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Why We Need An X Prize for Eco-Friendly Air Travel
Alex Steffen, 26 Sep 06

Air travel presents one of the stickiest problems we face.

On the one hand, in a rapidly globalizing world, we need to fly to do business, build networks and see loved ones. Indeed, to many people (including myself, to be honest), the ability to travel easily and keep a global community is one of the greatest accomplishments of our civilization.

On the other hand, air travel is frying the planet. While air travel contributes only 3% of humanity's total CO2 emissions (making them a problem only a few times larger than, say, coal fires), air travel is growing at an astounding rate. And while engines are growing more efficient, planes are also getting larger and flights more frequent, meaning that air travel may effectively undo many of the gains so far made in cutting CO2:

Friends of the Earth commissioned a study from the Tyndall Centre for Climate Change Research to work out what growth of 6.4% a year (its average through the 1990s) would mean for Britain over the next 40-50 years. It concluded that the total CO2 discharges from air-traffic would soon offset all the reductions in carbon emissions scheduled under British government policies to comply with Kyoto. The European Commission (presumably neutral on such matters) accepts that, by 2012, the growth in aviation would offset more than a quarter of the reductions that its richer members hoped for

Furthermore, for a variety of reasons having to do with chemical emissions and contrail formation (the white "tails" jets leave behind them), it turns out that airplanes have a climate impact that's actually 2-4 times greater than their CO2 emissions alone would indicate.

To make matters even worse, we seem unable to innovate our way out of this jam. Sure, there are plenty of ideas: We can run flights more efficiently, making sure more of them are full and their routes are as short as possible. We can outfit planes with electric motors for tarmac use, allowing them to run their jet engines less. We can replace the wiring with fiber optics, making the planes lighter. We can use biofuels to make the planes slightly more carbon neutral (though the percentage of biofuels that can actually be effectively mixed into jet fuel turns out to be rather low).

But the brutal truth is that these are marginal improvements. And so far, we haven't done better than an average increase in efficiency of about 1% a year. As Sir John Rose (CEO of Rolls-Royce) has said, with our current limitations "technological innovation alone cannot solve this."

All this makes George Monbiot's recent screed On the flight path to global meltdown worth paying attention to.

In it, Monbiot drops the news in a rude, if accurate, way:

As the Intergovernmental Panel on Climate Change discovered, "There would not appear to be any practical alternatives to kerosene-based fuels for commercial jet aircraft for the next several decades." There is, in other words, no technofix. The growth in aviation and the need to address climate change cannot be reconciled. In common with all other sectors, aviation's contribution to global warming must be reduced in the UK by some 87% if we are to avoid a 2C rise in global temperatures. Given that the likely possible efficiencies are small and tend to counteract each other, an 87% cut in emissions requires not only that growth stops, but that most of the aeroplanes flying today be grounded. I realise that this is not a popular message, but it is hard to see how a different conclusion could be extracted from the available evidence.

This means the end of distant foreign holidays, unless you are prepared to take a long time getting there. It means that business meetings must take place over the internet or by means of video conferences. It means that transcontinental journeys must be made by train or coach. It means that journeys around the world must be reserved for visiting the people you love, and that they will require both slow travel and the saving up of carbon rations. It means the end of shopping trips to New York, parties in Ibiza, second homes in Tuscany and, most painfully for me, political meetings in Porto Alegre - unless you believe that these activities are worth the sacrifice of the biosphere and the lives of the poor.

Here's the rub: I don't think people are going to stop flying.

I'm not even sure they should. Indeed, if air travel could somehow miraculously have no negative environmental impacts, I'd almost be willing to endorse the idea that the growth in international air trips would be a pretty good indicator of some kinds of planetary progress. We can't hold together a globalized society without frequent travel, and if I have to bet on which will break under the pressure first -- globalization or planetary ecosystems -- my money would be on cargo ships sailing even on rising seas, supertankers sailing through hurricanes to deliver oil to sinking cities.

International air travel is also one of those services for which no reasonable substitute exists. We can imagine car-sharing, compact communities and transit substituting quite reasonably for the private auto in many cases. We can look to new building materials to substitute for concrete and clean energy sources to replace coal. But what is the alternative to flying? Blimps?

But I also think it's wrong, perhaps almost evil, to imagine that the only course we can steer is straight ahead into disaster.

So, here's my answer: we need better jets. We need to crack a seemingly insolvable problem and design carbon-neutral, non-toxic air transportation.

We have a pretty good mechanism for getting people to tackle dramatic challenges: prizes. Look, for instance, at the X Prize, which set a ten million dollar prize for the first group to fly a private craft into space twice.

There's already an X Prize on the way for the first team that can "design, build and sell super-efficient cars that people want to buy". But a ton of people are already working on improving the auto -- you can read news of their efforts here every Sunday -- while most people seem to despair of the challenge of greening air travel.

What we need is a prize, a big prize, a prestigious prize, given to the first team that can, say, cut by three-quarters airplane emissions (got to start somewhere) in a commercially practical way. That's a goal vastly more meaningful, and, in the long run, more vital than putting a colony on the moon.

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The necessity of the airline industry is huge. It won’t go away, and adaptation is key.

However, the production of large planes, and the upswing in the industry means that one larger, newer plane with good emissions, means less flights on older, smaller, less environmental aircraft. There is a lot more of “in place of” rather than “adding on to” than you imply.

On a route between two Asian cities that might use several Boeing 737s to operate, will one day be operated by fewer flights on one, large, Airbus A380 with several advancements in their engines.

Also, with the recovery of the airline industry, planes are filling up and flying more efficiently. With airlines knowing that they can now fly a full plane as opposed to a half-full one from a few years ago, they can better apply the right size of aircraft to various routes. This will cut extraneous flights, and thus save on unnecessary emissions.

I agree wholeheartedly about creating a challenge that needs to be responded to. I think of the privatized space race won by Burt Rutan’s Scaled Composites. Allow an advertisement deal and a check from someone like Richard Branson, and before you know it, you’ve got people competing for technological advancements.

What more of an incentive can be given to a company like GE? We need more room for new players that can take advantage of such rewards, and therefore a more competitive aviation development industry.

Posted by: Phil Derner ,Jr. on 26 Sep 06

Good points, though I'm not sure, again, that those efficiencies are within an order of magnitude of the challenge...

The Economist on the A380:

"THE double-decker A380, the biggest airliner the world has seen, landed at Heathrow last month to test whether London's main airport could handle the new 550-seater, due to enter commercial service at the end of this year. It was a proud moment for Britain's Rolls-Royce, the makers of the aircraft's Trent 900 engines. Rolls-Royce says the four Trents on the A380 are as clean and efficient as any jet engine, and produce “as much power as 3,500 family cars”. A simple calculation shows that the equivalent of more than six cars is needed to fly each passenger.

Take the calculation further: flying a fully laden A380 is, in terms of energy, like a 14km (nine-mile) queue of traffic on the road below. And that is just one aircraft. In 20 years, Airbus reckons, 1,500 such planes will be in the air. By then, the total number of airliners is expected to have doubled, to 22,000. The super-jumbos alone would be pumping out carbon dioxide (CO2) at the same rate as 5m cars."

Posted by: Alex Steffen on 26 Sep 06

Very high speed trains are an alternative. They require a lot more infrastructure: rails, tunnels, electric power, and run efficiently only with high passenger volumes (long trains), but the potential energy savings are much greater than is possible with flight.

Posted by: Arthur Smith on 26 Sep 06

If air travel contributes 3% of total emissions.. why worry about it just now?

Isn't a more pressing need figuring out what to do with all the cars, trucks, poorly insulated houses, and coal plants?

We need super cheap, efficient solar cells & we need cheap, long life, high density battery technology.

We don't have either of those just yet, so why not have an X Prize for them, first?


Posted by: Matt on 26 Sep 06

There is one fact you didn't put into line :
while favorising contacts between world population, planes also increase diseases diffusion.

Chicken flue wasn't just a joke, a major disease propagated by plane travellers will, in my mind, be the final solution to this problem, because we won't find another useable solution.

Posted by: litteuldav on 26 Sep 06

Alex, you ask if Blimps are the alternative. I think so, but we can't compare it to today's planes.

We'd have to call it something like "air cruising". At about 150 km/h, New York to Paris would take two days, which seems fairly reasonable to me.

Less jet lag, far less C02, and if done properly, an enjoyable travel experience (hmm... good food, free wireless?). This may start as a very small niche, but I think it's within the realm of the possible.

Posted by: Daniel Haran on 26 Sep 06

It is not just air passenger travel that needs to be looked at. Air cargo is growing at a slightly faster rate then passenger travel, due partly to high technology goods coming from Asia.

These freight operators have not focused on efficiency like passenger airline companies because it is easier to pass on fuel surcharges to each piece of cargo, rather than a person.

The Fed-Ex's, UPS's, and DHL's of the world have an equal responsibility ahead.

Posted by: Todd on 26 Sep 06

That's a goal vastly more meaningful, and, in the long run, more vital than putting a colony on the moon.

I think that is backwards, unless by "long run" you mean "short run". I'm all for vastly cleaner air travel, but in the long run a moon colony is a first step towards getting out of the solar system, we will need to do within a few billion years (sun -> red giant), if not sooner (environmental catastrophe, asteroid, etc). That said, that is "in the long run". I don't think we should even *think* about a moon base for 30-50 years or even more. And actually getting out of the solar system could most likely wait 1,000 years or more.

@ Matt,
It seems to me that there is a lot more research going into solar cells and batteries right now than is going into superplanes. Of course, prizes for those wouldn't hurt, but I am not sure it is needed.

@ Daniel Haran,
Sound like a good plan to me. It should be great for vacations and other things that are not time sensitive.

Posted by: Kelly Clowers on 26 Sep 06

Airports could have nuclear water-splitting and hydrogen liquefaction plants. Liquid hydrogen is bulky, and this fact is often innumerately advanced as a fatal objection to its use as aircraft fuel. The loss of cabin volume to fuel tank growth when liquid hydrogen replaces kerosene is indeed substantial, but in large wide-bodied aircraft it turns out not to be prohibitive; it's less than a third. Lots more here in PDF format.

If aircraft come to fly faster and higher than today's, filling the upper half of the cabin with liquid hydrogen could mitigate the increase in passengers' cosmic ray exposure due to altitude, although even at 10 to 14 km they're already getting an increased dose, and very seldom is any concern shown over this. (Airliner crew is the occupation with the highest work-related ionizing radiation dose.)

Posted by: G. R. L. Cowan, former H2 fan, still likes H2 aircraft on 26 Sep 06

Think outside the box - the solution is telepresence. Why fly your body to the other side of the globe of you can experience being there without the hassle.

You can imagine a sliding scale of this. It starts with renting time to control a stereo vision robot to take a tour of the Pyramids (can happen at night local time, day your time) or the Louvre. Extra income for the location, extra possibilities for you. This could be accessed from home (if you have the equipment and bandwidth) or from a "travel-parlour".

With technological advances the experience can be come richer involving the transmission or tactile and perhaps olfactory data.

Farfetched? Well I think this has more chance of succeeding than an X-prize for air travel. Accelerating people to 1000km per hour, maintaining that for hours against frictional forces is never going to be that efficient.

Posted by: brianthesmurf on 26 Sep 06

At last - a debate interesting enough for me to post on Worldchanging since Jamais left!
I'm with you on this one, Alex. I went to India more than a year ago but have felt too guilty to go on any long-haul flights since - and right after I'd had the most amazing, humbling experience of my life by going there. I'm desperate to go back, but the planet-trashing amounts of CO2 released by my trip would leave me feeling too damn bad.
We have to find another way. I'm inclined to think that the convenience of teleconferencing may help, but it (or anything like it) is never going to be a substitute for being there.
Perhaps we need to look at what we are flying FOR as a first step. Zac Goldsmith recounts the tale of a supermarket boss in Britain rebuffing his congratulations on the sale of local apples at a store. The manager explained that they were flown to South Africa and back simply to be waxed! One of my friends was flown to India for five days, ostensibly to check out company operations there (though at least four hours each day was spent in a car going through Bangalore). These types of air travel are not only unrewarding - they are largely unneccessary. Maybe a tax could be applied for returning from somewhere too soon!
If we cannot find a way of greening air travel, we should at least ensure that only the most rewarding and important (that includes opening our eyes to the world) travel is undertaken.
Beyond that, perhaps we can also be thinking for ways that airtravel can benefit the environment - for example distributing harmless 'chaff' to reflect some of the suns rays out of the atmosphere.
Eventually, I tentatively suggest, we are going to have to speed up the worlds carbon cycles to keep pace with the human way of life - pssibly through genetically modified trees etc.

Posted by: Daniel Johnston on 26 Sep 06

I'm surprised no one has mentioned this yet: biofuels. You can make airplanes carbon neutral if you grow the fuel (thus extracting the CO2 from the atmosphere).

We need the innovations in electric automobiles in order to free up the dense liquid-chemical biofuels for places where that density is actually required: namely airplanes and rocketships.


Posted by: Eric Boyd on 26 Sep 06


There is, unfortunately, simply no substitute for F2F.

This is bourne out by, well, essentially everyone who's ever been part of a virtual network and found themselves face to face with their comrades. The bandwidth is just orders of magnitude greater than even the best telepresense.

I suspect there will never come a day when any virtual travel will equal the experience us primates have from sitting and eating together and talking.

Posted by: Alex Steffen on 26 Sep 06

I have a cultural comment. Air travel and airports are a matter of pride for emerging nations. They know they have really joined the Big Guys when they have a mobile, air-traveling population and a modern airport -- or better yet, several.

In the US, airports proudly proclaim that they are International as soon as they get their first flight to Canada or Mexico. In Malaysia, Penang Airport is just as proudly billed as a Domestic airport! They are really proud to have a few flights to Kuala Lumpur. It is the mark of modernity.

This is one more area where telling developing nations that they need to make reductions is not going to go over well...

Posted by: Kim on 26 Sep 06

I like airships. But I think the buoyancy is a problem. Hydrogen is dangerous (at least perceptually), and helium is too expensive, especially on large scale.

There is a cheap and safe alternative: vacuum. A cubic metre of air at 0.1 atm weighs about the same as a cubic metre of hydrogen, and has the same buoyancy. The obvious problem is keeping the envelope from collapsing under pressure. I don't think that's unsolvable.

Anyway, getting to more immediate palliatives. I think the biggest contributor of airplanes to global warming is those contrails. What can be done to tackle them? Can the particle size be varied so that contrails scatter solar radiation backwards rather than forwards? They would then stop acting as a blanket (and may even become a radiator! Now *that* would be useful!!)

Posted by: Tony Fisk on 26 Sep 06


While it is true that we can always think of situations where there is no substitute for actually being there, let's not dismiss telepresence too quickly. For a lot of applications I think it will be sufficient. If it reduces global air travel, so much the sweeter for the planet.

Onsite fabrication will also reduce the need for global freightage.

Posted by: Pace Arko on 26 Sep 06


Dear friend,

Hydrogen filled, computer controlled, cargo carrying airships minimize your eco-footprint. With our vertical take off and landing cargo ships we can land just about anywhere there is a large open field. We can pick up your cargo then fly it to its destination and land and unload. That gives you point to point transportation but we can also deliver from one point to many points. Instead of landing the airship we use GPS guided parachutes and drop the packages out when we get near each destination. (the packaging is reusable, of course). We will be able to deliver your cargo to up to 10,000 different customers in the tri-state area.

Remember, we have been able to minimize our eco-footprint by eliminating the use of roads or rails. Thats a more than 95% reduction in impact.

Click to contact LITTLE FEET SHIPPING new rates start Oct 2010.

Posted by: jim moore on 26 Sep 06

I think you're right -- we're in even a deeper conundrum with jet fuels than gasoline. There is no jet fuel alternative that has the required energy density, let alone fewer emissions. The only sustainable options -- barring any breakthroughs -- are flying less and flying slower. I love traveling, and being an aerospace engineer I love flying especially. But it's time to realize that my passions are helping to kill the planet.
Interested in solutions, not despair.

Posted by: PeakEngineer on 26 Sep 06


I understand how you feel but 20 years ago most people couldn't conceive of virtual networks. Today we have that and we are seeing the beginnings of telepresence in the guise of Massively-Multiplayer Online Role-Playing games (MMORPGs).

Already there are people more than happy to spend hourse in these MMORPG environments rather than the real-world. I for one expect telepresence to benefit greatly from both the technological advances in MMORPGs and from the acceptance that this is a socially acceptable and rich way to interact.

Physically being there is so 20th century! :-)

Posted by: brianthesmurf on 26 Sep 06

Some grist for the mill:


Posted by: Tony Fisk on 27 Sep 06

Back in the 1980s, McDonnell-Douglas tested a version of the MD80 with propfan (GE: Unducted Fan) engines - the fuel burn was reduced by 30 per cent. However, then along came the oil counter-shock and nobody cared any more.

I've seen estimates of near-term (out to 2016) savings in aerodynamic design of another 12 per cent and air-traffic control efficiency savings of 10 per cent. (More direct great circle routes, less holding, and continuous-descent approaches) So that's a 52 per cent cut. Even 10 per cent biofuel would get us not far from a two-thirds reduction.

Weirder designs could get more savings from aerodynamic efficiency - the future of aviation might look like the Northrop flying wing of the 1940s.

As far as weird fuel goes, I like the SOLZINC process and methanol.

Posted by: Alex (*Not Steffen*) on 27 Sep 06

I have been flying a lot, and buy the offsets, but still feel guilty.

Right now, I'm in China, trying to learn mandarin and research renewable energy.

But, my other half lives in NY. Now, I want sustainable change as much as all you who read this site, but I'm no Gandhi. No amount of carbon emission guilt can keep me away from my love.

How about eliminating first and business classes, that way more people can fit on a plane (especially for international flights)? Maybe I just don't understand why someone would pay $10000+ for a first class ticket, seems like a waste of money, and you could fit three or more normal coach seats in the space they take, thus lessening the number of flights.

Posted by: John Romankiewicz on 27 Sep 06

I'm surprised that no one has noted that long-distance trips were possible before airplanes. They took longer. Not everyone could afford them of course, but since then, we have supposedly become prosperous. If we're prosperous, we're supposed to have free time. (I'm old enough to remember predictions that "in the future, technological advances will mean that people won't know what to do with all their leisure time.")

Cars reshaped landscape so that those without cars are disadvantaged. Airplanes reshaped time - since you can be on the other side of the world in 24 hours, you damn well better be, or your competitor will beat you there. Trains and dirigibles atrophied, cruise ships became havens of the rich, and our time became compressed. The speed of airplanes reshaped time so we need that speed.

I went to New Zealand last year, helping destroy the climate in the process. I'd feel more prosperous if my life afforded me the time to travel to places like that in a more leisurely way.

And when was the last time the journey itself was enjoyable? Fast transport turns the landscape into a television show, and the journey into an endurance test. (A graffito I'd like to leave in the L.A. airport: "LAX-SUX".)

In a Bright Green world, we'd have enough time to enjoy our journeys as well as our destinations. The X-Prize might be for a way for people to earn their livings in 6 to 8 months a year.

Posted by: David Foley on 27 Sep 06


I agree with you: the best solution would be to increase the amount of leisure time to make land/sea travel plausible. Hell, if I had six months of the year to travel, I would walk. That would be bitchin. Travel should be in the process, not in the destination; and we all know that being cramped into a compressed tin car that is going 500+ mph isn't exactly fun.

@Alex (Steffen):

Why do you say that Monbiot's article was rude? (I am just curious). One of the things I like about GM is that he doesn't mince words. I tend to agree with you though, I doubt people will stop flying (so I might invest in some property that is at least 40m above sea level). Unless oil prices make the air travel an insanely priced luxury, or this some enormous sea-change in (Northern) feelings toward travel, I suspect the planes will keep carrying people off for weekend getaways, and fish will continue to fly into east coast restaurants from Hawaii.

Posted by: livingfossil on 27 Sep 06

Let's not forget that the jets are only part of the pollution/consumption problems of air travel. The service vehicles (fuel trucks, tugs, luggage haulers, etc.) are not subject to the more stringent emission controls that registered on-road vehicles are. I'd like to see a map of CO2 concentrations around a major US airport and compare it to gridlock on an LA freeway. There is (was?) a program a few years back called ILEAV (Inherently Low-Emissions Airport Vehicle) Pilot Program that was supposed to cut back on GHG and ozone pollution at 10 US Airports. Google search on ILEAV yields lots of 404 errors indicating to me that the program was scrapped by the current administration. Or maybe it was replaced by the Voluntary Airport Low Emissions (VALE) Program?

Posted by: Xtraspatial on 27 Sep 06

LH2 merged with the "blended wing-body" (Google: "BWB aircraft") design seems the way to go. Looks like a stingray - - massive interior space for passengers in the center tubes, cargo outboard of them, and fuel outboard of the cargo feeding engines at the rear of the airframe. With HDTV views of the flight's progress, who needs windows?

Currently, BWB design devt seem held hostage by the mil side of Boeing and some slow-moving scale model test experiments.

Posted by: Mike McCarthy on 2 Oct 06

There is a Beech tree outside my house. It weighs 6 tonnes. It is about 100 years old and since 25% of the live weight of any tree is comprised of fixed atmospheric carbon, it has sequestered, over its life, roughly 1.5 tonnes of CO2 ~ equivalent to an economy return flight London - New York. This is a simplified equation, taking no account of radiative forcing, other ghg's, con trails etc.
At treeflights we plant trees for people who want to put a little back when they fly. We don't promise carbon neutrality and we dont pretend we can solve the problem.
As you point out people are just not going to stop flying so the question is: fly and don't care about the atmosphere or fly and try to put something back.
Our fight for mitigation is going to be a hell of a lot more serious in 100 years - when the trees we plant next week will just be starting to do their best work.

Posted by: Ru Hartwell on 3 Oct 06

My take on this issue is that too many people are locked into the jet plane as the only way to travel fast. And I think that's wrong - the jet plane, like all other energy-intensive technologies, is obsolete.

For transcontinental travel, the answer is surely the train. In the 3 hours you typically wait at an airport, a modern train can travel 900km. Factor in the consideration that the train can run city centre to city centre, and there is no time advantage to air travel anywhere except Siberia.

For transoceanic travel - well, the Graf Zeppelin flew round the world in 1929 , and I'm sure we can do a lot better today. Her big sister, the Hindenburg, used less energy in flight than the sunlight falling on her envelope. Either could be run on ethanol, and note that the water created by burning ethanol is heavier than the fuel itself, so there would be no weight-loss problem.

The technologies exist. I suspect the real issue is one of mindset.

Posted by: Robert Firth on 3 Oct 06

Dear Mr Steffen

You write:

"So, here's my answer: we need better jets. We need to crack a seemingly insolvable problem and design carbon-neutral, non-toxic air transportation."

I hardly know where to start. Unfortunately, the general public don't have the beginnings of the faintest clue about the massive organised technology suppression that has been going on for over 70 years.

Let me just say we already have "better jets" that meet your criterion. One example. The B2 Bomber. An Electrogravitic, global range, no fuel anti gravity aircraft that flies at at least Mach 3.

The US Military Industrial Complex with their Dr Strangelove mentality will never allow this technology to be used by mere civilians nad viciously suppress all attempts by anybody to develop it for the general well being and development of the human race.

The technology is all out there in the public domain in the patent record.

You probably think I'm a nut. What always strikes me is that people think their absence of knowledge is knowledge of absence.


Posted by: Emphyrio on 7 Oct 06



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