Climate change is a profound global-scale challenge to the sustainability of human society and the biosphere. This entry introduces the key scientific research on climate change and its ethical implications. It begins by summarizing the key types of anthropogenic climate forcing agents including CO2, CH4, N2O, and air pollution including particulate matter (PM) and their sources. A combination of mitigation, restoration, and adaptation strategies currently being considered is introduced and compared. Global climate change intersects with many academic disciplines, and this entry attempts to provide a holistic overview of the current observations of climate change based on scientific and ethical considerations. Our analysis includes the atmosphere and hydrosphere, and the impacts of climate change on society. The aim is to provide a fuller account of climate change from perspective of disciplines not often seen together, thus providing a more comprehensive account of the most defining problem of our time.