Demographic changes across the world pose one of the biggest challenges of the 21st century. Longer lifespans and shifting fertility rates bring with them an array of global health issues. In this lecture, Professor Sarah Harper, Co-Director of the Oxford Institute of Population Ageing, will talk about the causes and effects of population change and the global age structural shift, and Professor Robyn Norton, Co-Director of The George Institute for Global Health, will address the implications of these changes on global health.