Essential Climate Variables (ECV) are the key to understand climate-induced changes of the Earth. The Remote Sensing Research Group (led by Prof. Dr. Stefan Wunderle) contributes with their knowledge and experience in processing of satellite data (mainly NOAA- and MetOp-AVHRR) to these investigations. The analysis of long-term ECVs (e.g. snow extent, land surface temperature, albedo, lake surface water temperature, fires, aerosol optical depth, etc.) is based on our received and archived satellite data with 1km resolution (1980 until today) covering Europe. Furthermore, we are working with the new global EUMETSAT AVHRR FDR in 4km spatial and daily resolution (1980 - 2022) including the latest cloud mask provided by CM SAF (CLARA A3). All projects are performed in close cooperation with numerous national and international institutes as well as agencies.