BBC mentions with a slightly disparaging slant biofuels for planes. While there's little chance of replacing all petroleum- with bio-jet fuel, the bio stuff *is* being used by several airlines, and even the US military, to reduce the petroleum content of jet fuel. Bio's expensive and not easy to source in quantity, but it exists and works fine. Biodiesel works, as well, but again cost and availability are issues that keep it from being used in quantity.

Biofuels may be relatively (how are they produced and distributed?) good for greenhouse gases, but they aren't a lot better (slightly better in some tests) than their petroleum-based cousins. After all, to make the engines work right, they have to be pretty close to the dinosaur fuels in chemical composition, and the engines still produce all those nasty health-destroying things like particulate matter. Biofuels can be, though, near-zero sulfur which does help, though that's not unique to bio; diesel fuel has been produced from natural gas which is also near-zero sulfur (but very expensive).