Why do we need biofuels?

This seems a rather good question to ask for anyone working and/or supporting the expansion of biofuels for transport. Today, I ran a lecture/workshop on this very question with over 30 doctoral candidates from Lund University in Sweden. This educational activity is part of a one week doctoral course, which is entitled - The Biofuels of Today and Tomorrow - and it has been organised by LU Biofuels. Here is my presentation, which challenged the doctoral students to think broadly about biofuels for transport. I was challenged myself with a number of tough questions ...