Humanity has a serious CO2 problem. It is clear that increasing CO2 emissions are destabilizing the climate and a degree of climate change is now ‘locked in’ to the Earth System from historical CO2 emissions. In this module we will study the basics of the carbon cycle and how CO2 emissions have changed Earth, with a specific focus on the ocean. We will assess the potential to harness natural processes to increase carbon sinks (‘geoengineering’) and the critique the viability of these processes compared to CO2 emission cuts. An introduction to the socio-economics of CO2 emissions, carbon neutrality and sustainability will also be provided as these are critical for creating solutions to climate change. A key skill developed in this module will be the ability to find, read and review scientific papers at the cutting-edge of the field.