Biomass is a modern name for the ancient technology of burning plant or animal material for energy production (electricity or heat), or in various industrial processes as raw substance for a range of products. It can be purposely grown energy crops (e.g. miscanthus, switchgrass), wood or forest residues, waste from food crops (wheat straw, bagasse), horticulture (yard waste), food processing (corn cobs), animal farming (manure, rich in nitrogen and phosphorus), or human waste from sewage plants.The argument that biomass combustion is carbon neutral is contested. The traditional use of wood in cook stoves and open fires produces pollutants, which can lead to severe health and environmental consequences. The EU and UN consider biomass a renewable energy source.