But biomass can be a large source of carbon dioxide to the atmosphere if large tracts of forest are burned because of drought and demands to clear the land for agriculture and development. Landfills are rich sources of methane. Biomass and other materials disposed of in landfills decay to form landfill gas, which is mostly methane. The release of landfill methane to the air boosts greenhouse gas levels. But landfill gas can be captured and run through gas turbines to produce electricity, turning trash into treasure.
Animal waste is also a challenge to carbon management.
According to ORNL's John Sheffield, who is also director of the Joint Institute for Energy and Environment at the University of Tennessee, U.S. farms for raising cattle, poultry, and swine to help feed the world have 1.4 billion tons of wet manure, which annually emits almost 3 million metric tons of methane, a greenhouse gas. Cleverly applied technological solutions could allow farmers to sell manure as a feedstock for producing methane for energy and for making other products. Income from the animal waste feedstock will help farmers offset the costs of controlling pollution from farm chemicals such as fertilizers, pesticides, pathogens, antibiotics, and hormones. Burning gas from methane hydrate ice. Another challenge to carbon management is methane hydrates, which harbor a huge amount of natural gas in the ocean and Arctic permafrost.