This document discusses climate change and global warming. It explains that greenhouse gases like carbon dioxide and methane trap heat in the atmosphere and cause the planet to warm over time. While carbon dioxide is the most abundant greenhouse gas, methane and nitrous oxide are more potent but present in smaller amounts. The effects of global warming are already appearing around the world, such as rising sea levels and shifts in animal habitats. Reducing the use of fossil fuels can help limit further climate change.