How do archaea affect Earth's greenhouse gases?

Archaea play a significant role in the regulation of Earth's greenhouse gases through both the production and removal of methane, a potent greenhouse gas.1

• Methane Production: Methanogenic archaea, which are specialized prokaryotes, are responsible for producing at least 80 percent of the methane in the atmosphere. These organisms thrive in anaerobic environments, such as swamps, marshes, soil, and the digestive tracts of ruminant animals. Terrestrial methanogens, particularly those in environments like rice fields, are estimated to generate approximately 10–25 percent of global methane emissions.21
• Methane Removal: Conversely, certain uncultivated archaea found in deep-sea marine sediments help mitigate greenhouse gas levels by removing methane through the process of anaerobic oxidation.1

While archaea are essential to these natural cycles, it is important to recognize that human activities—such as industrial processes and the use of fossil fuels—are the primary drivers of the current, dangerous increase in atmospheric carbon dioxide, which is the leading cause of global climate change.3