The effects of human activity on atmospheric composition, focused on global warming, the carbon cycle, air pollution, and the ozone layer. Fundamentals of atmospheric and oceanic chemistry (spectroscopy, kinetics, isotopic analysis, and biogeochemical cycling of GHGs) are related to the modern understanding of climate change, air quality, ozone depletion, based on resources such as satellite missions, field campaigns, lab studies, and scientific assessment reports. We also examine how society's future energy needs could be met in a manner with less impact on atmospheric composition than the present heavy reliance on combustion of fossil fuels.