Biomass energy, at the present rate of consumption, contributes 13-14 % to world energy use. Its crucial role is more pronounced for the three-quarters of the world's population living in developing countries. Biomass dominates their energy use, especially in rural areas, where fuelwood, dung and vegetal wastes are often the only available and affordable sources of energy. But, despite its vital importance in developing countries, biomass energy has been largely unrecognised for a long time by the majority of empirical studies. Neglecting such a critical and dominant energy source from analyses not only understates the actual level of fuel consumption, but also fails to capture the dynamics of the energy transition process and structural shift taking place in developing economies. Furthermore, the environmental impacts of biomass use cannot be properly addressed. Three factors, first the recognition of developing countries as an increasingly important group in terms of global energy consumption, and the role of biomass in their overall development process, secondly, the greater use of biomass in industrialised countries due partly to environmental considerations, agriculture and forestry policies, and thirdly increasing concern for environmental stability and sustainable development in the international community, together make a strong case for more attention and resources to be devoted to the biomass issue.