Concern grows over pollution from jets

[hb06]

"Much remains unknown about climate change and the role aviation plays, though climate scientists express particular concern about jet emissions in the upper atmosphere, where the warming effect from some pollutants is amplified."

"Now, aviation is believed to be less a factor in the Earth's warming than power plants or vehicular traffic. But its emissions are considerable. On a New York-to-Denver flight, a commercial jet would generate 840 to 1,660 pounds of carbon dioxide per passenger. That's about what an SUV generates in a month."

http://www.usatoday.com/money/biztravel/20...tion-usat_x.htm

[TonyPSchaefer]

There's nothing we can do about it. God gave man the knowledge to build jets because She wants us to fly jets. Initially, of course, so we could more quickly bomb the crap out of each other and fight better but also for long-distance travel. Our hands are tied.

[Delta Flyer]

Newsweek recently had Richard Branson discussing how he plans to make airline travel green...

[Beryl Octet]

<div class='quotetop'>QUOTE(TonyPSchaefer @ Dec 20 2006, 09:31 AM) [snapback]364542[/snapback]</div>

There's nothing we can do about it. God gave man the knowledge to build jets because She wants us to fly jets. Initially, of course, so we could more quickly bomb the crap out of each other and fight better but also for long-distance travel. Our hands are tied.
[/b]

Don't worry, when peak oil starts kicking in a few years, these problems will solve themselves.

[MegansPrius]

<div class='quotetop'>QUOTE(HBO6 @ Dec 20 2006, 03:14 AM) [snapback]364478[/snapback]</div>

"Now, aviation is believed to be less a factor in the Earth's warming than power plants or vehicular traffic. But its emissions are considerable. On a New York-to-Denver flight, a commercial jet would generate 840 to 1,660 pounds of carbon dioxide per passenger. That's about what an SUV generates in a month."
[/b]

Interesting article. And a bit distressing, in that jets are already pretty fuel efficient due to jet fuel being one of their largest operating expenses.

Nonetheless...the distance from Denver to New York is about 1778 miles (per mapquest), which I can only imagine is a good deal more miles than the average SUV drives in a month. I just wish I knew how they got that figure. It makes it sound like jets generate a lot more CO2 than US autos (and a quick bit of searching proved inconclusive: 83000 or so SUVs in use, 24000 high altitude flights per day, each major airline carrier listing an active fleet of 400-700 planes, a sort of consensus that planes and cars emit about the same amount of co2 per passenger mile but plane journeys are much farther, etc..).

In any event, the poking about eventually led me to the union of concerned scientists website http://www.ucsusa.org/ which I'd never seen before, and, while not containing the source for this airplane study, has a lot of interesting info, including their number one tip for reducing your carbon footprint: buy a fuel efficient car.

And as for Tony's post, well, maybe we could harness the CO2 from Jets and put it into bombs. Then we could really (wait for it) ... drop carbon emissions.

[chogan]

<div class='quotetop'>QUOTE(HBO6 @ Dec 20 2006, 02:14 AM) [snapback]364478[/snapback]</div>

"Much remains unknown about climate change and the role aviation plays, though climate scientists express particular concern about jet emissions in the upper atmosphere, where the warming effect from some pollutants is amplified."

"Now, aviation is believed to be less a factor in the Earth's warming than power plants or vehicular traffic. But its emissions are considerable. On a New York-to-Denver flight, a commercial jet would generate 840 to 1,660 pounds of carbon dioxide per passenger. That's about what an SUV generates in a month."

http://www.usatoday.com/money/biztravel/20...tion-usat_x.htm
[/b]

Always the nerd, I looked up the data and it appears that about 2.5% of total US energy consumption is for aviation, near as a I can tell. That's something around 8% of all liquid petroleum producs used in the US. Take 8% of US oil use, burn a good bit of it in the stratosphere - I could believe that might be an issue.

Further facts: Boeing says a loaded 747 gets about 53 passenger-miles per gallon, or roughly one-fifth the gas mileage of a full-loaded Prius. (That is, a gallon of fuel takes five passengers about 10 miles in a 747, but about 50 in a Prius). That 53 PMPG figure yields pretty much exactly the low-end carbon number cited in the article, assuming 22 lbs C02/gallon of fuel. (However, for an SUV to yield the low-end carbon number in the article, if it were driven at the US average 15,000 miles a year, it would have to get 31 MPG. So, the SUV they have in mind must be a Ford Escape Hybrid.)

At that PMPG mileage, a 6000 mile round trip from DC to California, for a family of four, would consume enough fuel to go 22,000 miles in a 48 mpg Prius.

All of that, of course, just pro-rates the jet's total fuel consumption / total passengers. Which is fair, I guess, but a bit ignorant -- the marginal impact of adding a person onto a plane is going to be far less than that. So, in some sense, if the jet's going to fly anyway, and it's not full, your decision to fly versus drive adds only a small increment to total C02 if you fly. That's quite unlike your decision to drive, where all the C02 is attributable to you.

How small is that marginal increment. That issue has already be quantified, in the context of fatter Americans requiring more jet fuel, here http://www.boingboing.net/2004/11/05/super...g_of_ameri.html

Based on the data there, plus some rummaging at the DOE, I calculate that the marginal fuel cost is about one-quarter of the average fuel cost. Roughly. So if you're of average weight (185 lbs with baggage was cited as the figure typically used by airlines), the incremental fuel that the jet burns to carry your weight is about one-quarter of the average for the entire plane and trip. So, on the margin, my family of four's decision to park the Prius and drive is roughly a wash, in terms of total additional fuel consumption for that trip,comparing the total additional fuel the jet burns (assuming our weight is average), versus the fuel the Prius would burn. Ignoring the fact that the fuel gets burned in the stratosphere.

Not sure how I would resolve the issue of average versus marginal fuel use. Guess I'd assume whatever made me feel better about the mode of transportation I had chosen.

[Delta Flyer]

Branson's article

[chogan]

<div class='quotetop'>QUOTE(Delta Flyer @ Dec 20 2006, 10:58 AM) [snapback]364583[/snapback]</div>

Branson's article
[/b]

Decent article. The two here-and-now changes amounted to not using the engine while moving slowly over the ground, and planning your travel to be more efficient in traffic jams. Good advice for anybody.

[Tideland Prius]

Honda's going into the plane business with "HondaJet"

It'll be interesting to see how they can transfer their knowledge about building fuel efficient auto engines into aircraft engine.

[ShellyT]

It isn't just engines. The airframes need to be improved. A flying wing is more efficient than the standard air plane shape.