Natural scientists have joined forces to develop Earth System Science (ESS), a bold response to the mounting contradiction between the planet's limits and humanity's accelerating demands. However, interdisciplinary insights from social scientists are urgently needed to understand the various ways in which social and natural systems relate to each other, and to analyse the driving social forces within the anthroposphere. This timely volume is a rallying call for a 'World System Science' (WSS) in which social scientists and historians would step into this gap. International Relations experts draw from the fields of history, economics, and sociology to develop methodologies for a social science-led response to the political challenges of the Anthropocene. They identify areas of common ground where Earth System Science and World System Science might work together to generate and promote planetary stewardship, improving humanity's chances of surviving the Anthropocene crisis and looming tipping points in the earth system.