Methanogens are a group of microorganisms that produce methane as a metabolic byproduct. They belong to the domain of Archaea and are typically found in anaerobic environments, such as swamps, marshes, and the digestive tracts of ruminants like cows. Methanogens play a crucial role in the carbon cycle by breaking down organic matter and releasing methane gas. These microorganisms thrive in extreme conditions, including high temperatures and salinity. Methanogens are essential for various ecological processes, including the decomposition of organic materials and the formation of natural gas. Their activity contributes to greenhouse gas emissions, making them significant in discussions about climate change.