Agriculture has a poor environmental record. It is responsible for nearly a quarter the world's total greenhouse gas emissions. With the online system CoolFarmTool, farmers can control how many climate noxious gases they produce. Together with national and international partners from business, science, and the agricultural sector, the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences is optimising the application. In the future emissions will be determined with the help of satellite data and the emission data will be networked with modern farm management systems. It is a valuable tool that farmers can use to reduce their ecological footprint, for example, by avoiding over-fertilisation.