Bioethanol.

Use acres of fields to grow wheat and such, and you can use the bioethanol produced to power your car. The great thing is the CO2 emissions are less than what the growing wheat and plants actually take in, so you've effectively got a fuel that doesn't harm the environment in any way.

A British company called "British Sugar" is engaging in a pioneering project to develop UK-based bioethanol. The bioethanol can be produced from UK-gorwn Sugar Beet and Wheat.

The bioethanol is mixed in with the petrol and reduces the CO2 emissions by 50%.

And the great thing is, it's compatible with cars. It won't destroy the engines. A 5% use of bioethanol in the UK would give the equivalent carbon savings to taking 1 million cars off the road.