Biomass just means materials from plants and animals. We’ve been burning wood for generations to cook with and to keep warm. In some places we even cook with manure (animal dung). In the last few decades many more people have been burning biomass for heating and electricity and a small percentage of petrol and diesel comes from biomass too. Planting lots of trees and crops for burning sounds like a great idea. But is it? The smoke can cause health problems and if we grow more crops just for burning then we need much more land. Land that otherwise would be for growing food or kept as natural forest or rainforest. A lot of effort and energy is used to make and transport biomass today and this means that a lot of biomass is not really that green. Most scientists regard biomass as halfway between fossil natural gas burning and renewables or nuclear power in terms of real emissions of greenhouse gases. Improvements in biomass burning for electricity may come if carbon capture is used. However, the large land area needed for biomass is still an issue.