Professor Paul Palmer, Professor of Quantitative Earth Observation, presents "A Brief History of Atmospheric Carbon Dioxide". In this talk Professor Palmer will discuss measurements of atmospheric carbon dioxide and how they a) are used to understand the nature and geographic origin and fate of carbon dioxide, and b) can be used to underpin the development of effective emission reduction policies to mitigate the effects of future climate change. This lecture is part of the University's "Our Changing World" public lecture series, which examines the global challenges facing society, and the role of academia in meeting these challenges. This lecture was recorded on 8 October 2013 at the University of Edinburgh's Appleton Tower.