The main objective of this course is to apply thermodynamic principles to understand the role of water in the Earth's climate system. The course closely follows the textbook "Thermodynamics of Atmospheres and Oceans" by Curry and Webster. It starts by developing the basic concepts of classical thermodynamics that are important for understanding the climate system. These basic concepts will then be applied to address major processes in the atmosphere and ocean, including cloud formation, precipitation processes and thermohaline circulation. The course finally delves into specific climate topics that bear a substantial thermodynamic component, including climate sensitivity, feedbacks and the hyrdological cycle.