Pig farming (IMAGE) University of Bonn Caption Pig farming produces a lot of excrement, which is stored as slurry. Methane is released from this through decomposition processes. Credit Photo: Veronika Overmeyer / University of Bonn Usage Restrictions Please use this picture only in connection with the press release. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.