Ethane Methane Ratio (IMAGE) Penn State Caption The resulting oil and gas methane emissions inventory developed in this study compared to the U.S. Environmental Protection Agency Oil and Gas methane emissions inventory. Overall, this study finds methane emissions to be larger than the government inventory by more than 50%. Credit Zachary Barkley, Penn State Usage Restrictions non commercial use only License Licensed 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.