[thedoc (OP)]

Are big planes really damaging the ozone layer?  If they are, when will we have better engines?
Asked by @drugsworker, via Twitter


                                        Visit the webpage for the podcast in which this question is answered.

[chapter podcast=3465 track=11.08.21/Naked_Scientists_Show_11.08.21_8887.mp3]  ...or Listen to the Answer[/chapter] or [download as MP3]

[thedoc (OP)]

We answered this question on the show...



Chris -   We've got to bear in mind that big planes are going to pump out a lot of CO₂ and CO₂ will increase global temperatures and at high temperatures, I think, the equilibrium has shifted in favour of making less ozone and degrading more ozone.  So you would have less ozone.
Dave -   And I think, if the plane is flying through the stratosphere, as concord was, then just pumping water in there can form little ice crystals which are very bad for ozone, but lower down, I don't think that's a big effect.
Chris -   So the height is important thing.
Dave -   I think that's certainly a very, very important thing.
Chris -   But presumably quite small in comparison with CFCs, chlorofluorocarbons, the things we used to put in fridges, which are known to be terrible for ozone.
Dave -   Yes and I think essentially there aren’t many planes up in the stratosphere flying around, especially now, since concord has given up the ghost.

[Phil1907]

Doc - that really isn't much of an answer, more casual casual speculation.

The answer is no - their unlikely to affect the ozone one way or the other.

[yor_on]

I heard someone say that the airlines each year transport more people than the population of China. If that is true surely that too must have an impact?

"In 2000, the world's commercial jet airlines carried approximately 1.09 billion people on 18 million flights" from Boeing.
=

That's only commercial flights btw. "A plane like a Boeing 747 uses approximately 1 gallon of fuel (about 4 liters) every second. Over the course of a 10-hour flight, it might burn 36,000 gallons (150,000 liters). According to Boeing's Web site, the 747 burns approximately 5 gallons of fuel per mile (12 liters per kilometer)."

No, I'm not saying that it is worse than a car, even though it will depend on what cars we compare it to, but it surely should have a added impact on the climate.
=

As for the exhaust?

How much CO2 is released by Aeroplane. When it comes to the amount of miles yearly though? I don't know.

"I wish I had myself a horse,
You can't grow roses from exhaust.
I wish I'd listened to my old dad,
He said: two wheels good and four wheels bad."

That should be read as meaning a Suzuki RF naturally It goes on nuthin, and some gas

This one is sweet Advanced Airships. Especially the vacuum driven ones.
==

And finally the ozone layer specifically. This one is from NASA.

"Oxides of nitrogen (chemically abbreviated as NOx and pronounced "nocks") increase the production of ozone at typical cruise altitudes of subsonic air travel. These emissions are formed as a result of burning fossil fuels at very high temperatures. Therefore, aircraft emissions containing NOx increase the production of ozone. Aircraft emit significant amounts of NOx when their engines are at their hottest during takeoff and slightly smaller amounts while cruising.

In 1993, a study of toxic emissions at Chicago's Midway Airport revealed that arriving and departing planes released more pollutants than the industrial pollution sources in the surrounding 16-square-mile area. A more recent study at London's Heathrow airport showed that aircraft contributed between 16 and 35 percent of ground level NOx concentrations."

NASA. Although dirigibles are the ones catching my interest I must admit.