Biology-- Methane Mystery Solved (image) DOE/Oak Ridge National Laboratory Share Print E-Mail Caption Studies indicate that microorganisms in the tree trunks of living Eastern cottonwood trees emit the greenhouse gas methane. Credit © 2018 Daniel Z. Yip, et al. New Phytologist © 2018 New Phytologist Trust Usage Restrictions None Share Print E-Mail 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.