Atmospheric Ammonia Trends, 2002-2016 (IMAGE) University of Maryland Caption This map shows global trends in atmospheric ammonia (NH3) as measured from space from 2002 to 2016. Hot colors represent increases due to a combination of increased fertilizer application, reduced scavenging by acid aerosols and climate warming. Cool colors represent decreases due to reduced agricultural burning or fewer wildfires. Credit Juying Warner/GRL Usage Restrictions None 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.