airplanes don't have a direct solution in terms of emissions - it's not completely out of the realm of plausibility to redesign the way that airplanes function, but because the planes require a large infusion of energy to lift, there is not a way to port the existing technology.

so, if we could build runways on the top of skyscrapers five miles into the sky, we could kind of glide from place to place, but that's not much of a solution for obvious reasons.

if you look around online, you'll find various schemes trying to take advantage of things like angular momentum to get lift-off, but these are approaches to creating efficiencies - they are not sustainable solutions.

the disappointing reality is that air travel as we know it probably won't present a sustainable option for itself until we find a way to manipulate antimatter. it's the thrust. you need a way to create a lot of energy all at once, and we only really know two ways to do that - combustion or nuclear fission, neither of which are desirable. i've been arguing for years that the future is anti-matter, and we actually do have a reservoir of it not far from us...

http://www.sciencemag.org/news/2011/08/antimatter-belt-found-circling-earth

when anti-matter and matter interact, it produces pure energy in truly frightening quantities. so, you'd just need to find a way to harness it - a problem, because touching it in any way causes it to explode. still. if we could...

in the mean time, could we combust something else? that's a good question. for a long time, people were talking about hydrogen, but it's not well suited for airplanes. in theory, we could potentially find some way to convert electricity into a chemical storage and then combust it into something safer to emit, but it obviously opens up questions around whether what we're emitting is really safe, and the technology simply isn't available to us.

so, when it comes to air flight, there's not a way to "change the system" - this is something we need to do less of. and, what are some better options?

well, if you're going to a city on the same continent that isn't very far up the interstate - new york to washington, los angeles to seattle, montreal to toronto - is there any reason you have to fly? probably not. you may want to argue there's no ethical consumption in capitalism and get on your plane with a clean conscience, but that would just make you an asshole - not an idiot, exactly, because the truth is that you probably don't actually care, which is why it was so easy to convince you, in the first place. this isn't stupidity, so much as it's malice. take a train.

now, i don't have exact numbers in front of me, but i'm certain that if we focused on building a high-speed electric rail system, and then brutally taxed local air travel, it would drastically reduce emissions at minimal cost to anybody's convenience. the key is in ensuring that the rail system is actually fast, and actually sources from clean electricity. that's the best answer we're going to come up with - fly less, ride more. and, you have to come to terms with that - the choice is in your hands, with this.

that leaves the issue of intercontinental flights as a problem, and there may not be a way around it. even if we could built boats that operate at the speed of sound, we probably wouldn't want to. could we build tunnels under the water? maybe - depends where. but, intercontinental flights might be something we can't get rid of. we don't need zero carbon, remember - we just need to get below a certain level.

local flights, though, are something that should stop. there's no solution to this - and it's largely unnecessary. we just shouldn't be doing it.