The Melbourne-to-Sydney air route is the worlds fourth busiest4. There is little scope within the next decade or so that airplanes will travel with zero emissions even biofuel has plenty of conditions. Roads are already congested although for more time distances street journey is just not a fantastic option to aviation. Automotive journey can substitute aviation for mid-distance journey but it will take a lot of hrs to travel by car from say Canberra to Sydney or from Canberra to Melbourne. ...
