This is the first of nine lessons in the Visualizing and Understanding the Science of Climate Change website. This lesson is an introduction to Earth's climate and covers key principles regarding Earth's unique climate, atmosphere, and regional and temporal climate differences.

This peer-reviewed educational video explains human-caused climate change including the greenhouse effect. The role that greenhouse gases play in absorbing and re-emitting longwave radiation is illustrated. Information on how scientists know that the observed global warming is a result of human activities that burn fossil fuels is concisely explained.