This lecture provides an overview of the CleanCloud project, which focuses on the transition of clouds and climate to a post-fossil aerosol regime. The instructor discusses the project's objectives, including targeted field experiments in European climate hotspots, the development of advanced retrieval algorithms, and contributions to satellite mission calibration. The project aims to improve climate models using machine learning and data assimilation while assessing the role of aerosols in convective systems and extreme weather events. The lecture highlights the consortium's diverse expertise, which includes partners from various European institutions, and outlines the scientific structure organized into three clusters: process understanding, convective lifecycle, and predictions and projections. The instructor emphasizes the importance of understanding aerosol-cloud interactions in a cleaner world and the implications for climate forcing. The lecture concludes with a discussion of the project's deliverables and milestones, showcasing the collaborative efforts of the consortium in addressing climate challenges.