This thesis develops the notion of the bioenergy transition as the long-term transformation of biomass from a local resource into a global commodity. An historical assessment is combined with interdisciplinary analysis that focuses especially on liquid biofuels and highlights the environmentally innovative case of bioethanol. The bioenergy transition is investigated from several different perspectives: technical-economic, socio-economic, socio-technical and political-economic. Linkages across different levels from household to global are analysed in relation to the effectiveness of bioenergy policies. In addition to studies at household and national levels, a North-South perspective is taken by including two major regions: the European Union (EU) and the Southern African Development Community (SADC). The relation of EU biofuels policy to international climate and trade regimes is assessed to show how regional-global linkages affect policy design and implementation. Household bioenergy markets in developing countries are poorly articulated and difficult to link to other sectors; a detailed choice model in Ethiopia showed that product-specific factors should be evaluated to inform design of programmes and policies. Municipal and sub-national markets for bioenergy have been successfully linked to national policies to coordinate supply and demand in Brazil and Sweden. Regional market development for biofuels has great potential in southern Africa but regional-national linkages currently remain unexploited. National level efforts remain quite important in terms of energy security and environmental innovation, as evidenced in Brazil, Malawi and Sweden. Biofuels sustainability criteria in the EU Renewable Energy Directive (EU-RED) were evaluated in relation to the international climate and trade regimes and were found to shift some costs onto developing countries. One of the mechanisms for assuring biofuels sustainability is bilateral agreements, which remain untested but potentially effective. Cross-level linkages were often unexploited in the cases studied; national approaches cannot easily capture complementarities across sectors and scales in biophysical and economic terms. Linking biofuels markets across different levels from household to global through regional development policies and specialised governance mechanisms could help to steer the bioenergy transition towards sustainability. / <p>QC 20141112</p>