The document discusses the greenhouse effect and global warming. It describes how greenhouse gases like carbon dioxide, methane, and nitrous oxide trap heat in the atmosphere, causing average global temperatures to increase. As temperatures rise, the document predicts glaciers will melt and sea levels will rise by 20-65 cm by 2100, flooding many coastal areas. The enhanced greenhouse effect will significantly impact global temperatures, climate, ecosystems, agriculture, and human health and livelihoods according to the text.