Sustainability of biomass based fuel use requires that in biomass production erosion and water usage do not exceed addition to stocks of soil and water and that levels of nutrients and organic matter in soils do not decrease. Levels of volatile carbon compounds and N2O in the atmosphere should remain unaffected. To maintain ecosystems services of nature useful to mankind, restriction of biomass production to degraded and currently fallow land is to be preferred. Also sustainability of biomass-for-energy use requires a high efficiency recycling of nutrients present in ashes and low emissions of persistent organics, acidifying compounds and heavy metals due to biomass combustion. Meeting such conditions requires major efforts. (c) 2004 Elsevier Ltd. All rights reserved.