There will be airplanes in 100 years, and they will be carbon neutral.

On my current trip to Europe one thing that I have been thinking about is the future of flight, and how sustainable it will be in the future. I have been pretty convinced that hydrogen will be the choice in the long-term future, and understand there are large hurdles to creating a global hydrogen structure. There are a few points I wish to make.

1. Natural gas is currently used here in Georgia and across Europe for transportation and it is as safe as gasoline. It also is as efficient, and people use it here with SUVs that get about 30 MPG, which with modern technology is impossible to achieve with gasoline. Natural gas however is not carbon neutral, and there is a finite supply of it, so even though it might last my generation, it won't be useful in the extreme long term, like oil. The world currently consumes 93 million barrels (or 14.786 billion liters, I use metric, the math is easier and has fewer rounding errors) per day (which will increase with the rise of China and eventual development of Africa) and our current proven natural gas supply is 22,000,000 million liters, which means (assuming the rate of consumption stays constant, which is unreasonable) that we have enough natural gas to last 648 years assuming there is no massive increase in demand. The problem however is that natural gas is not carbon neutral, which will mean that global warming will continue. It could be used as a small step as hydrogen is being improved, but the storage and nature of natural gas is not that different from hydrogen. The issue is that natural gas is not available in every country, which means it won't be a local resource for everybody. Natural gas production by country This means that if a cartel like OPEC was formed between Russia, Iran, Turkmenistan, and Qatar they would control over half of the world's natural gas supply. This is not acceptable.
2. The other alternative I see having potential is hydrogen. I am a big fan of hydrogen and the major advantage is that hydrogen is the most ubiquitous element in the universe. It is one component of water, which is one of the most ubiquitous molecules on Earth, and since fuel cell cars emit water vapor there won't be a major effect on the climate. The largest hurdle is making sure there enough energy to break the hydrogen bonds in the water molecule, which will mean we need to harness more renewable energy which has been underway for a long time. There are two large advantages to hydrogen over natural gas. The first is it won't cause negative effects to our environment, which is why I prefer it to natural gas. The second is that hydrogen is also found in water, which makes it available across the world, while natural gas is available in only certain places, a large number, but not everywhere. This prevents the formation of a cartel that could effectively control the price of hydrogen, which is good for the global economy. From an economical or environmental perspective this is the answer.
3. Electric cars take too long to charge to be a truly viable and likable alternative, and I think there is a much more likely return on investment on hydrogen than electric cars.
4. The reason that oil won't last is because we will get into a really desperate situation in 60 years when oil will be gone if we stay the course. 1,500,000 million barrels of oil available divided by 93 million barrels a day yields 44 years left until oil runs out if consumption stays constant and there isn't a random discovery of a trillion barrels of oil which I am not anticipating. There will be no oil left in 2070, and I plan on being alive at that point. With China, India, and Africa developing 30 years would be a more reasonable estimate for when we will run out. I am optimistic, because I see that we can do this. We have to do this.

The largest complaint I have seen about changing things, whether it is making the world freer or moving towards better economic systems is that it takes so long to get things done. Our politicians who should be leading us to a better world get trapped in the pattern of whining "it's so hard" so nothing ever gets done. Yes, making a new economy is not going to be easy, no, it is not going to be a 5 second download onto your computer. It is not going to be a 2 minute transfer of money across the world, or a email zipping to your antipode in 10 seconds. It will take time, like anything good, but like college, kids, friendships, a flight to visit someone, or freedom it will be worth every second of the hard work and sometimes waiting when it is complete.

Sources:

http://www.resilience.org/stories/2006-12-03/nasa-alternative-fuels-aviation which inspired the post, along with years of research and thinking about the sustainability of my current trip. This talks directly about hydrogen in flight and how hydrogen is extremely efficient compared to the alternatives.

http://www.telegraph.co.uk/motoring/columnists/jamesmay/8338090/Cracking-the-problem-of-hydrogen-fuel-future.html which has an excellent conclusion I completely agree with.

http://www.theverge.com/2013/4/4/4182524/breakthrough-hydrogen-fuel-production-researchers-extract-gas-from-plants is a recent breakthrough. Hydrogen currently is seeing a lot of breakthroughs over the past ten years, and this is just one of them.

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2060304 outlines issues on a new hydrogen economy.

www.newenergy.is is about the current hydrogen economy being developed in Iceland and is proof that it can be done.

*19 June Correction: I made an error and said that water is an element, I have fixed my elementary mistake.