What gas, produced from decomposition, is predominantly released from landfills?

The gas predominantly released from landfills due to decomposition is methane. This process occurs as organic waste, such as food scraps and yard trimmings, breaks down in anaerobic conditions—an environment where oxygen is scarce. During the decomposition of organic matter, microorganisms consume the material and produce methane as a byproduct.

Methane is a potent greenhouse gas, known to have a significantly higher heat-trapping potential than carbon dioxide over a shorter time frame. While carbon dioxide is also produced during decomposition, it is in lower amounts compared to methane when organic materials decompose anaerobically.

Ozone is not a direct product of landfill decomposition, but rather a result of chemical reactions in the atmosphere involving pollutants. Sulfur oxide, typically associated with fossil fuel combustion, is not a significant product of landfill decomposition either. Thus, methane stands out as the primary gas released from landfills, aligning with the understanding of how waste decomposes in such environments.