This course discusses the processes that control Earth's climate - and as such the habitability of Earth - with a focus on the atmosphere and the global hydrological cycle. The course balances overview lectures (also covering topics that have high media coverage like the 'Ozone hole' and 'Global warming', and the impact of volcanoes on climate) with selected in-depth analyses. The lectures are complemented with homework based on real data, demonstrating basic data analysis techniques employed in climate sciences.