Comments on: Airbus A380 more fuel-efficient than a Toyota Prius

By: N F

N F — Tue, 27 Nov 2007 10:05:53 +0000

As someone has already pointed out, the fact that cheap flights are available, means that people will use them. Just because they are available, does not make it morally correct to use them, whether or not they are more or less efficient than other forms of transport.

Take the example of nuclear impulse rocket engines. They are acutely ‘dirty’ and dangerous so we use other forms of rocket engines. The problem with air and car etc. transport is that they are chronically dangerous so we stick are heads in the sand and pass the problem to the next generation who will say, “what were they thinking of!”

By: Yue Li

Yue Li — Wed, 31 Oct 2007 01:40:27 +0000

I encourage everyone who posted comments that are pro air traveling thoroughly read the June 10, 2007 Economist article, The Sky’s the Limit – Aircraft Emissions. Some text of that article has been quoted on this blog, but that does not give you a full picture of the impact of air traveling, which the author intended to articulate.

By: J Richard

J Richard — Sun, 26 Aug 2007 17:23:06 +0000

To counter daves point on the efficiency of a 3500 mile flight vs 8000, while taking off does consume more fuel, the max efficiency gain tops out at about 3500 miles, since flying longer than that means carrying large quantities of heavy fuel, which hurts fuel economy.

By: Morgan Jones

Morgan Jones — Thu, 31 May 2007 09:49:03 +0000

You have failed to mention that Co2 released at altitude has a radiative forcing effect twice that of co2 released at ground level.

By: Dennis Forbes

Dennis Forbes — Mon, 09 Apr 2007 14:01:51 +0000

Not only are aircraft seldom completely full (even to the real-world configurations where they generally have far fewer seats) — I’ve flown in 7×7 flights with less than a dozen passengers, but they didn’t cancel the flight because that piece of hardware was necessary for the next leg — their is significant empty-aircraft shuttling that occurs to fulfill service levels.

By: dave

dave — Wed, 04 Apr 2007 21:54:00 +0000

A couple comments:
- planes consume much more energy when they’re taking off than when they’re in steady-state flight. So a typical 3500 mile new york to london route is going to be a lot less efficient than an 8000 mile route.
- energy consumption does not equal environmental impact. Unlike cars, planes have no emissions controls, and release their exhaust directly into the upper levels of the atmosphere.

By: Dan Mitchell

Dan Mitchell — Tue, 27 Mar 2007 14:47:02 +0000

Probably also important to consider the impact of energy consumption and CO2, etc. production by the support infrastructure for the airplane. The airports at both ends create a certain environmental load as does the transportation system in and out of, and within the airport.

To be honest, you’d have to also consider additional associated costs for the Prius.

It is interesting to think about the non-obvious environmental costs of things. I’ve often wondered whether it makes more environmental sense for me to drive my decent mileage small car to visit relatives 900 miles away or fly and rent a car when I get there.

By: Brad Templeton

Brad Templeton — Sun, 25 Mar 2007 20:11:15 +0000

Total cost analysis is hard to do, but most of the figures I have seen suggest rail as the winner, though they were not accounting the cost of the land. It’s certainly the energy winner — low rolling resistance, and big long trains slipstreaming against the largest cost of energy in travel, namely air resistance.

The figure given more a typical aircraft is about 50 pax-miles/gallon. When I tell people this it actually shocks them in the reverse way. They assume it’s much more efficient than that. Effectively they are learning that flying to the other coast — which we do so casually, burns a similar amount of fuel to driving there, 2 people in a typical car, which they would think of as fuel-extravagant.

As efficient as the 380 might be, the truth is these vehicles encourage us to make much longer trips. I drive about 10,000 miles per year but I fly 25,000 to 30,000 and this is not uncommon. For a large number of people, their jet flying will be the lion’s share of their emissions contribution.

By: philg

philg — Sun, 25 Mar 2007 19:23:04 +0000

I think the biggest fuel economy/environmental impact problem with commercial airliners is that they are so fast and convenient that they encourage additional trips. It is true that I will consume less oil by going to Los Angeles on a jetliner than by driving in a Prius, but I am a lot more likely to make the trip on JetBlue than I would be to drive any kind of car for five days. In the old days, nobody went to Europe more than once per year since sailing across on an ocean liner took so long. Now plenty of people will go to Europe 5-10X per year for business and pleasure (what could be more fun than paying $5 for a Diet Coke?).

By: Russil Wvong

Russil Wvong — Sun, 25 Mar 2007 04:41:39 +0000

The Economist ran an article on CO2 emissions from aircraft in its 8 June 2006 issue.

In America, land of the gas-guzzler, the Federal Aviation Administration has calculated that the energy used to carry one passenger for one mile is greatest in sport-utility vehicles, pick-up trucks and transit buses. It says cars and commercial aircraft come out roughly equal. But a study for the European Commission reached a different conclusion. Assuming that aircraft are 70-75% full and cars contain 2.5 people (since longer distances usually imply family trips), CE Delft, a Dutch consultancy, came up with a comparison between different forms of travel. Coaches performed best, followed by liquefied-gas and diesel-powered cars or inter-city trains. Long-haul flights of more than 1,500km were 50% worse than petrol cars for each passenger-kilometre. Short-haul flights (where a smaller proportion of the time is spent on energy-efficient cruising and more on profligate climbing and descending) were fully three times worse than petrol cars.