Researchers from the CNRS and the Université Libre de Bruxelles (ULB) have prepared the first global map of the distribution of atmospheric ammonia (NH3) by analyzing measurements taken by satellites between 2008 and 2016. The IASI interferometer developed by the CNES allowed them to catalog more than 200 ammonia sources, two-thirds of which had never been identified before. These sources are essentially sites of intensive livestock production and industrial activity. The team’s findings are published in Nature (December 5).