Bioenergy - for what and how much?

How long will bioenergy last for the energy systems of the future? How much can we get out of forests and agricultural land – and what should we use it for? Is it wise to use it for conversion into vehicle fuel, or should it be used for generating heat and electricity? What regulatory instruments are needed for increasing the use of bioenergy? What conflicts will there be between increased biofuel production and various environmental targets? How is the supply of food doing out in the world? And how good is bioenergy in actually preventing climate change?