Agricultural and industrial activities are some of the top culprits releasing ammonia into the atmosphere. Excessive ammonia impacts air quality, leads to acidification in the environment, and contributes to climate change. Until now, the total contribution of sources, both natural and anthropogenic, to atmospheric ammonia was unknown. Researchers recently used satellite data to create a high resolution map of ammonia hotspots around the world. The study used nine years of IASI (Infrared Atmospheric Sounding Interferometer) measurements to map out locations with high concentrations of ammonia. Using additional aerial and satellite imagery, publicly available inventories, and online sources, the authors classified the activities responsible for generating each ammonia hotspot. The study found 248 hotspots with diameters smaller than 50 kilometers. All but seven of those hotspots were linked to anthropogenic activities. 83 hotspots were found to be ammonia sources from intensive animal farming. 158 hotspots were found to be industrial in origin, of which 130 sites were linked to factories producing NH3-based fertilizer. Six hotspots couldn’t be linked to a definitive source. Only one hotspot, the mudflats of Lake Natron in Tanzania was of a natural source. While there are many sources of natural emissions for ammonia, the authors note that most are too small to be remotely sensed by IASI data.
Van Damme, M., Clarisse, L., Whitburn, S., Hadji-Lazaro, J., Hurtmans, D., Clerbaux, C., & Coheur, P. F. (2018). Industrial and agricultural ammonia point sources exposed. Nature, 564(7734), 99.