• Algae;
  • bioethanol;
  • biofuels;
  • energy balance;
  • jatropha;
  • miscanthus;
  • photosynthetic efficiency;
  • population;
  • sugarcane

The present world population is largely fed by ‘industrialised agriculture’. This, in turn, depends on massive inputs of fossil fuels. While this energy expenditure is inescapable, it is an expensive way of ‘converting oil into potatoes'. Arguably, in view of global climate change, ever increasing population, ever increasing oil prices, ever diminishing availability of water and arable land, this is not sustainable. Despite the fact that biofuels inevitably compete for resources that might otherwise be used to grow, store and distribute food, they are frequently held to be desirable and feasible ‘green’ substitutes for fossil fuels and even that they spare carbon emissions to the atmosphere. This article challenges the absurdity of such ‘retro-agriculture’ (i.e. except in a few local circumstances) incurring yet more energy expenditure. It seeks to illustrate the misinformation on which some of the advocacy of biofuels has been based.