Citizen Science is enjoying increasing popularity in a variety of disciplines. Especially in environmental and ecological sciences, the research approach with its set of methods holds great potential. Biodiversity research, water ecology, land cover or forest research are just a few examples where Citizen Science is applied.
However, researchers also encounter challenges and limitations when planning and implementing Citizen Science projects. Issues such as the recruitment of Citizen Scientists and their motivation throughout the course of the project, ensuring data quality, or ethical aspects of data use can pose challenges for project leaders. The article discusses these issues using practical examples from earth observation, geography, climate change research and biodiversity research.