The quantity of CO₂ that is released in the atmosphere when wood is burning is comparable to the quantity released during the decomposition of wood. This quantity corresponds to the CO₂ that is taken from the air for a tree to proceed with photosynthesis. Stability is therefore created. So in theory, the production of CO₂ is nil. The use of wood as a source of energy enters the natural cycle of carbon. However, the use of fossil fuels brings about the release of CO₂ taken from prehistorical vegetation; therefore increasing it's concentration in the atmosphere.

The production of energy from biomass also induces a more efficient management of agricultural, forestry, industrial and urban wastes; wastes that also let off CO₂.