The disruption of the nitrogen cycle by the human creation of reactive nitrogen has created one of the major challenges for humankind. Global reactive nitrogen emissions into the air have increased to unsurpassed levels and are currently estimated to be four times larger than pre-industrial levels. As a consequence, the deposition of atmospheric reactive nitrogen has increased causing ecosystem and species loss. Ammonia (NH3) as fertilizer is essential for agricultural production and is one of the most important reactive nitrogen species in the biosphere. NH3 is also a precursor to PM2.5 which has been associated with various health impacts. Despite its significance, there is still relatively much uncertainty in the global budget of NH3. Until recently there were only a few measurements available worldwide as ammonia is expensive to measure with only a few instruments being able to reliably measure ammonia at atmospheric concentrations. Recent developments have made it possible to now measure NH3 reliably with satellite remote sensing, which opens the way to better restrict the NH3 budget and monitoring atmospheric concentrations in near real time. In this seminar Enrico Dammers will tell about NH3 remote sensing with satellite and ground based instruments and give some insight into future applications.