And also... Apparently you can get 400 gallons of biodiesel from an acre of land. This is roughly 16,000 miles per year ( assuming 40mpg ). There are over 40million vehicles in the uk averaging 12,000 miles per year. Therefore we would need 30 million acres of diesel crops growing to support this. There are 60 million acres of land in the uk. Therefore if we turned half this over to diesel crops we would be self sufficient and would not have to rely on fossil fuels. Obviously there would be issues with the amount of land available. However I propose the following solution. Reduce the number of vehicles on the road.........exterminate the population of Greater London...after all, are they really needed.....this would bring the vehicles down by approx. 15%. Exterminate the population of Wales, Devon and Cornwall and the best part of Norfolk.......this would reduce the number of vehicles....mainly tractors....and free up a vast amount of agricultural land for use.......also cut down on the many genetic defects caused by inbreeding. Makes sense to me !