Carbon dioxide (CO2) is the greenhouse gas which has, by far, the greatest impact on climate change. CO2 is becoming even more important owing to continued, escalating use of fossil fuel energy and CO2's very long lifetime in the atmosphere. Predicting future climate or defining `dangerous' climate change is challenging, in large part because the Earth's carbon cycle is very complex and not fully understood. You will learn about the atmospheric, oceanic and terrestrial components of the carbon cycle, how they interact with each other, and how they interact with climate in so-called `feedbacks'. The understanding of the carbon cycle gained from this module is an important foundation for all climate change research. Emphasis is given to the most recent, cutting-edge research in the field. Co-taught with ENV-MA31.