Peter Madden asks, "What should greens do about air travel?" The problem is twofold. Planes are responsible for about 3 percent of carbon emissions. But thanks to NO2 emissions from planes, and the fact that water vapor emitted at or near stratospheric levels (where planes fly) acts as forcing and not just as feedback (as at ground level), the actual effect on climate is about triple that from CO2 -- about 9 percent and rising.
Yes, yes, part of solution to all these problems is to tax environmental effects, and to stop massive subsidies of environmentally destructive things (like airports). But what technical means exist to respond to such signals? Is the world going to have become a bigger place again, with less travel?
Here are the technical means to replace air travel:
- Trains: Trains can replace almost all air miles occurring over land, replacing fuel with renewable electricity and avoiding all stratospheric and near-stratospheric emissions for those miles.
CyberTran, though mainly discussed as a commuter system, has a 150 mph version that can replace most short-haul flights.
Faster trains, like Japan's bullet trains and perhaps ultimately MagLev systems, cold replace longer flights. Such faster trains, unlike Cybertran, are not notably more energy efficient than planes. But they can run on renewable electricity, and don't produce stratospheric emissions. - Communications to replace transportation: Videoconferencing, telecommuting, and other forms of electronic communication have already replaced a certain amount of flying in the business world. The technology to do this improves every year. Skype provides better video conferencing for free than you could have gotten for thousands of dollars seven years ago.
- Concentrate flights: Schedule flights during daytime hours rather than at night, and during the summer rather than winter. While at first glance this may appear to be "free," it is actually one of them most expensive solutions: take the same capital and amortize it over many fewer hours.
Another solution I've heard people suggest is using ships and boats more. While there is nothing wrong with this, it is not very practical for business trips, and for leisure substituting a different kind of travel -- one where the journey is more important than the destination.
So what should greens do about air travel now? The same thing they should do about everything else: take political action to change the infrastructure of society. Yes, there are things you can do to cut your personal carbon profile. But ultimately we depend on society's infrastructure, and we will only become a low-carbon society when that infrastructure is low-carbon.
In the meantime, I'd suggest fewer in-person national and international conferences about climate change, and more video conferencing (at a fraction of the cost).
Comments
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kmp Posted 12:05 am
23 Feb 2007
Our open space disappears so quickly; I believe that if we do not work very hard to protect a few large corridors of land, large predators like the grizzly will disappear. Since large predators are at the top of the food chain, their disappearance necessarily causes ripple effects on the entire eco-system.
I would much prefer to support efforts at new technology (there's that word again) that would address air travel's environmental problems, than to lay down train tracks across the nation, and cut down even more trees to do so.
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Gar Lipow Posted 12:20 am
23 Feb 2007
In the long run trains can substitute for a lot of our roads and highways - so this is a gain, not a loss for biodiversity.
In terms of improving planes - at level we would need, does not look likely in the short or medium one. Most people think it will take us twenty years to develop a plane as fast as our current jets with a low climate impact.
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amazingdrx Posted 1:19 am
23 Feb 2007
If a huge new defense contract were issued? Get on this Washington state legislators. Democrats can inherit the wind of legendary defense pork barrel democrat Scoop Jackson and do something green that still brings in the big contractor "donations" (bribes).
With three times the mileage or more, air force planes could carry even more napalm!! Excellent.
The army funded a hybrid hummer, the navy even has a wave power station in Hawaii.
http://amazngdrx.blogharbor.com/blog
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caniscandida Posted 1:33 am
23 Feb 2007
Just so that we all understand: flight between, say, Toronto and Vancouver involves costly transportation from somewhere livable in or around Toronto to the Toronto airport, and also transportation from the Vancouver airport to somewhere livable in or around Vancouver. And that extra transportation on either end costs something.
On the other hand, trains usually put us down within cities, within significantly small distances of our ultimate destinations.
Also, I entirely trust Gar, that the building of new roads to accommodate vehicles must surely be a bigger threat to such animals as grizzlies than a renewed interest in railroads, which in North America are already mostly in place.
(Lamy, New Mexico, is perhaps a bit anomalous in this regard. It is the train stop for Santa Fe, several miles to the south of that glorious city. Otherwise, Lamy itself is barely anything. But the tracks between Topeka and Albuquerque have stayed in the lowlands, and climbing up to Santa Fe, higher than Denver, was apparently almost always too much of a challenge. When last I traveled that way, there was a shuttle bus, with a very nice driver, who took $20 and more for the favor of your being driven between Lamy and any of a few large hotels in Santa Fe, and vice versa.)
We ought to be able to replace much airplane travel with trains. We also ought to be able to replace much interstate truck travel with trains. There will apparently be a need for local-service trucks and buses, between train stations and bus stations, and center-city locations, for a long time to come. Surely that is preferable to the absurd status-quo, a drive of at least a half hour from some lifeless exurban wasteland called an airfield.
Chickens are our cousins!
So are other sensitive animals!
Enough is enough!
No more factory farms!
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amazingdrx Posted 1:48 am
23 Feb 2007
Not to mention, this device would fit in an electric car to make it a serial plugin hybrid.
A picture of the device I keep on touting! Thanks Boeing.
http://amazngdrx.blogharbor.com/blog
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Gar Lipow Posted 2:06 am
23 Feb 2007
Pretty hard. A jet engine's power comes in part from the compression, but also from ignition and expansion of hot gases. In other words burning something, and extreme heat is part of what drives an airplane jet engine. Making a jet engine that depends 100% on electricity to compress air is not just a matter of scaling: it is something fundamentally different from what we are doing now. It is not physically impossible: some of the tricks rocket scientists are working on might adapt to powering a true 100% electric jet. But no one has built a working model. I don't think anyone has even created a computer model for a billion dollar prototype. (Sometimes you will hear the term "all-electric airplane" used to refer to an aircraft where all auxillary power comes from electricity. But the jet engine still runs on fuel.) We can and have built all-electric turbo props and all-electric helicopters - though ranges are limited. But, as far as I know, nobody has built an all-electric, or all fuel cell based jet plane.
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amazingdrx Posted 2:31 am
23 Feb 2007
The solid oxide fuel cell produces electricity and hot gases, the hot gases power a microturbine generator. By combination the efficiency can get over 75%.
The turbofan SOFC engine would use the electric power from the fuel cell stack to power the fan with an electric motor and use the hot gases to provide additional power in the turbine part of the turbofan. The compression would be done by the compressor in the turbofan.
The SOFC/turbine is explained more completely in this article.
http://thefraserdomain.typepad.com/energy/2006/10/efffici ...
http://amazngdrx.blogharbor.com/blog
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Gar Lipow Posted 2:41 am
23 Feb 2007
>This yields a dry (no steam) hybrid-cycle power system that promotes unprecedented electrical generation efficiency.
Only - a jet engine does not use electricity for thrust. Electricity on air craft is for starting an engine, and for auxillary services. So I'd still be curious to see figures on water emissions and fuel use per amount of thrust. I suspect there is a reason this is being considered only for auxillary services and not to power the main engine. But I don't know that. I'd like to see the numbers.
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amazingdrx Posted 2:47 am
23 Feb 2007
It would need a very high power electric motor built into the turbofan rotor somewhere. The newest brushless DC electric car motors without permanent magnets might be suitable, they are much lighter than their predecessors.
But I admit this is mainly sci-fi, as are a lot of my speculative concepts.
http://amazngdrx.blogharbor.com/blog
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sunflower Posted 3:11 am
23 Feb 2007
Saving time requires energy squared. Double speed cost four times the energy. Four times the speed costs sixteen times the energy. No escape from reality.
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Gar Lipow Posted 3:22 am
23 Feb 2007
Which is where things like Maglev on the ground come it. Not more energy efficienct, but able to use wind and solar electricity - which makes them carbon efficient.
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willa Posted 6:45 am
23 Feb 2007
There's a smaller spur line from Lamy to Santa Fe--originally it went up to Espanola, and I think even to Taos, but those tracks are all gone, as far as I know. Supposedly the new commuter service will use/is using the existing track from Albuquerque to Lamy and then Lamy to Santa Fe, but I haven't been home enough lately to know how/if it's working.
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Jianguoxu Posted 11:21 pm
26 Feb 2007
Now, safety may still be a concern...
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Gar Lipow Posted 2:59 am
27 Feb 2007
The problem here is that hydrogen may decrease CO2 and NOx, but it increases water vapor. Near the ground water vapor is a feedback, but at that height water vapor is a forcing. And water vapor as a forcing is more powerful than CO2, even more powerful than NO2 (though not as long lasting). In short, planes are the one place where hydrogen (even from wind or solar electricity) has no greenhouse benefits.
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sunflower Posted 3:41 am
27 Feb 2007
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atreyger Posted 3:52 am
27 Feb 2007
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sunflower Posted 4:46 am
27 Feb 2007
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Gar Lipow Posted 3:50 am
28 Feb 2007
OK - so that leaves runnning low flying jets on biofuel. (Someone has developed a process for jet biofuel that makes a fuel comparable to kerosene.) But running less efficient planes on biofuel is not going to leave much for anybody else if you continue to use planes as much as we do.
You can't do much of it, because there is a limit to how much biofuel we can produce sustainably. Although one of the arguments against biofuel is the high energy inputs use to produce it. But in this case the fuel is doing something that, say, solar heat or low carbon electricity can't. So if you have to use these as inputs to produce biofuel with a very small net energy gain, it might still be worthwhile. Substituting internet communication and trains wherever possible is the first step. But running those jets we need to fly (mainly the ones over water) at low altitudes on biofuel might be the last step.
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Delay And Deny Posted 3:59 am
28 Feb 2007
Back in the 1960s I used to make model airplanes...which required model airplane glue. Yes, I know what you're going to say, but I didn't sniff it other than the sidestream fumes.
Then around the 1970's they came out with "safe" model glues. They were based around citrus bases of some sort and smelled like lemons and oranges. They took the original model airplane glue off the market.
You know what? That new glue was terrible! It never dried and the pieces just kind of sagged with the rudder of my B-17 just falling limp to one side.
That always seems the way with "alternatives" or "safe substitute". Engineers know: you don't get something for nothing. You can't go around expecting to make everything all Green and still get the power and utility of traditional technology.
Everything has its cost.
Did Mankind not yet learn that?
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ffletcher Posted 4:52 am
28 Feb 2007
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Gar Lipow Posted 5:00 am
28 Feb 2007
Not going to be as fast as a jet.
Contrary to JB, in most cases green tech can be as fast, efficient convenient ect as brown tech. But air travel across water is an exception. While stuff like MagLev can get us across land as fast as airplanes (though probably at a higher price), travel across water will simply have to be done less or more slowly.
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