 Large amounts of pollutants such as sulphurous oxides (SOx), nitrous oxides (NOx), and particulate matter (PM) are produced from the combustion of fossil fuels and biomass; the World Health Organization estimates that 7 million premature deaths are caused each year by air pollution.Biomass combustion is a major contributor.In addition to producing air pollution like fossil fuel combustion, most biomass has high CO2 emissions.