of it. To me it is the relativity to other humans that is important. So I'm willing to listen to arguments where my/our actions are upsetting the balances of nature in a measurable way. If you can't measure it, then how do I know that I'm measuably improving the world I live in?