In this chapter, we trace the origins of air pollution and global warming, beginning with the last ice age, over 10,000 years ago. Indoor air quality became a concern around 2500 BC, and coal was mined by the Romans in Britain and the Rhineland to heat public baths and for the smelting of iron ores. Urban air quality soon became an issue in Greek and Roman cities. It was not until 1824 that the greenhouse effect was discovered and the role of carbon dioxide described. It was Arrhenius in 1896 who first quantified global warming from increases in carbon dioxide concentrations. In the meantime, carbon dioxide concentrations started to climb from 280 ppm (parts per million) to over 400 ppm today. Ground-level ozone was recognised as a problem after the Second World War by Haagen-Smit in 1952 by examining the causes of Los Angeles smog. He identified how ozone was formed by the action of sunlight on nitrogen oxides and volatile organic compounds. Regional air quality became a serious concern and international bodies, such as the United Nations Economic Committee for Europe (UNECE), were set up to ensure co-operation between countries to tackle emissions. It was the advent of atomic bomb testing, leading to nuclear fallout all over the world in the 1950s, which introduced scientists and governments to global air pollution. Scientific studies then led to the study of transport of carbon dioxide from industrial regions in the northern hemisphere to all parts of the globe and the associated global warming. We now have the Intergovernmental Panel on Climate Change (IPCC) and the Framework Convention on Climate Change (UN FCCC) to regulate the emissions of carbon dioxide and other greenhouse gases and to monitor global warming consequences.