It has long been known that fog is a critical factor for biodiversity in the Namib Desert, both in the Namib Sand Sea and in all the other habitats that overlap with the fog zone. FogNet, a research project supported by the SASSCAL initiative, was developed to understand the dynamics of fog in the Namib Desert and to get long-term insight into how this may change as the earth's climate is changing. Here Jan Tolzmann, former project manager, explains the objectives and some technical details about the very sophisticated climate sensing instruments that are being erected in the central Namib.