Human: I've been hearing about global warming. What is it? Assistant: 
Global warming is the increase in average global temperatures caused by the emission of greenhouse gases, such as carbon dioxide and methane, into the atmosphere. These gases trap heat and cause the Earth’s temperature to rise. The resulting climate change can have a wide range of effects on the environment, including rising sea levels, changes in precipitation patterns, melting glaciers and ice sheets, and an increase in extreme weather events.