While burning biomass releases a large amount of carbon dioxide into the atmosphere hence it is not zero carbon.
However, the plants that provide the energy-producing biomass collect almost as much CO2 through photosynthesis as is produced when the biomass is burned, making biomass a carbon-neutral energy source.
The biomass contains between 35 and 65 percent of its dry weight in carbon (50 percent is often taken as a default value).
Dead biomass is made up of plant detritus and includes dead wood and litter.
The main advantage of biomass is that it cannot be exhausted like fossil fuels.
Biomass might serve as a major source of renewable energy that can be utilized as a long-term substitute for fossil fuels due to the abundance of plants on Earth.