Biofuels received USD 15 billion in subsidies in OECD Member countries in 2007, but did they deliver benefits in terms of climate change or oil security? Present policies make no link between support for biofuels and their environmental performance, and biofuels do not all perform equally well. In fact, much of the current ethanol and biodiesel production may result in higher overall emissions of greenhouse gases than using conventional transport fuels - gasoline and diesel. The papers published in this report examine the economics of biofuels and assess the potential of conventional biofuel production in OECD countries, Brazilian ethanol exports and some second generation biofuels to supply world markets with transport fuels. The Round Table analysed the critical issues for governments in determining support for biofuels, particularly the level of greenhouse gas emissions throughout the life-cycle of these fuels and the wider environmental impacts of farming biomass.It also reviewed recent progress in developing certification systems for biofuels - an essential tool for tying support to achievement in reducing greenhouse gas emissions, although certification cannot be expected to prevent rainforest destruction for the development of biofuel crop plantations. The report concludes with a short list of recommendations for policy reform if support for biofuels is to contribute effectively to mitigating greenhouse gas emissions.