Like most energy resources, biomass energy has the potential to do harm, especially to the environment. Harvesting biomass for energy at unsustainable rates would damage ecosystems. It can also produce harmful air pollution, consume large amounts of water and produce net greenhouse emissions.
Biomass energy also has a lot of potential to do good. Low-carbon biomass can provide a significant fraction of the renewable energy needed to reduce emissions of heat-trapping gases such as carbon dioxide. So long as the biomass is produced sustainably, biomass energy can meet current energy needs while causing little to no harm and without diminishing resources.