Checkout the flying saucer design for the ultra eco plane for the CleanEra project. The recently formed project is playing with ideas around greener modes of air travel, aiming to reduce 50% less CO2 reduction than other jets.
They claim that such designs could reduce carbon emissions and noise levels by, at most, 10 to 15 percent.
Check out the article at LiveScience for additional info.
I am just excited to see such a cool design. Doesn’t hurt that it is aimed at the greater good.