What are the gases produced during the breakdown of waste in landfills called?

The gases produced during the breakdown of waste in landfills are commonly referred to as decomposition gases. This terminology accurately describes the byproducts of organic material's anaerobic decay processes that occur in landfills. As waste decomposes, particularly organic materials such as food and yard waste, bacteria break down these materials without oxygen, resulting in various gases such as methane and carbon dioxide. Methane is particularly noteworthy because it is a potent greenhouse gas and is often captured for use as an energy source.

The other terms provided do not specifically encompass the scientific processes or the range of gases produced. For instance, "decomposition vapors" might imply a more generalized release, not specifically referencing the gases caused by anaerobic decomposition. "Waste emissions" could refer to broader contaminants that include particulates and other forms of pollution, whereas "landfill fumes" suggests a less precise mixture without focusing on the biological processes involved. Therefore, "decomposition gases" is the most accurate and accepted term within environmental science and waste management contexts.