Increasing amounts of carbon dioxide in the atmosphere are having a profound impact on our Earth system. Our atmosphere and ocean are warming, driving changes in ice, habitats and biodiversity. This module will introduce students to the fundamental theory behind the global carbon cycle, specifically the role of the ocean in cycling carbon, and the implications for climate. Students will explore how carbon is partitioned between the atmosphere, land and ocean in the contemporary and past Earth system, understand how the ocean stores 50 times more carbon than the atmosphere, and consider the impact of increasing carbon dioxide on the organisms living on land and in the ocean. The module will be delivered through weekly lectures and interactive workshops, with two assignments assessing testing skills in critical thinking and numeracy using simple numerical models.